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October 17, 2019
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https://www.sciencedaily.com/releases/2019/10/191017162222.htm
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First report of cotton blue disease in the United States
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In August 2017, Kathy S. Lawrence, a plant pathologist at Auburn University, received a call from Drew Schrimsher of Agri-AFC, who had discovered foliar distortion and leaf curling and rolling on approximately 50,000 acres of cotton in southeastern Alabama. After ruling out herbicide damage, Schrimsher contacted Lawrence, and she visited the fields 2 days later.
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Lawrence took samples and sent them to Judith K. Brown at the University of Arizona. After 7 months of research, Brown connected the symptoms to cotton blue disease, caused by Reported from six counties in coastal Alabama in 2017, cotton blue disease affected approximately 25% of the state's cotton crop and caused a 4% yield loss. The disease was reported again in 2018, affecting 3-100% of cotton fields in Alabama but causing only a 1% yield loss.Symptoms, which include slowed plant growth, loss of chlorophyll, and dwarfing of infected leaves, usually do not appear until late August after full bloom. To date, there are no recommended strategies for management of this disease.
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Agriculture & Food
| 2,019 |
October 17, 2019
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https://www.sciencedaily.com/releases/2019/10/191017101233.htm
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Photosynthesis Olympics: Can the best wheat varieties be even better?
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Scientists have put elite wheat varieties through a sort of "Photosynthesis Olympics" to find which varieties have the best performing photosynthesis. This could ultimately help grain growers to get more yield for less inputs in the farm.
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"In this study we surveyed diverse high-performing wheat varieties to see if their differences in photosynthetic performance were due to their genetic makeup or to the different environments where they were grown," said lead researcher Dr Viridiana Silva-Perez from the ARC Centre of Excellence for Translational Photosynthesis (CoETP).The scientists found that the best performing varieties were more than 30 percent better than the worst performing ones and up to 90 percent of the differences were due to their genes and not to the environment they grew in."We focused on traits related to photosynthesis and found that some traits behaved similarly in different environments. This is useful for breeders, because it is evidence of the huge potential that photosynthesis improvement could have on yield, a potential that hasn't been exploited until now," says Dr Silva-Perez.During the study, published recently in the "The results that we obtained from our "Photosynthesis Olympics," as we like to call them, are very exciting because we have demonstrated that there is scope to make plants more efficient, even for varieties working in the best conditions possible, such as with limited water and fertiliser restrictions. This means for example, that breeders have the potential to get more yield from a plant with the same amount of nitrogen applied," says CoETP Director Professor Robert Furbank, one of the authors of this study.Photosynthesis -- the process by which plants convert sunlight, water and CO2 into organic matter -- is a very complex process involving traits at different levels, from the molecular level, such as content of the main photosynthetic enzyme Rubisco, to the leaf, such as nitrogen content in the leaf and then to the whole canopy level."This work is an important result for the CoETP, which aims to improve the process of photosynthesis to increase the production of major food crops such as wheat, rice and sorghum. There is a huge amount of collaboration, both institutional and interdisciplinary, that needs to take place to achieve this type of research. Without the invaluable cooperation between statisticians, plant breeders, molecular scientists and plant physiologists, we would have never achieved these results," says co-author Tony Condon from CSIRO and the CoETP.
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Agriculture & Food
| 2,019 |
October 17, 2019
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https://www.sciencedaily.com/releases/2019/10/191017101235.htm
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Deep water sites off the US northeast coast are suitable for offshore blue mussel farms
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Offshore mussel farm sites need to have the right temperature, food availability, and the right currents. According to a study by researchers at NOAA's Northeast Fisheries Science Center, several suitable locations can be found off the Northeastern U.S.
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Their findings, published in the A number of research projects have been conducted in the past few decades at pilot mussel farms in Rhode Island Sound near Martha's Vineyard, off the Isle of Shoals in New Hampshire, and north of Cape Ann in Massachusetts. Results were encouraging, but no commercial ventures have gone forward.The authors acknowledge that these waters are busy and already subject to numerous competing and overlapping uses. They argue that finding the optimum locations for farms, where the conditions can support the kind of production that will be profitable, is an essential first step in development. If farms are going to compete with other uses, then managers and entrepreneurs alike need to know as much as possible about the requirements and benefits of offshore shellfish farms -- especially when some uses must be excluded so that others may thrive."There is great potential for sustainable farming of shellfish in New England federal waters," said lead author Darien Mizuta. Mizuta is a National Research Council postdoctoral fellow at the Northeast Fisheries Science Center's Milford Laboratory in Milford, Connecticut. "This is supported by national economic data, which is the topic of our next publication."Co-author Gary Wikfors agrees. "Blue mussels have an established market, are commercially important to the region, and we know the culture technologies," he said. "They are the main bivalve shellfish imported into the U.S, mainly from Canada. We import 225 times as much as we are producing, and U.S. consumption is growing. Increasing national production would help our food security and lessen the seafood trade deficit." Wikfors is a shellfish scientist and director of the Milford Laboratory.The study may be the first using an historical series of environmental data to examine a large area of the Northeast U.S. coastal shelf ecosystem for aquaculture suitability. It also reports some of the first measurements of mussel feeding performance in offshore New England, considered a highly suitable area for the development of ocean farming activity.Mizuta and Wikfors focused their research on finding the optimal submersion depth for longlines and mussel ropes, depths that would maximize the production efficiency of commercial offshore farming operations. They conducted a habitat suitability analysis based on open source temperature and chlorophyll data from national datasets. Temperature affects the ability of the mussels to adhere to farming rope and to survive, while chlorophyll concentration provides an estimation of food availability.At an experimental mussel farm off Cape Ann, they measured mussel feeding performance in spring and summer to confirm that mussels were at the ideal depth. Environmental data were collected at the same time.Blue mussels (Researchers examined oceanographic data on temperature and chlorophyll from 2005 to 2012 to identify suitable submersion depths for mussel ropes in New England federal waters. Their results suggest that mussel ropes submerged during summer to a minimum depth of 15 meters (roughly 50 feet) in northern areas and to a 20-meter (roughly 65-foot) minimum depth in southern areas of New England have the optimum temperature and abundant phytoplankton biomass for growing blue mussels.The Milford researchers measured biodeposition, an indicator of feeding success, at an experimental shellfish farm off Rockport, Massachusetts to validate predicted depth. Using these data, they confirmed satisfactory mussel feeding, digestion and food assimilation functions. In this phase of the study, Mizuta and Wikfors were assisted by researchers at the Northeastern Massachusetts Aquaculture Center at Salem State University's Cat Cove Marine Laboratory, which maintains the experimental farm.Promising local areas have shallow temperature gradients, such as off Long Island, Cape Ann, Massachusetts and off New Hampshire. With current farm designs, it should be possible to adjust the depth of mussel ropes, keeping them within their ideal temperature range. Recommended depths can also be adjusted to future temperature increases associated with climate change."There are other environmental, technical, and social aspects of offshore ocean farming that we did not attempt to address in this study," Wikfors said. "Our goal was to contribute to fundamental knowledge needed by entrepreneurs for farm planning, specifically focusing on geographic location and depth deployment of longlines. Studies like this should be region-specific because the environment will affect productivity, design, and management and therefore the overall success of the farm as a business."
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Agriculture & Food
| 2,019 |
October 16, 2019
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https://www.sciencedaily.com/releases/2019/10/191016124610.htm
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Newly identified compounds could help give fire ants their sting
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Native to South America, imported fire ants have now spread to parts of North America and elsewhere around the world. These invasive pests have painful stings that, in some cases, can cause serious medical problems, such as hypersensitivity reactions, infections and even kidney failure. Now, researchers reporting in ACS'
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Imported fire ants, including red (The researchers collected venom from red, black and hybrid imported fire ants by placing ants under a microscope and touching their abdomens repeatedly with a small piece of filter paper. In response, the ants protruded their stingers and released drops of venom, which the filter paper absorbed. The team then analyzed venom components on the paper. By coupling solid-phase microextraction with gas chromatography-mass spectrometry, they identified 10 pyridine alkaloids whose signals were previously hidden by other alkaloids. The various ant species had slightly different pyridine alkaloid profiles, as did worker and winged female ants within each species. These compounds could open new avenues of research on the toxicological properties of fire ant venom, the researchers say.
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Agriculture & Food
| 2,019 |
October 16, 2019
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https://www.sciencedaily.com/releases/2019/10/191016074746.htm
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Novel virus type may shed light on viral evolution
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Viruses are non-living creatures, consisting of genetic material encased in a protein coat. Once the virus infects a living organism, it can replicate itself and continue on. But what happens if a virus lacks the proper tools to infect an organism? How can it propagate?
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An international collaboration led by scientists at Tokyo University of Agriculture and Technology (TUAT) in Japan has uncovered a novel virus that may help answer those questions. They published their results online, ahead of print, on July 22 in Viruses constantly change, combining and recombining into different varieties of themselves. They gain and lose function and either die out or become stronger than ever. This process occurs especially quickly on pig farms, where many pigs interact in filthy environments -- it's the ideal setting for viruses to evolve. The team, led by Professor Tetsuya Mizutani, corresponding author on the paper and Director at the Research and Education Center for Prevention of Global Infectious Disease of Animal, TUAT, discovered a unique virus in such a location."Recombination among different viral families occurs at pig farms all over the world," Mizutani said. "These recombinant viruses have the potential to connect with a host in a novel way."It is known that normal enterovirus G (EV-G) presents as diarrhea in pigs. In this study, the researchers found a new type 2 of EV-G in the pigs' feces. They also found that this new EV-G type 2 can't possibly invade a host cell on its own."The recombinant virus we found in this study has no structural proteins," Mizutani said. "This means the recombinant virus cannot make a viral particle."Viruses must make a viral particle to invade a living host cell. Without it, they cannot enter a host cell and use its facilities to replicate itself. According to Mizutani, this particular virus may be partnering up with a "helper virus" to gain access to a host cell, but the mechanism underlying this process is unclear."We may be facing an entirely new system of viral evolution," Mizutani said. "We are wondering how this new virus came to be, how it infects cells or how it develops a viral particle. Our future work will be on solving this mystery of viral evolution."
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Agriculture & Food
| 2,019 |
October 16, 2019
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https://www.sciencedaily.com/releases/2019/10/191016074750.htm
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Accelerating global agricultural productivity growth is critical
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The 2019 Global Agricultural Productivity Report, "Productivity Growth for Sustainable Diets, and More," released today by Virginia Tech's College of Agriculture and Life Sciences, shows agricultural productivity growth -- increasing output of crops and livestock with existing or fewer inputs -- is growing globally at an average annual rate of 1.63 percent.
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According to the report's Global Agricultural Productivity Index, global agricultural productivity needs to increase at an average annual rate of 1.73 percent to sustainably produce food, feed, fiber, and bioenergy for 10 billion people in 2050.Productivity growth is strong in China and South Asia, but it is slowing in the agricultural powerhouses of North America, Europe, and Latin America.The report calls attention to the alarmingly low levels of productivity growth in low-income countries, where there also are high rates of food insecurity, malnutrition, and rural poverty.Agricultural productivity growth in low-income countries is rising at an average annual rate of just 1 percent. The UN Sustainable Development Goals call for doubling the productivity of the lowest-income farmers by 2030.The GAP Report was released at the World Food Prize in Des Moines, Iowa. Speakers at the GAP Report Launch event included Tim Sands, president of Virginia Tech; Miguel Garcia Winder, undersecretary for agriculture for Mexico; Rose Mwonya, vice chancellor of the Egerton University in Kenya; and Alan Grant, dean of Virginia Tech's College of Agriculture and Life Sciences.The report calls for a strong focus on countries with high rates of population growth, persistent low levels of agricultural productivity, and significant shifts in consumption patterns -- the primary drivers of unsustainable agricultural practices, such as converting forests to crop and rangeland."These productivity gaps, if they persist, will have serious ramifications for environmental sustainability, the economic vitality of the agriculture sector, and the prospects for reducing poverty, malnutrition, and obesity," said Ann Steensland, author of the 2019 GAP Report and coordinator of the GAP Report Initiative at Virginia Tech.The 2019 GAP Report examines the pivotal role of agricultural productivity in achieving global goals for environmental sustainability, economic development, and improved nutrition."Decades of research and experience tell us that by accelerating productivity growth, it is possible to improve environmental sustainability, while ensuring that consumers have access to the foods they need and want," said Tom Thompson, associate dean and director of global programs for the Virginia Tech College of Agriculture and Life Sciences.Productivity growth is generated by such innovations as precision agriculture technology and improved seeds and best practices for nutrient management and animal health. Attention to ecosystem services, such as pollination and erosion prevention, can increase and sustain productivity gains over time.The GAP Report looks at the powerful combination of agricultural technology, best farm management practices, and attention to ecosystem services in supporting productivity growth, sustainability, and resilience.Historically, productivity growth has been strongest in high-income countries, such as the U.S, with significant environmental benefits.Due to widespread adoption of improved agricultural technologies and best farm management practices, especially in high-income countries, global agricultural output has increased by 60 percent, while global cropland has increased by just 5 percent during the past 40 years.Between 1980 and 2015, productivity gains led to a 41 percent decrease in the amount of land used in U.S. corn production, irrigation water use declined 46 percent, greenhouse gas emissions declined 31 percent, and soil erosion declined (tons of soil loss per acre) by 58 percent.Animal agriculture in the U.S. has experienced similar productivity gains, dramatically reducing the environmental footprint of the livestock production. According to Robin White, assistant professor of animal and poultry science at Virginia Tech, if livestock production in the U.S. was eliminated, total U.S. greenhouse gas emissions would decline by only 2.9 percent.The Global Agricultural Productivity Index tracks global progress toward sustainably producing food, feed, fiber, and bioenergy for 10 billion people in 2050.In the absence of further productivity gains in Total Factor Productivity, more land and water will be needed to increase food and agriculture production, straining a natural resource base already threatened by climate change.Unable to afford higher-priced nutrient-dense foods, such as animal proteins and fruits and vegetables, consumers will rely on foods made from cheaper cereal grains for most of their calories, exacerbating skyrocketing obesity rates in adults and children.The GAP Report describes six strategies for accelerating productivity growth: investing in public agricultural R&D and extension, embracing science- and information-based technologies, improving infrastructure and market access, cultivating partnerships for sustainable agriculture and nutrition, expanding regional and global trade, and reducing post-harvest loss and food waste.Beginning this year, the GAP Report was produced by Virginia Tech's College of Agriculture and Life Sciences. The GAP Report brings together expertise from Virginia Tech and other universities, the private sector, NGOs, conservation and nutrition organizations, and global research institutions. The report is part of the Global Programs Office unit within the College of Agriculture and Life Sciences that builds partnerships and creates global opportunities for students and faculty.Productivity data for the GAP Index are provided by the USDA Economic Research Service. The GAP Report is available to view and download at Agricultural productivity, measured as Total Factor Productivity, increases when the output of crops and livestock increases using existing, or less, land, labor, fertilizer, capital, and livestock.The GAP Report is supported by the Virginia Tech College of Agriculture and Life Sciences and its supporting partners: Bayer Crop Science, Corteva Agriscience, John Deere, The Mosaic Company, and Smithfield Foods.The GAP Report's consultative partners are ACDI/VOCA, Congressional Hunger Center, Farm Foundation, Global Alliance for Improved Nutrition, HarvestPlus, Inter-American Institute for Cooperation on Agriculture, International Potato Center, The Nature Conservancy, New Markets Lab, Purdue Center for Global Food Security, Supporters of Agricultural Research Foundation, Tanager, and the Daugherty Water for Food Global Institute.
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Agriculture & Food
| 2,019 |
October 15, 2019
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https://www.sciencedaily.com/releases/2019/10/191015131518.htm
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New genome sequence of the date palm
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Researchers at NYU Abu Dhabi's Center for Genomics and Systems Biology (NYUAD CGSB) and the UAEU Khalifa Center for Genetic Engineering and Biotechnology (KCGEB), working with other institutions, have developed an improved assembly of the genome for the date palm using long-read sequencing technology. This improvement over the current versions of the genome will help advance further research, and also inform the propagation practices of this essential MENA region food source.
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In addition, the researchers have identified the genes and mutations that lead to color change and the levels of major sugars in date palm fruit -- including the genes for the enzyme invertase that breaks down sucrose into glucose and fructose. The mapping of these fruit color and sugar genes was conducted using genome-wide association studies (GWAS). GWAS has been used for mapping important disease genes in humans, and this is the first time it has been applied to date palms.While date palms (Lead scientist and Silver Professor of Biology, New York University and part of NYU Abu Dhabi Center for Genomics and Systems Biology, Michael Purugganan commented: "As we face challenges in food security for the future, we will need to continue to study the genome of food crops like date palm to help us in our struggle to provide food security in the world. Our progress in expanding the genome of the date palm is finally unlocking some of the secrets that explain how this tree species has continued to thrive in varied, challenging ecosystems."The sequencing of the date palm genome and the first GWAS mapping in this fruit tree was an international effort led by NYUAD and KCGEB, and also included researchers in the US, Switzerland, France, UK, Saudi Arabia, and Mexico.
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Agriculture & Food
| 2,019 |
October 15, 2019
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https://www.sciencedaily.com/releases/2019/10/191015131424.htm
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Tiny droplets allow bacteria to survive daytime dryness on leaves
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Microscopic droplets on the surface of leaves give refuge to bacteria that otherwise may not survive during the dry daytime, according to a new study published today in
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Understanding this bacterial survival strategy for dry conditions may enable scientists to develop practices that support healthy plant microbiomes in agricultural and natural settings.The surface of an average plant leaf is teeming with about 10 million microbes -- a population comparable to that of large cities -- that contribute to the health and day-to-day functioning of the plant. Scientists have long wondered how bacteria are able to survive as daytime temperatures and sunlight dry off leaf surfaces."While leaves may appear to be completely dry during the day, there is evidence that they are frequently covered by thin liquid films or micrometre-sized droplets that are invisible to the naked eye," says co-lead author Maor Grinberg, a PhD student at Hebrew University's Robert H. Smith Faculty of Agriculture, Food, and Environment in Rehovot, Israel. "It wasn't clear until now whether this microscopic wetness was enough to protect bacteria from drying out."To answer this question, Grinberg, together with co-lead author and Research Scientist Tomer Orevi and their team, recreated leaf surface-like conditions in the laboratory using glass plates that were exposed to various levels of humidity. They then conducted experiments with more than a dozen different bacteria species in these conditions.They observed that while these surfaces appeared dry to the naked eye, under a microscope bacteria cells and aggregates were safely shielded in miniscule droplets. Interestingly, larger droplets formed around aggregates of more than one cell, while only tiny droplets formed around solitary cells. This microscopic wetness is caused by a process called deliquescence -- where hygroscopic substances, such as aerosols, that are prevalent on leaves absorb moisture from the atmosphere and dissolve within the moisture to form the droplets."We found that bacteria cells can survive inside these droplets for more than 24 hours and that survival rates were much higher in larger droplets," Orevi explains. "Our results suggest that through methods of self-organisation, for example by aggregation, these cells can improve their survival chances in environments frequently exposed to drying."These findings could have important implications for agriculture as human practices may inadvertently interfere with this bacterial survival mechanism, endangering the health of crops and natural vegetation, according to senior author Nadav Kashtan, PhD, Assistant Professor at Hebrew University's Robert H. Smith Faculty of Agriculture, Food, and Environment. "A greater understanding of how microscopic leaf wetness may protect the healthy plant microbiome and how it might be disrupted by agricultural practices and human aerosol emissions is of great importance," he says.Kashtan also notes that similar microscopic surface wetness likely occurs in soil, in the built environment, on human and animal skin, and potentially even in extra-terrestrial systems where conditions might allow, suggesting such bacterial survival strategies are not limited to leaf surfaces.
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Agriculture & Food
| 2,019 |
October 15, 2019
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https://www.sciencedaily.com/releases/2019/10/191015075241.htm
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Taming the wild cheese fungus
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The flavors of fermented foods are heavily shaped by the fungi that grow on them, but the evolutionary origins of those fungi aren't well understood. Experimental findings published this week in
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In the paper, microbiologists report that wild-type "In fermented foods, there's a lot of potential for microbes to evolve and change over time," said Wolfe.Wolfe's lab at Tufts University in Medford, Mass., focuses on microbial diversity in fermented foods, but he says the new experiments began with an accidental discovery. His lab had been growing and studying But over time, researchers noticed changes in some of the lab dishes containing the stinky mold. "Over a very short time, that funky, blue, musty-smelling fungus stopped making toxins," Wolfe said. The cultures lost their bluish hue and turned white; they smelled like fresh grass and began to look more To study that evolution in real-time, Wolfe and his collaborators collected fungal samples from a cheese cave in Vermont that had been colonized by wild strains of After one week, Wolfe said, the molds appeared blue-green and fuzzy -- virtually unchanged -- in all the experimental tests. But over time, in the dishes where the mold grew alone, its appearance changed. Within three or four weeks of serial passage, during which mold populations were transferred to new dishes containing cheese curds, 30-40 percent of the mold samples began to look more like In follow-up analyses, Wolfe and his team tried to identify genomic mutations that might explain the quick evolution but didn't find any obvious culprits. "It's not necessarily just genetic," Wolfe said. "There's something about growing in this cheese environment that likely flips an epigenetic switch. We don't know what triggers it, and we don't know how stable it is."Researchers suspect that the microbes used in most fermented foods -- including cheese, but also beer, wine, sake, and others -- were unintentionally domesticated, and that they evolved different flavors and textures in reaction to growing in a food environment. Wolfe says his lab's study suggests that wild strains could be domesticated intentionally to produce new kinds of artisanal foods.Starting with cheese, of course. "The fungi that are used to make American camembert are French," said Wolfe, "but maybe we can go out and find wild strains, bring them into the lab, and domesticate them. We could have a diverse new approach to making cheese in the United States."
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Agriculture & Food
| 2,019 |
October 15, 2019
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https://www.sciencedaily.com/releases/2019/10/191015115359.htm
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Soil on moon and Mars likely to support crops
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Researchers at Wageningen University & Research in the Netherlands have produced crops in Mars and Moon soil simulant developed by NASA. The research supports the idea that it would not only be possible to grow food on Mars and the Moon to feed future settlers, but also to obtain viable seed from crops grown there.
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Wieger Wamelink and his colleagues at Wageningen University & Research, cultivated ten different crops: garden cress, rocket, tomato, radish, rye, quinoa, spinach, chives, peas and leek. The researchers simulated the properties of Lunar and Martian regolith and "normal" soil (potting soil from Earth) as a control.Nine of the ten crops sown grew well and edible parts were harvested from them. Spinach was the exception. Total biomass production per tray was the highest for the Earth control and Mars soil simulant that differed significantly from Moon soil simulant. The seeds produced by three species (radish, rye and garden cress) were tested successfully for germination.The article, "Crop growth and viability of seeds on Mars and Moon soil simulants," by Wieger Wamelink and colleagues has been published in De Gruyter's open access journal, "We were thrilled when we saw the first tomatoes ever grown on Mars soil simulant turning red. It meant that the next step towards a sustainable closed agricultural ecosystem had been taken," said Wieger Wamelink.
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Agriculture & Food
| 2,019 |
October 15, 2019
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https://www.sciencedaily.com/releases/2019/10/191015113320.htm
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The makeup of mariculture: Global trends in seafood farming
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When Florida families settle down to enjoy a seafood dinner they may not realize the main dish wasn't freshly caught in the nearby Gulf of Mexico, but rather farmed off the coast of Panama.
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The process of farming seafood in the ocean, known as mariculture, is a growing trend yet little is known about the trajectories of its development. That's why a team of Florida State University researchers set out to shed some light on the industry.FSU postdoctoral researcher Rebecca Gentry, doctoral student Elizabeth Bess Ruff and Assistant Professor of Geography Sarah Lester examined more than 50 years of data from 1950 to 2016 from more than 100 countries around the world.Their study, published in "Aquaculture is an increasingly important component of global food production," Gentry said. "Therefore, understanding patterns of development has important implications for managing our changing global food systems and ensuring economic development, food security and environmental sustainability."Gentry and her team examined different development trajectories of mariculture production overall and that of specific groups of species, such as fish and crustaceans. They found that countries with relatively stable production farmed a greater diversity of species than countries with other development trajectories.For example, stable countries produced 15.2 species on average, compared to 6.5 for countries who have experienced a crash in production. Lester pointed out that this result suggests that increasing the diversity of mariculture crops could support more robust and resilient seafood production.Additionally, researchers found the type of species grown had a positive connection with a country's development trajectory. Specifically, countries that initially farmed molluscs, such as oysters or mussels, were more likely to have stable production than countries that started with farming fish.Researchers also found that governance and economic indicators were related to trajectories of mariculture production. For instance, low production countries tended to have lower annual gross domestic product (GDP) scores, lower governmental regulatory quality and lower levels of internet connectivity. Further, the team demonstrated that many countries had stabilized their mariculture production at a level far below their potential productivity."This indicates that governance, regulatory or economic changes could unlock further opportunities for growth," Gentry said. "Environmental regulations are important for preventing significant environmental decline, local over-development and unsustainable farm practices. However, for those countries currently failing to meet their mariculture potential, policies to encourage thoughtful growth may be worth considering."The study is just one part of a larger National Science Foundation-funded project led by Lester that is examining the socioeconomic and ecological drivers of mariculture development."This type of multidisciplinary research is essential for better understanding the current effects and future potential of marine aquaculture -- which will be all the more important as the global human population continues to increase and we reach the sustainable limits of other types of food production," Lester said.
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Agriculture & Food
| 2,019 |
October 11, 2019
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https://www.sciencedaily.com/releases/2019/10/191011165320.htm
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How preprocessing methods affect the conversion efficiency of biomass energy production
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Research on energy production from biomass usually focuses on the amount of energy generated. But it is also important to consider how much energy goes into the process, a component that is often neglected, says Tony Grift, professor of Agricultural and Biological Engineering in the College of Agricultural, Consumer and Environmental Sciences and the Grainger College of Engineering at the University of Illinois.
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Grift is co-author on a new study, published in "Our goal was to determine how much energy it takes to prepare these materials. It's a comprehensive look at various preprocessing methods and their relationship to conversion efficiency," he explains.The two materials were chosen because of their importance for energy production. Miscanthus is typically grown as an ornamental crop, but it has a high amount of biomass and grows easily with very little nitrogen use. Sugarcane bagasse is the byproduct left over after sugarcane is crushed to extract the juice for sugar.The study was done in collaboration with chemists from University of California at Berkeley. Grift says the interdisciplinary approach makes the research unique, because it considers the whole energy balance. The U of I researchers studied the energy expenditure of harvesting and preprocessing materials, while the Berkeley chemists focused on converting the biomass to glucose, which is used to make ethanol.The researchers defined the percentage of inherent heating value (PIHV), which measures the amount of energy going into and out of the production process. "It tells you that you have a certain amount of biomass, which contains a certain amount of energy. How much energy do you spend on processing? You don't want to spend more than 5% of the total energy value," Grift says.The researchers subjected the two materials to nine different preprocessing methods, either separately or as a blend. Preprocessing is done for various reasons, Grift explains. After the crop is harvested, it needs to be transported to a processing plant, and to make transportation efficient, the material first undergoes a process called comminution, in which is it chopped or cut into smaller pieces, and then it is compressed.Grift explains that harvesting and compression do not add much to the energy equation. The main source of energy expenditure is comminution, or size reduction. That brings the energy expenditure to 5%. "Smaller particle sizes make compression easier," he says. "It's also better for energy production, because it provides a larger surface area for enzymes to attach to in the conversion process. But comminution takes a certain amount of energy, so there is a tradeoff."The preprocessing methods included chopped and cut stems, pelletization, comminution, and various levels of compression. Of the nine treatment groups, five included miscanthus, three included sugarcane bagasse, and one included a blend of the two products. The processed materials were all subjected to the same chemical processes to release the glucose.The researchers also evaluated the effects of particle size, compression level, and blending on biomass conversion efficiency. The results showed that comminution had a positive effect on the efficiency of miscanthus but not sugarcane bagasse, while the opposite was the case for pelletization. The researchers also found that a 50/50 blend of the two materials had higher conversion efficiency than sugarcane bagasse, but there was no significant difference compared to miscanthus alone.The results can be used to help make biomass energy production more efficient, Grift says."The differences are not huge. But if you want to do something on a larger scale it's actually quite important to figure these things out," he explains.Grift emphasizes that the results are preliminary and should be examined in further studies.Continued research is needed to substantiate the findings and to broaden the knowledge base to other products and other preprocessing methods.
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Agriculture & Food
| 2,019 |
October 11, 2019
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https://www.sciencedaily.com/releases/2019/10/191011112238.htm
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Family of crop viruses at the molecular level
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For the first-time we can take a molecular-level look at one of the world's deadliest crop killers.
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The Luteoviridae are pathogenic plant viruses responsible for major crop losses worldwide. Transmitted by aphids, the viruses infect a wide range of food crops including cereals, legumes, cucurbits, sugar beet, sugarcane and potato.Until now researchers have been unable to generate the quantities of these viruses needed to study their structures in high resolution.Now a team of researchers have used recent advances in plant expression technology to generate sufficient quantities of the pathogen to allow more detailed scrutiny with state of the art microscopy techniques.The method involves infiltrating a type of tobacco plant with the genes necessary to create virus-like particles (VLPs). From the inserted genetic information, the VLPs self-assemble inside the plant host. This technique avoids the need to handle the infectious virus.Using the VLPs extracted from the plants the team from the John Innes Centre and the Astbury Biostructure Laboratory at the University of Leeds could observe the viral structures to high resolution by cryo-electron microscopy.This provided, for the first time, a molecular-level insight into how the luteovirid capsid forms and suggests how it is transmitted by aphids. The method may help unlock the secrets of other viruses, say the team involved in the study.Professor George Lomonossoff of the John Innes Centre says. "This development provides a platform for the development of diagnostic tools for this important family of plant viruses that cause enormous loses worldwide."Professor Neil Ranson from the University of Leeds adds: "The combination of plant expression technology and structural biology is hugely exciting, and we can use it to understand the structures of many other types of virus."Plant virus infection is responsible for global economic losses estimated at $30billion.The Luteoviridae attack the plant vasculature which causes severe stunting leading to crop loss. The family includes barley yellow dwarf virus and potato leafroll virus which cause crop losses to a value of £40-60m per year in the United Kingdom.The full study 'Combining Transient Expression and Cryo-EM to Obtain High-Resolution Structures of Luteovirid Particles' appears in the Cell Press journal
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Agriculture & Food
| 2,019 |
October 10, 2019
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https://www.sciencedaily.com/releases/2019/10/191010125609.htm
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Tracking wild pigs in real time and understanding their interaction with agro-ecosystems
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Domestic pigs can be cute, but invasive wild pigs -- also known as feral swine -- are another matter entirely. First brought to the U.S. by early European settlers, wild pigs have earned a reputation for being highly destructive creatures in North America. With few natural predators aside from humans, and the highest reproductive potential of any mammal of similar size, two to six million are wreaking havoc in at least 39 states and some Canadian provinces. In Texas alone, they do hundreds of millions of dollars in damages annually. They tear up recreational areas, occasionally even terrorizing tourists in state and national parks, and squeeze out other wildlife. In agricultural fields, wild pigs may eat the crops or indirectly damage them, or the soil, by creating wallows, scent marking, rooting up plants, or destroying fencing and equipment.
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A new study in the Ecological Society of America's journal Understanding how, when, and why they use different food resources is important because it may be a significant contributing factor in their expansion and invasion into new ecosystems.In previous studies, researchers typically conducted studies in a lab. In this studyLead author Mark Wilber, a postdoctoral fellow at Colorado State University, and colleagues from the U.S. Department of Agriculture's (USDA) National Wildlife Research Center and around the U.S. studied GPS data from tagged wild pigs collected from 24 previous movement studies. Data from 326 individual wild pigs were used to trace their movement and time spent in crops. The USDA keeps track of yearly crops across the country, detailed down to plots of 30 by 30 meters, and it records when those crops are planted and harvested, which is the time they are most vulnerable to being consumed by pigs. Using the GPS and detailed crop data, the researchers learned how much time pigs spent in various different crops relative to their abundance and the abundance of non-agricultural food sources.The authors expected to find that wild pigs use crops more often when other food options are scarce. They also expected to find an exponential relationship between crop availability and pig usage, where a higher abundance of crops leads pigs to exploit them much more often. This is largely because as crops become more plentiful, the benefits of using them outweigh the risks of being trapped or killed.Many states allow hunters to kill wild pigs year-round without limits, or to capture them alive to be slaughtered, processed, and sold to restaurants as exotic meat -- further complicating control efforts because it incentivizes their existence. Thousands more are shot from helicopters. The goal of USDA's National Feral Swine Damage Management Program (NFSDMP) is to minimize damages and eradicate wild pigs where possible, says Sarah Chinn of University of Georgia."Managing populations is difficult because some landowners want wild pigs on their land while others don't," explains Chinn. "Those that have crops need to control their losses while others might want the wild pigs around for recreational hunting or even profit." Management options for landowners include lethal removal, exclusion, repellents, and supplemental feeding (to keep pigs away from profitable crops), but lethal control is the method most used by the NFSDMP.Wild pigs may want to avoid these crop-associated risks. So, the researchers also expected to find that pig use of crops decreases when the availability of non-agricultural food increases.Their expectations of the study seem supported. Overall, wild pigs eat and damage agriculture more when it is highly available, but this behavior lessens when non-agricultural food sources are also highly available.Wilber says he and his colleagues are excited to show how commonly-collected animal movement data, and publicly-available agricultural data, can be used to understand how invasive pests use and damage resources in different ecosystems, and to better predict how fast they expand into new areas. He adds, "An improved understanding of foraging behavior will help managers more effectively control invasive pests in the United States and elsewhere."
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Agriculture & Food
| 2,019 |
October 10, 2019
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https://www.sciencedaily.com/releases/2019/10/191010113242.htm
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Scientists track wheat aphids and their natural enemies for better pest management in Pakistan
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For the first time, CABI scientists have studied the distribution and population dynamics of wheat aphids and their natural enemies in Pakistan through seasons and periods of time. This research could be useful to develop better pest management methods and safer, healthier crops in wheat production.
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The two-year study led by Dr Muhammad Faheem across ten farms in five Punjab districts sought to discover the relationship between different timings, seasons, space and the presence of aphids and the insects that eat them -- particularly syrphid flies -- in varying deliberately-selected farming scenarios; combinations of rice, arid and cotton.Wheat aphids are well known pests of the cereal crop -- causing up to 20 to 80% loss of wheat yield, particularly in Pakistan where over 26.3 million tons of wheat was produced in 2017-18 and where wheat accounts for 10 percent of value added in agriculture. The presence, spread or influx of aphids had led to considerable economic loss especially comparing the average yield of wheat in Pakistan with neighbouring India and Bangladesh.In the paper published by There are several reasons cited for the findings made including behaviour differences among species; ultimately this study provides baseline data for further investigation into two approaches in aphid management -- top down, the use of natural enemies and bottom up, the use of fertilisation and irrigation.Dr Faheem also remarked that "understanding where aphids will tend to infest, and at what time is necessary to effectively manage use of biocontrol agents." The researchers recommend further study as a follow on to this baseline for better understanding of how wheat aphids and their natural enemies are spread in order to improve integrated pest management programs.
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Agriculture & Food
| 2,019 |
October 10, 2019
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https://www.sciencedaily.com/releases/2019/10/191010104934.htm
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Plant death may reveal genetic mechanisms underlying cell self-destruction
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Hybrid plants -- those produced by crossing two different types of parents -- often die in conditions in which both parents would survive. It's called hybrid lethality. Certain hybrid tobacco plants, for example, thrive at 36 degrees Celsius, but die at 28 degrees Celsius, which is the temperature at which both parents would thrive.
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A team of researchers at Tokyo University of Agriculture and Technology (TUAT) based in Japan have begun to unravel the molecular mechanisms by which hybrid tobacco plant cells meet their demise. The researchers published their results online on July 15 in When moved to the lower temperature, hybrid tobacco cells induce a process called programmed cell death. It sounds dramatic, but it's normal and healthy -- to a point. In humans, for instance, skin cells slough off when new ones are ready to take over. It's a constant renewal. However, in some circumstances, the cells become overzealous and die off before there are replacements available, causing the entire organism to die."What induces programmed cell death related to hybrid lethality in plants?" asked Tetsuya Yamada, paper author and associate professor at the United Graduate School of Agricultural Science at Tokyo University of Agriculture and Technology. "This is the problem we set out to better understand."The researchers used powerful imaging tools to see inside the hybrid cells. They found protein aggregates -- proteins that are misfolded or otherwise mutated -- accumulated in hybrid cells."We found programmed cell death is induced in plant cells by the accumulation of protein aggregates resulting from loss of protein homeostasis," Yamada said.Protein homeostasis refers to the intricate and fragile balance between the development of new proteins and the death of old proteins in the already delicate cellular ecosystem. The loss of homeostasis may resulted from an autoimmune response, which is induced after the temperature shift, according to Yamada.In an effort to combat this cellular decay, the researchers treated hybrid tobacco cells with a type of salt (sodium-4-phenylbutyrate) known to help proteins fold properly. Yamada calls it a "chemical chaperone." It not only stopped the accumulation of protein aggregates, but it also stopped what had previously been the irreversible progression of cell death.Next, Yamada and the researchers plan to further investigate how the accumulation of protein aggregates are involved in inducing programmed cell death, specifically in relation to disease resistance and environmental stress in plants."We will also clarify the molecular mechanisms involved in the regulation of protein homeostasis," Yamada said. "The ultimate goal is to establish a genetic improvement technique for developing crop varieties with improved disease resistance and environmental stress tolerance by enhancing the function of maintaining protein homeostasis."
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Agriculture & Food
| 2,019 |
October 9, 2019
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https://www.sciencedaily.com/releases/2019/10/191009132321.htm
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Antibiotic resistance in food animals nearly tripled since 2000
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The growing appetite for animal protein in developing countries has resulted in a smorgasbord of antibiotic consumption for livestock that has nearly tripled the occurrence of antibiotic resistance in disease-causing bacteria easily transmitted from animals to humans, according to a recent report in the journal
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Researchers from ETH Zurich, the Princeton Environmental Institute (PEI), and the Free University of Brussels gathered nearly 1,000 publications and unpublished veterinary reports from around the world to create a map of antimicrobial resistance in low- to middle-income countries. They focused on the bacteria Escherichia coli, Campylobacter, Salmonella, and Staphylococcus aureus, all of which cause serious disease in animals and humans.Between 2000 and 2018, the proportion of antibiotics showing rates of resistance above 50% in developing countries increased in chickens from 0.15 to 0.41 and in pigs from 0.13 to 0.34, the researchers reported. This means that antibiotics that could be used for treatment failed more than half the time in 40 percent of chickens and one-third of pigs raised for human consumption.The researchers found that antibiotic resistance in livestock was most widespread in China and India, with Brazil and Kenya emerging as new hotspots. Since 2000, meat production has accelerated by more than 60% in Africa and Asia, and by 40% in South America, as countries on those continents shifted from low- to high-protein diets. More than half of the world's chickens and pigs are in Asia."This paper is the first to track antibiotic resistance in animals globally and it finds that resistance has gone up dramatically during the past 18 years," said co-author Ramanan Laxminarayan, a senior research scholar in PEI. The research was supported by the PEI Health Grand Challenge program and included co-author Julia Song, a graduate of Princeton's Class of 2018 and a past PEI research assistant."We certainly do want higher-protein diets for many people, but if this comes at the cost of failing antibiotics, then we need to evaluate our priorities," Laxminarayan said.Meat production accounts for 73% of global antibiotic use. Antibiotics have made large-scale husbandry and widespread meat consumption possible by reducing infection and increasing the body mass of livestock.The skyrocketing emergence of antibiotic resistance in livestock is especially troubling in developing countries, said first author Thomas van Boeckel, an assistant professor of health geography and policy at ETH Zurich. Those nations continue to experience explosive growth in meat production and consumption, while access to veterinary antimicrobials remains largely unregulated.The researchers suggest that developing nations should take action to restrict the use of human antibiotics in farm animals and that affluent nations should support a transition to sustainable farming, possibly through a global fund to subsidize biosafety and biosecurity improvements. Otherwise, the unrestricted use of antibiotics in even greater numbers of animals raised for human consumption could lead to the global spread of infectious bacteria that are increasingly difficult to treat."Antimicrobial resistance is a global problem," said Van Boeckel, who was a Fulbright Scholar at Princeton from 2013-2015. "This alarming trend shows that the drugs used in animal farming are rapidly losing their efficacy."
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Agriculture & Food
| 2,019 |
October 9, 2019
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https://www.sciencedaily.com/releases/2019/10/191009131746.htm
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No soil left behind: How a cost-effective technology can enrich poor fields
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Many farmers across sub-Saharan Africa try to coax crops out of sandy soils that are not ideal for holding water and nutrients. Their harvests are predictably poor. A traditional approach would have them apply more fertilizers and use irrigation, but both of these options require access to resources and infrastructure that many of them do not have. A relatively new technology modeled for eight African countries, and currently being tested in Zimbabwe, shows potential for substantially improving harvests through increased water retention and accumulation of organic material to make soils more fertile.
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The technology consists of long strips of polyethylene membranes installed in a U-shape below and near the root zones of crops. Known as subsurface water retention technology (SWRT), these membranes have mostly been used in different soils in other regions of the world. Now for the first time, their impact was modeled for Africa. Projected results showed that the SWRT could increase maize yields in the eight African countries in the study by close to 50 percent and capture some 15 million tons of carbon in 20 years."With this new technology, sandy soil has the potential to lead a new green revolution," said George Nyamadzawo, a professor at Bindura University in Zimbabwe.The researchers said this simple technology, if deployed and adopted at scale, could address major issues facing sub-Saharan African farmers, including food security and erratic rainfall patterns, while also helping countries meet climate change mitigation targets. The study was published in "We should refuse to allow sandy soils to limit smallholder farmers from reaching their full potential," said Ngonidzashe Chirinda, a researcher at the International Center for Tropical Agriculture (CIAT) who co-authored the research. "In arid and semiarid regions with poor soils, smallholder communities continue to suffer due to soil-based poverty. Our research shows SWRT has the potential to effectively change this without recurring to traditional and potentially expensive remedies."For the study, SWRT was modeled for the sandy soils of eight countries in Southern Africa and Eastern Africa: Angola, Botswana, Kenya, Namibia, Mozambique, South Africa, Tanzania, and Zimbabwe. The main objective of the study was to model scenarios of adoption of SWRT and estimate increases in maize yields, crop biomass, and soil carbon sequestration.Co-authors include scientists at the Swedish University of Agricultural Sciences (SLU), in Sweden; Jomo Kenyatta University of Agriculture and Technology, in Kenya; Cape Peninsula University of Technology, in South Africa; Bindura University of Science Education, in Zimbabwe; and Michigan State University (MSU), in the United States."Potential benefits are obvious with new technologies such as SWRT, but there is a need to overcome non-technical barriers; this requires support from decision-makers who can put in place the necessary policies and financial mechanisms to support farmer adoption," said Libère Nkurunziza, the lead author and researcher at SLU. "Similar technologies should be tested and adapted to smallholder farmer conditions to solve productivity challenges on sandy soils."Using data collected in other regions where SWRT has been tested, the authors made their projections for Africa. The technology is now being tested in Zimbabwe, through a new Swedish Research Council-funded project, called Productive Sands, that is being led by SLU."The new innovative, long-term SWRT will lead the way for modifying soils that best assist plant resilience to changing climates and associated weather patterns, enabling smallholder farmers of sandy soils to establish reasonable nutritious food supplies and annual income across all nations," said Alvin Smucker, a co-author from MSU and one of the pioneers of the technology."This fabulous contribution constitutes another great example of the need for increasing public and private investments in applied research on new agronomic practices and particularly those focusing on the management of soil fertility as an effective and efficient way of securing food production as well as sequestering carbon," said Ruben Echeverría, the Director General of CIAT."Congratulations to the authors for the research results and for building a great research partnership."
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Agriculture & Food
| 2,019 |
October 9, 2019
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https://www.sciencedaily.com/releases/2019/10/191009075339.htm
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Mapping white clover heritage
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Four-leaved clovers may or may not bring good luck. What's indisputable is that all white clovers, whether with three or four leaves, have many benefits.
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The United States Department of Agriculture calls white clover "one of the most important pasture legumes." In New Zealand, it is one of the main species, along with ryegrass, grown in pastures.On farms, white clover provides multiple services. Bacteria in clover root nodules 'fix' atmospheric nitrogen and make it available to crops. White clover is a great source of protein for farm animals. In cities, white clover often accompanies the grass used in lawns and playgrounds.Despite its many uses, white clover breeders in New Zealand did not have access to a comprehensive map of the population structure or genetic landscape of white clover diversity in the country. Now, researchers in New Zealand have created the first detailed map of white clover ancestry and genetics."This 'pedigree map' -- achieved via pedigree analysis -- will serve as an important resource to white clover breeders," says Valerio Hoyos-Villegas, lead author of the study. "It will also help make more informed decisions in the breeding of different white clover varieties."For all crops, different varieties may be needed to grow in different environments for varying purposes. For example, some crop varieties might need to be drought resistant. Others may be bred to have high yields while growing on poor soils.In addition to gaining a resource for breeding white clover varieties with desired traits, researchers also found information on the heritage of the species. Pedigree analysis provided this vital information.For example, the researchers were able to confirm the genetic makeup of the plants initially used to establish white clover crops in New Zealand. They could trace how these initial group of plants, brought in by early plant breeders, were the basis for other varieties of white clover developed later."Understanding this genetic history of white clover will help maximize diversity in breeding populations," says Hoyos-Villegas. A diverse breeding population can help breeders develop varieties of white clover with more desired traits.The researchers focused on a collection of white clover germplasm, maintained in the Margot Forde Germplasm Centre (seed bank) in Palmerston North, New Zealand. Germplasm refers to genetic resources or material maintained for breeding or conservation goals."Safeguarding germplasm is the most inexpensive and efficient method of genetic conservation for important plants," says Hoyos-Villegas. But, simply having a germplasm collection is of limited use. "We have created a curated resource of pedigree information," he says. "This resource can be used by any breeder or geneticist interested in using the white clover germplasm."The study also provides a summary and results of white clover breeding efforts over the last 80 years. The historical nature of the research threw up some unique obstacles. "We were dealing with data from many different sources," says Hoyos-Villegas. "One of the main challenges was curating the data to reach a standard that gave us confidence in the results."The researchers collected and analyzed a lot of historical information in the study. Now, their results can serve as a launch pad for future research and breeding efforts. For example, researchers can use the pedigree analysis to associate traits of interest with specific genes."We can also cross populations of white clover based on data from the pedigree analysis," says Hoyos-Villegas. "We can test these populations to determine what sort of novel genetic variations we can create." These data can then be used to complement ongoing breeding efforts in the private sector.Researchers are now thinking about expanding pedigree analysis into different species beyond clover. "It would be very useful to extend this analysis to other important forage species," he says. "Perennial ryegrass, which is often used as a companion species to clover in pastures, would be a great next choice."
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Agriculture & Food
| 2,019 |
October 8, 2019
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https://www.sciencedaily.com/releases/2019/10/191008212134.htm
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Worrisome badger behavior inside the cull zone
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A study led by researchers at international conservation charity ZSL (Zoological Society of London) and Imperial College London has found that culling drives badgers to roam 61% further afield -- helping to explain why the practice, intended to reduce bovine TB transmission, can sometimes exacerbate the problem instead.
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Published in the Badgers were also found to visit 45% more fields each month, and the odds of a badger visiting neighbouring territories each night increased 20-fold -- potentially increasing the risk of TB transmission both to cattle and to other badgers. These changes were witnessed as soon as culling began, meaning even badgers that were killed may have first spread the infection over wider areas while management was being implemented.Badgers however spent less time outside of their setts in culled areas -- spending on average 91 minutes less per night out and about. ZSL scientists believe this could be linked to reduced competition and increased food availability as badgers are removed from the population.The research group from ZSL's Institute of Zoology, and Imperial's MRC Centre for Global Infectious Disease Analysis, studied 67 badgers across 20 cattle farms in areas with and without farmer-led culling in Cornwall, collecting GPS-collar data between 2013 and 2017.Lead author and ZSL-Imperial PhD researcher, Cally Ham explained: "Badgers spend a large proportion of the night foraging for food above-ground, and as culling reduces the size of the population, competition for food will also be reduced. We believe this accounts for the reduced activity levels, as well as bold individuals becoming obvious targets for culling and being quickly removed from the population."Because culling partly relies on shooting badgers moving around at night, the fact that badgers were active for fewer hours per night could actually be undermining culling efforts to further control badger numbers."Professor Rosie Woodroffe at ZSL's Institute of Zoology, said: "As badger-to-cattle transmission is likely to occur through contamination of their shared environment, and TB bacteria can remain viable for long periods of time in the environment, the effects of increases in ranging behaviour could create a source of infection for several months -- long after the individual badger has been culled. In contrast, studies have shown that vaccination prompts no changes in badgers' ranging behaviour."Since the UK Government implemented the culling policy in 2011, ZSL scientists have been working to understand whether badger vaccination -- a non-lethal alternative to culling -- could be used to reduce the infection of TB in the UK's badger population, and so help control TB in cattle.
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Agriculture & Food
| 2,019 |
October 8, 2019
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https://www.sciencedaily.com/releases/2019/10/191008133011.htm
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DNA metabarcoding useful for analyzing human diet
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A new study demonstrates that DNA metabarcoding provides a promising new method for tracking human plant intake, suggesting that similar approaches could be used to characterize the animal and fungal components of human diets. The study, published in the journal
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"DNA sequencing has given us a large amount of new data on things like microbiology in the gut and personal genetics. This study suggests that the same powerful technology could also start telling us about what we eat, which is often a hard thing to measure," said senior study author Lawrence David, PhD, assistant professor, Center for Genomic and Computational Biology, Duke Molecular Genetics and Microbiology.Many preexisting methods for dietary assessment exist, but most rely on a person's ability to report what they ate. This means that they are subject to errors in memory, bias people have in reporting, and the cognitive ability of a person answering a survey. DNA metabarcoding is an alternative way to obtain dietary information that uses food DNA in stool as a biomarker. Researchers can amplify food DNA from a fecal sample, sequence it, and map those sequences back to foods using a reference database. "I think of DNA metabarcoding very much like a barcode at a supermarket. We can think of a particular DNA sequence as a unique identifier for a particular food species," said second study author Brianna Petrone, a graduate student at Duke University School of Medicine.Dr. David and co-first author Aspen Reese, PhD, now a junior fellow at Harvard University, launched the study after they met the ecologists Rob Pringle, PhD, at Princeton University and Tyler Kartzinel, PhD, now at Brown University, who originally used DNA metabarcoding to study complex food webs of herbivores in the African savanna. "We wondered whether their method would work in people," said Dr. David. "There is a growing body of work in the microbiome field indicating that specific foods are likely to be altering or shaping levels of specific bacteria in the gut, but we often don't have accompanying diet data for the microbiome studies."To conduct their study, the researchers pulled DNA out of cold storage that had been extracted from stool samples from a previous study. "We happened to do a study a couple years ago where we were preparing foods for participants in a microbiome diet intervention, and we knew exactly what they were eating in a given week when their stool was being collected," said Dr. David.The researchers sequenced a barcode region from chloroplast DNA in stool samples from 11 individuals consuming both controlled and freely selected diets. They successfully amplified plant DNA in roughly 50% of samples, which increased to 70% in samples from individuals eating a controlled plant-rich diet. The majority of sequenced plant DNA matched common human food plants, including grains, vegetables, fruits and herbs. "Overall, there was good broad agreement between the foods that were listed in the diaries kept by the study participants and the ones that we sequenced from stool," said Dr. David. "If a food was written in the diet record, about 80% of the time, we also found it by this metabarcoding approach."The relatively high PCR failure rate and inability to distinguish some dietary plants at the sequence level suggest the potential for future refinements to improve the method. For example, cabbage, broccoli, Brussel sprouts and kohlrabi are all cultivars of the same species, and researchers were unable to tell them apart by their sequence in the chloroplast barcode region. Coffee was the only food recorded in the diet that was never detected with DNA metabarcoding, perhaps because its DNA was deteriorated or diluted by roasting and brewing.Dr. David forsees DNA metabarcoding being used in future studies, as well as renewed the possibility of diet analysis in older studies. "Similar to this study, I could imagine this getting used on archived DNA to see whether or not there are underlying dietary differences that might explain some of the microbiome patterns that may have been observed in a study," said Dr. David. "Going forward, we can also imagine this being used in new microbiome studies to identify relationships between specific foods and gut bacteria, as well as in broader studies of nutrition as a complement to traditional diet assessment techniques."
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Agriculture & Food
| 2,019 |
October 8, 2019
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https://www.sciencedaily.com/releases/2019/10/191008115938.htm
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Cheap as chips: Identifying plant genes to ensure food security
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An international team of scientists led by the University of Goettingen has developed a new approach that enables researchers to more efficiently identify the genes that control plant traits. This method will enable plant breeders and scientists to develop more affordable, desirable, and sustainable plant varieties. The application will be most valuable for the fruit, vegetable and grain crops that not only end up on our dinner table, but are also critical for global food security and human nutrition. The research was published in
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The new method is an extension of a tool known as GWA (Genome Wide Association). GWA studies use genetic sequencing technologies coupled with advanced statistics and computation to link differences in the genetic code with particular traits. When using GWA to study plants, researchers typically manage large sets of genetically identical plants. However, developing these sets of "inbred lines" is costly and time-consuming: it can take over six years of preparation before such a study can even begin. The new technique is modelled after an approach often used to study human DNA, in which DNA samples from thousands of individual people, who are certainly not identical, are compared.The researchers wanted to discover whether this approach would be successful in plants. Since measurements of individual plants can be highly variable, the scientists developed a method that enabled them to combine the advantages of a GWA study with additional statistical analysis techniques. To test their idea, they investigated whether their combination of approaches could accurately detect genes involved in plant height, a trait that has been extensively studied in the scientific literature. The scientists planted four fields of an early variety of white maize (white corn) and measured the height of the plants. They identified three genes, from the potential 39,000 genes in the maize genome, which were controlling plant height. The effects of all three of these genes were supported by previous studies on other maize varieties. This showed that their method had worked."Scientists usually have to measure huge numbers of genetically identical plants in order to have a powerful enough study for finding genes," says Professor Timothy Beissinger, head of the Division of Plant Breeding Methodology at the University of Goettingen, "but we used a diverse maize population and showed that our approach was powerful without relying on identical plants at all." Abiskar Gyawali, a University of Missouri (USA) PhD student who is the first author, went on to say, "This is great news for researchers interested in finding genes in crops where inbred lines are not available or are time-consuming to produce."Beissinger stated, "The exciting thing is that this study reveals the potential for our method to enable research in other food crops where research funding is not as high. Due to industry and government support, resources are already available to do large-scale studies in maize. But for scientists studying the countless vegetables, fruits, and grains that many communities rely on, funding for massive studies simply isn't possible. This is a breakthrough which will enable cheap and quick identification of trait-gene associations to advance nutrition and sustainability in food crops world-wide."
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Agriculture & Food
| 2,019 |
October 8, 2019
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https://www.sciencedaily.com/releases/2019/10/191008104701.htm
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Sweet corn growers, processors could dramatically increase yield, profit
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In an industry struggling to maintain profitability, it's curious that U.S. processing sweet corn -- the corn that ends up in cans and freezer bags -- is falling so far below its potential. Yet, that's what a new study in
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According to Martin Williams, an ecologist with USDA-ARS and associate professor in the Department of Crop Sciences at the University of Illinois, processing sweet corn in the Midwest is grown at an average population of 24,000 plants per acre. But through years of small-plot field trials, his team has shown that certain hybrids are naturally density tolerant, and their performance improves when planted at higher population sizes. His research also indicated that increasing populations of density-tolerant hybrids improved profit to both contract growers and vegetable processors.The results were promising, but it wasn't clear how well small-plot trials in Central Illinois translated to farmers' fields throughout the Midwest."While processors were aware of our early work in small-plot field trials, some -- myself included -- were skeptical about the extent to which the industry could increase efficiency by adjusting plant population size," says Williams, co-author of the Williams and Illinois graduate student Daljeet Dhaliwal conducted on-farm trials throughout Illinois, Minnesota, and Wisconsin over a five-year period. The on-farm trials started with two hybrids, but one was pulled from the project early, so the researchers focused on fields grown with 'DMC 21-84', a known density-tolerant hybrid. They coordinated with processors and growers to plant test strips at population sizes ranging from 17,000 to 44,000 plants per acre.Having a range of population sizes made it possible for the researchers to find the sweet spot where both yield and profit peaked. After planting the trials, which were nested inside production fields, growers continued to manage their fields as usual. At harvest, the researchers hand-harvested and measured marketable ears, and simulated processing by husking ears and cutting kernels with industry-grade equipment. In addition, they conducted an economic analysis to quantify profitability.As the research team expected, there was no single optimal population size throughout the region. The optimum population was higher for irrigated fields than rainfed fields, and it was higher for fields in the south (e.g., Central Illinois) than the north (e.g., central Wisconsin). However, in every single field, the optimum population size for DMC 21-84 was higher than the current standard. And those optimum populations increased yield of marketable ears by an average of 0.53 tons per acre.At $75 per ton, that's an extra $40 per acre in profit to the grower.However, vegetable processors choose the hybrid, provide seed of that hybrid, and set the population size. So any change requires processor buy-in. Do processors benefit from increasing population of a density-tolerant hybrid?"Yes," Williams says. "Our five years of research in growers' fields throughout the Midwest show that the processor could benefit on average up to $120 to $280 per acre, even after paying the cost of extra seed."Williams emphasizes that he is not telling the processing industry to increase population sizes for all hybrids, or in every field. "We know for a fact that several of the popular hybrids cannot tolerate higher population sizes. Nothing good would come of increasing populations for those. But for density-tolerant hybrids, we're not currently taking full advantage of their genetic potential by growing them at populations established for their predecessors."Seed companies in the business of developing new sweet corn hybrids have taken note. For instance, Illinois Foundation Seeds, Inc. is testing processing hybrids at 27,500 plants per acre in Illinois and 26,000 plants per acre in Wisconsin.Charlie Thompson, director of research for IFSI says, "Moving forward, our hybrids will be performing well at higher population sizes than are currently planted in the market."Crookham Company and Snowy River Seeds are also working towards expanding their lines of density-tolerant hybrids, according to Dustin Batt, Crookham's research manager and sweet corn breeder.Williams knows the processing industry as a whole is concerned about the economic sustainability of sweet corn production. While the U.S. leads sweet corn innovation and production globally, rising production costs, coupled with stagnant yields and contract prices, have created an economic hardship. Recent announcements of processing plant closures later this month in Mendota, Illinois, and Sleepy Eye, Minnesota, will impact more than a thousand employees and growers."Plant density tolerance transformed field corn productivity over the last half century," Williams says. "Our research shows that utilizing the trait in sweet corn has significant economic advantages to sweet corn growers and processors."
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Agriculture & Food
| 2,019 |
October 7, 2019
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https://www.sciencedaily.com/releases/2019/10/191007180035.htm
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Urban, home gardens could help curb food insecurity, health problems
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Food deserts are an increasingly recognized problem in the United States, but a new study from the
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Researchers from the University of California at San Francisco partnered with Valley Verde, a community-based urban garden organization in Santa Clara County, California, to better understand participants' perceptions of the health benefits and acceptability of urban home gardening programs. Interest in such programs has been on the rise, and this is a critical next step before beginning large-scale trials of how effective they are."This home-based model can play a vital role in urban agriculture and has the potential to directly impact health by tying the garden to the household," said lead author Kartika Palar, PhD, Department of Medicine, University of California San Francisco, San Francisco, CA, USA. She added that home and community gardens are complementary approaches to urban agriculture, together promoting a more resilient local food system.Researchers followed 32 participants -- mostly Hispanic/Latinos and women -- in Valley Verde's gardening program for one year. The program serves a predominantly low-income and immigrant population, providing them with the knowledge, skills and tools needed to grow their own organic vegetable gardens.Valley Verde staff provided 10 monthly workshops for each participant focused on organic gardening skills building as well as nutritional education, like strategies to increase vegetable, fruit and whole-grain intake; healthy shopping strategies; and culturally preferred healthy recipes.Participants were interviewed before, during and after the program to track what they learned and how they were implementing it. Nearly every participant indicated they ate more vegetables and fruits because of the program, citing increased affordability, accessibility, freshness, flavor and convenience of the garden produce."We had some delicious meals with lots of peas because the winter peas were doing really well, and then we could just draw on that when you're out of options," a 47-year-old female participant said in the study, describing how the garden helped during times of the month when money ran low. "[Fruits and vegetables] are a more steady supply. Yeah, it isn't like, 'Oh guess what? In this pay period we can actually afford some salad.' Now we just go and just harvest it and just have it all the time.""I value more the things that I cook, and the things that I get from my garden, over the things I buy," a 34-year-old male participant said in the study. "There's a big difference....I feel good that I grew it and I am eating something that I grew. So for me, it's priceless."Participants also frequently described having less stress, as well as a rise in exercise and drop in sedentary behavior both for adults and children. Tending the garden led to more physical activity because of the need to water, weed, harvest and plant at regular intervals.The study suggests an urban gardening model that integrates home gardening with culturally appropriate nutrition and gardening education has the potential to improve a range of health behaviors that are critical to preventing and managing chronic disease, especially among low-income, urban Hispanic/Latino households."Urban agriculture is an important community resource that may contribute not only to nutrition and health, but also to urban development and social connection," said Dr. Sheri Weiser, MD, the senior author of the study. She added that combining urban home gardening with nutrition education is an innovative strategy to help to reduce the burden of preventable diseases, such as diabetes, in low-income populations with limited access to healthy food.
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Agriculture & Food
| 2,019 |
October 7, 2019
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https://www.sciencedaily.com/releases/2019/10/191007164349.htm
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Machine learning helps plant science turn over a new leaf
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Father of genetics Gregor Mendel spent years tediously observing and measuring pea plant traits by hand in the 1800s to uncover the basics of genetic inheritance. Today, botanists can track the traits, or phenotypes, of hundreds or thousands of plants much more quickly, with automated camera systems. Now, Salk researchers have helped speed up plant phenotyping even more, with machine-learning algorithms that teach a computer system to analyze three-dimensional shapes of the branches and leaves of a plant. The study, published in
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"What we've done is develop a suite of tools that helps address some common phenotyping challenges," says Saket Navlakha, an associate professor in Salk's Integrative Biology Laboratory and Pioneer Fund Developmental Chair.A plant's environment helps dictate its structure, which is related to its health. Scientists trying to understand plant growth, engineer more resilient plants or boost crop production often want to measure detailed characteristics of a plant's leaves and shoots. To do this phenotyping in a high-throughput way, many researchers use camera systems that take images of each plant from various angles and assemble a three-dimensional model. However, some measurements are hard to take with these stitched-together images.Recently, some have turned to a new method, called 3D laser scanning, to capture the structure of plant architectures. Researchers shine a laser at each plant to "paint" its surface with the beam. The resulting data -- called a 3D point cloud -- portrays the fine detail of the plant's surface. But quantitatively analyzing the point clouds can be challenging since the technology is so new and the datasets so large."The resolution and accuracy of this data is much higher," says Navlakha. "But the methods that have been developed for analyzing leaves and branches in 2D images don't work as well for these 3D point clouds."Navlakha, along with UC San Diego graduate student Illia Ziamtsov, used a 3D laser scanner to scan 54 tomato and tobacco plants grown in a variety of conditions. Then, they inputted the resulting 3D point clouds into machine-learning algorithms that let them teach the program how to phenotype the plants. The technique involved the researchers first indicating manually where leaves and shoots on the plants were. Then, the software began to automatically recognize these features."It's like teaching things to a baby," says Navlakha. "You give them examples of what a leaf looks like and what a branch looks like, and eventually they can identify a plant they've never seen before and pick out the leaves and branches."The researchers focused on teaching the program to make three phenotype measurements that scientists often use -- separating stems from leaves, counting leaves and their size, and outlining the branching patterns of a plant. They found they were successful: for example, the method had a 97.8 percent accuracy at identifying stems and leaves."This kind of object detection has been used in self-driving cars and for identifying construction and furniture items," says Ziamtsov. "But applying it to plants is totally novel."Navlakha and Ziamtsov want to continue fine-tuning the approach; differentiating two close-together leaves can still be challenging, for instance. And the current version of the software may not work on all types of plants. They hope to generalize the software to work on plants from vines to trees, and also to analyze roots."There are a lot of challenges in agriculture right now to try and increase crop production and sequester carbon better," says Navlakha. "We hope our tool can help biologists address some of these broader challenges."Navlakha and Ziamtsov will release their software as open-source for other researchers to use. They hope the software will speed up plant research, since it makes high-throughput phenotyping faster and easier."Doing this kind of analysis by hand is very laborious," says Ziamtsov. "Our tool does it quickly and pretty accurately."The work was supported by grants from the Pew Charitable Trusts, the National Science Foundation and the National Institutes of Health.
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Agriculture & Food
| 2,019 |
October 7, 2019
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https://www.sciencedaily.com/releases/2019/10/191007153453.htm
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Ancient Maya canals and fields show early and extensive impacts on tropical forests
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New evidence in Belize shows the ancient Maya responded to population and environmental pressures by creating massive agricultural features in wetlands, potentially increasing atmospheric CO2 and methane through burn events and farming, according to geographical research at The University of Texas at Austin published in the
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Prior research proposed that the Maya's advanced urban and rural infrastructure altered ecosystems within globally important tropical forests. But in the first study to combine airborne lidar (light detection and ranging) imagery with excavation and dating evidence in wetlands, researchers found the Birds of Paradise wetland field complex to be five times larger than previously discovered and found another, even larger, wetland field complex in Belize.Altogether, the study shows the Maya had "earlier, more intensive and more wide-ranging anthropogenic impacts" on globally important tropical forests than previously known, adding to the evidence for an early and more extensive Anthropocene -- the period when human activity began to greatly affect Earth's environment."We now are beginning to understand the full human imprint of the Anthropocene in tropical forests," said Tim Beach, the study's lead author, who holds the C.B. Smith, Sr. Centennial Chair. "These large and complex wetland networks may have changed climate long before industrialization, and these may be the answer to the long-standing question of how a great rainforest civilization fed itself."The team of faculty members and graduate students acquired 250 square kilometers of high precision laser imagery to map the ground beneath swamp-forest canopy, unveiling the expansive ancient wetland field and canal systems in Belize that the Maya depended on for farming and trade through periods of population shifts, rising sea levels and drought.Evidence showed that the Maya faced environmental pressures, including rising sea levels in the Preclassic and Classic periods -- 3,000 to 1,000 years ago -- and droughts during the Late/Terminal Classic and Early Postclassic periods -- 1,200 to 900 years ago. The Maya responded to such pressures by converting forests to wetland field complexes and digging canals to manage water quality and quantity."These perennial wetlands were very attractive during the severe Maya droughts, but the Maya also had to be careful with water quality to maintain productivity and human health," said Sheryl Luzzadder-Beach, the study's co-author, who holds the Raymond Dickson Centennial Professorship at UT Austin.Similarly, the researchers posit the Maya responded to large population shifts and changing demands for food production during the Late Preclassic to the Early Postclassic -- about 1,800 to 1,000 years ago -- by expanding their network of fields and canals in areas accessible by canoe to the broader Maya world. Within the fields, the researchers uncovered evidence of multiple ancient food species, such as maize, as well as animal shells and bones, indicating widespread protein harvesting.The researchers hypothesized that expanding the wetland complexes added atmospheric CO"Even these small changes may have warmed the planet, which provides a sobering perspective for the order of magnitude greater changes over the last century that are accelerating into the future," Beach said.The researchers hypothesize the Maya wetland footprint could be even larger and undiscernible due to modern plowing, aggradation and draining. Additional research on the region and its surrounding areas is already revealing the extent of wetland networks and how the Maya used them, painting a bigger picture of the Maya's possible global role in the Early Anthropocene."Understanding agricultural subsistence is vital for understanding past complex societies and how they affected the world we live in today," Beach said. "Our findings add to the evidence for early and extensive human impacts on the global tropics, and we hypothesize the increase of atmospheric carbon dioxide and methane from burning, preparing and maintaining these field systems contributed to the Early Anthropocene."
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Agriculture & Food
| 2,019 |
October 7, 2019
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https://www.sciencedaily.com/releases/2019/10/191007123236.htm
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Nodulation connected to higher resistance against powdery mildew in legumes
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Scientists have long known that nodulation is important to plant health. Nodulation occurs when nodules, which form on the roots of plants (primarily legumes), form a symbiotic relationship with nitrogen-fixing bacteria that deliver nutrients to the plant. This process is a key part of sustainable agriculture and makes legumes an important source of protein for much of the world. However, recent research from RWTH Aachen University shows that nodulation might positively impact the plant's microbiome in other ways.
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This research, published in Additionally, this research showed that after undergoing nodulation, these plants show a greater resistance against powdery mildew, a fungal disease that displays white powdery spots on the leaves and stems of plants. The scientists hypothesized that this might be directly connected to the increased levels of salicylic acid."While our work is basic research, it is knowledge that contributes to our understanding of plant defense and plant nutrition, which will be helpful in shaping sustainable agriculture," says leading author Hannah Kuhn, who adds, "Most of the lab work was done by undergrad students. I am very proud of their engagement and the intellectual impact that they gave to enable the project."
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Agriculture & Food
| 2,019 |
October 7, 2019
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https://www.sciencedaily.com/releases/2019/10/191007113323.htm
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Genome-edited bull passes on hornless trait to calves
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For the past two years, researchers at the University of California, Davis, have been studying six offspring of a dairy bull, genome-edited to prevent it from growing horns. This technology has been proposed as an alternative to dehorning, a common management practice performed to protect other cattle and human handlers from injuries.
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UC Davis scientists have just published their findings in the journal All data were shared with the U.S. Food and Drug Administration. Analysis by FDA scientists revealed a fragment of bacterial DNA, used to deliver the hornless trait to the bull, had integrated alongside one of the two hornless genetic variants, or alleles, that were generated by genome-editing in the bull. UC Davis researchers further validated this finding."Our study found that two calves inherited the naturally-occurring hornless allele and four calves additionally inherited a fragment of bacterial DNA, known as a plasmid," said corresponding author Alison Van Eenennaam, with the UC Davis Department of Animal Science.Plasmid integration can be addressed by screening and selection, in this case, selecting the two offspring of the genome-edited hornless bull that inherited only the naturally occurring allele."This type of screening is routinely done in plant breeding where genome editing frequently involves a step that includes a plasmid integration," said Van Eenennaam.Van Eenennaam said the plasmid does not harm the animals, but the integration technically made the genome-edited bull a GMO, because it contained foreign DNA from another species, in this case a bacterial plasmid."We've demonstrated that healthy hornless calves with only the intended edit can be produced, and we provided data to help inform the process for evaluating genome-edited animals," said Van Eenennaam. "Our data indicates the need to screen for plasmid integration when they're used in the editing process."Since the original work in 2013, initiated by the Minnesota-based company Recombinetics, new methods have been developed that no longer use donor template plasmid or other extraneous DNA sequence to bring about introgression of the hornless allele.Scientists did not observe any other unintended genomic alterations in the calves, and all animals remained healthy during the study period. Neither the bull, nor the calves, entered the food supply as per FDA guidance for genome-edited livestock.Many dairy breeds naturally grow horns. But on dairy farms, the horns are typically removed, or the calves "disbudded" at a young age. Animals that don't have horns are less likely to harm animals or dairy workers and have fewer aggressive behaviors. The dehorning process is unpleasant and has implications for animal welfare. Van Eenennaam said genome-editing offers a pain-free genetic alternative to removing horns by introducing a naturally occurring genetic variant, or allele, that is present in some breeds of beef cattle such as Angus.
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Agriculture & Food
| 2,019 |
October 5, 2019
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https://www.sciencedaily.com/releases/2019/10/191005134022.htm
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Economic impacts of colony collapse disorder
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The work of a Montana State University professor examining the economic impacts of colony collapse disorder among commercial honeybees was published in the
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Randy Rucker, a professor in the Department of Agricultural Economics and Economics in the MSU College of Agriculture, began looking into colony collapse disorder several years ago with colleagues from North Carolina State University and Oregon State University, for the purpose of estimating its economic impacts. The onset of the disorder was an unexpected shock to commercial beekeeping and pollination markets that first received national attention in the winter of 2006-07 when mortality rates were estimated to be almost 30%.Colony collapse disorder is still a poorly understood phenomenon, wrote Rucker and his co-authors in the paper's introduction. Since its onset, along with other pollinator health issues such as the Varrona mite, which feeds on developing bees, it has caused significant concern among beekeepers and the public."With colony collapse disorder, a beekeeper goes out and virtually all the worker bees are gone," said Rucker. "Twenty thousand, 30,000, 40,000 worker bees, just gone. There are very few dead worker bees on the ground near the colony, and the queen, the brood and all the food are still there. But the bees are just gone."With so little known about what causes colony collapse disorder, Rucker and his team set out to identify its economic ripple effects by examining trends in four categories: number of commercial honeybee colonies nationwide, honey production, prices of queens and packaged bees and pollination fees charged by commercial beekeepers to growers. The team found some surprising results.Bee population is known to fall during the winter, said Rucker. Prior to the onset of colony collapse disorder, the average winter mortality rate was about 15%. Beekeepers have long known how to replace dead hives and are prepared to deal with losses, typically in one of two ways.The first method of offsetting winter losses is called splitting, where a beekeeper takes half the bees in a healthy colony, moves them to a struggling colony and adds a newly fertilized queen, purchased for $18-25 and received through the mail. After about six weeks, there are once again two healthy hives.The other way to increase colony numbers after winter losses is to simply buy a package of bees, also through the mail, which includes a fertilized queen and several thousand worker bees. Beekeepers place the bees in the dead hive and then watch as a healthy hive develops. Both methods are relatively easy and inexpensive for beekeepers -- and have remained so after the onset of colony collapse disorder, the study found."Beekeepers know how to replace dead hives," said Rucker. "As winter mortality increased after CCD appeared and beekeepers worried about having enough hives to meet their pollination contracts in the spring, they responded by splitting more hives in mid- to late summer and would then end up with the number they needed."Even with more hives split and more bees purchased, the prices of queens and packaged bees have not increased dramatically, the study found. From this result, the authors infer that "the supply of queens and packaged bees is sufficiently elastic that any increases in demand associated with CCD have not resulted in measurable increases in price."The team found similar results when they examined trends in colony numbers and honey production. While there were pre-existing downward trends in both metrics before the onset of colony collapse disorder, the rate of decline has not increased, said Rucker. In fact, colony numbers in 2018 were higher than they had been over the last 20 years.The sole instance of a pronounced negative impact came when the team studied trends in pollination fees for commercial crops. Even there, however, only one commercially important crop showed a significant increase in price: almonds."Almonds get pollinated in February or March, and it's really the only major crop that requires pollination during that time of year," said Rucker. With about a million acres of almonds in need of pollination each year, it takes about 70% of U.S. managed honeybee colonies to get the job done.Pollination fees for almonds rose from roughly $70 to almost $160 -- adjusted for inflation -- over the winters of 2004-05 and 2005-06, but Rucker and his co-authors noticed something unusual about the timing. Those increases happened before colony collapse disorder appeared on the scene over the winter of 2006-07."Almond pollination fees did go up substantially, but they went up before CCD hit," said Rucker. "You can't attribute those increases to colony collapse disorder."The bottom line, he said, is that while there have been changes in the commercial pollinator markets, few can be directly linked to colony collapse disorder or any other recent pollinator health concerns. This is good news for beekeepers and consumers alike, he added."When we started this project, we expected to find huge effects, but we found very small ones," said Rucker. "The only effects we found on consumers, for example, is that they probably pay about 10 cents more for a $7, one-pound can of almonds at the grocery store."The reason the disorder's impacts are so small, said Rucker, is directly linked to the fact that most beekeepers know that bees and honeybee colonies are going to die over the course of the year, and they have developed methods of dealing with those fluctuations. As a result, they have been able to react quickly to disruptions like CCD. But there are still a lot of unknowns about the disorder, and the paper focused on the particular overlap of colony collapse disorder and economics."The bottom line is that beekeepers are savvy [businesspeople]," he said. "Our research provides reason for optimism about the future ability of commercial beekeepers to adapt to environmental or biological shocks to their operations and to pollination markets. It says nothing, however, about non-managed pollinators. Data on those pollinators' populations are sparse, and the impacts of maladies like CCD on their populations are not well understood. There is definitely much more work to be done to grasp the effects of CCD and other threats to bee health."
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Agriculture & Food
| 2,019 |
October 3, 2019
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https://www.sciencedaily.com/releases/2019/10/191003155241.htm
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Daddy daycare: Why some songbirds care for the 'wrong' kids
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Interspecific feeding -- when an adult of one species feeds the young of another -- is rare among songbirds, and scientists could only speculate on why it occurs, but now, Penn State researchers have new insight into this behavior.
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Like many scientific findings, this comes from pursuing a larger, unrelated question. In this case, whether noise pollution from Marcellus Shale natural gas development is disrupting songbird reproduction and behavior in Pennsylvania's forests. The researchers conducted this work at Penn State's Russell E. Larsen Agricultural Research Center."There are numerous hypotheses to explain why interspecific feeding behavior might occur, but in most cases observers can only speculate on the cause because they lack information on the nesting histories of the species involved," said Julian Avery, assistant research professor of wildlife ecology and conservation in the College of Agricultural Sciences. "But in this case, we had much more information."For the industrial noise pollution study, researchers placed 80 nest boxes along gravel roads and fields in pairs, with paired boxes slightly more than three feet apart and about 100 yards between pairs. They paired the nest boxes to maximize settlement by Eastern bluebirds and tree swallows, which often are willing to nest in close proximity.The researchers subjected 20 of the paired boxes to noise that played 24 hours a day from large speakers placed just behind the nest boxes. The sound was recordings of a shale-gas compressor that looped to create continuous noise, loud enough to simulate an active compressor station.As part of the study, researchers recorded behavioral observations using cameras in the nest boxes. They observed each box once during incubation, once when the nestlings were young and a third time when nestlings were older."We crossed our fingers and hoped birds would move into the site to occupy those boxes, and they did in large numbers, so we had a nice experimental treatment between birds nesting in quiet boxes and birds nesting in very noisy boxes," Avery said. "We'll be reporting soon on how the industrial noise pollution affected the birds, but first this interspecific feeding component is fascinating."Lead researcher Danielle Williams, who received a master's degree in wildlife and fisheries science in 2018, recorded the number of feeding events at the boxes by each parent in three-hour observations and analyzed the footage. That's how she learned about the male bluebird repeatedly feeding tree swallow nestlings in Box 34B. songbird in handThis nest contained four 10-day-old tree-swallow nestlings. The second box in the pair, 34A, contained four Eastern bluebird eggs. The bluebird pair occupying box 34A had fledged young from box 34B more than a month before. The tree swallows then took over the box and laid their eggs, forcing the bluebirds to move to box 34A for their second brood."We inserted a camera into nest box 34B for an older nestling observation, and during the three-hour observation period, the male Eastern bluebird nesting in box 34A was shown providing food to the tree swallow nestlings 29 times," Williams said. "When I looked at the video, I realized that there was a bluebird male in there caring for the young."The researchers, who noted that many songbirds do not recognize the begging calls or the appearance of their own young, believe the male bluebird, because he had nested in this box earlier in the season, was confused. He made a "place-based decision" to care for the young tree swallows."In this case, we think the male -- since he was primed to raise nestlings and respond to begging behavior -- was duped because he was hearing all of these begging calls and remembered this box," Avery said. "It's especially cool because he is going in and out of the box as the female tree swallow does as well." songbird chicksThe bluebird even perched beside the female tree swallow on the box lid, Avery added."You'd think at that point the male bluebird would realize the gig was up," he said. "He is engaged in very detailed behavior, even picking up and removing the tree swallow chicks' waste. He doesn't seem to have a clue."The findings, recently published in the "With all the other random observations out there of interspecific feeding behavior, observers never had any indication what was driving it," he said. "With this we do, and we know to what degree the urge to care for young overrides other considerations."Margaret Brittingham, professor of wildlife resources and extension wildlife specialist, also was involved in this research.Penn State's Schreyer Institute for Teaching Excellence, the Association of Field Ornithologists and the U.S. Department of Agriculture's National Institute of Food and Agriculture funded this study.
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Agriculture & Food
| 2,019 |
October 3, 2019
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https://www.sciencedaily.com/releases/2019/10/191003140955.htm
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Toxin promotes cattle-to-cattle transmission of deadly Escherichia coli strains
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Shiga toxin subtype 2a (Stx2a) may play a key role in promoting the colonization and transmission of life-threatening Escherichia coli strains in cattle, according to a study published October 3 in the open-access journal
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Specific In the new study, McNeilly and Gally tested whether Stx2a is important for calf-to-calf transmission by comparing "This study demonstrates for the first time an important role for Shiga toxin subtype-2a (Stx2a) in enhancing transmission of Escherichia coli O157 between cattle, the most important reservoir of infection for these dangerous human pathogensm," adds McNeilly. "This explains the successful emergence of Stx2a positive Gally comments, "The study is important as it explains why the Stx2a toxin subtype has become common in
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Agriculture & Food
| 2,019 |
October 3, 2019
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https://www.sciencedaily.com/releases/2019/10/191003135713.htm
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Plants alert neighbors to threats using common 'language'
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New research from Cornell University shows that plants can communicate with each other when they come under attack from pests.
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The study shows that plants can share messages in the form of airborne chemicals known as volatile organic compounds (VOCs) that transfer information among plants.Andre Kessler, professor of ecology and evolutionary biology at Cornell, and his team looked at Solidago altissima, a species of goldenrod native to the Northeast, and monitored the impact of a specific herbivore: the goldenrod leaf beetle.The big finding is what Kessler calls "open-channel communication." When plants are under attack, their smells -- carried by VOCs -- become more similar."So, they kind of converge on the same language, or the same warning signs, to share the information freely," Kessler said. "The exchange of information becomes independent of how closely related the plant is to its neighbor."The research found that neighboring plants pick up on warning VOCs and prepare for the perceived threat, such as an incoming insect pest."What we very often see when plants get attacked by pathogens or herbivores is, they change their metabolism," Kessler said. "But it's not a random change -- in fact, those chemical and metabolic changes are also helping them cope with those attackers. It's very much like our immune system: though plants don't have antibodies like we have, they can fight back with pretty nasty chemistry."That chemistry includes defensive compounds. For example, some of the VOCs can attract predacious insects, or parasitoids, which kill the herbivore and save the plant.Such findings could have practical applications around the world."For a long time, people have thought about using plant-to-plant interactions in organic agriculture to protect crop plants, especially when you have intercropping systems," Kessler said. "We are involved in work on a system in Kenya -- called 'push-pull' and developed by the International Center for Insect Physiology and Ecology -- which is based on manipulating the flow of information to control a pest in corn fields."
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Agriculture & Food
| 2,019 |
October 3, 2019
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https://www.sciencedaily.com/releases/2019/10/191003103517.htm
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First maps of areas suitable for spotted lanternfly's establishment in US and world
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Maps identifying the areas suitable for establishment of the spotted lanternfly (SLF) in the United States and other countries have been published in the
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The SLF, originally from China, has spread to Korea and Japan, and has been found most recently in the United States in Pennsylvania, New Jersey, Virginia and Delaware. These insects are pests of many agricultural crops including almonds, apples, blueberries, cherries, peaches, grapes and hops as well as hardwoods such as oak, walnut and poplar, among others. USDA and state partners have been working to contain SLF populations since 2014.There is the potential for far reaching economic damage if the SLF becomes widely established in the United States.Within the United States, SLF could eventually become established in most of New England and the mid-Atlantic states, the central United States, and Pacific coastal states, explained ecologist Tewodros Wakie with the ARS Temperate Tree Fruit and Vegetable Research Unit in Wapato, Washington, who led the project."Earlier attempts to predict the spread of the spotted lanternfly using a less sophisticated model had indicated a potential for the pest to become established in warmer areas such as southeastern Florida and in tropical countries," Wakie said. "But we made use of a more complex model called MAXENT that depends on a wider number of environmental factors including temperature, elevation and rainfall as well as the current known locations of the species.MAXENT has proven to be much more accurate at predicting where species are likely to spread compared to 16 other methods on 266 species."There are numerous examples where new populations of species were discovered following MAXENT predictions. Our lab group used MAXENT to predict the potential distribution of oriental fruit moth, and apple maggot, and predictions have been more accurate than anything previously," said Wakie.Eleven European countries and large parts of the Northeast United States and the Pacific Northwest were found to be prime habitat for SLF establishment in place of tropical locales with MAXENT.The most important factor in predicting SLF establishment is the mean temperature of the driest quarter of the year; it cannot be too hot or too cold, about 0 degrees C plus or minus 7 degrees C (a temperature range between 19 and 45 degrees F), Wakie explained.Another important factor in predicting SLF's possible range is the presence of the tree of heaven -- an invasive plant that also originated from China. Although not the only host plant for SLF, it is a highly important host plant for the insect. Studies are underway to identify additional host plants and to find the right biocontrol system.Results from this study can be used to guide SLF surveys and prioritize management interventions for this pest, Wakie added.The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.
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Agriculture & Food
| 2,019 |
October 3, 2019
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https://www.sciencedaily.com/releases/2019/10/191003103513.htm
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Genomes of parasitic mites harming the world's bees sequenced
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Honey bee colony collapse has devastating consequences for the environment, the global economy, and food security worldwide. The culprits behind some of the destruction -- parasitic
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Researchers from the Ecology and Evolution Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) sequenced the genomes of the two The scientists' findings, published in "When you look outside, every species you see has managed to survive infestation by parasites or diseases. Many organisms haven't met the challenge and have gone extinct," said Professor Alexander Mikheyev, the last author of the study. "We want to understand the coevolutionary interactions between mites and bees to save the honey bee from such a fate."Two distinct species of the To better understand how the mites and bees co-evolved over time, Mikheyev, postdoctoral researcher Dr. Maeva Techer, and their collaborators sequenced the genomes of each of the two Despite these similarities, genetic evidence indicated that the mite species followed separate evolutionary paths. These divergent strategies of adaptation may make it more difficult for the host species to develop a tolerance to multiple parasites at once."The implication is that if you're trying to fight parasites, the methods that might work for one might not work for another due to differing mechanisms for adapting to the host," said Mikheyev.Mikheyev and Techer hope the sequenced genomes can help lay the foundation for species-specific interventions to address colony collapse, while also furthering scientific understanding of parasite evolution and adaptation."It's important to consider that parasites are constantly evolving, and, in many ways, they have a greater potential to evolve than honeybees because they reproduce quickly," Mikheyev said. "As we're trying to fight these parasites, we have to remember that our target is always moving."
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Agriculture & Food
| 2,019 |
September 30, 2019
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https://www.sciencedaily.com/releases/2019/09/190930180958.htm
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Biologists track the invasion of herbicide-resistant weeds into southwestern Ontario
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A team including evolutionary biologists from the University of Toronto (U of T) have identified the ways in which herbicide-resistant strains of an invasive weed named common waterhemp have emerged in fields of soy and corn in southwestern Ontario.
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They found that the resistance -- which was first detected in Ontario in 2010 -- has spread thanks to two mechanisms: first, pollen and seeds of resistant plants are physically dispersed by wind, water and other means; second, resistance has appeared through the spontaneous emergence of resistance mutations that then spread.The researchers found evidence of both mechanisms by comparing the genomes of herbicide-resistant waterhemp plants from Midwestern U.S. farms with the genomes of plants from Southern Ontario."We used modern methods of genome analysis to look at the genetic similarity of different populations of these plants," explains Julia Kreiner, a PhD candidate in the Department of Ecology & Evolutionary Biology (EEB) in U of T's Faculty of Arts & Science and lead author of a study published today in "To our surprise, we found that the genomes of some resistant plants in Ontario were nearly identical to those in very distant U.S. plants. This was evidence that the Ontario plants were very closely related to the U.S. plants and suggests that the former came from seeds that were just picked up from one field and dropped in another."While Kreiner and her collaborators did not determine exactly how the seeds were physically transported, this propagation -- known as gene flow -- is typically accomplished in different ways. Seeds can be carried by water, or in the digestive tracts of animals, or from field to field by way of farm equipment. And especially with a wind-pollinated plant like common waterhemp, genes can also be spread via wind-borne pollen.The same DNA analysis identified some resistant plants that did not genetically match any other plants suggesting they appeared through the independent emergence of a genetic mutation conveying resistance.The researchers were surprised to discover both mechanisms at play."We have two regions, Walpole Island and Essex County in southwestern Ontario, where waterhemp populations evolved resistance," says Stephen Wright, a professor in ecology & evolutionary biology at U of T and a co-author of the study."Because of their proximity, our expectation was that they would have shared the same origin of resistance. But our results suggest different origins -- from the movement of seed from a source population in the U.S. as well as independent evolution of resistance in a local population."According to John Stinchcombe, also a professor in ecology & evolutionary biology at U of T and a co-author, "One of the most striking findings is that we see both ways that weeds could become resistant happening on really short time scales. Evolution is happening very quickly, and using multiple mechanisms."Detlef Weigel, a co-author from the Max Planck Institute in Germany added, "Because herbicide-resistant waterhemp had appeared in the U.S. long before such plants were found in Canada, we were convinced that evolution of herbicide resistance is very rare and had occurred only once. Now that we know that it can occur repeatedly, the next question is whether one can slow down the evolution of new genetic variants that make waterhemp herbicide resistance."In addition to the U of T cohort, co-authors included weed scientists from the University of Illinois and the University of Guelph Ridgetown Campus; and genome and developmental geneticists at the Max Planck Institute for Developmental Biology in Germany.The researchers studied strains of the common waterhemp -- aka Amaranthus tuberculatus -- that are resistant to glyphosate, one of the most widely used herbicides in the world, commonly known by its trade name Roundup."Waterhemp is one of the most problematic agricultural weeds in North America," explains Kreiner. "In the U.S., common waterhemp and the closely related Amaranthus palmeri are causing all kinds of havoc in terms of crop productivity and crop yields.""Waterhemp first appeared in one county in Ontario in the early 2000s. And as of this year, we've found them in seven different counties in the province. So, it's spreading."Kreiner suggests that the findings underline the importance of strictly following agricultural practices designed to minimize gene flow and staunch resistant strains as they arise."The fact that we're seeing a spread involving all of these mechanisms shows that managing the problem is a real challenge and that it will require integrating management approaches across different scales," explains Kreiner.For example, it illustrates the importance of thoroughly cleaning agricultural residue from rented farm equipment -- which is used on multiple farms in a season -- in order to minimize the transport of seeds from field to field."It also shows the importance of practices like rotating herbicides from season to season," says Kreiner. "And rotating crops between corn, soy and wheat. It's practices like these that will minimize the emergence of resistance and limit seed movement."At the same time, Kreiner warns that the occurrence of herbicide resistance is an inevitable evolutionary process and that the challenge requires further study."Management practices still don't treat the underlying cause, which is that herbicide resistance is evolving repeatedly," she says. "And so with these new genomic resources and approaches, I'm now trying to understand what makes a weed a weed. What are the factors that might make these weeds more likely to evolve resistance and be more problematic than others?"At this point, we're running out of herbicides. These plants have evolved resistance to pretty much every herbicide we've come up with. And it doesn't seem like there's ever going to be a herbicide that a weed can't eventually evolve resistance to."There may be other strategies for controlling these weeds -- like weed-control technologies based on robotics and machine learning," she suggests. "But even then, the weed has a way to evolve around that, so it's a really difficult challenge."
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Agriculture & Food
| 2,019 |
September 30, 2019
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https://www.sciencedaily.com/releases/2019/09/190930161912.htm
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Pineapple genome sequences hint at plant domestication in a single step
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As their Latin name indicates, pineapples are truly "excellent fruits" -- and thanks to a freshly completed genome sequencing project, researchers have gained a new understanding of how human agriculture has shaped the evolution of this and other crops.
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An international team led by Ray Ming, University of Illinois Professor of Plant Biology and member of the Carl R. Woese Institute for Genomic Biology, published their analysis of the genome of the red pineapple, a plant grown for fiber production and as an ornamental, in "We have chosen major pineapple cultivars worldwide . . . to test our hypothesis of 'one-step operation' in domestication of clonally propagated crops," Ming said. He highlighted this aspect of the researchers' work as one of the primary goals of the study.Pineapples are a little bit exotic yet pleasingly familiar; large, spiky fruits with sweet, juicy yellow flesh. The newly sequenced variety of this study, Ananas comosus var. bracteatus, is different from this standard grocery store variety. It produces a small fruit that is not suitable for consumption and is grown in gardens for decoration or to form a security hedge. Unlike many cultivars of pineapple, it is able to self-pollinate.Ming and his colleagues sequenced and assembled the red pineapple genome, using the genome of previously sequenced fruit pineapple as a reference and comparator. They also re-sequenced the genomes of 89 pineapple accessions (samples of plant tissue) from multiple cultivars. By comparing similarities and differences in DNA sequence across different types of pineapple, they were able to trace how natural and artificial selection shaped key traits and established distinct varieties.Pineapple plants can be grown from vegetative tissues, such as the leafy top of a fruit, a slip, or a sucker. The team hypothesized that for some cultivars, domestication might have been achieved in a single step -- starting a variety with a cutting from a likely plant -- rather than over years of breeding. They developed a novel bioinformatic method that looked for long strings of similar sequence at the ends of chromosomes."To our surprise and delight, extensive terminal runs of homozygosity [similarity] were detected in cultivar 'Singapore Spanish'," Ming said. He explained that this discovery was best explained by many years of exclusive clonal propagation: "One sexual recombination could interrupt terminal runs of homology formed over thousands of years. This novel method can be applied to study domestication history of other clonally propagated crops such as potato, sugarcane, cassava, banana, and many tree fruit crops."Comparison across genomes also allowed Ming and his coauthors to identify genes that support traits distinguishing different cultivars. For example, differing activity levels of multiple genes appear to support higher leaf fiber production in the red pineapple, and the sweetness of a particular cultivar of fruit pineapple is likely related in part to selection on a particular sugar transporter gene. The study also yielded additional evidence for the involvement of certain genes in allowing or prohibiting self-pollination.Overall, Ming said, he was most excited to find strong support for the idea that with clonal propagation, some plants were immediately and successfully domesticated."The co-existence of punctuated sexual reproduction and "one-step operation" in domestication of clonally propagated crops implies rapid domestication of clonally propagated crops is possible," he said. "One example is macadamia, and most macadamia cultivars in Hawaii were selected from seedlings of wild macadamia trees, just one generation away from the wild germplasm."
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Agriculture & Food
| 2,019 |
September 30, 2019
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https://www.sciencedaily.com/releases/2019/09/190930101521.htm
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You don't have to go cold turkey on red meat to see health benefits
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A new study has found that halving the amount red and processed (RPM) meat in the diet can have a significant impact on health, reducing the amount of LDL 'bad' cholesterol in the blood which cuts the risk of developing heart disease.
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Red and processed meat (RPM) include fresh pork, beef, lamb and veal and meats that have been smoked, cured or preserved (other than freezing) in some way. These meats are typically high in saturated fatty acids which cause an increase in LDL cholesterol. This is the "bad" cholesterol that collects in the walls of blood vessels, where it can cause blockages and raise the chance of a heart attack.Increasing awareness of the risks associated with eating red and processed meat has led to a growing number of people adopting vegetarian and vegan diets, which cut out meat completely. Researchers at the University of Nottingham wanted to find out if reducing the amount of red meat eaten, rather than cutting it out completely, would have a positive effect on the health of the subjects taking part.The results, published today in the journal For this intervention trial, 46 people agreed to reduce their red meat intake over a period of 12 weeks by substituting it for white meat, fish or a meat substitutes, or by reducing the portion size of their red meat. They kept a food diary during the study and were given blood tests at the beginning and intervals throughout.Professor Andrew Salter, from the University of Nottingham's School of Biosciences led the study and says: "With a high saturated fatty acid, content red and processed meat has been linked to heart disease, and other chronic diseases, particularly colon cancer. Studies have shown that in people who eat the most meat, there is a 40% increased risk of them dying due to heart disease. The results of the present study showed that, even in relatively young and healthy individuals, making relatively small changes to RPM intake induced significant changes in LDL cholesterol which, if maintained over a period of time could potentially reduce the risk of developing heart disease."As well as reducing levels of LDL cholesterol, reseachers were surprised to also see a drop in white and red cells in the blood.Dr Liz Simpson from the University of Nottingham's School of Life Sciences is co-author on the study, she explains: "Meat is a rich source of the micronutrients (vitamins and minerals) required for the manufacture of blood cells, and although it is possible to obtain these nutrients in plant-based diets, our results suggest that those reducing their meat intake need to ensure that their new diet contains a wide variety of fruit, vegetables, pulses and whole grains to provide these nutrients.Professor Salter is also part of the Future Food Beacon at the University of Nottingham which is undertaking research to find more sustainable ways to feed a growing population in a changing climate. He explains: "As well as improving people's health, reducing the amount of red meat we eat is also important from a food security and sustainability perspective, as livestock production utilizes a large proportion of our natural resources and is a major contributor to greenhouse gas production. Part of our research is centred on finding more sustainable, alternative sources of food that provide us with the protein and other nutrients supplied by meat, but without the negative health and environmental effects "
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Agriculture & Food
| 2,019 |
September 26, 2019
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https://www.sciencedaily.com/releases/2019/09/190926114153.htm
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How a protein connecting calcium and plant hormone regulates plant growth
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Plant growth is strongly shaped by environmental conditions like light, humidity, drought and salinity, among other factors. But how plants integrate environmental signals and the developmental processes encoded in their genes remains a mystery.
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A new Tel Aviv University study finds that a unique mechanism involving calcium, the plant hormone auxin and a calcium-binding protein is responsible for regulating plant growth. Researchers say that a protein that binds to calcium regulates both auxin responses and calcium levels, creating an interface that determines how plants grow.The study was led by Prof. Shaul Yalovsky of TAU's George S. Wise Faculty of Life Sciences and published in "Determining the mechanisms that underlie the developmental plasticity of plants is essential for agricultural innovation," Prof. Yalovsky explains. "It was believed for several decades that calcium and auxin interfaced during a plant's development, but the exact mechanisms underlying this 'cross-talk' were unclear."We have discovered that auxin communicates with calcium through a binding protein called CMI1. We believe our research will have long-term applications for farmers and agricultural experts, who will be able to harness this information to adapt future generations of plants to extreme environmental conditions such as high temperatures, drought and high salinity in the soil."The levels of the plant hormone auxin determine where leaves develop on a plant, how many branches a plant has and how roots develop. Calcium levels change in plants in response to environmental signals like high or low temperatures, touch and soil salinity, as well as in response to auxin levels."Prior to our research, it was unclear how the interaction between calcium and auxin took place," adds Prof. Yalovsky. "Now we know that when auxin levels are high, the levels of the newly discovered binding protein CMI1 are high. We discovered that this protein regulates auxin responses and calcium levels and that it binds to calcium."Plant responses to auxin are either slow or rapid. Slow responses take place over the course of hours and days and depend on gene expression pathways, whereas rapid responses take place within minutes. The characteristics of CMI1 enable rapid responses to auxin levels, which depend on the presence of calcium."We used a very wide collection of tools and approaches that allowed us to carry out our analyses starting from the level of the whole plant, down through the level of tissue and cells, and finally to the level of molecules," Prof. Yalovsky concludes. "The next step will be to identify the cellular components that interact with the protein that we discovered."
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Agriculture & Food
| 2,019 |
September 26, 2019
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https://www.sciencedaily.com/releases/2019/09/190926101323.htm
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Study champions inland fisheries as rural nutrition hero
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Synthesizing new data and assessment methods is showing how freshwater fish is an invisible superhero in the global challenge to feed poor rural populations in many areas of the world.
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But there's a problem: Invisibility is the wrong superpower.Researchers from Michigan State University (MSU) and the Food and Agriculture Organization (FAO) of the United Nations have pulled together the most recent data and innovative approaches to measuring and communicating the impact inland fisheries have on food security, sustainability and economies. Fish harvests from the world's rivers, streams, floodplains, wetlands, lakes, inland seas, canals, reservoirs and even rice fields can seem like forgotten, poor relatives of the better documented global fisheries in the oceans.Yet in "A fresh look at inland fisheries and their role in food security and livelihoods" in the latest edition of Now enough data has been compiled to generate a global economic valuation of inland fisheries. The economic value of reported global inland catch (in terms of first-sale value) is estimated at $24 billion. That's approximately 24% of estimated first-sale value for marine fisheries even though total inland catch is only about 13% of marine catch. These new values suggest that the first landing prices of inland fish are higher than the average for marine fish, indicating their importance in local rural economies."Inland fisheries are providing crucial micronutrients and animal-source protein to sustain some 159 million people -- sometimes the only protein accessible and affordable to them," said Bennett, an assistant professor of fisheries at CSIS. "At the same time, as we're worried food production systems are threatened by climate change, agricultural runoff, habitat alteration from hydropower development and other alternative uses of freshwater. We need to be looking more closely at the efficiency of inland fisheries in respect to land, water and energy use."The paper explores the scope of freshwater fish, and the difficulties in getting accurate representation of impact. What is clear is those who depend on the operations -- particularly women who are underrepresented both in fishing and post-harvest work like fish trade and processing -- are at risk both in access to work, and health and safety risks.The paper outlines the known and unknown factors of inland fisheries, and the need to better quantify that which is currently compelling anecdotes. It also points out the tantalizing aspects of this sector of fishing -- freshwater fish is one of the only accessible source of animal food to many of the poor, and it can be harvested fruitfully at a small scale, often without needing motor-powered boats and can have low-tech processing. Ninety-five percent of inland fisheries catch comes from developing countries, and 43 percent comes from low-income food-insecure countries.To manage and sustain those benefits, the authors note it is critical to continue to improve methods for understanding of how much inland fish is being caught and how catches are changing over time."Even though inland fisheries catch equals 12% of global fish production (not accounting for underreporting), in particular places these catches are absolutely crucial to survival," Funge-Smith said. "Improving assessment methods is key toward ending the vicious cycle in which data gaps lead to inland fisheries being undervalued in policy discussions, and lack of policy support undermines important data tracking systems."
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Agriculture & Food
| 2,019 |
September 25, 2019
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https://www.sciencedaily.com/releases/2019/09/190925154024.htm
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Soil microbes play a key role in plant disease resistance
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Scientists have discovered that soil microbes can make plants more resistant to an aggressive disease -- opening new possibilities for sustainable food production.
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Bacterial wilt disease caused by Researchers from the University of York working with colleagues from China and the Netherlands, investigated the effect of the soil microbiome on the plant-pathogen interaction. Infections are often 'patchy' in the field not affecting the whole crop and the cause for this is unknown.Dr Ville Friman from the Department of Biology said: "Even though we have discovered that the pathogen is present everywhere in tomato fields, it is not capable of infecting all the plants. We wanted to understand if this spatial variation could be explained by differences in soil bacterial communities."To study the effect of soil microbiome for disease development, the scientists used a newly developed experimental system that allowed repeated sampling of individual plants in a non-destructive manner. This allowed scientists to go back in time and compare healthy and diseased plant microbiomes long before visible disease symptoms.The sampling method allowed them to compare the micro-organisms that were present in the soils of those plants that remained healthy or became infected. Their analysis showed that the microbiomes of surviving plants were associated with certain rare taxa and pathogen-suppressing Pseudomonas and Bacillus bacteria.Dr Friman added: "We found that improved disease resistance could be transferred to the next plant generation along with the soil transplants analogous to fecal transplants used in medicine."Our results show that it is important to focus not only the pathogen but also the naturally-occurring beneficial micro-organisms present in the rhizosphere. While the beneficial role of microbes for humans and plants have been acknowledged for a long time, it has been difficult to disentangle the cause and effect and important bacterial taxa based on comparative data."The team are currently developing and testing different microbial inoculants for crop production. The research has opened up the possibility in the future that bacteria could be used as 'soil probiotics' to protect plants from pathogens.
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Agriculture & Food
| 2,019 |
September 25, 2019
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https://www.sciencedaily.com/releases/2019/09/190925092356.htm
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Scientists find ways to improve cassava, a 'crop of inequality' featured at Goalkeepers
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Today, as world leaders gather for the UN General Assembly, hundreds of emerging leaders focused on fighting global inequality came together at the Bill & Melinda Gates Foundation's third annual Goalkeepers event in New York City. Among them, University of Illinois scientist Amanda De Souza highlighted a crop of inequality called cassava, which has starchy, tuberous roots that sustain more than 500 million people in sub-Saharan Africa, yet cassava has been largely neglected by research and development compared to the staple crops of wealthier regions. Recently, De Souza and a team from Realizing Increased Photosynthetic Efficiency (RIPE) published a study in
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"For smallholder farmers who depend on tiny plots of land to feed and support their families, cassava is a 'backup' crop when other crops fail," De Souza said at Goalkeepers, where she described her work to improve cassava through the RIPE project. "Especially for women, who represent a majority of smallholder farmers, cassava is a savings account. It is a resource they can harvest all year to pay for things like medical treatments and their children's school fees."The RIPE project is an international effort to develop more productive crops by improving photosynthesis -- the natural, sunlight-powered process that all plants use to fix carbon dioxide into carbohydrates that fuel growth, development, and ultimately yields. RIPE is supported by the Gates Foundation, the U.S. Foundation for Food and Agriculture Research (FFAR), and the U.K. Government's Department for International Development (DFID).Led by RIPE researchers at Illinois and Lancaster University, this study examined factors that limit photosynthesis in 11 popular, or farmer-preferred, African varieties of cassava with the goal to eventually help cassava overcome photosynthetic limitations to boost yields.First, the team examined the photosynthetic limitations of cassava exposed to constant high levels of light, like a plant would experience at midday with cloudless skies. In these conditions, and like many crops, cassava's photosynthesis is limited (by as much as 80 percent) by two factors: One half is due to the low speed that carbon dioxide molecules travel through the leaf to reach the enzyme that drives photosynthesis, called Rubisco. The other half is because Rubisco sometimes fixes oxygen molecules by mistake, wasting large amounts of the plant's energy.Next, the team evaluated the limitations of photosynthesis under fluctuating light conditions. Surprisingly, and unlike most crops, Rubisco was not the primary limiting factor when leaves transitioned from shade to sunlight, like when the sun comes out from behind a cloud. Instead, cassava is limited by stomata, which are microscopic pores on the surface of leaves that open to allow carbon dioxide to enter the plant but at the cost of water that escapes through these same pores. Stomata are partially closed in the shade and open in response to light when Rubisco is active."Rubisco is the major limiting factor during this transition from shade to light for most plants, including rice, wheat, and soybean," De Souza said. "Cassava is the first crop that we have found where stomata limit photosynthesis during these light transitions more than Rubisco."Illinois' Postdoctoral Researcher Yu Wang created a computer model to quantify how much cassava would gain by overcoming this limitation. According to the leaf-level model, if stomata could open three times faster, cassava could fix 6 percent more carbon dioxide each day. In addition, cassava's water use efficiency -- the ratio of biomass produced to water lost by the plant -- could be improved by 16 percent.In addition, the team found that it takes as long as 20 minutes for cassava to transition from shade to full light and reach the maximum rate of photosynthesis, which is quite slow compared to other crops such as rice that can transition in just a few minutes. However, the fastest variety of cassava could transition almost three times faster and fix 65 percent more carbon dioxide into carbohydrates than the slowest variety. Closing this gap is another opportunity to improve cassava's productivity."Plants are constantly moving from shade to light as leaves shift and clouds pass overhead," said RIPE Director Stephen Long, Ikenberry Endowed University Chair of Crop Sciences and Plant Biology at Illinois' Carl R. Woese Institute for Genomic Biology, who contributed to this study. "We hope that the variation that we discovered during these light transitions among cassava varieties can be used to identify new traits, and therefore opportunities for us to improve cassava's photosynthetic efficiency and yield potential."
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Agriculture & Food
| 2,019 |
September 25, 2019
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https://www.sciencedaily.com/releases/2019/09/190925075734.htm
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Turning up the heat for weed control
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Weeds are thieves. They steal nutrients, sunlight and water from our food crops. In the case of sugarcane, yield refers to the amount of biomass and the sucrose concentration of the cane, which ultimately determines the amount of sugar produced. Two weedy culprits, namely itchgrass and divine nightshade, reduce cane biomass and sucrose yield.
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These two weeds are a growing problem in Louisiana, where nearly half of the United States' sugarcane is grown. Itchgrass competition can reduce the sugar yield in cane by 7-17%. And, the longer it competes with sugarcane, the more the sugar yield is reduced. Although divine nightshade is a relative newcomer to Louisiana, it can reduce sugar production by up to 43%. Therefore, researchers are looking at the effect of heat to control itchgrass and divine nightshade seed before it emerges in sugarcane fields.Burning sugarcane fields is common after harvest to reduce crop residue on the fields. This helps promote the growth of the next year's crop, as the residue has been found to reduce cane biomass. Research on flame weeding and other forms of heat to control weeds is of interest in the U.S., largely because of herbicide-resistant weeds. So, Douglas Spaunhorst and his research team looked to find the right temperature to control weed seed during the normal sugarcane residue burns."Integrated weed management strategies have become more common in U.S. agriculture," says Spaunhorst, who is based at the USDA-ARS Sugarcane Research Unit in Houma, Louisiana. "Mechanical types of weeding, like cultivation, burning, and seed crushers, show a lot of promise.""Evaluation of non-chemical strategies for itchgrass and divine nightshade management is limited," says Spaunhorst. Chemical-alternative weed control can help slow herbicide-resistance evolution. "In fields historically under sugarcane cultivation, no chemical-resistant divine nightshade or itchgrass has been reported," says Spaunhorst. "However, a few examples have been found where resistant itchgrass became established in soybean fields."One of the tricks of weed control by burning is creating the right conditions. Burning can kill the actual weed plant, and it can also kill weed seeds retained on the soil surface. "Once weed seeds are buried below the soil surface, killing seed using heat is difficult," says Spaunhorst. "The soil acts as an insulator to protect seeds, similar to a heat shield on a space shuttle that protects astronauts as they reenter into Earth's atmosphere. But, the temperature, length of time of exposure, and other variables need to be determined for each weed species."During 2017 and 2018, researchers from Spaunhorst's team researched the effects of heat on weed seeds in the lab. After collecting seeds, they applied temperatures of 100, 150 and 200°C to various groups. Times of heat exposure varied as well.Once the seeds had been heat-treated, they were planted to see if they would grow in a greenhouse. This is where the seeds from the two weedy species differed in how they reacted to heat. This makes sense, because each is from a different family of plants.A more important variable for heat tolerance is that the seeds of the plant have different structures. "Itchgrass seed is protected by an outer coating, similar to a husk," says Spaunhorst. "However, divine nightshade seeds are located inside a fluid-filled berry. The fluid inside the berry seems to insulate the seed from high temperatures for short periods."Now that the team has collected lab and greenhouse results, the next step will be to apply these conditions in the field. It's easy to control temperatures in an oven, but care will need to be taken to get the temperatures just right in the field. Wet crop residue in the field may not completely burn and produce temperatures too low to kill weed seeds. The burns will be started just like prairie burns -- a little fuel, some wind, and a match."We know that high temperatures can kill itchgrass and divine nightshade seed," says Spaunhorst. "Now we will experiment with temperature probes in the soil -- both at the surface and just below. We expect that residue density and moisture will be significant factors in the next results. After we do the field burns, we will collect the seed and attempt to grow plants in the greenhouse again."Spaunhorst and his team have taken a process already in place -- burning the residue of sugarcane -- to see if it can be optimized as a dual-purpose procedure. If so, they can help sugarcane farmers keep their yields high, with fewer nutrient-stealing weeds getting in the way.
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Agriculture & Food
| 2,019 |
September 24, 2019
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https://www.sciencedaily.com/releases/2019/09/190924125022.htm
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Could we feed one million people living on Mars?
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A provocative new study looks at the resource utilization and technological strategies that would be needed to make a Mars population of one million people food self-sufficient. A detailed model of population growth, caloric needs, land use, and potential food sources showed that food self-sufficiency could be achieved within 100 years. The study is published in
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In the article entitled "Feeding One Million People on Mars," coauthors Kevin Cannon and Daniel Britt, University of Central Florida, Orlando, evaluated different food sources and quantitatively modeled the shifting balance between food supplied provided from Earth and that produced locally on Mars over time. The model is based on a diet composed of plants, insects, and cellular agriculture, which can produce "clean" meat and fish, algae, chicken-less eggs and cow-less milk. The study takes into account the energy, water, and other systems needed for food production. The researchers discuss the implications of their findings and present recommendations for future research."To meet the human right of survival, some minimum daily requirement for calories and nutrition will be a necessary activity for settlement on any moon or planet. Anything above these minimum requirements, however, could be a commercial activity," says Editor-in-Chief of New Space Ken Davidian, who has worked in the commercial space transportation industry for over 30 years. "It's not hard to imagine that coffee, or extra fruit, or any food item that exceeds the minimum requirements, would be a fungible item, if customers want to indulge themselves."
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Agriculture & Food
| 2,019 |
September 24, 2019
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https://www.sciencedaily.com/releases/2019/09/190924112050.htm
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'Report card' on diet trends: Low-quality carbs account for 42 percent of a day's calories
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Despite years of steady advice and guidance on healthy eating, a 'report card' on the American diet shows adults are still consuming too many low-quality carbohydrates and more saturated fat than recommended, according to researchers at the Friedman School of Nutrition Science and Policy at Tufts University and the Harvard T.H. Chan School of Public Health. The study, published today in
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Although the study identified some dietary improvements, it also found that low-quality carbohydrates from refined grains, starchy vegetables, and added sugars accounted for 42 percent of the typical American's daily calories. High-quality carbs, from whole grains and whole fruits, accounted for only 9 percent. Over the study period:The study authors note that any dietary improvements were less pronounced for older people and those of lower income or educational attainment:"Although there are some encouraging signs that the American diet improved slightly over time, we are still a long way from getting an 'A' on this report card. Our study tells us where we need to improve for the future," said co-senior author Fang Fang Zhang, nutrition epidemiologist at the Friedman School of Nutrition Science and Policy at Tufts University. "These findings also highlight the need for interventions to reduce socioeconomic differences in diet quality, so that all Americans can experience the health benefits of an improved diet."The study drilled down into consumption trends of specific nutrients, such as plant-based protein and saturated fatty acids, which the researchers said provide insights on how changes in food sources might offer health benefits."For example, most of the proteins that Americans consumed were from meats -- including red and processed meat. Proteins consumed from seafood and healthy plant sources, such as whole grains, nuts, and legumes, remained a much smaller proportion," said co-senior author Shilpa Bhupathiraju, research scientist at the Harvard T.H. Chan School of Public Health, also with Harvard Medical School and Brigham and Women's Hospital. "Our research suggests that Americans have an opportunity to diversify their sources of protein to include more seafood, beans, soy products, nuts and seeds.""Because low-quality carbs are associated with disease risk, taking in higher-quality carbs could mean better health for Americans in the future," said first author on the study, Zhilei Shan, nutritional epidemiology fellow at the Harvard T.H. Chan School of Public Health. At the time of this study, he was also working under the auspices of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.The study examined the diets of 43,996 adults using data from the National Health and Nutrition Examination Survey (NHANES). Participants are representative of the national adult population and completed at least one valid 24-hour dietary recall from nine consecutive cycles of the NHANES (1999 to 2016). Researchers used the USDA's Food and Nutrition Database for Dietary Studies (FNDDS) to estimate nutrient intake. To assess overall diet quality, the researchers used the Healthy Eating Index (HEI)-2015, which measures adherence to the 2015-2020 Dietary Guidelines for Americans.Limitations of the study include the fact that self-reported food recall data is subject to measurement error due to daily variations in food intake, but steps were taken to improve estimates.
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Agriculture & Food
| 2,019 |
September 23, 2019
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https://www.sciencedaily.com/releases/2019/09/190923104138.htm
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Soap from straw: Scientists develop eco friendly ingredient from agricultural waste
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A scientist has discovered a way of using one of the world's most abundant natural resources as a replacement for humanmade chemicals in soaps and thousands of other household products.
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An innovative research project, published this month and led by the University of Portsmouth, has demonstrated that bails of rice straw could create a 'biosurfacant', providing an alternative non-toxic ingredient in the production of a vast variety of products that normally include synthetic materials which are often petroleum based.The biotechnology project set out to solve one of the planet's most pressing environmental problems, looking for a way of reducing the amount of humanmade chemicals in everyday life. It has been co-supervised by the University of Portsmouth's Centre for Enzyme Innovation, working in conjunction with Amity University in India and the Indian Institute of Technology.The study was looking for a natural replacement for chemical surfactants, a main active ingredient in the production of cleaning products, medicine, suncream, make-up and insecticides. The surfactant holds oil and water together, helping to lower the surface tension of a liquid, aiding the cleaning power and penetration of the product.Dr Pattanathu Rahman, microbial biotechnologist from the University of Portsmouth and Director of TeeGene, worked with academics and PhD Scholar Mr Sam Joy from 2015 to create a biosurfacant by brewing rice straw with enzymes. The scientists believe this environmentally friendly method results in a high quality ingredient that manufacturing industries are crying out for.Dr Rahman said: "Surfactants are everywhere, including detergent, fabric softener, glue insecticides, shampoo, toothpaste, paint, laxatives and make up. Imagine if we could make and manufacture biosurfacants in sufficient quantities to use instead of surfactants, taking the humanmade chemical bonds out of these products. This research shows that with the use of agricultural waste such as rice straws, which is in plentiful supply, we are a step closer."Scientists behind the research believe the use of biosurfactants created from rice straw or other agricultural waste could have a positive ecological effect in a number of ways:Dr Rahman explains: "The levels of purity needed for biosurfactants in the industries in which they're used is extremely high. Because of this, they can be very expensive. However, the methods we have of producing them make it much more economical and cost efficient. It's a very exciting technology with tremendous potential for applications in a range of industries."The study shows that biosurfactants could be a potential alternative for the synthetic surfactant molecules, with a market value of $US2.8 billion in 2023. The considerable interest in biosurfactants in recent years is also due to their low toxicity, biodegradable nature and specificity, which would help them meet the European Surfactant Directive.Dr Rahman says the process of producing biosurfacants calls for new attitudes to soap and cleaning products.He explains: "Most people consider soap to be an effective means of removing bacteria from their skin. However, we have flipped this concept on its head by discovering a way to create soap from bacteria. They have anti-microbial properties suitable for cosmetic products and biotherapeutics. This approach will channelise the majority of the waste management solutions and could create new job opportunities."
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Agriculture & Food
| 2,019 |
September 23, 2019
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https://www.sciencedaily.com/releases/2019/09/190923082252.htm
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New AI app predicts climate change stress for farmers in Africa
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A new artificial intelligence (AI) tool available for free in a smartphone app can predict near-term crop productivity for farmers in Africa and may help them protect their staple crops -- such as maize, cassava and beans -- in the face of climate warming, according to Penn State researchers. The team will unveil the new tool -- which will work with their existing AI assistant, called "PlantVillage Nuru" -- to coincide with the United Nations Climate Action Summit to be held today (Sept. 23) at the U.N. Headquarters in New York City.
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"Hundreds of millions of African farmers are already suffering from the effects of climate change," said David Hughes, associate professor of entomology and biology. "For example, earlier this year, which has been the hottest year on record, Mozambique was hit with two cyclones, both among the strongest ever recorded in East Africa. They caused almost $1 billion in damages and destroyed nearly 80 percent of staple crops throughout the region. They also changed rainfall patterns across East Africa, which further affected the crops."Hughes added that the majority of these farmers remain unprepared for the climate change impacts that are yet to come. For instance, many of the more than 95 percent of African farmers who rely solely on rain to irrigate their crops will be unable to deal with the increasing drought conditions that are expected, he said.PlantVillage Nuru is an existing AI assistant that is being used across Africa to diagnose crop diseases. The researchers have rigorously tested the performance of their machine-learning models with locally sourced smartphones in the typical high light and temperature settings of an African farm. In these tests, the app was shown to be twice as good as human experts at making accurate diagnoses, and it increased the ability of farmers to discover problems on their own farms.Now PlantVillage Nuru can draw in data from the United Nations' WaPOR (Water Productivity through Open access of Remotely sensed derived data) portal, a database that integrates 10 years' worth of satellite-derived data from NASA and computes relevant metrics for crop productivity given the available water. PlantVillage Nuru also incorporates weather forecast data, a soil dataset for Africa, and the United Nations Crop Calendar, which is a series of algorithms on adaptive measures that can be taken under certain conditions. The PlantVillage AI tool incorporates tens of thousands of data points across Africa with hundreds more being collected every day All of these data are freely available to the global community, who can work collectively to improve the AI.Specifically, the AI assistant has the opportunity to integrate diverse data streams to provide information about drought tolerance of crops and which crops are suitable in which areas, for example. In addition, the app offers advice that could help farmers learn about crop varieties that are climate-resilient, affordable irrigation methods, and flood mitigation and soil conservation strategies, among other best practices.Although the tool is smartphone based, it can be accessed through a webpage to inform diverse stakeholders. In Kenya, the PlantVillage AI tool informs messages that are then sent out to SMS phones across the country. According to Hughes, the team hopes that over time and with the right support, it will be able to extend that service to all of Africa, potentially helping millions of farmers prepare for climate warming."Our goal is to nudge behavioral changes that will help farmers prepare their farms to be climate ready," said Hughes. "There are proactive behaviors, such as planting for increased crop diversity, promoting soil moisture conservation and engaging in water harvesting, that are known to increase resiliency. Our AI tool is in the early stages, but it will get better over time and with more training. We are releasing it now so we can kick-start the necessary collaboration we need to help African farmers adapt to climate change. As the African proverb says: 'If you want to go fast, go alone. If you want to go far, go together.' Climate change means we must act together to help those most in need."The governments of Ireland, Netherland, Norway and Belgium funded this work along with the Bill & Melinda Gates Foundation and the Huck Institutes of the Life Sciences at Penn State.
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Agriculture & Food
| 2,019 |
September 19, 2019
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https://www.sciencedaily.com/releases/2019/09/190919181133.htm
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The next agricultural revolution is here
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As a growing population and climate change threaten food security, researchers around the world are working to overcome the challenges that threaten the dietary needs of humans and livestock. A pair of scientists is now making the case that the knowledge and tools exist to facilitate the next agricultural revolution we so desperately need.
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Cold Spring Harbor Laboratory (CSHL) Professor Zach Lippman, a Howard Hughes Medical Institute investigator, recently teamed up with Yuval Eshed, an expert in plant development at the Weizmann Institute of Science in Israel, to sum up the current and future states of plant science and agriculture.Their review, published in Beneficial changes like these were first discovered by chance, but modern genomics has revealed that most of them are rooted in two core hormonal systems: Florigen, which controls flowering; and Gibberrellin, which influences stem height.Lippman and Eshed suggest that in an age of fast and accurate gene editing, the next revolutions do not need to wait for chance discoveries. Instead, by introducing a wide variety of crops to changes in these core systems, the stage can be set to overcome any number of modern-day challenges.To explain their point, the scientists reviewed research that focused on key moments in agricultural history, such as the Green Revolution.Before the 1960s, fertilizing for a large wheat yield would result in the plants growing too tall. Weighed down with their grainy bounty, the wheat stems would fold and rot away, resulting in yield losses. It was only after Nobel laureate Norman Borlaug began working with mutations that affect the Gibberellin system that wheat became the shorter and reliable crop we know today. Borlaug's dwarfing was also applied to rice, helping many fields weather storms that would have been catastrophic only years before. This reapplication of the same technique to a different plant hinted that a core system was in play.More recent examples Lippman and Eshed mention include the changes undergone by cotton crops in China. There, growers turned the normally sprawling, southern plantation plant into a more compact, faster flowering bush better suited for China's northern climate. To do so, they took advantage of a mutation that affects Florigen, which promotes flowering, and its opposite, Antiflorigen.This kind of change is related to Lippman's works. He often works with tomatoes and explained that an Antiflorigen mutation in tomato was also the catalyst that transformed the Mediterranean vine crop into the stout bushes grown in large-scale agricultural systems throughout the world today. What's striking, Lippman said, is that cotton is quite unlike any tomato."They're evolutionary very different in terms of the phylogeny of plants. And despite that, what makes a plant go from making leaves to making flowers is the same," he said. "That core program is deeply conserved."As the review details, this has defined what makes an agricultural revolution. A core system -- either Gibberellin, Florigen, or both -- is affected by a mutation, resulting in some helpful trait. In a moment of pure serendipity, the plants boasting this trait are then discovered by the right person.It then takes many more years of painstaking breeding to tweak the intensity of that mutation until it affects the system just right for sustainable agriculture. It's like tuning an instrument to produce the perfect sound.Lippman and Eshed note that CRISPR gene editing is speeding up that tuning process. However, they show that the best application of gene editing may not be to just tune preexisting revolutionary mutations, but instead, to identify or introduce new ones."If past tuning has been creating genetic variation around those two core systems, maybe we can make more variety within those systems," he said. "It would certainly mitigate the amount of effort required for doing that tuning, and has the potential for some surprises that could further boost crop productivity, or adapt crops faster to new conditions."More of that genetic variety could also set the stage for new agricultural revolutions. By introducing genetic variation to those two core systems that define most revolutions, farmers might get to skip the serendipitous waiting game. Chickpea is one example."There's a lot more room for us to be able to create more genetic diversity that might increase productivity and improve adaptation survival in marginal grounds, like in drought conditions," Lippman said.Drought resistance is just one benefit of under-utilized crops. Past revolutions have allowed crops to be more fruitful or to grow in entirely new hemispheres. Having a means to continue these revolutions with more crops and at a greater frequency would be a boon in a crowded, hungry, and urbanizing world."Given that rare mutations of Florigen/Antiflorigen and Gibberellin/DELLA mutations spawned multiple revolutions in the past, it is highly likely that creating novel diversity in these two hormone systems will further unleash agricultural benefits," the scientists wrote.
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Agriculture & Food
| 2,019 |
September 19, 2019
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https://www.sciencedaily.com/releases/2019/09/190919142246.htm
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Wild animals' immune systems decline with age, sheep study finds
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It is well established that weakened immune systems in old age affect people's health and fitness, but a study suggests that it is also an issue for wild animals.
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Researchers studying wild Soay sheep on the remote St Kilda archipelago have revealed that the animals' immune responses to parasitic worms decline through adulthood.Animals that show faster deterioration in resistance to the worms -- which live in the sheep's gut -- are more likely to die during the following winter.The findings provide the first evidence linking declining immune function and survival in wild animals.Deterioration of the immune system in old age -- a process called immunosenescence -- is a huge issue for human health, as it reduces people's ability to fight viruses and bacteria, researchers say.The team believes their findings could offer insights into how people's ability to ward off larger parasites like worms might also decline in old age.Researchers from the University of Edinburgh, Moredun Research Institute and Centre for Biodiversity Dynamics, Norway, made the discovery using blood samples taken from Soay sheep between 1990 and 2015.Analysis of more than 2,000 samples taken across the lifetime of almost 800 animals revealed that levels of antibodies against a common worm infecting the sheep fell in old age.The study, published in the journal The research was carried as part of a long-term study of Soay sheep, which began in 1985. The animals have lived wild on the islands of St Kilda -- a world heritage site owned and managed by the National Trust for Scotland -- for thousands of years.Professor Dan Nussey, from the University of Edinburgh's School of Biological Sciences, who co-led the study, said: "Our work provides the first evidence that deterioration in immune function in old age plays an important role in wild animal populations. It also provides rare clues from outside the laboratory that our ability to fight worm infection might fade as we age. Most studies of worm infections in humans focus on children and young adults in developing countries, with much less attention paid to older individuals."Dr Tom McNeilly, of the Moredun Research Institute, said: "With the drive for more efficient farming practices, efforts are being made to extend the productive life-span of livestock species, with means the average age of farmed animals is likely to increase in future. Studies such as these are critical as they provide important information on the likely consequences of farming older animals in terms of their ability to fight infectious diseases."Susan Bain, the National Trust for Scotland's Western Isles Manager, said: "For anyone who visits St Kilda, the Soay sheep are a highlight, being living artefacts of the archipelago's past -- a relic from the earliest settlers. I therefore find it fascinating that these castaways from a lost culture still have things to teach us today. This new research shows that there is still a lot more to discover about this ancient breed and their environment."
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Agriculture & Food
| 2,019 |
September 19, 2019
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https://www.sciencedaily.com/releases/2019/09/190919142211.htm
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Antimicrobial resistance is drastically rising
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The world is experiencing unprecedented economic growth in low- and middle-income countries. An increasing number of people in India, China, Latin America and Africa have become wealthier, and this is reflected in their consumption of meat and dairy products. In Africa, meat consumption has risen by more than half; in Asia and Latin America it is up by two-thirds.
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To meet this growing demand, animal husbandry has been intensified, with among other things, an increased reliance on the use of antimicrobials. Farmers use antimicrobials to treat and prevent infections for animals raised in crowded conditions but these drugs are also used to increase weight gain, and thus improve profitability.This excessive and indiscriminate use of antimicrobials has serious consequences: the proportion of bacteria resistant to antimicrobials is rapidly increasing around the world. Drugs are losing their efficacy, with important consequences for the health of animals but also potentially for humans.Low- and middle income countries have limited surveillance capacities to track antimicrobial use and resistance on farms. Antimicrobial use is typically less regulated and documented there than in wealthy industrialized countries with established surveillance systems.The team of researchers led by Thomas Van Boeckel, SNF Assistant Professor of Health Geography and Policy at ETH Zurich, has recently published a map of antimicrobial resistance in animals in low- and middle-income countries in the journal The team assembled a large literature database and found out where, and in which animals species resistance occurred for the common foodborne bacteria Salmonella, E. coli, Campylobacter and Staphylococcus.According to this study, the regions associated with high rates of antimicrobial resistance in animals are northeast China, northeast India, southern Brazil, Iran and Turkey. In these countries, the bacteria listed above are now resistant to a large number of drug that are used not only in animals but also in human medicine. An important finding of the study is that so far, few resistance hotspots have emerged in Africa with the exception of Nigeria and the surroundings of Johannesburg.The highest resistance rates were associated with the antimicrobials most frequently used in animals: tetracyclines, sulphonamides, penicillins and quinolones. In certain regions, these compounds have almost completely lost their efficacy to treat infections.The researchers introduced a new index to track the evolution of resistance to multiple drugs: the proportion of drugs tested in each region with resistance rates higher than 50%. Globally, this index has almost tripled for chicken and pigs over the last 20 years. Currently, one third of drugs fail 50% of the time in chicken and one quarter of drug fail in 50% of the time in pigs."This alarming trend shows that the drugs used in animal farming are rapidly losing their efficacy," Van Boeckel says. This will affect the sustainability of the animal industry and potentially the health of consumers.It is of particular concern that antimicrobial resistance is rising in developing and emerging countries because this is where meat consumption is growing the fastest, while access to veterinary antimicrobials remains largely unregulated. "Antimicrobial resistance is a global problem. There is little point in making considerable efforts to reduce it on one side of the world if it is increasing dramatically on the other side," the ETH researcher says.For their current study, the team of researchers from ETH, Princeton University and the Free University of Brussels gathered thousands of publications as well as unpublished veterinary reports from around the world. The researchers used this database to produce the maps of antimicrobial resistance.However, the maps do not cover the entire research area; there are large gaps in particular in South America, which researchers attribute to a lack of publicly available data. "There are hardly any official figures or data from large parts of South America," says co-author and ETH postdoctoral fellow Joao Pires. He said this surprised him, as much more data is available from some African countries , despite resources for conducting surveys being more limited than in South America.The team has created an open-access web platform Van Boeckel hopes that scientists from countries with more limited resources for whom publishing cost in academic journal can be a barrier will be able to share their findings and get recognition for their work on the platform. "In this way, we can ensure that the data is not just stuffed away in a drawer" he says, "because there are many relevant findings lying dormant, especially in Africa or India, that would complete the global picture of resistance that we try to draw in this first assessment. The platform could also help donors to identify the regions most affected by resistance in order to be able to finance specific interventions.As meat production continues to rise, the web platform could help target interventions against AMR and assist a transition to more sustainable farming practices in low- and middle-income countries. "The rich countries of the Global North, where antimicrobials have been used since the 1950s, should help make the transition a success," says Van Boeckel.The research was funded by the Swiss National Science Foundation and the Branco Weiss Fellowship.
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Agriculture & Food
| 2,019 |
September 19, 2019
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https://www.sciencedaily.com/releases/2019/09/190919125318.htm
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Biologists untangle growth and defense in maize, define key antibiotic pathways
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Studying the complex layers of immunity in maize, a staple for diets around the world, scientists have identified key genes that enable surprisingly diverse antibiotic cocktails that can be produced as defensive blends against numerous disease agents. Biologists describe how they combined an array of scientific approaches to clearly define 6 genes that encode enzymes responsible for the production of key maize antibiotics known to control disease resistance.
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In order to meet the demands of growing human populations, agricultural production must double within the next 30 years. Yet the health of today's crops and the promise of their yield face a rising slate of threats -- from pests to chaotic weather events -- leading to an urgent need to identify effective, natural plant defense strategies.Biologists have access to a wealth of genomic and biochemical data, but rapidly deciphering entire biochemical pathways that protect key crops of global significance remains a significant challenge. Scientists are peeling away at the layers of immunity in maize, a staple for diets around the world, to determine if there are key genes that enable surprisingly diverse antibiotic cocktails that can be produced as defensive blends against numerous disease agents.Now, a systematic and combined approach to identifying such genes in crop defense has been developed by Yezhang Ding, Alisa Huffaker and Eric Schmelz of the University of California San Diego and their colleagues and is described in "We need to know which crop defense mechanisms are effective and what we can do sustain or further improve them," said Schmelz. "Coauthors and collaborators in China are already taking some of the maize genes we characterized and are using them to significantly improve disease resistance in rice."Historically, defining a complete new biochemical pathway in crops has required stepwise progress and often the better part of an entire research career. In the new study, the UC San Diego biologists describe how they combined an array of scientific approaches to clearly define six genes that encode enzymes responsible for the production of key maize antibiotics known to control disease resistance.Maize plants lacking small molecule antibiotic defenses, derived from a skeleton of 20 carbon atoms known as diterpenoids, commonly suffer dramatic increases in fungal disease susceptibility."Most people appreciate that pine trees are heavily protected by sticky acid resins that kill or deter a majority of microbes and insects," said Schmelz. "We describe a complete maize biosynthetic pathway that also makes acid resins on-demand at the site of fungal attack. Interestingly, almost the entire pathway is derived from evolutionarily recent gene duplications from diverse hormone pathways related to plant growth and human testosterone metabolism."One of the evolutionary steps was a comparatively recent gene duplication three million years ago from the hormone pathway responsible for plant growth called gibberellins. In a step not clearly borrowed from hormone biosynthesis, two highly promiscuous oxidative enzymes (with broad substrate and product specificity) termed cytochrome P450s were characterized to produce unique reactions different from known conifer pathways. In total, the effort leveraged more than 2,000 plant samples, each with 36,861 transcripts, spanning 300 different maize lines to systematically narrow candidates and define a maize pathway for antibiotics effective against fungal pathogens.
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Agriculture & Food
| 2,019 |
September 18, 2019
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https://www.sciencedaily.com/releases/2019/09/190918131525.htm
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Actions to save coral reefs could benefit all ecosystems
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Scientists say bolder actions to protect coral reefs from the effects of global warming will benefit all ecosystems, including those on land.
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In an article published in Prof Tiffany Morrison and Prof Terry Hughes suggest a new, holistic approach to safeguarding coral reefs by focussing on land as well as the ocean."We must take a new, bolder approach to tackle the underlying causes of coral reef decline," lead author Prof Morrison said. "This means fixing the causes on a global, as well as local, scale -- both in the sea and on land."As an example, to protect the Great Barrier Reef, Prof Morrison suggests policymakers in Australia should replace coal-fired power with renewable energy sources, develop land-based aquaculture, and restore or rehabilitate terrestrial vegetation and wetlands in the 425,000-square-kilometre catchment of the Great Barrier Reef."Done strategically, these actions can reduce global emissions, capture carbon, curb agricultural runoff onto coastal reefs while also enhancing people's livelihoods and food security," she said.The "Current approaches to protect coral reefs are not enough to stem the ongoing decline," Prof Hughes said."Attempts to grow corals in aquaria or underwater nurseries are futile unless we address the major threats," he said."Reefs won't disappear if we tackle the root cause of their decline; global carbon emissions need to be slashed to 45% of 2010 levels by 2030."The authors suggest that a bolder, scaled-up approach to the stewardship of land and sea -- focused initially on coral reefs -- could itself help society meet this goal.Coral reefs cover only 0.5% of the ocean floor, but they support almost 30% of the world's marine fish species. 400 million people depend on reefs for work, food and protection from waves, storms and floods."What we're suggesting is not impossible," the authors said. "Countries such as Costa Rica, states such as California and cities such as Copenhagen have all taken up initiatives to curb greenhouse gas emissions and provide alternative economic opportunities that set powerful examples for the rest of the world."The article urges scientists, policymakers, non-governmental organisations and philanthropists to develop similarly bold strategies to protect reefs, other ecosystems and people in a warming world.
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Agriculture & Food
| 2,019 |
September 18, 2019
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https://www.sciencedaily.com/releases/2019/09/190918123034.htm
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New tool improves beekeepers' overwintering odds and bottom line
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A new tool from the Agricultural Research Service (ARS) can predict the odds that honey bee colonies overwintered in cold storage will be large enough to rent for almond pollination in February. Identifying which colonies will not be worth spending dollars to overwinter can improve beekeepers' bottom line.
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Beekeepers have been losing an average of 30 percent of overwintered colonies for nearly 15 years. It is expensive to overwinter colonies in areas where winter temperatures stay above freezing. So a less expensive practice of overwintering bee colonies in cold storage is becoming popular.This new tool calculates the probability of a managed honey bee colony surviving the winter based on two measurements: the size of colony and the percent varroa mite infestation in September, according to ARS entomologist Gloria DeGrandi-Hoffman, who headed the team. DeGrandi-Hoffman is research leader of the ARS Carl Hayden Bee Research Center in Tucson, Arizona.By consulting the probability table for the likelihood of a colony having a minimum of six frames of bees -- the number required for a colony to be able to fulfill a pollination contract for almond growers come February -- beekeepers can decide in September if it is economically worthwhile to overwinter the colony in cold storage."The size of a colony in late summer or early fall can be deceiving with respect to its chances of making it through the winter. Even large colonies with more than 12 frames of bees (about 30,000 bees) have less than a 0.5 probability (50 percent chance) of being suitable for almond pollination if they have 5 or more mites per 100 bees in September," DeGrandi-Hoffman said.Even with this cost-cutting help, the research team found that revenue from pollination contracts by itself is not likely to provide a sustainable income to a beekeeper anymore. They followed 190 honey bee colonies and recorded all costs.Considerable resources were expended to feed colonies and on varroa mite and pathogen control. Costs were about $200 per colony.Almond pollination contracts paid an average of $190 per colony in 2019.One way for beekeepers to remain economically viable as a business, is to produce a honey crop from their bees. This is most often facilitated by moving colonies to the Northern Great Plains where bees can forage for nectar and pollen from a wide variety flowering plants."The situation has changed a lot. It is more expensive to manage honey bees with costs to feed colonies when flowers are not available and to control varroa mites. And it is more difficult to find places for honey bee colonies that provide the diverse nutrition they need," said DeGrandi-Hoffman. "Pollination revenue alone is just not adequate for beekeepers to stay in business. But we need beekeepers because managed bees are a lynchpin in agricultural production today."Successfully using cold storage will help beekeepers' bottom line, but we are really just learning what the best management practices should be with cold storage," she added.
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Agriculture & Food
| 2,019 |
September 18, 2019
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https://www.sciencedaily.com/releases/2019/09/190918075743.htm
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Sesame yields stable in drought conditions
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Texas has a long history of growing cotton. It's a resilient crop, able to withstand big swings in temperature fairly well. However, growing cotton in the same fields year after year can be a bad idea. Nutrients can get depleted. Disease can lurk in the ground during the winter season, only to attack the following year. Thus, rotating cotton with other crops could be a better system.
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Agronomists have been researching various alternative crops that will grow well in western Texas. This area is part of the Ogallala water aquifer, which has been hit extremely hard the past few decades by drought. Another crop, sorghum, grows well with low water availability, but the yield can be greatly affected by drought conditions.Irish Lorraine B. Pabuayon, a researcher at Texas Tech University (TTU), is on the team looking at an alternative crop for west Texas: sesame.Like cotton and sorghum, sesame is also a "low-input" crop. This means it does not need a great deal of water, something that vegetable crops, corn and wheat need regularly and in large quantities."When introducing new crops to a water-limited system, it is important for growers to justify the water requirements of the new crops," says Pabuayon. "Properly determining the water requirements of the crops is important. Management decisions for wise use of limited water resources requires understanding a crop's moisture requirements."Pabuayon and the TTU team found that even under conditions that lowered sorghum and cotton yields, sesame performed well. This could be good news for west Texas farmers."Our results showed that sesame yields were not significantly altered under water-deficit conditions," says Pabuayon. "Sesame continued to have consistent yields, even when water-deficit conditions decreased sorghum's yield by 25% and cotton's yield by 40%."Having another crop that has good market value and can grow well during drought could benefit west Texas farmers. According to Pabuayon, sesame seeds are commonly used for food consumption and other culinary uses. The seeds are high in fat and are a good source of protein. Sesame is a major source of cooking oil. The remaining parts of sesame, after oil extraction, are good sources of livestock feed. Sesame has uses in the biodiesel industry, and even in cosmetics. This means there are multiple markets for the tiny seeds."Provided that the market price of sesame can support current yields, the results are favorable for low-input sesame production in west Texas," says Pabuayon. "However, the relatively low yields of sesame (per acre, compared to cotton and sorghum) suggest opportunities for additional genetic advancement. Currently, sesame varieties available for Texas are well-suited as an alternative crop for water-limited crop production systems.
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Agriculture & Food
| 2,019 |
September 17, 2019
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https://www.sciencedaily.com/releases/2019/09/190917133044.htm
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Genomic migration analysis shows antibiotic resistance moving from humans to animals
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A Clemson University professor's research has documented the movement of antibiotic resistance in humans into animal species.
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College of Science researcher Vincent Richards recently published results that draw attention to reverse zoonosis, or pathogens moving from human populations to animals.Every year, tens of thousands of Americans get sick from a variety of diseases contracted from animals. Known as zoonotic diseases, these infections are transmitted through food, water or direct contact with the animals. They include salmonella, E. coli, anthrax and cat scratch disease, to name a few.While the U.S. Centers for Disease Control and other health agencies keep tabs on animal-to-human diseases, there's a dearth of knowledge about reverse zoonosis.According to Richards, humans have acquired antibiotic-resistant genes, most likely through the overuse and abuse of prescription antibiotic drugs."I found actual cases of transmission of these antibiotic resistance genes from humans into livestock, companion animals and wildlife," said Richards, who speculates that the genetic material was transmitted via animal handling or through wastewater runoff.Richards reported these findings in an article titled "Population gene introgression and high genome plasticity for the zoonotic pathogen Streptococcus agalactiae," which was recently published in In the study, he and his collaborators analyzed a global set of 901 genome sequences of the bacteria Streptococcus agalactiae (also known as group B Strep) from nine different host species -- humans, cows, dogs, fish, frogs, gray seals, dolphins, goats and a camel -- to better understand the transmission process. Streptococcus agalactiae can cause life-threatening illnesses like meningitis, pneumonia and sepsis in newborn babies. In addition, the bacterium is a leading cause of bovine mastitis, an inflammatory disease that limits milk production in dairy cows."One of the things that makes the bacteria so interesting is its wide host range," said Richards, an assistant professor in the department of biological sciences. "It doesn't just infect humans and cows, it infects a whole range of terrestrial and aquatic mammals, reptiles and amphibians, and fish. It has quite the taxonomic range for a bacteria."As part of the analysis, Richards grouped the genes into core and dispensable categories. Core genes are shared by all the genomes, while dispensable genes only appear in some species' genomes. Together, the core and dispensable genes make up the pan-genome (the entire gene set of all strains of a species).In classifying the genes as either core or dispensable, Richards was surprised to discover that only about 10 percent of the pan-genome was core while 90 percent was dispensable.Significantly, the study showed how high bacterial genome plasticity can produce an expansive and yet highly partitioned pan-genome, which in turn facilitates further expansion of the pan-genome. Plasticity allows bacteria to adapt their DNA quickly so they can survive changes in their environment. As the pan-genome expands, continued adaptation to a diverse landscape of niches produces multiple biochemically diverse and divergent populations.This population expansion can cause directionally biased spillover, demonstrating how genes selected in one niche or host can ultimately be transmitted into another."You have genes that are adapted to a particular population now being transferred into another population," Richards said. "A particular gene for antibiotic resistance that was selected in human populations is now being transmitted into animal populations."In the future, Richards hopes to apply the genomic methods utilized in this study to his group's research on related strep bacteria found in the human mouth. Specifically, he'd like to examine the role that certain metatabolic genes have in tooth decay in children.
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Agriculture & Food
| 2,019 |
September 17, 2019
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https://www.sciencedaily.com/releases/2019/09/190917100453.htm
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Ethanol fuels large-scale expansion of Brazil's farming land
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A University of Queensland-led study has revealed that future demand for ethanol biofuel could potentially expand sugarcane farming land in Brazil by five million hectares by 2030.
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UQ School of Earth and Environmental Sciences researcher Milton Aurelio Uba de Andrade Junior said that because Brazil produced ethanol from sugarcane, future biofuel demand would directly impact land use."Our study has modelled scenarios forecasting future ethanol demand based on different trajectories for gross domestic product, population growth, fuel prices, blending policies, fleet composition and efficiency gains," he said."A high demand scenario fuelled by strong economic and population growth, soaring gasoline prices, and ambitious blending targets, could mean that current demand for ethanol in Brazil will be doubled by 2030."If this scenario occurs, then Brazil will need an additional five million hectares of land for sugarcane crops to meet this high demand."Mr de Andrade Junior said that most of the additional sugarcane farms were likely to expand into pasturelands, minimising impact on native forests."A key assumption of our modelling is that Brazil's land-use policies, such as the sugarcane agro-ecological zoning, will continue to promote the increase of agricultural yields while minimising environmental impacts," he said."However, in the current context of high uncertainty on the environmental agenda, such land use policies need to be closely monitored and supported to ensure that the country's natural ecosystems and biodiversity remain protected."
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Agriculture & Food
| 2,019 |
September 16, 2019
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https://www.sciencedaily.com/releases/2019/09/190916212510.htm
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To address hunger, many countries may have to increase carbon footprint
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Achieving an adequate, healthy diet in most low- and middle-income countries will require a substantial increase in greenhouse gas emissions and water use due to food production, according to new research from the Johns Hopkins Center for a Livable Future based at the Johns Hopkins Bloomberg School of Public Health.
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The paper will be published online September 16 in the journal Obesity, undernutrition, and climate change are major global challenges that impact the world's population. While these problems may appear to be unrelated, they share food production and consumption as key underlying drivers. By recognizing the role of food production in climate change, this study examines the challenges of simultaneously addressing hunger and the climate crisis at both the individual and country levels.For their analysis, the researchers developed a model that assessed how alterations to dietary patterns across 140 countries would impact individual- and country-level greenhouse gas emissions and freshwater use. They used this model to assess the per capita and whole country climate and water footprints of nine plant-forward diets. The plant-forward diets examined ranged from no red meat, pescatarian, lacto-ovo vegetarian, and vegan, among others.A key finding of the study showed that a diet in which the animal protein came predominantly from low food chain animals, such as small fish and mollusks, had nearly as low of an environmental impact as a vegan diet. Researchers also determined that a diet that involved reducing animal food consumption by two-thirds -- termed by study authors as "two-thirds vegan" -- generally had a lower climate and water footprint than the more traditional lacto-ovo vegetarian diet."Our research indicates there's no one-size-fits-all diet to address the climate and nutrition crises. Context is everything, and the food production policies for each country must reflect that," says senior author of the study, Keeve Nachman, PhD, director of the Food Production and Public Health program at the Johns Hopkins Center for a Livable Future and an assistant professor with the Bloomberg School's Department of Environmental Health and Engineering.To counter these climate impacts and to address diet-related morbidity and mortality, the authors recommend, based on this report, that high-income countries accelerate adapting plant-forward diets. The authors emphasize that an examination of these diets and their environmental footprints allows for consideration of dietary recommendations or behavioral changes that would balance health and nutrition needs, cultural preferences, and planetary boundaries."Our data indicate that it is actually dairy product consumption that explains much of the differences in greenhouse gas footprints across diets. Yet, at the same time, nutritionists recognize the important role dairy products can have in stunting prevention, which is a component of the World Bank Human Capital Index," says study co-author, Martin Bloem, MD, PhD, director of the Johns Hopkins Center for a Livable Future and the Robert Lawrence Professor of Environmental Health at the Bloomberg School. The World Bank's Human Capital Index calculates the contribution of health and education to the productivity of future generations of workers."The study findings highlight the difficulty in prescribing broad dietary recommendations to meet the needs of individual countries," says Bloem.A food's country of origin can have enormous consequences for climate, according to the study. For example, one pound of beef produced in Paraguay contributes nearly 17 times more greenhouse gases than one pound of beef produced in Denmark. Often, this disparity is due to deforestation resulting from grazing land. "Where you get your food from matters," says Nachman. "Trade patterns have an important influence on countries' diet-related climate and fresh water impacts."The methodology used in the study allows for new data-driven comparisons between countries and regions, and also takes into account the different contexts and conditions in these countries. The study integrates country-specific data such as current food availability and trade and import patterns with information about greenhouse gas and water use burdens that are associated with the production of specific food items by country of origin. It also takes into account the carbon emissions associated with land use changes for purposes of food production."It would be satisfying to have a silver bullet to address carbon footprints and the impact of food production; however, with problems as complex and global as nutrition, climate change, freshwater depletion, and economic development, that's not possible," says Bloem. "There will always be tradeoffs. Environmental impact alone cannot be a guide for what people eat; countries need to consider the totality of the nutritional needs, access, and cultural preferences of their residents. The good news is this research can be a part of the solution, as it now gives policymakers a tool to develop nationally appropriate strategies, including dietary guidelines, that help meet multiple goals."The study was funded by the Columbus Foundation.
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Agriculture & Food
| 2,019 |
September 16, 2019
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https://www.sciencedaily.com/releases/2019/09/190916170116.htm
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Early rice farmers unwittingly selected for weedy imposters
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Early rice growers unwittingly gave barnyard grass a big hand, helping to give root to a rice imitator that is now considered one of the world's worst agricultural weeds.
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New research from Zhejiang University, the Chinese Academy of Sciences and Washington University in St. Louis provides genomic evidence that barnyard grass (Barnyard grass is a globally common invasive weed of cultivated row crops and cereals. The new study was published Sept. 16 in the journal "In Asia, rice farmers have traditionally planted and weeded their paddies by hand. Any weeds that stick out are easily detected and removed," said Kenneth Olsen, professor of biology in Arts & Sciences. "Over hundreds of generations, this has selected for some strains of barnyard grass that specialize on rice fields and very closely mimic rice plants. This allows them to escape detection."Olsen collaborated on data analyses and interpretation for the new study. He is working with the study's corresponding author, Longjiang Fan of Zhejiang University, on other research related to rice evolutionary genomics and agricultural weed evolution.This study sequenced the genomes of rice-mimic and non-mimic forms of the weed as a step towards understanding how this process has occurred.This form of mimicry, called Vavilovian mimicry, is an adaptation of weeds to mimic domesticated plants. In the case of barnyard grass, the rice mimics grow upright like a rice plant instead of sprawling along the ground like most barnyard grass. They also have green stems like rice plants instead of the red stems more commonly found in the weed."With the advent of agriculture about 10,000 years ago, humans all over the planet began creating a wonderful habitat for naturally weedy plant species to exploit," Olsen said. "The most successful and aggressive agricultural weeds were those that evolved traits allowing them to escape detection and proliferate in this fertile new environment."The researchers estimate that the mimic version of However, while common barnyard grass is a major agricultural weed in the U.S., the rice mimic form has never become widespread in the main rice growing region -- the southern Mississippi valley.Olsen speculates that this is because U.S. rice farmers rely on mechanized farming instead of hand labor."Without farmers out in the fields planting and weeding by hand, there's not such strong selection for weeds to visually blend in with the rice crop," he said.
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Agriculture & Food
| 2,019 |
September 16, 2019
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https://www.sciencedaily.com/releases/2019/09/190916143951.htm
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Palmer amaranth's molecular secrets reveal troubling potential
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Corn, soybean, and cotton farmers shudder at the thought of Palmer amaranth invading their fields. The aggressive cousin of waterhemp -- itself a formidable adversary -- grows extremely rapidly, produces hundreds of thousands of seeds per plant, and is resistant to multiple classes of herbicides, including glyphosate.
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Palmer's resistance to PPO-inhibiting herbicides, a group of chemicals that disrupt chlorophyll synthesis, is especially problematic with glyphosate out of the picture. Farmers had been turning to PPO-inhibitors as an effective alternative, until resistance was discovered in waterhemp in 2001 and in Palmer in 2011.Pat Tranel from the University of Illinois has been working to understand the mechanisms of resistance to PPO-inhibitors for years, and was the first to discover key mutations in both weed species. Now, in two new studies, he goes farther to explain Palmer's evil genius."We knew Palmer had the same molecular mechanism as waterhemp to resist PPO-inhibitors, a genetic mutation known as the gly-210 deletion, and at least one more. Now we know that it evolved the gly-210 deletion independently, rather than picking it up through hybridization with waterhemp," says Tranel, associate head and professor of molecular weed science in the Department of Crop Sciences at U of I.This is important in two ways. It's good news that scientists aren't finding evidence of hybridization between the two superweeds, at least not so far. But the fact that Palmer evolved the same mutation independently, and at least one more to boot, shows just how wily the weed is.Tranel and his team determined the evolutionary origins of the gly-210 mutation by looking at the genetics of resistant plants of both species that were growing together in a Kentucky field. Being in close proximity for several years should have provided opportunity for hybridization, if it was going to happen."We know from lab experiments that they are capable of hybridizing, so the fact that it's not happening in the field is a good thing. The more they can and do hybridize, the more concerns we'd have," Tranel says.Only about a third of the Palmer plants in the Kentucky field had the gly-210 deletion. The rest were using a different mutation -- an arginine substitution -- to ward off PPO-inhibitor damage."The finding that this population of Palmer has two different mutations is a concern because if you look forward in the future, Palmer is well positioned to deal with future PPO chemistries. It can use whichever is more effective against a new PPO."It's also well positioned to combine the two mutations to create a double mutant, with both mutations on the same copy of the chromosome. Chemistry designed to kill plants with the gly-210 deletion won't be able to kill double mutants," Tranel says. "In my opinion, it's just a matter of time until we see double mutants in the field."Tranel's second new study explains why Palmer amaranth took a decade longer than waterhemp to develop the gly-210 deletion, and reveals another diabolical truth about the species: Palmer amaranth appears to be naturally tolerant to post-emergence PPO-inhibitor application.It has long been recognized that the timing of post-emergence PPO application is especially critical for Palmer amaranth, relative to waterhemp. If Palmer plants aren't sprayed before they reach about 4 inches, it's all over."If you wait too long, you miss 'em. And too long can be a matter of a single day because Palmer grows so fast. It can go from a 4-inch plant where you could control it to a 6-inch plant literally in a day," Tranel says.For Tranel, the pattern suggests a natural tolerance to post-emergence PPO-inhibitors. Tolerance describes the ability of a species to handle a substance, in this case PPO herbicides. Resistance, on the other hand, happens at the population level; localized populations of the species evolve mutations in response to repeated exposure to the substance. For example, corn is tolerant to atrazine. It can handle being sprayed and doesn't need to evolve a mutation to handle it in a particular population.The idea is that Palmer amaranth has a natural tolerance to PPO inhibitors and didn't need to develop resistance. That's why it took longer to evolve the gly-210 mutation. But, until now, no one had specifically studied Palmer's tolerance to the chemistry before.Tranel confirmed it by growing Palmer and waterhemp plants with and without the gly-210 mutation side-by-side and applying different formulations of pre-emergence and post-emergence PPO-inhibitors. The post-emergence applications were done early (smaller than 4 inches) or late (taller than 4 inches)."We found that 'sensitive' Palmer plants without the mutation survived just as well as resistant waterhemp when sprayed post-emergence," Tranel says.On the other hand, the research team found that pre-emergence formulations effectively controlled both species."The difference in tolerance between Palmer and waterhemp goes away at the pre-emergence stage," Tranel says. "Ultimately, that's the take-home message here. If you're dealing with these weeds, especially Palmer amaranth, and you want to incorporate a PPO-inhibitor as an alternative effective mode of action, you'll have much better luck if you use it in a pre-emergence application."
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Agriculture & Food
| 2,019 |
September 16, 2019
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https://www.sciencedaily.com/releases/2019/09/190916143949.htm
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Harnessing tomato jumping genes could help speed-breed drought-resistant crops
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Once dismissed as 'junk DNA' that served no purpose, a family of 'jumping genes' found in tomatoes has the potential to accelerate crop breeding for traits such as improved drought resistance.
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Researchers from the University of Cambridge's Sainsbury Laboratory (SLCU) and Department of Plant Sciences have discovered that drought stress triggers the activity of a family of jumping genes (Rider retrotransposons) previously known to contribute to fruit shape and colour in tomatoes. Their characterisation of Rider, published today in the journal "Transposons carry huge potential for crop improvement. They are powerful drivers of trait diversity, and while we have been harnessing these traits to improve our crops for generations, we are now starting to understand the molecular mechanisms involved," said Dr Matthias Benoit, the paper's first author, formerly at SLCU.Transposons, more commonly called jumping genes, are mobile snippets of DNA code that can copy themselves into new positions within the genome -- the genetic code of an organism. They can change, disrupt or amplify genes, or have no effect at all. Discovered in corn kernels by Nobel prize-winning scientist Barbara McClintock in the 1940s, only now are scientists realising that transposons are not junk at all but actually play an important role in the evolutionary process, and in altering gene expression and the physical characteristics of plants.Using the jumping genes already present in plants to generate new characteristics would be a significant leap forward from traditional breeding techniques, making it possible to rapidly generate new traits in crops that have traditionally been bred to produce uniform shapes, colours and sizes to make harvesting more efficient and maximise yield. They would enable production of an enormous diversity of new traits, which could then be refined and optimised by gene targeting technologies."In a large population size, such as a tomato field, in which transposons are activated in each individual we would expect to see an enormous diversity of new traits. By controlling this 'random mutation' process within the plant we can accelerate this process to generate new phenotypes that we could not even imagine," said Dr Hajk Drost at SLCU, a co-author of the paper.Today's gene targeting technologies are very powerful, but often require some functional understanding of the underlying gene to yield useful results and usually only target one or a few genes. Transposon activity is a native tool already present within the plant, which can be harnessed to generate new phenotypes or resistances and complement gene targeting efforts. Using transposons offers a transgene-free method of breeding that acknowledges the current EU legislation on Genetically Modified Organisms.The work also revealed that Rider is present in several plant species, including economically important crops such as rapeseed, beetroot and quinoa. This wide abundance encourages further investigations into how it can be activated in a controlled way, or reactivated or re-introduced into plants that currently have mute Rider elements so that their potential can be regained. Such an approach has the potential to significantly reduce breeding time compared to traditional methods."Identifying that Rider activity is triggered by drought suggests that it can create new gene regulatory networks that would help a plant respond to drought," said Benoit. "This means we could harness Rider to breed crops that are better adapted to drought stress by providing drought responsiveness to genes already present in crops. This is particularly significant in times of global warming, where there is an urgent need to breed more resilient crops."This work was supported by the European Research Council and the Gatsby Charitable Foundation.
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Agriculture & Food
| 2,019 |
September 16, 2019
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https://www.sciencedaily.com/releases/2019/09/190916114026.htm
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Carp aquaculture in Neolithic China dating back 8,000 years
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In a recent study, an international team of researchers analyzed fish bones excavated from the Early Neolithic Jiahu site in Henan Province, China. By comparing the body-length distributions and species-composition ratios of the bones with findings from East Asian sites with present aquaculture, the researchers provide evidence of managed carp aquaculture at Jiahu dating back to 6200-5700 BC.
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Despite the growing importance of farmed fish for economies and diets around the world, the origins of aquaculture remain unknown. The Shijing, the oldest surviving collection of ancient Chinese poetry, mentions carp being reared in a pond circa 1140 BC, and historical records describe carp being raised in artificial ponds and paddy fields in East Asia by the first millennium BC. But considering rice paddy fields in China date all the way back to the fifth millennium BC, researchers from Lake Biwa Museum in Kusatu, Japan, the Max Planck Institute for the Science of Human History in Jena, Germany, the Sainsbury Institute for the Study of Japanese Arts and Cultures in Norwich, U.K., and an international team of colleagues set out to discover whether carp aquaculture in China was practiced earlier than previously thought.Jiahu, located in Henan, China, is known for the early domestication of rice and pigs, as well the early development of fermented beverages, bone flutes, and possibly writing. This history of early development, combined with archaeological findings suggesting the presence of large expanses of water, made Jiahu an ideal location for the present study.Researchers measured 588 pharyngeal carp teeth extracted from fish remains in Jiahu corresponding with three separate Neolithic periods, and compared the body-length distributions with findings from other sites and a modern sample of carp raised in Matsukawa Village, Japan. While the remains from the first two periods revealed unimodal patterns of body-length distribution peaking at or near carp maturity, the remains of Period III (6200-5700 BC) displayed bimodal distribution, with one peak at 350-400 mm corresponding with sexual maturity, and another at 150-200 mm.This bimodal distribution identified by researchers was similar to that documented at the Iron Age Asahi site in Japan (circa 400 BC -- AD 100), and is indicative of a managed system of carp aquaculture that until now was unidentified in Neolithic China. "In such fisheries," the study notes, "a large number of cyprinids were caught during the spawning season and processed as preserved food. At the same time, some carp were kept alive and released into confined, human regulated waters where they spawned naturally and their offspring grew by feeding on available resources. In autumn, water was drained from the ponds and the fish harvested, with body-length distributions showing two peaks due to the presence of both immature and mature individuals."The size of the fish wasn't the only piece of evidence researchers found supporting carp management at Jiahu. In East Asian lakes and rivers, crucian carp are typically more abundant than common carp, but common carp comprised roughly 75% of cyprinid remains found at Jiahu. This high proportion of less-prevalent fish indicates a cultural preference for common carp and the presence of aquaculture sophisticated enough to provide it.Based on the analysis of carp remains from Jiahu and data from previous studies, researchers hypothesize three stages of aquaculture development in prehistoric East Asia. In Stage 1, humans fished the marshy areas where carp gather during spawning season. In Stage 2, these marshy ecotones were managed by digging channels and controlling water levels and circulation so the carp could spawn and the juveniles later harvested. Stage 3 involved constant human management, including using spawning beds to control reproduction and fish ponds or paddy fields to manage adolescents.Although rice paddy fields have not yet been identified at Jiahu, the evolution of carp aquaculture with wet rice agriculture seems to be connected, and the coevolution of the two is an important topic for future research.
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Agriculture & Food
| 2,019 |
September 16, 2019
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https://www.sciencedaily.com/releases/2019/09/190916081432.htm
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Reduce, reuse, recycle: The future of phosphorus
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When Hennig Brandt discovered the element phosphorus in 1669, it was a mistake. He was really looking for gold. But his mistake was a very important scientific discovery. What Brandt couldn't have realized was the importance of phosphorus to the future of farming.
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Phosphorus is one of the necessary ingredients for healthy crop growth and yields. When farms were smaller and self-sufficient, farmers harvested their crops, and nutrients rarely left the farm. The family or animals consumed the food, and the farmer could spread manure from their animals onto the soil to rebuild nutrients. This was a fairly closed-loop phosphorus cycle.But, as the world's population increased, so did food and nutrition needs. More of a farmer's harvest, and therefore nutrients, was sold off the farm. Agriculture adapted by developing many new growing methods, as well as fertilizers. Most phosphorus fertilizers use the world's supply of phosphate rock as a main ingredient. That main modern source is a finite resource and it's running out. Phosphate rock is also hard to mine and process."There is an urgent need to increase phosphorus use efficiency in agroecosystems," says Kimberley Schneider, a research scientist with Agriculture and Agri-Food Canada. "There are many chemical, physical and biological processes that affect the availability of phosphorus to crops." This is why farmers place great importance in having enough phosphorus for their crops.Different plants can use phosphorus more efficiently than others. "Phosphorus use efficiency is the ability to yield more crop per unit of phosphorus taken up by the plant," explains Schneider. "There is potential for crop breeders to develop new varieties that use phosphorus in even more efficient ways. They can also breed crops that work with mycorrhizal fungi in the soil to help increase their phosphorus absorption. Focusing on breeding plants that work well in low phosphorus soils will take an interdisciplinary approach."Since some crops can increase soil phosphorus availability for future crops, growers could focus on crop rotations that take advantage of this. Cover crops and green manures can also contribute to phosphorus availability in many conditions. For example, one study found sorghum did well with phosphorus use after alfalfa or red clover, but not after sweet clover. Getting the right combinations for the right crops and fields will be important.Soil organic matter is known to indicate soil health. It can improve plant phosphorus availability by allowing for greater root access to phosphorus and by releasing plant available phosphorus. Currently, soil organic matter is not part of the soil fertility measurements on farms, so this is an area of future research potential.Many soils contain one or more types of friendly fungus called arbuscular mycorrhizal fungi. They work with plant roots to exchange "life chores." The fungi help free up phosphorus and other nutrients, while the plants make sugar compounds that the fungi use for growth. Of course, the fungi and roots must be able to be near one another for this exchange to happen. Researchers are looking at the promise of building up and better utilizing mycorrhizal fungi populations in soils.Phosphorus is the 6th most common element on earth. Yet, it is a limiting factor in crop yields. Excess phosphorus in the wrong place -- streams, lakes and other waterbodies -- causes pollution. How did this come to be?Let's trace the "life cycle" of a phosphorus molecule. Most phosphate rock is mined on the continents of Europe and Africa, although some deposits are available elsewhere. After it is made into fertilizer, this phosphorus is then moved to farms. From there, the phosphorus is used by a plant to make a product, perhaps a soybean. The soybean is removed from the farm and manufactured into tofu. It is then transported to your local grocery store, where you buy it and bring it home. If you live in a city, after you enjoy your meal of fried tofu, the waste your body produces flushes down the toilet. If you live in a rural area, it goes into the septic system.Thus, the life cycle of this illustrative phosphorus molecule shows a broken cycle. The molecule originates far away from its final resting place. Because of modern day life, the phosphorus cycle that used to exist on farms is broken. The more urban society becomes, the more broken the phosphorus cycle is -- unless scientists come up with answers to close the loops again.Agricultural scientists are working with wastewater managers to develop ways to put those deserving phosphorus molecules back to work on the farm. "While most currently available phosphorus recovery technologies may not seem economically viable, the environmental and social benefits are important," says Schneider. "There are also other valuable products of phosphorus recovery, such as organic matter, other nutrients, and even water.""Increasing phosphorus use efficiency in agroecosystems must be a priority to reduce reliance on fertilizer and to minimize the effects on the environment," says Schneider. "There are many possibilities for the agricultural system to improve the use of phosphorus. The outcome will be an agroecosystem that still feeds the world, while protecting the natural resources that help us grow our food and live healthy lives."This article was recently published in a special section in the
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Agriculture & Food
| 2,019 |
September 12, 2019
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https://www.sciencedaily.com/releases/2019/09/190912140456.htm
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Controversial insecticides shown to threaten survival of wild birds
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New research at the University of Saskatchewan (USask) shows how the world's most widely used insecticides could be partly responsible for a dramatic decline in songbird populations.
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A study published in the journal The study found that white-crowned sparrows who consumed small doses of an insecticide called imidacloprid suffered weight loss and delays to their migration -- effects that could severely harm the birds' chances of surviving and reproducing."We saw these effects using doses well within the range of what a bird could realistically consume in the wild -- equivalent to eating just a few treated seeds," said Margaret Eng, a post-doctoral fellow in the USask Toxicology Centre and lead author on the study.Eng's collaborators on the research were biologist Bridget Stutchbury of York University and Christy Morrissey, an ecotoxicologist in the USask College of Arts and Science and the School of Environment and Sustainability.Neonicotinoids are the most commonly used class of agricultural insecticides. They are often applied as a seed coating or as a spray on most major crops worldwide.Although the toxic effects of neonicotinoids were once thought to affect only insects, most notably pollinators such as bees, there is growing evidence that birds are routinely exposed to the pesticides with significant negative consequences."Our study shows that this is bigger than the bees -- birds can also be harmed by modern neonicotinoid pesticides which should worry us all," said Stutchbury.Until now, researchers had not been able to assess what happens to pesticide-exposed birds in the wild. The USask and York University scientists used new lightweight tagging technologies and a collaborative research network called the Motus Wildlife Tracking System to track the effects in the sparrows' natural habitat.The researchers exposed individual sparrows to small doses of the pesticide, imidacloprid, in southern Ontario, Canada during a stopover on the birds' spring migration. Each bird's body composition was measured before and after exposure, and a lightweight radio transmitter was attached to the bird's back to track its movements in the wild.Birds given the higher dose of the pesticide lost six per cent of their body mass within just six hours. That one dose also caused birds to stay 3.5 days longer, on average, at the stopover site before resuming their migration compared to control birds."Both of these results seem to be associated with the appetite suppression effect of imidacloprid. The dosed birds ate less food, and it's likely that they delayed their flight because they needed more time to recover and regain their fuel stores," said Eng.Because the researchers used controlled dosing, they were able to confirm a cause and effect between neonicotinoid exposures and delayed migration, not just a correlation that is more typical of field studies.In North America, three-quarters of bird species that rely on agricultural habitat have significantly declined in population since 1966. The results of the new study show a mechanism by which pesticides could be directly contributing to this drop-off."Migration is a critical period for birds and timing matters. Any delays can seriously hinder their success in finding mates and nesting, so this may help explain, in part, why migrant and farmland bird species are declining so dramatically worldwide," said Morrissey, senior author on the study.The three researchers examined the effects of neonicotinoids in a previous study using captive sparrows. The new research reinforces the weight loss effect seen in that 2017 study. Captive birds in the earlier study were also found to become disoriented as a result of neonicotinoid exposure."We didn't see that result in wild birds here," said Eng. "In the real-world, birds likely avoid migratory flight while recovering from the effects of the toxin."Funding for the research published in
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Agriculture & Food
| 2,019 |
September 12, 2019
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https://www.sciencedaily.com/releases/2019/09/190912124825.htm
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Satellite study of Amazon rainforest land cover gives insight into 2019 fires
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Throughout August and early September 2019, media around the world have reported on the extensive forest fires ravaging Brazil's Amazon rainforest. Much of the concern stems from the Amazon's significance to regulating the world's climate. According to the Associated Press, the Amazon absorbs 2 billion tons of carbon dioxide every year -- about 5% of global emissions. Thus, fires in the region eat away at this carbon-absorbing capacity while at the same time adding carbon to the air through burning.
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A recent study in the peer-reviewed journal "This is the first study to examine the biosphere-atmosphere interactions in the Amazon with such high spatial resolution satellite imagery," said de Oliveira, a postdoctoral researcher in the Department of Geography & Atmospheric Science at KU. "We tried to understand the impacts of land-cover changes and deforestation in general. When you clear-cut the forests, and you convert it either to pasture or agriculture -- or cut the forest, but for some reason don't plant anything and then have a type of vegetation called 'secondary succession' -- our idea was to try to understand how that impacts energy, like the radiative fluxes and water fluxes, or evaporation in general."In the paper, de Oliveira and his colleagues analyzed information from both satellites in space and weather stations on the ground in the Amazon. With data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Large?Scale Biosphere?Atmosphere Experiment in Amazonia (LBA), they examined surface energy and water changes over different land?cover types in one wet year and one drought year in eastern Rondônia state, Brazil. The team also found statistically significant differences in several important measures prior to and after one year of deforestation."Using NASA satellite images with high spatial resolution (15m) obtained by the ASTER sensor in Rondônia state, in the south-western Brazilian Amazon, we found that deforestation and consequent transition to pasture or agriculture to grow soybean tend to increase in two to four times the soil and air temperatures in the region," de Oliveira said. "We also observed an approximately three times higher evapotranspiration over forested areas in comparison with nonforested areas."The researchers discovered significant variances between areas on opposite sides of the Ji-Paraná River, one side of which had suffered more deforestation than the other side, located within the Jaru Biological Reserve protected area. They measured spatial variation of albedo (or the fraction of the incident sunlight that the surface reflects), net radiation (or the total energy, derived from sunlight, that's available at the surface), soil and sensible heat fluxes (or how much heat is transferred from the surface to the atmosphere), and evapotranspiration (the process by which water is transferred from the land to the atmosphere by evaporation from the soil and by transpiration from plants).De Oliveira, who was raised in Brazil, said the rest of the world depends on the Amazon region to help moderate global climate."It's important because it's the largest rainforest in the world," he said. "Precipitation in the tropics, all the water fluxes that go on in the tropics, affect the whole world. The Amazon has a very important role in that. There's no other area in the world like the Amazon's unique ecosystem. It's pretty fascinating. I'm from South Brazil, a totally different environment than the Amazon. You could compare it with Kansas. But when I started studying for my master's degree, my adviser told me, 'You're going to work in the Amazon rainforest.' And I told her I'd never been there. But I spent two months in the rainforest doing research. And of course, you know, I fell in love. I'm very passionate about the Amazon and have been there so many times since then, so I have a lot of experience and stories of things that have happened there."The KU researcher cautioned that although forest fires in the Amazon have received attention in the media this year, the fires happen to a greater or lesser degree every year."Fires in the Amazon happen every year during the dry season," de Oliveira said. "We have agricultural areas, areas that were deforested in the past -- but in order to clear the area for the next year, or to make the soil a little bit better for the next year, they set a fire. They claim they're only setting fire to burn agricultural lands. But sometimes the fire gets out of control, and it plays a part in more deforestation. Fires get out of control in agricultural land and reach the forest and burn the forest. But these fires happen in the Amazon every year, so it's pretty straightforward. The worst years were in 2005, 2010 and 2015 because of severe drought events. Everything was really dry, and the fires would get out of control. There are no natural fires in the Amazon. They're all set by human beings."De Oliveira's co-authors on the study were Nathaniel Brunsell, professor and chair of KU's geography & atmospheric science department; Elisabete Moraes, Yosio Shimabukuro, Celso von Randow and Luiz E.O.C. Aragao of the Brazilian National Institute for Space Research; Thiago dos Santos of the University of Michigan and Renata de Aguiar of the Federal University of Rondônia.
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Agriculture & Food
| 2,019 |
September 12, 2019
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https://www.sciencedaily.com/releases/2019/09/190912113238.htm
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The 'pathobiome' -- a new understanding of disease
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Cefas and University of Exeter scientists have presented a novel concept describing the complex microbial interactions that lead to disease in plants, animals and humans.
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Microbial organisms and viruses cause many diseases of plants and animals.They can also help protect from disease, for example the complex communities of microbes in the human gut, which are very important for our health.However, very little is known about these microbes and how they cause and prevent disease.The pathobiome concept opens a door on this unexplored world of microbial diversity and how it controls all other organisms on the planet.It will change the way we approach health and disease control in animals, plants and humans.Traditional approaches to describe infectious disease in plants, animals and in humans are based on the concept that single pathogens are responsible for the signs or symptoms of disease observed in those hosts.The pathobiome concept explains that in reality, disease occurrence is much more complex.Today sees the publication of a paper exploring the pathobiome concept, a novel way of seeking to understand diseases of plants and animals, including humans.The concept acknowledges that all organisms are in fact complex communities of viruses, microbes and other small organisms (e.g. parasites) which can interact to affect health or disease status at any given time.These complex communities continually interact with their hosts, sometimes conferring benefits (e.g. "good" bacteria in the human gut microbiome), and at other times causing harm by contributing to disease.When these communities combine to cause disease they are termed "pathobiomes" -- a recognition of their collective shift away from the healthy-state "symbiome."The recognition that the pathobiome plays a key role in those signs and symptoms of disease that we observe in the host is becoming a more accurate way of considering disease than by simply referring to it as the outcome of the effects of a single pathogen (e.g. the influenza virus).Even when a single agent is implicated, its effects are likely to be modified (enhanced or mitigated) by others in the accompanying pathobiome and so should not be considered in isolation in the disease process.The influence of the surrounding environment on animal and plant health is hugely important too.For example, aquatic organisms live in a microbial soup; there are millions of microbes and viruses in every drop of fresh and seawater.Some of these are already known to cause diseases in different organisms.In other cases, microbes not previously thought to be pathogenic can, in fact, become so under certain environmental conditions.As a result of this we are revising our understanding of what a pathogen actually is as we start to recognise that this can be determined by the context in which a microbe finds itself.Professor David Bass, lead author at Cefas, said: "The vast majority of cells in our bodies are bacterial, not human."Therefore, we are walking ecosystems -- interacting communities of many different organisms."This is also true for all other animals and plants."The organisms in these complex communities play key roles in determining the health of their host animals and plants."The pathobiome concept will lead to understanding these relationships better and help us manage disease in crop plants and animals, wildlife, pets and ourselves."Professor Charles Tyler, of the University of Exeter said: "As we seek to better understand how pathogens cause diseases, we increasingly recognise that the environment, of both the host and pathogen, plays a vital role."The concept of the pathobiome seeks to understand how interactions between organisms in, and immediately surrounding, a host, together with the associated physicochemistries of those environments enable or inhibit an organisms' ability to cause disease."As such this presents a more holistic and realistic approach to understanding the disease process."It is great to see this conceptual paper coming out of the Centre for Sustainable Aquaculture Futures -- a partnership between the University of Exeter and Cefas, where disease diagnosis, avoidance and mitigation of disease in aquaculture is a major focus."Professor Grant Stentiford, co-author and Science Theme Lead for Animal and Human Health at Cefas said: "Conceptualising the pathobiome as a community of microbes which have the capacity to change in the host over space (e.g. between tissues and organs) and time, and are associated with observable changes in the health of the host, will revolutionise our understanding of how to describe and manage disease in animals and plants."In the case of farmed animals and plants, optimising those conditions which discourage formation of a pathobiome may become as important as existing controls, which aim to minimise exposure to single, specific pathogens."
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Agriculture & Food
| 2,019 |
September 12, 2019
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https://www.sciencedaily.com/releases/2019/09/190912080009.htm
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Finding (microbial) pillars of the bioenergy community
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Stems, leaves, flowers and fruits make up the biggest chunk of potential living space for microbes in the environment, but ecologists still don't know a lot about how the microorganisms that reside there establish and maintain themselves over the course of a growing season.
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In a new study in Microorganisms that dwell in the phyllosphere are thought to play a role in their host's growth and health. And, like their subterranean kin, the topside microbiome affects how much phosphorus, nitrogen and other nutrients bioenergy crops can keep out of our waterways and atmosphere.Shade says the first step in determining how to maximize production of these bioenergy crops is figuring out which taxa, or kinds of organisms, are long-term residents and which might just be passing through.Shade and her colleagues wanted to ask two questions: does the phyllosphere microbiome change across seasons; and, if so, what role does the soil play in the yearly dance between plants and microbes? To find out, they tapped miscanthus and switchgrass fields at MSU's Kellogg Biological Station in Hickory Corners, established in 2008 as part of a GLBRC biofuel cropping system experiment.Shade's lab members sampled microbial communities from bioenergy crop leaves every three weeks for one full growing season for miscanthus and two for switchgrass. They defined core microbes as those that consistently could be detected on leaves at the same time points across their fields, and that persistently appeared over sampling periods."If we found a microbe in one field, but not another, it couldn't be called a core member at that specific interval," she said. "We also expect these communities to change with the seasons, so we want to make sure we capture as many of those important taxa as possible."It turns out that many core microbes on bioenergy plant leaves originate in the soil and are fairly consistent across seasons. This means the phyllosphere microbiome can be targeted for cultivation, just like the crops on which they grow.The team identified hundreds of leaf microbiome members and compared them to thousands that live in the soil with a deep sequencing technique provided by the Joint Genome Institute, a Department of Energy Office of Science user facility."Because of our relationship to JGI, we were able to get some really good coverage of the diversity in our soil communities, something we couldn't have done on our own," Shade said.Some microbes found at consistent but low levels in the soil turned out to be core members of leaf communities."This suggests that the leaf environment is a specific habitat where certain organisms fit," Shade said. "The fact that we find them in the soil means the ground is a possible reservoir for these taxa."To evaluate the idea further, Shade and her team set up a statistical model to mimic results as if microbes were randomly distributed between a plant's leaves and the nearby soil, then compared the output to their real-life observations.The models showed that, indeed, the microbial community on miscanthus and switchgrass leaves aren't distributed by chance."They're not just randomly blowing onto leaves and sticking, so something in the environment is selecting for these taxa above the soil," Shade said. "Because the patterns on the ground are different than the ones we see on the leaves, there's reason to believe many of these core leaf members are there on purpose."The next step will be to home in on which of the core microbiome members have important functions for the plant."Now that we have a whole bunch of community data from the microbiome that includes thousands of taxa," Shade said, "we can understand which of these core members are just hanging out on the plant, and which ones have an impact on growth and health.""If we can understand how that microbial community is changing its interactions with its host over a season, we might be able to leverage that to benefit the plant," she added.
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Agriculture & Food
| 2,019 |
September 11, 2019
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https://www.sciencedaily.com/releases/2019/09/190911142742.htm
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Public support for gene drives in agriculture tied to limits
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The first national survey inquiring about American attitudes toward agricultural gene drives -- genetic modification techniques that can be used to "drive" a genetic trait or characteristic through a given insect pest population to help commercial crop production by squelching harmful pest effects -- shows more support for systems that are limited in scope and aimed at non-native insects.
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The survey of more than 1,000 American adults, conducted by researchers at North Carolina State University and the University of Wisconsin-Madison, can help inform further development of these gene drive systems in agriculture, an important consideration as the speed of technological development outpaces public understanding of the issues surrounding the technology.Zack Brown, assistant professor of agricultural and resource economics at NC State and the corresponding author of a paper describing the research, said that people were more apt to support gene drive systems that controlled the spread of the drive. He added that respondents also more strongly favored gene drives targeting non-native species; they had a harder time supporting genetic changes to native insects. More than 50% of respondents supported controlled gene drive systems targeting non-native species.Respondents also showed greater levels of support for gene drive systems that genetically alter an insect but leave it in the environment -- taking away its ability to carry a pathogen causing a crop disease, for example -- than systems meant to suppress or eradicate insect populations, although those differences were not large.Nearly 50% of respondents opposed uncontrolled gene drive systems that would eliminate native species, with another 25% showing neither opposition nor support."This is valuable information for scientists because controllability is difficult to design in gene drive systems," Brown said.Other survey findings included increased opposition to gene drive systems among people who seek out food labeled non-genetically modified. Interestingly, though, their support exceeded opposition for limited gene drive systems targeting non-native species.The research arose from a 2016 National Academies report that recommended gene drive research continue in parallel with ecological risk assessment and engagement with stakeholders and the public. Brown, lead author Michael Jones and coauthors realized that there was little to no published research on public perceptions of gene drive technology in an agricultural context."This is the right time -- while the technology is still under development and before any release decisions have been made -- to gain insights into what the public thinks, what types of information they prioritize from researchers, and who is trusted to carry out this sensitive research," said Jones, an NC State Ph.D. candidate in agricultural and resource economics. "Proactively incorporating this feedback into technology design and risk assessment helps align the science with public values and the needs of diverse economic ecosystems."The process began with in-person, open-ended discussions about gene drive technologies and their possible uses and drawbacks with groups of consumers recruited from grocery stores. This method of conducting focus group discussions helped identify and distill the most important questions to be asked in the Web survey questionnaire.Jason Delborne, associate professor of science, policy and society at NC State and co-author of the study, contributed to the design of the focus groups. "The focus groups provided a space for real conversations, where regular consumers learned about the potential for applying gene drives in agriculture and explored together their hopes and concerns. Inclusive deliberation about emerging technologies is a key foundation for responsible innovation," he said.The researchers used a Web-based questionnaire that allowed glimpses into how respondents interacted with information presented on gene drive systems and available FAQs. Jones said respondents spent a great deal of time looking through information when compared with other surveys."Maybe the fact that respondents went through a lot of research on our Web-based survey gave them a more nuanced perspective," Brown says. "That seems to be reflected in the survey responses."The study also showed public perceptions on which organizations to trust with research into gene drive systems. Universities and the U.S. Department of Agriculture were the most trusted, with more than 60% calling those organizations very or somewhat trustworthy. Respondents were less trusting of foreign universities and the U.S. Dept. of Defense; small and large private companies were least trusted."The public wants a trusted body to be a leader here," Brown said. "In this case, it's American universities and the USDA."
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Agriculture & Food
| 2,019 |
September 11, 2019
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https://www.sciencedaily.com/releases/2019/09/190911125117.htm
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Corn one step closer to bacterial leaf streak resistance
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Bacterial leaf streak, a foliar disease in corn, has only been in the United States for a handful of years, but Tiffany Jamann says it's a major problem in the Western Corn Belt.
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"We don't have hard numbers yet, but this pathogen in other systems can cause up to 20% yield losses," says Jamann, an assistant professor in the Department of Crop Sciences at the University of Illinois and co-author of a new study in the journal The disease-causing bacteria squirm in through open pores -- stomata -- on the leaf surface, then set up shop between veins to form long greyish streaks. Although no one has determined precisely what's happening inside the plant, Jamann says the necrotic lesions are disrupting the photosynthetic capacity of the leaf. And that hurts yield.To make matters worse, bacterial leaf streak looks similar to a fungal disease of corn, gray leaf spot. Farmers may confuse the two diseases and spray fungicide, which is not only ineffective, it's an unnecessary cost.Currently, there is no chemical control agent for bacterial leaf streak, and no completely resistant corn hybrids exist. But, in the By inoculating 26 diverse corn lines with the disease and selecting promising lines for further analysis, they found corn varieties with moderate resistance and genetic regions associated with increased levels of resistance."Although we didn't identify any large-effect resistance genes, the study is the first report of host resistance to bacterial leaf streak that has ever been published," Jamann notes.The team also looked for relationships between resistance to bacterial leaf streak and three other foliar diseases of maize, for which host resistance is better understood. The hope was that the same genes would also have an effect for bacterial leaf streak, but the relationships were not clear-cut."We find that the genetic architecture of resistance is complex, with lots of regions of the genome contributing to resistance," Jamann says.Although the researchers didn't identify a "smoking gun," the information provided in the study should still be useful to breeders in the process of developing new hybrids with resistance to bacterial leaf streak. And that's key."Management practices can only go so far in reducing losses due to this disease. You can't always control the conditions to avoid disease spread," Jamann says. "Ultimately host resistance is going to be critical."
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Agriculture & Food
| 2,019 |
September 11, 2019
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https://www.sciencedaily.com/releases/2019/09/190911113032.htm
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Conserving rare species for the maintenance of Mediterranean forests
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A study led by researchers from the Department of Plant Biology and Ecology at the University of Seville has shown the importance of conserving rare species for the maintenance of complex ecosystems like Mediterranean forests. Therefore, for these species, it becomes essential to understand the factors that make conservation successful. This research has been published in the review
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Specifically, this work focused on the pine forests in the Iberian Peninsula. Currently, these forests are exposed to threats that will worsen in the future, including the consequences of climate change (which are severe in this area of the Mediterranean) and disturbances caused by human beings (forest exploitation, expansion of farming, etc.)In the case study, the start of mining activity made it necessary to manage a pine forest, situated in Niebla (Huelva), near to the Doñana National Park. One of the species present in this forest system is a woodland carnation, Dianthus inoxianus. "It is not a very common plant, and is only present in this and other pine forests near the provinces of Huelva and Seville. It is always found in sandy soil. This carnation is officially catalogued as an endangered species and its uniqueness in numerous characteristics has been shown in previous studies. Due to this uniqueness, it probably has a key role in the ecosystem that it lives in, so it should be considered in any local conservation and restoration plan," states the University of Seville teacher Francisco Balao. For that reason, he adds, an experiment was carried out in a fenced-off area within the pine forest in the study, with the aim of understanding the best conditions for "translocating" it, that's to say, for planting it somewhere else as a means of conservation for this species of carnation.This study indicated that the success of translocation is limited by two periods of stress: the phase immediately after planting and the first summer. To survive these stages, the experts have shown that various factors are important, like having a mild climate during the first weeks and being properly watered until the end of the first summer. As for climate, radiation and temperature influenced the success of translocation. Also, the method of translocation had an effect on the results that were obtained. So, the situation is different if the plant is transported directly from its natural habitat or if it is brought from a greenhouse. Due to all this and evaluating the economic cost, the best options according to this University of Seville research group is to translocate plants in winter that have been picked directly from their habitat (without the need for watering) or, in spring, to translocate plants grown in a greenhouse and to water them until the end of the first summer.The use of this information will improve future conservation plans for Mediterranean pine forests and this species of endangered carnation.
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Agriculture & Food
| 2,019 |
September 11, 2019
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https://www.sciencedaily.com/releases/2019/09/190911113021.htm
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How can we feed the world without overwhelming the planet?
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Sustainable Development Goal (SDG) 2 calls for ending hunger, achieving food security and improved nutrition, and promoting sustainable agriculture. The environmental challenges posed by agriculture are however massive, and many fear that they will only become more pressing as we try to meet the growing need for food worldwide. IIASA researchers and colleagues from Japan propose alternative hunger eradication strategies that will not compromise environmental protection.
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Despite encouraging progress made in reducing the number of people that go hungry worldwide, one in nine people remain undernourished, more than 30 million children under the age of five are dangerously underweight, and poor nutrition is responsible for the deaths of nearly 3.1 million children under five each year. Across the globe, an estimated 821 million people were undernourished in 2017, and by 2050, the world will likely have two billion more mouths to feed. One approach to meeting the dietary needs of a rapidly growing world population is by increasing food production through agricultural intensification and expansion. This will however inevitably have negative effects on the environment such as air and water pollution, biodiversity loss, and increased greenhouse gas emissions. At the same time, it is well known that hunger is much more a result of unequal access to food across populations, even within single countries where undernourishment often coexists with obesity, rather than lack of agricultural production overall. This fact is however too often forgotten when hunger eradication strategies are being considered.In their study published in the journal The first alternative hunger eradication strategy explored in the study, focuses exclusively on bridging the nutrition gap of the undernourished population, which can be realized through targeted government support in the short-term. Such a strategy would include food and nutrition programs that provide food in-kind transfers, school-feeding programs, vouchers for food, income support programs, and safety-nets, without the need to wait for economic growth. This more immediate strategy is termed, support-led security. In this scenario, eradicating hunger by 2030, means providing sufficient food to an additional 410 million people who would otherwise remain undernourished under a business as usual scenario. When focusing on the undernourished only, the additional global agricultural production necessary would only be 3%, with corresponding limited negative effects on the environment.These negligible effects are in strong contrast with an alternative scenario, where hunger eradication is achieved through a general increase in food consumption typically associated with sustained economic growth leading not only to a reduction in the prevalence of undernourishment, but also to an increase in over-consumption. Apart from the fact that such a strategy would not allow the timely achievement of SDG2 (2030), as many decades of economic growth would be necessary, it would require a seven times higher (+20%) growth in food production. This would in turn require 48 Mha of additional agricultural land and also increase greenhouse gas emissions by 550 Mt CO2eq/year in 2030."This paper demonstrates that providing enough food to the undernourished requires an only marginal increase in overall agricultural production and thus also has very limited trade-offs with the environment. Undernourishment is indeed not a problem of agricultural production capacity but of the current economic and political system. This means that there are no good excuses not to tackle it," says Center Head for Environmental Resources Development and Deputy Program Director of the Ecosystems Services and Management Program at IIASA, Petr Havlik, who is one of the authors of the study.Additional analysis shows that if equity of food distribution is accompanied by a reduction in over-consumption and food waste, as well as improved agricultural intensification, undernutrition can be eradicated while at the same time reducing agricultural production, thus leading to multiple benefits for environmental sustainability."The required amount of food for hunger eradication and the negative impacts on the environment are much reduced by combining hunger eradication with improved equity in food distribution such as reduced food waste and over-consumption, together with agricultural research and development to increase crop yields in developing regions," says study lead-author Tomoko Hasegawa, a researcher at IIASA, Ritsumeikan University and NIES. "Our research shows that to achieve multiple goals, only one policy is not enough. We need to combine different policies to avoid unintended negative impacts on others. This implies that to end hunger without pressuring the environment, we need not only policies that address hunger, but also policies related to food waste and over-consumption, as well as ones related to agricultural research and development to increase crop yields in developing regions."
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Agriculture & Food
| 2,019 |
September 11, 2019
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https://www.sciencedaily.com/releases/2019/09/190911101525.htm
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Advanced breeding paves the way for disease-resistant beans
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For many people in Africa and Latin America, beans are an important staple. Historically described as "the meat of the poor," beans are rich in protein and minerals, affordable and suitably filling. That is why they are served daily, often with several meals.
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In many regions, however, plant diseases severely reduce bean yields. For example, the dreaded angular leaf spot disease can cause yield losses of up to 80 percent -- especially in Africa, where smallholders rarely have the opportunity to protect their crops with fungicides.Working with Bodo Raatz and his team at the International Center for Tropical Agriculture (CIAT), ETH researchers from the group led by Bruno Studer, Professor of Molecular Plant Breeding, investigated the resistance of beans to angular leaf spot disease. Their findings are now enabling disease-resistant bean varieties to be bred more rapidly and selectively for the world's various bean-producing regions.Their method is built upon genome analyses of those beans that are potentially suitable for breeding new, resistant varieties. The resulting genetic profiles provide information as to whether the progeny from crossbreeding two varieties will be resistant to the pathogenic fungus's different, locally occurring strains (known as pathotypes).Michelle Nay, who carried out the project as part of her doctoral thesis in Studer's group, started by gathering as many different bean seeds as possible from CIAT's seed repository. In total, she collected 316 different varieties that displayed characteristics suitable for breeding resistance to the fungus that causes angular leaf spot disease.Next, Nay planted the beans from her collection in Uganda and Colombia, both in greenhouses and in the field. Her aim was to find out if and indeed how the different varieties react to the fungus's various pathotypes in each country, and then to identify the genetic basis of disease resistance.Nay also created a high-resolution genetic profile for each of the 316 bean types based on variations in their DNA known as genetic markers, and identified which markers occurred only in the disease-resistant beans. She subsequently used these markers to predict which progeny would be resistant to which pathotypes in a given country, and which ones would be susceptible to disease."Our method speeds up the breeding process considerably," Studer says. It's a big step forward because crossbreeding had previously been a numbers game and involved testing every single plant for its resistance, he explains. Now, on the basis of a genetic test, it is possible to predict a plant's resistance without testing it in laborious field trials. "This is a huge help in bean breeding and great news for people who rely heavily on beans as a staple of their diet," Studer says.The group's work to provide disease-resistant beans will also help to cut down on global pesticide use. As things stand today, Studer explains, fungicide use is common for bean cultivation in Latin America, but almost non-existent in Africa because many farmers don't have access to pesticides, or don't know how to use them safely and efficiently: "Disease-resistant beans are a double win: famers in Latin America can reduce their pesticide use while farmers in Africa can increase their crop yield pesticide-free."CIAT distributes the seeds from this project to various sub-organisations who then supply them to breeders. The analytical method for determining genetic markers is relatively simple and inexpensive to apply, making it viable for use in agricultural laboratories in the countries concerned. It costs less than 0.2 CHF to test a genetic marker, Nay explains, which is an affordable amount for laboratories in less affluent countries. What's more, all the findings from this study are available through open access. "This way, our work reaches the people who really need these kind of resources," Nay emphasises.Nay and Studer worked on this project in close collaboration with CIAT. The global research centre runs the largest breeding programme in the tropics and has several thousand varieties of bean in its seed repository. At its headquarters in Colombia, CIAT breeds new bean varieties, tests the seeds, and, in partnership with the Pan-Africa Bean Research Alliance, makes the seeds available to farmers for cultivation.In collaboration with CIAT, Studer and his group will now conduct a follow-up project to refine their breeding method. While the researchers previously focused on markers for one specific disease, the new project will take a more holistic approach as they attempt to use such genome profiles to predict as many plant characteristics as possible.
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Agriculture & Food
| 2,019 |
September 11, 2019
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https://www.sciencedaily.com/releases/2019/09/190911091355.htm
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Swapping pollinators reduces species diversity
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University of Kansas plant biologists Carolyn Wessinger and Lena Hileman appreciate the sheer beauty of a field of colorful wildflowers as much as the next person. But what really gets their adrenaline pumping is understanding the evolutionary forces that render Earth's blooms in such a stunning array of shapes and hues.
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A lot of that diversity stems from the birds and the bees.Flowers depend on these and other pollinators to reproduce, and they can adapt strategically to attract these creatures -- sometimes altering their traits so dramatically that they lure an altogether new pollinator.But not all such strategies are created equal. In a new paper published in "Approximately 35% of the world's crop species rely on animal pollinators for productivity," said Hileman, professor of ecology & evolutionary biology. "Diverse natural communities of flowering plants and associated pollinators contribute to maintenance of pollinator populations important for crop reproduction."The KU study focused on Penstemon, a genus commonly known as beardtongues. Most of the nearly 300 Penstemon species in North America are pollinated by bees, indicating a successful long-term partnership. But more than 15 lineages of this perennial wildflower have switched to attract hummingbird pollinators instead of bees."Because Penstemon has ditched bees for hummingbirds so many times, it is an ideal group of plants to examine the long-term consequences of switching to hummingbird pollination," said Wessinger, a postdoctoral fellow in Hileman's lab. "In a sense, nature has provided us with a large number of replicated experiments to study."Those experiments reveal that once a branch of the Penstemon family tree shifts to hummingbird pollination -- perhaps because bees have become less abundant or reliable pollinators -- the evolution of new species on that branch slows or stops.To demonstrate this pattern, the KU scientists collected and sequenced DNA representing the entire genome from about 100 related species of Penstemon, then reconstructed their relationships in a phylogenetic tree with common ancestors at its roots. The results surprised them: Any time a hummingbird-pollinated species emerged on the tree, it appeared alone or with just one or two other hummingbird-adapted species."This makes hummingbird pollination a surprisingly rare trait across the sampled Penstemon species, given the large number of times this pollination switch has occurred -- 17 times in our sample," Wessinger said.To make the flight from bee to hummingbird, Penstemon change in substantial ways. Think of it as a courtship story: Bee meets flower. Flower boasts bluish to purple petals visible to bee's eyes and a short, open structure ideally suited to accommodate a stocky insect seeking nectar. The flower's stamen are positioned to deposit pollen on the bee's back when it lands.Pollination ensues. Ecosystem lives happily ever after.Until nature introduces a plot twist. Over evolutionary time -- thousands to millions of years -- red flowers evolve, with long tubular petals and production of more nectar than the bee needs. The spark is gone.But these new traits lure a different suitor. Hummingbird zips in craving a huge energy reward to fuel its hyper-speedy metabolism. It sips nectar through its long tongue while hovering -- no landing platform required. Romance blossoms anew.So what keeps hummingbird-pollinated Penstemon from continuing to form new species once they've made this transition?Perhaps the switches have occurred so recently that there simply hasn't been enough time for hummingbird-pollinated species to become more common, the researchers posited. Through state-of-the-art statistical modeling, though, they ruled out that theory."Our findings indicate that the type of pollinator a flowering plant species relies upon will impact how likely that flowering plant lineage is to persist over long periods of evolutionary time," Hileman said. "This result suggests that the fact that we see so many insect-pollinated plants in nature is partly because they are highly successful at speciating and resisting extinction compared to hummingbird-adapted flowering plants."One question the study leaves unanswered is why the hummingbird strategy reduces diversity. The researchers have a few theories that they hope to explore next. Their favorite? Species diversification often occurs because groups of flowers become isolated from one another by a canyon or mountain, for example. As the split populations experience different selective pressures over time, they might adapt and diverge enough to form new species."Perhaps hummingbirds move pollen great distances in the course of their seasonal migrations," Wessinger said. "Such long-distance pollination could help maintain genetic connections between geographically distant populations, hindering the speciation process."Interestingly, similar studies conducted in tropical regions have produced opposite results. Hummingbird pollination in those areas has been linked to similar or higher diversification rates than bee pollination."I think that might have to do with differences in hummingbird behavior in the tropics versus North America," Wessinger said. "Tropical hummingbirds can often be territorial, taking up residence in a certain patch of flowers and keeping competitors at bay. They might not be moving great distances between plants."Wessinger and Hileman's study is part of a broader body of research supported by $2.5 million in grants from the National Science Foundation. The funding is helping them and a Duke University collaborator dig deeper into the genetic processes that shape the complex bee-adapted and hummingbird-adapted flowers of Penstemon.As they begin to explore why hummingbird pollination reduces diversity in Penstemon, they'll need to collect samples from geographically isolated species in the wild. Wessinger is excited to get out of the lab and into the field, where the thrill of discovery awaits."There's so much adrenaline," she said of searching for native flowers. "If I can't find a population, I get really frustrated. You're camping at high elevations; maybe you're not sleeping great. Everything feels overly emotional. But when you find what you're looking for, then it's just elation."
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Agriculture & Food
| 2,019 |
September 10, 2019
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https://www.sciencedaily.com/releases/2019/09/190910194251.htm
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Every time the small cabbage white butterfly flaps its wings it has us to thank
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The caterpillar form of an unassuming, small, white butterfly is among the world's most invasive pests affecting agricultural crops, and a newly published paper by a consortium of scientists documents how humans have helped it spread for thousands of years.
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Through close examination of genetic variation and similarities between existing populations, and comparisons of historical data regarding infestations of Pieris rapae in Brassicaceae crops -- like cabbage, canola, bok choy and turnips -- the researchers document how humans helped the small cabbage white butterfly spread from Europe across the world. Led by Sean Ryan, formerly a postdoctoral researcher in the Department of Entomology and Plant Pathology at the University of Tennessee Institute of Agriculture, the team of scientists from eight institutions partnered with more than 150 volunteer citizen scientists from 32 countries to detail the pest's range and current genetic diversity.Published online on September 10, 2019, in the "The success of the small cabbage white butterfly is the consequences of human activities. Through trade and migration humans humans helped to inadvertently spread the pest beyond its natural range, and through the domestication and diversification of mustard crops, like cabbage, kale and broccoli, humans provided it with the food its caterpillars would need to flourish," says Ryan.Prior to the study, historical records provided some indication of when this agricultural pest arrived in each new continent it invaded. However, the timing, sources, and routes remained unsolved. What's more, such detailed knowledge is crucial in developing an effective biological control program as well as for answering basic questions associated with the invasion process, such as genetic changes and how species adapt to new environments.The research team took to social media to ask the public for help. The approach was similar to how researchers have been expanding our understanding of human ancestry through in-home DNA sampling kits. Instead of asking people to swab their cheek, the butterfly research team asked citizen scientists to grab a butterfly net, then catch and send small cabbage white butterflies to the team for genetic testing. Ryan, currently with Exponent, Inc., in Menlo Park, California, then used the DNA from the submitted specimens to analyze genetic data and determine how the small cabbage white spread across the world. More than 3,000 butterflies were submitted. The samples cover nearly the entire native and invaded ranges of the butterfly and comprise 293 localities.The researchers found that the small cabbage white butterfly likely originated in eastern Europe and then spread into Asia and Siberia when trade was increasing along the Silk Road. The researchers also found that, as expected, Europe was responsible for the introduction of the small cabbage white to North America. Surprisingly, the introduction into New Zealand came from San Francisco, California. Also, the butterflies living in central California and the surrounding area are genetically distinct from all other butterflies in North America and appear to be the consequence of a few butterflies hitching a train ride from the eastern U.S. to San Francisco. Although each invasion into a new area or country led to significant loss of genetic diversity, the invasions were successful, hence the abundance of small cabbage white butterflies today.Citizen science -- research in which members of the public play a role in project development, data collection or discovery -- is subject to the same system of peer review as conventional science. Its power lies in its ability to help conventional studies overcome challenges involving large spatial and temporal scales. Social media and the internet are key tools that allow citizen scientists, who are often share similar interests through memberships in nature-based groups or professional societies, enhance the scale and scope of a particular project and its impact on society."Citizen science projects have been growing exponentially over the last decade, opening doors to new scientific frontiers and expanding the limits of what was once feasible," says DeWayne Shoemaker, professor and head of the UT Department of Entomology and Plant Pathology, and one of the paper's co-authors. "The relatively unique approach we took was asking the public to help collect -- not just observe -- these agricultural pests, and in so doing we were able to extract information recorded within the DNA of each individual butterfly. That information, when aggregated, told a story about the collective past of the small cabbage white butterfly.""The international success of our citizen science project -- the Pieris Project -- demonstrates the power of the public to aid scientists in collections-based research addressing important questions in invasion biology, and ecology and evolutionary biology more broadly," says Ryan. He believes the use of collection-based citizen science projects will help society more accurately document ecological and evolutionary changes, which can lead to improvements in crop management and success as well as better environmental controls for invasive species.
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Agriculture & Food
| 2,019 |
September 10, 2019
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https://www.sciencedaily.com/releases/2019/09/190910105353.htm
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Earliest evidence of milk consumption found in teeth of prehistoric British farmers
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Researchers have found the earliest direct evidence of milk consumption anywhere in the world in the teeth of prehistoric British farmers.
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The research team, led by archaeologists at the University of York, identified a milk protein called beta lactoglobulin (BLG) entombed in the mineralised dental plaque of seven individuals who lived in the Neolithic period around 6,000 years-ago.The human dental plaque samples in the study are the oldest to be analysed for ancient proteins to date globally and the study represents the earliest identification of the milk whey protein BLG so far.The Neolithic period in Britain ran from 4,000 to 2,400 cal. BC and saw the emergence of farming, with the use of domesticated animals such as cows, sheep, pig and goats, alongside crops such as wheat and barley. Archaeologists have also discovered evidence of complex cultural practices, with Neolithic communities building large monumental and burial sites.The ancient human remains tested in the study come from three different Neolithic sites -- Hambledon Hill and Hazleton North in the south of England, and Banbury Lane in the East Midlands. Individuals from all three sites showed the presence of milk proteins from cows, sheep or goats, suggesting people were exploiting multiple species for dairy products.Dental plaque can offer unique insights into the diets of ancient people because dietary proteins are entrapped within it when it is mineralised by components of saliva to form tartar or 'dental calculus'.Lead author of the study, Dr Sophy Charlton, from the Department of Archaeology at the University of York, said: "The fact that we found this protein in the dental calculus of individuals from three different Neolithic sites may suggest that dairy consumption was a widespread dietary practice in the past."It would be a fascinating avenue for further research to look at more individuals and see if we can determine whether there are any patterns as to who was consuming milk in the archaeological past -- perhaps the amount of dairy products consumed or the animals utilised varied along the lines of sex, gender, age or social standing."The discovery of milk proteins is particularly interesting as recent genetic studies suggest that people who lived at this time did not yet have the ability to digest the lactose in milk. To get around this, the ancient farmers may have been drinking just small amounts of milk or processing it into other foodstuffs such as cheese (which removes most of the lactose), the researchers say.'Lactase persistence', which allows for the continued consumption of milk into adulthood, is the result of a genetic mutation in a section of DNA that controls the activity of the lactase gene. However, the mechanisms behind how and when we evolved this ability remain a mystery.Dr Charlton added: "Because drinking any more than very small amounts of milk would have made people from this period really quite ill, these early farmers may have been processing milk, perhaps into foodstuffs such as cheese, to reduce its lactose content.""Identifying more ancient individuals with evidence of BLG in the future may provide further insights into milk consumption and processing in the past, and increase our understanding of how genetics and culture have interacted to produce lactase persistence."
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Agriculture & Food
| 2,019 |
September 9, 2019
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https://www.sciencedaily.com/releases/2019/09/190909121247.htm
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Lack of reporting on phosphorus supply chain dangerous for global food security
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Our global food production system uses 53 million tonnes of phosphate fertilizers annually, processed from 270 million tonnes of mined phosphate rock . Estimates show up to 90% phosphate loss from mine to fork . A considerable part of this loss is phosphate pollution in water, some of which creates "dead zones," areas where little or no marine life can survive. With an increase in food demand by 60% towards 2050, our food production system will need even more phosphate fertilizers. But where do the fertilizers come from and where do they go?
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UN estimates a population increase to 9 billion by 2050, correlated with a 60% increase in food demand. In a world where almost a billion people are undernourished and where we waste up to half of all food we produce, this will pose new challenges to our global food supply chain and production system. A key variable for food production is the supply of phosphate fertilizers, most of which come from the mining and processing of phosphate rock. Only a handful of countries produce and export phosphate rock and phosphate fertilizers in a phosphate market that is tending towards a Moroccan monopoly. The later stages of the supply chain also see up to 90% losses and the transformation of phosphorus from a valued resource into one of the main causes for eutrophication.A new study conducted at Stockholm University and the University of Iceland shows that while Phosphorus is a key element to global food security, its supply chain is a black box. This can lead to social, political and environmental issues, which in turn can create phosphorus supply crises. The results are published in the article "Opening access to the black box: The need for reporting on the global phosphorus supply chain" in "Cradle-to-grave reporting along the phosphorus supply chain can reveal the untold story about the social, environmental, ethical and economic price we pay for the food we see on our supermarket shelves. It can also help countries -- most of which are dependent on phosphate imports -- tailor better policies to decrease the vulnerability of their agricultural sector" says Eduard Nedelciu, researcher at the Department of Physical Geography at Stockholm University and main author of the study.The study, which is part of a larger European research project called Adaptation to a new Economic Reality identifies four main challenges with reporting on phosphorus and phosphate fertilizers. First, terminologies and methodologies that are used to report on phosphate deposits are not harmonized and sometimes not transparent -- this makes estimations of reserves and resources inaccurate and unreliable. Second, the phosphorus supply chain has up to 90% losses, which are poorly documented. Losses occur along all segments of the supply chain and this fragmentation of information makes it hard to accurately report on how much is lost and where. Better reporting could help design methods to decrease losses and increase efficiency. Third, there are environmental and social consequences occurring along the supply chain of phosphorus. For example, mining and processing phosphate rock is polluting water bodies and is dangerous to human health. Moreover, the phosphorus that leaks from agricultural land and sewage systems into the water can cause eutrophication and the so-called "dead-zones": areas in our oceans and seas where life cannot be supported anymore. But there is a social and ethical aspect to phosphorus too. Phosphate rock is increasingly mined from contested areas, such as Western Sahara, in what has been described by some as "illegal exploitation." Fourth, open access to data along the phosphorus supply chain is lacking. The authors reinforce the idea that public knowledge on phosphorus and its supply chain is necessary due to its direct link to food, a basic human right. Also, reporting on phosphorus can help better assess progress on a number of global indicators for sustainability, such as the Sustainable Development Goals.Marie Schellens puts the study into perspective: "Phosphorus information is power. Reliable and regular data gathering can leverage corporate social responsibility as well as political action. Both are needed to tackle many of the issues identified along the supply chain. Transparency can foster a sustainable and socially just supply chain for decades to come."
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Agriculture & Food
| 2,019 |
September 6, 2019
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https://www.sciencedaily.com/releases/2019/09/190906172458.htm
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Not all meat is created equal: How diet changes can sustain world's food production
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If you wanted to really mess with the world's food production, a good place to start would be in Morocco. They don't grow much here, but it is home to mines containing most of the world's known reserves of phosphate rock, the main source of the nutrient phosphorus. Most of us across the globe, most days, will eat some food grown on fields fertilized by phosphate rock from these mines.
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Phosphorus is an essential mineral to grow food, but research suggests that this is being mined unsustainably. If reserves run low, food production will be constrained and starvation entirely possible.Now, David Vaccari, an environmental engineer at Stevens Institute of Technology, and colleagues have developed a model to describe how phosphorus flows through the global food system. The model, reported in the Sept. 4 issue of "Phosphate is spread across the planet but hardly recycled," said Vaccari, a pioneer in phosphate research who led the work. "The model allows us to answer specific 'what if' questions to see how certain changes in human behavior could significantly improve the conservation of this resource and by extension, help sustain the world's food production."In the past, the phosphorus cycle was practically closed: crops were eaten by humans and livestock while their feces were used as natural fertilizers to grow crops again. These days, the cycle is broken. Each year phosphate rocks are mined and turned into fertilizer. This is converted into crops which are transported to cities for food. Some phosphorus is lost at every step along the way and winds up in the environment. Runoff from farms goes into waterways, food waste goes to landfills, and the human waste goes to the sewage disposal, most of which ultimately ends up in the sea. A cycle has become a linear process.Vaccari and colleagues model this cycle, with "knobs" that can be turned up or down to create different conservation scenarios. When a knob is turned -- e.g. fraction of animal meat in diet, fraction of food that is wasted, fraction of human waste recycled -- the model, which factors in leaks and losses from the food system, loops back to calculate the degree to which phosphate mining could be reduced.The model shows several interesting results:The world, however, is not about to run out of phosphorus. At current usage rates, known phosphorus reserves could sustain agricultural production for several centuries, according to Vaccari. But unlike nitrogen, which makes up 78 percent of the atmosphere (and a main ingredient in fertilizer), phosphate is a finite resource -- and "new sources of phosphorus will be hard to come by," said Vaccari.Reducing phosphate mining has other advantages. When phosphorus "leaks" from the agricultural, food production and waste disposal systems, it contributes to severe water pollution problems such as harmful algal blooms in lakes and in the coastal zone. Aside from the long known public health issues and economic impact of algal blooms in fishing communities, a deadly variety of algae has recently caused several dog deaths in the Southern United States."Phosphorus is essential for life," said Vaccari. "So the plan is to keep it around for a long time by mining phosphate sustainably and responsibly -- and this model helps us look at optimal ways on how to do that."
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Agriculture & Food
| 2,019 |
September 4, 2019
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https://www.sciencedaily.com/releases/2019/09/190904130651.htm
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Super shrimp could increase yield and prevent human disease
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Single-sex prawns could help alleviate poverty, reduce disease and protect the environment, according to researchers at Ben-Gurion University of the Negev (BGU) who have developed a monosex prawn that may make this winning trifecta possible.
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In a groundbreaking study in Nature's To achieve an efficient biotechnology for all-female aquaculture in the economically important prawn (Macrobrachium rosenbergii), the researchers achieved -- for the first time -- WW males using androgenic gland cells transplantation which caused full sex-reversal of WW females to functional males. Crossing the WW males with WW females yielded all-female progeny lacking the Z chromosome.The research is being conducted by BGU Prof. Amir Sagi, who also serves as a member of the National Institute for Biotechnology in the Negev (NIBN), and his Ph.D. student, Tom Levy, in collaboration with Enzootic, a Beer-Sheva, Israel-based startup company specializing in all-female monosex aquaculture biotechnologies."We were able to achieve the monosex population without the use of hormones or genetic modifications and thus address two major agricultural considerations: monosex populations and ecological concerns," says Levy. "Prawns serve as efficient biocontrol agents against parasite-carrying snails. And since we can now use monosex prawns, which do not reproduce, it reduces the hazard of prawns becoming an invasive species."The publication follows a study published in July in "With monosex prawns at profit-maximizing densities, the prawns substantially reduce intermediate host snail populations and aid schistosomiasis control efforts," says Prof. Sagi. "Integrated aquaculture-based interventions can be a win-win strategy in terms of health and sustainable development in schistosomiasis endemic regions of the world."Schistosomiasis is an acute and chronic disease caused by parasitic worms that can result in severe abdominal pain, diarrhea and blood in the stool. In women, urogenital schistosomiasis may present with genital lesions, vaginal bleeding, pain during sexual intercourse, and nodules in the vulva. In men, urogenital schistosomiasis can induce pathology of the seminal vesicles, prostate and other organs. The World Health Organization estimates that at least 220.8 million people each year require preventive treatment for the disease.In this study, Prof. Sagi and Dr. Amit Savaya of BGU joined forces with a large team of researchers around the world headed by Prof. Giulio De Leo of Stanford University to outline control strategies, drawing on both prawn aquaculture to reduce intermediate host snail populations and mass drug administration to treat infected individuals. Integrating both methods is found to be superior to either one alone.
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Agriculture & Food
| 2,019 |
September 3, 2019
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https://www.sciencedaily.com/releases/2019/09/190903105223.htm
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Birds in serious decline at Lake Constance
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At first glance, the numbers recorded between 1980 and 2012 appear to be quite balanced. 68 of the 158 bird species that inhabit the area around Lake Constance became more populous, while 67 species declined; each of these figures approximates to 43 percent of all the bird species in the region. The total number of species has even increased slightly: although eight species have died out, 17 have either returned to the region or settled there for the first time. These include the white stork, the peregrine falcon and the eagle owl, all of which have benefitted particularly from the protective measures put in place.
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This seeming contradiction is due to the fact that the most common species are disappearing particularly rapidly. Six of the ten most common bird species around Lake Constance have declined dramatically in number, while two have remained the same and only two have increased. The population of house sparrows, for example, has declined by 50 percent since 1980, at which time it was still the most common species. "These are really shocking figures -- particularly when you consider that the bird population started declining decades before the first count in 1980," explains Hans-Günther Bauer from the Max Planck Institute of Animal Behavior. Viewed over a lengthier period, the fall in numbers may therefore be even greater.It is particularly noticeable how differently the various habitats have been affected. The study indicates that bird populations around Lake Constance are dwindling particularly rapidly in countryside, which is intensively used by humans. This applies above all to modern farmland: 71 percent of the species that inhabit fields and meadows have declined in numbers, in some cases drastically. The partridge, for example, which was once a common inhabitant of the region's farmland, has completely died out around Lake Constance. The great grey shrike, the meadow pipit and the little owl have also disappeared from the area.One of the main reasons for this decline is the scarcity of food. According to the ornithologists, 75 percent of the bird species that eat flying insects and 57 percent of those that eat terrestrial invertebrates have decreased in number around Lake Constance. "This confirms what we have long suspected: the human extermination of insects is having a massive impact on our birds," says Bauer. In addition, today's efficient harvesting methods leave hardly any seeds behind for granivorous species. Moreover, the early, frequent mowing of large areas of grassland, the agricultural practice of monoculture, the early ripening of winter grains, the implementation of drainage measures and the shortage of fallow land are destroying the habitats of many species that live in the open countryside.However, the birds are disappearing not only from the fields and meadows but also from the towns and villages around Lake Constance. "The increasing need for order and decreasing tolerance of dirt and noise are making life more and more difficult for local birds. It appears that successful breeding is becoming increasingly rare since the birds are being forced to nest amid tower blocks, ornamental trees and immaculate kitchen gardens," says Bauer. Even species that can survive virtually anywhere, such as blackbirds (down 28 percent), chaffinches and robins (each down 24 percent) are suffering greatly due to the deteriorating conditions in settled areas.In contrast, the woodland birds around Lake Constance appear to be doing comparatively well. 48 percent of the forest-dwelling species are increasing in number, while only 35 percent are dwindling. One example is the spotted woodpecker, whose numbers have grown by 84 percent. Like other woodpeckers, it seems to have benefited from the larger quantities of timber in the forest. Furthermore, more of the species that inhabit the wetlands around Lake Constance have increased than decreased. The winners here include the mute swan.Nevertheless, the numbers of many forest-dwelling species are also declining. The wood warbler population, for example, has fallen by 98 percent, firecrest numbers by 61 percent. This is how the intensive use of timber around Lake Constance and the shorter felling intervals are making themselves felt. Trees containing nests are being felled even in protected areas, and breeding seasons are largely being ignored. Older trees are often felled for traffic safety reasons; new paths are laid in the forests and wet areas are drained.All in all, the last population count in 2010-2012 documents the same developments and causes as those that preceded it. However, the situation has clearly worsened in some cases. There is hardly any indication that things have changed for the better since then. "The living conditions for birds around Lake Constance have in fact deteriorated further over the last seven years. This means that their numbers have presumably fallen still further in this time," says Bauer.With its diverse structure and location in the foothills of the Alps, the Lake Constance region actually provides excellent living conditions for birds. However, the changes it has undergone over the last few decades are typical of densely populated regions with intensive farming and forestry. "This means that the rapid decline in the populations of many species that we have observed around Lake Constance is sure to be happening in other regions as well," says Bauer.The study is one of only a few long-term investigations of breeding bird populations ever conducted in Germany. In order to collect the most recent data, which dates from between 2010 and 2012, 90 volunteers joined the scientists and counted all the birds in an area of approximately 1,100 square kilometres surrounding Lake Constance. The ornithologists first recorded the bird population between 1980 and 1981 and have repeated the count every ten years ever since. The next count will take place between 2020 and 2022.- The scientists are calling for agricultural and forestry policy to be reconsidered in order to counteract the rapid loss of biodiversity.- Drastically restricting the use of insecticides and herbicides in forestry and agriculture, in public spaces and in private gardens- Significantly reducing the use of fertilisers- Converting at least ten percent of agricultural land to ecological conservation areas- Leaving some areas of arable land and grassland uncultivated in winter and during the breeding season- Late mowing outside the grassland birds' breeding season, maintenance of flower strips and fallow areas for seed production- At least five percent of woodland should be left completely unused- Creating natural gardens using indigenous plants
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Agriculture & Food
| 2,019 |
September 2, 2019
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https://www.sciencedaily.com/releases/2019/09/190902113623.htm
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Impact of climate change on global banana yields revealed
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Climate change could negatively impact banana cultivation in some of the world's most important producing and exporting countries, a study has revealed.
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Bananas are recognised as the most important fruit crop -- providing food, nutrition and income for millions in both rural and urban areas across the globe.While many reports have looked at the impact of climate change on agricultural production, the effect rising temperatures and changing rainfall has on crucial tropical crops such as the banana are less well understood.In a new study, led by Dr Dan Bebber from the University of Exeter, scientists have studied both the recent and future impact of climate change on the world's leading banana producers and exporters.It shows that 27 countries -- accounting for 86 per cent of the world's dessert banana production -- have on average seen increased crop yield since 1961 due to the changing climate resulting in more favourable growing conditions.However, crucially the report also suggests that these gains could be significantly reduced, or disappear completely, by 2050 if climate change continues at its expected rate.It suggests that 10 countries -- including the world's largest producer and consumer of banana India and the fourth largest producer, Brazil -- are predicted to see a significant decline in crop yields.The study does highlight that some countries -- including Ecuador (the largest exporter) and Honduras, as well as a number of African countries -- may see an overall benefit in crop yields.Dr Bebber, a Senior Lecturer in Biosciences at the University of Exeter said: "We're very concerned about the impact of diseases like Fusarium Wilt on bananas, but the impacts of climate change have been largely ignored. There will be winners and losers in coming years, and our study may stimulate vulnerable countries to prepare through investment in technologies like irrigation."Grown throughout the tropics and subtropics, bananas are a key crop for millions of people across the world. In Britain, for example, more than five billion bananas are purchased each year, and the UK accounts for seven per cent of the global export market.Such international trade can play a pivotal role to local and national economies in producing countries. For example, bananas and their derived products constitute the second largest agricultural export commodity of Ecuador and Costa Rica.Given this importance, predicting the potential impacts of climate change on banana production systems is crucial to ensuring its long-term survival.In this new study, the team assessed the climate sensitivity of global dessert banana productivity or yield using sophisticated modelling techniques.It showed that by 2050, any positive effects of climate change on average global banana yields, though likely to continue, will be significantly lessened.Ten countries are predicted to show at least a negative trend, if not strong declines in yields. These include some of the largest producers such as India and Brazil, as well as Colombia, Costa Rica, Guatemala, Panama and the Philippines, all of which are major exporters.Dr Bebber added: "It is imperative that we invest in preparing tropical agriculture for future climate change."Dr Varun Varma, Research Fellow at the University of Exeter and an author of the study said: "An open exchange of ideas is going to be critical going forward. We believe practical solutions already exist, but these are scattered across banana producing countries. This knowledge exchange needs to start now to counteract predicted yield losses due to climate change."Climate change impacts on banana yields around the world is published in
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Agriculture & Food
| 2,019 |
August 30, 2019
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https://www.sciencedaily.com/releases/2019/08/190830150757.htm
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Researchers determine pollen abundance and diversity in pollinator-dependent crops
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A new study provides valuable insights into pollen abundance and diversity available to honeybee colonies employed in five major pollinator-dependent crops in Oregon and California, including California's massive almond industry.
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The study, a collaboration between OSU and Texas A&M University, found that almond, cherry and meadowfoam provide ample pollen to honeybees, but highbush blueberry and hybrid carrot seed crops may not. In addition, California almonds don't provide as much pollen diversity as other crops, according to the findings, published in the The western honeybee is the major pollinator of fruit, nut, vegetable and seed crops that depend on bee pollination for high quality and yield. The findings are important because both pollen abundance and diversity are critical for colony growth and survival of the western honeybee, said study corresponding author Ramesh Sagili, associate professor of apiculture and honeybee Extension specialist in OSU's College of Agricultural Sciences."Pollen diversity is important for the growth and development of bees, and low amounts of pollen availability to honeybee colonies can dramatically affect brood rearing," Sagili said. "Beekeepers that employ their colonies for pollination of crops like hybrid carrot seed and highbush blueberry should frequently assess the amount of pollen stores in their colonies and provide protein supplements if pollen stores are low."Nectar and pollen provide essential nutrients for honeybees. A honeybee colony's protein source is pollen, which has varying amounts of amino acids, lipids, vitamins and minerals. These nutrients obtained from pollen are essential for honeybee larval development. Pollen largely contributes to the growth of fat bodies in larvae and egg development in the queen.Well-nourished individuals in a honeybee colony are able to withstand the effects of other stressors such as parasites and insecticides, in addition to the long-distance transport of colonies known as "migratory management." Bees are trucked across the county to pollinate various cropping systems -- more than 1 million hives are transported to California each year just to pollinate almonds.A diet low in pollen diversity hurts a colony's defense system, which consequently increases disease susceptibility and pesticide sensitivity. During critical crop bloom periods, growers rent large numbers of honeybee colonies to pollinate their crops. Approximately 2.5 million commercially managed honeybee colonies are used for crop pollination in the United States every year.Some cropping systems may put bees at risk for temporary nutritional deficiency if the crop plant's pollen is deficient in certain nutrients and bees are unable to find an alternative source of these nutrients, Sagili said."It's crucial for beekeepers and crop producers to understand the pollen abundance and diversity that honeybees encounter during crop pollination," he said, adding that blueberry and hybrid carrot seed producers can mitigate nutritional deficiencies by providing supplemental food or forage, including commercially available protein supplements for bees.Renting colonies to growers for pollination services is a significant source of income for commercial beekeepers, but it also requires them to repeatedly transport the colonies between crops throughout the growing season. In this study, the research team collaborated with 17 migratory commercial beekeepers for pollen collection from honeybee colonies in five different cropping systems from late February to August of 2012.They installed pollen traps on at least five colonies at each site and collected pollen from the colonies at the height of the blooming season. They found that California's vast almond footprint -- 1 million acres and counting -- provides more than enough pollen for the nearly 2 million honeybees employed to pollinate the orchards, but pollen diversity was low when compared with other crops."We think the reason for that is almonds bloom early in the year when there are so few plant species in bloom, so bees have few other forage options and primarily rely on almond pollen," Sagili said. "There are parts of the northern and southern ends of California's San Joaquin Valley where there are no other crops in bloom when almond trees bloom, which may further contribute to poor availability of diverse pollen."
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Agriculture & Food
| 2,019 |
August 29, 2019
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https://www.sciencedaily.com/releases/2019/08/190829184143.htm
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Suggested move to plant-based diets risks worsening brain health nutrient deficiency
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The momentum behind a move to plant-based and vegan diets for the good of the planet is commendable, but risks worsening an already low intake of an essential nutrient involved in brain health, warns a nutritionist in the online journal
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To make matters worse, the UK government has failed to recommend or monitor dietary levels of this nutrient -- choline -- found predominantly in animal foods, says Dr Emma Derbyshire, of Nutritional Insight, a consultancy specialising in nutrition and biomedical science.Choline is an essential dietary nutrient, but the amount produced by the liver is not enough to meet the requirements of the human body.Choline is critical to brain health, particularly during fetal development. It also influences liver function, with shortfalls linked to irregularities in blood fat metabolism as well as excess free radical cellular damage, writes Dr Derbyshire.The primary sources of dietary choline are found in beef, eggs, dairy products, fish, and chicken, with much lower levels found in nuts, beans, and cruciferous vegetables, such as broccoli.In 1998, recognising the importance of choline, the US Institute of Medicine recommended minimum daily intakes. These range from 425 mg/day for women to 550 mg/day for men, and 450 mg/day and 550 mg/day for pregnant and breastfeeding women, respectively, because of the critical role the nutrient has in fetal development.In 2016, the European Food Safety Authority published similar daily requirements. Yet national dietary surveys in North America, Australia, and Europe show that habitual choline intake, on average, falls short of these recommendations."This is....concerning given that current trends appear to be towards meat reduction and plant-based diets," says Dr Derbyshire.She commends the first report (EAT-Lancet) to compile a healthy food plan based on promoting environmental sustainability, but suggests that the restricted intakes of whole milk, eggs and animal protein it recommends could affect choline intake.And she is at a loss to understand why choline does not feature in UK dietary guidance or national population monitoring data."Given the important physiological roles of choline and authorisation of certain health claims, it is questionable why choline has been overlooked for so long in the UK," she writes. "Choline is presently excluded from UK food composition databases, major dietary surveys, and dietary guidelines," she adds.It may be time for the UK government's independent Scientific Advisory Committee on Nutrition to reverse this, she suggests, particularly given the mounting evidence on the importance of choline to human health and growing concerns about the sustainability of the planet's food production."More needs to be done to educate healthcare professionals and consumers about the importance of a choline-rich diet, and how to achieve this," she writes."If choline is not obtained in the levels needed from dietary sources per se then supplementation strategies will be required, especially in relation to key stages of the life cycle, such as pregnancy, when choline intakes are critical to infant development," she concludes.
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Agriculture & Food
| 2,019 |
August 29, 2019
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https://www.sciencedaily.com/releases/2019/08/190829152017.htm
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Crouching lion, hidden giraffe
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The behavior of giraffe groups with calves is influenced more strongly by the risk of predators than is the behavior of all-adult groups, which is mostly determined by the availability of food. An international team of researchers from Penn State and the University of Zürich studied giraffe behavior in a 2,000 square kilometer region of Africa and pinpointed some of the special requirements needed by mother giraffes to keep their babies safe. A paper describing the research, which can help land managers to protect the habitats most important for giraffes, appears online in the journal
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"Like all herbivores, giraffes need to find quality food to survive, but also need to avoid lions, or at least see them coming," said Monica Bond, PhD candidate from the University of Zürich and lead author of the paper. "Giraffes in our huge, unfenced study area can choose from among many different places to spend their time -- places with different kinds of trees and bushes, places deep inside protected parks, or places closer to farming towns or ranchlands where people live. There are lots of options in this landscape, including fewer lions outside the parks versus inside. So, we wondered how do these options influence giraffe grouping behavior?"The study found that groups composed of only adult giraffes were food-focused and not affected by predation risk. These adult groups formed the largest groups -- up to 66 individuals -- in the rainy season when food is plentiful, but formed smaller groups during the dry season when food is harder to find. In contrast, predation risk was a very important factor influencing groups of giraffes with calves."Giraffe calves are vulnerable to being killed by lions and other carnivores, while adults are typically large enough to escape predation," said senior author Barbara König, professor at the University of Zürich. "We were testing hypotheses about mother and calf behavior to see if their strategy was for calves to hide in thick bushes to avoid predators, be in the open to see predators coming, or be in large groups for many eyes and lower individual risk."The researchers showed that in areas with the most lions, groups with calves were found more often in dense bushes than in open grasslands, and that those groups were smaller in size. This observation supports the idea that giraffe mothers and calves have a strategy of hiding in dense bushes, rather than staying in open areas to better see lions or gathering in large groups to dilute the predation risk. Dense bushlands are therefore important habitat for giraffe calves that the researchers suggest should be protected. Some cattle ranchers promote shrub removal to encourage grass for their livestock, but this thinning of brush could be detrimental to giraffes and other animals that share the rangelands.The study also explored the influence of humans on giraffe grouping behaviors."Outside the parks, the human population has been rapidly expanding in recent years," said Derek Lee, associate research professor of biology at Penn State and co-author of the study. "Therefore, we felt it was important to understand how human presence affected grouping behavior, as natural giraffe habitat is ever-more dominated by people."Interestingly, adult females with calves were more likely to be found closer to traditional pastoralist compounds called bomas, made by livestock-keeping, non-farming people."We suspect this is because the pastoralists may disrupt predator behaviors to protect their livestock and this benefits the giraffe calves," said Lee.Conversely, groups with calves avoided areas close to the larger towns of farming people, suggesting a difference between traditional bomas versus more densely populated human settlements for giraffe mothers seeking food and safety for themselves and their calves."We were happy to find that traditional human settlements by ranchers appear to be compatible with the persistence of giraffe populations," said Bond. "But on the other hand, disturbances around towns likely represent a threat and should be limited in areas favored by giraffes. Masai giraffes are the world's tallest herbivores and are beloved by people around the globe, but they were recently classified as an endangered species by the International Union for Conservation of Nature (IUCN). The data in this study can help us know what places are most important for these magnificent animals."The study was part of the world's largest giraffe research project and used data from six years of systematic seasonal surveys across a 2,000 square kilometer area.
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Agriculture & Food
| 2,019 |
August 29, 2019
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https://www.sciencedaily.com/releases/2019/08/190829150736.htm
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Synthesis of UV absorbers from cashew nut shell liquid
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Researchers at Johannes Gutenberg University Mainz (JGU) in Germany, in collaboration with colleagues from the University of the Witwatersrand in Johannesburg in South Africa and the University of Dar-es-Salaam in Tanzania, succeeded in using cashew nut shell liquid (CNSL) as a substitute for petroleum in organic synthesis. Their aim was the development of a sustainable synthesis of soluble organic UV filters.
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The ultraviolet (UV) region of solar radiation is a potential health risk for humans and livestock. Extensive exposure may result in premature aging of the skin and even life-threatening forms of cancer. Moreover, the destructive power of natural UV radiation can also damage paints, coatings, and even plastics. One option to prevent radiation-induced damage is to employ chemical UV filters. These can either be mineral pigments such as titanium dioxide (titanium white) or organic compounds containing carbon atoms. Both are used as active ingredients in sunscreen, as paint additives, or as additives for the materials to be protected.Currently, both classes of UV filters are under fire for different reasons. The toxicity of some of the organic filters towards aquatic life is problematic. Unfortunately, practically all organic filters -- and the vast majority of all other organic chemicals around -- are being produced from petroleum.The international team of researchers led by Professor Till Opatz of the JGU Institute of Organic Chemistry and Professor Charles de Koning from Johannesburg used CNSL instead as a renewable starting material for the production of new UV filters. CNSL is produced in large quantity during the production of the nuts and cannot be used as food or feed. Thus, there is no competition between the use as a chemical raw material and the production of foodstuff. The utilization of CNSL can be regarded as an example of xylochemistry, in which woody biomass serves as the carbon source for chemical synthesis.The application of these chemically well-defined UV absorbers produced in this fashion in sunscreens, their compatibility with human skin, and their effects on various life forms remain to be investigated. This research, however, is beyond the scope of the current project funded by the German Federal Ministry of Education and Research (BMBF) and the South African partner organization NRF and will require the collaboration with industry.
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Agriculture & Food
| 2,019 |
August 29, 2019
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https://www.sciencedaily.com/releases/2019/08/190829124250.htm
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Seaweed farming as a versatile tool in effort to mitigate climate change
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According to the Intergovernmental Panel on Climate Change (IPCC), addressing carbon emissions from our food sector is absolutely essential to combating climate change. While land and agriculture took center stage in the panel's most recent report, missing was how the oceans at large could help in that fight.
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Seaweed, perceived by some as little more than marine debris on the beach, could be a new player in the effort to mitigate climate change. So say researchers at UC Santa Barbara, who investigated the carbon offsetting potential of seaweed aquaculture."It's not a silver bullet, nor an industry that exists yet," said Halley Froehlich, an assistant professor in the Department of Environmental Studies and in the Department of Ecology, Evolution and Marine Biology. "But it has huge potential." Froehlich is lead author of a first-ever global assessment of seaweed aquaculture's carbon sequestration scaling potential, which appears in According to Froehlich and co-authors Jamie Afferbach, Melanie Frazier and Benjamin Halpern from the National Center for Ecological Analysis and Synthesis, who synthesized diverse datasets from scientific literature, seaweed aquaculture could indeed be a powerful new way to sequester carbon. The process would involve cultivating seaweed and harvesting it for the purpose of sinking the algae in the deeper ocean, where the carbon stored in its tissues would remain 'buried.'"We really wanted to know if it could be beneficial, but also be realistic about its potential," Froehlich said of the research, which they bounded with constraints including nutrients, temperature and geographic suitability, as well as assessed production growth and cost. The researchers also investigated the mitigation potential on various scales with a focus on the food sector -- a major source of greenhouse gases and considerable hurdle to fight climate change.There is substantial suitable area -- roughly 48 million square kilometers -- in which seaweed could be farmed, and a relatively small proportion (0.001%) would be enough to render the entire global aquaculture industry carbon neutral, according to the study.However, the benefits don't scale proportionally against the much higher greenhouse gas-emitting global agricultural sector, in part due to cost and growth constraints, Froehlich said. Farming seaweed alone won't balance emissions from global food production, she added, but could be a useful new tool in a suite that includes other carbon reduction and offset measures such as cleaner sources of energy, reforestation and protection of carbon sinks.Greenhouse gas-mitigating seaweed farming could have the most potential when it comes to achieving local and regional carbon neutrality goals, the study found. California is particularly well-primed to reap the mitigating benefits of seaweed aquaculture, given the state's strong climate action policy and its long, nutrient-rich coast. An area of only 3.8% of the West Coast Exclusive Economic Zone (a marine zone that extends no more than 200 miles from the coast) would be enough to offset the carbon produced by the state's agriculture sector.Relative to the rest of the world, U.S. seaweed aquaculture is still somewhat in its infancy."The vast majority of seaweed aquaculture occurs in Southeast Asia," Froehlich said. While no measurable seaweed farming was occurring in the United States in 2016 -- the most recent time period of the study -- small seaweed farms are starting to emerge in the U.S., though primarily for food and other commercial purposes, and not for carbon sequestration.The U.S., meanwhile, is the world's second-biggest emitter of greenhouse gases, Froehlich pointed out, underscoring the need for solutions such as seaweed farming to mitigate the millions of tons of carbon dioxide equivalents the country emits per year. Fortunately, seaweed farming has other appealing and beneficial environmental effects, she noted."We like to call it 'charismatic carbon' because it has additional benefits," Froehlich said, "such as potentially providing habitat for fish and other marine life, reducing ocean acidification and oxygen depletion, and taking up excess nutrients in local areas."Seaweed cultivation's beneficial climate effects far outweigh the fact that it can't completely offset the country's food production greenhouse gas emissions. In fact, according to co-author Halpern, there is not -- and never will be -- a single tool for dealing with climate change."The problem has become too big for simple solutions," he said. "We need all hands on deck." While solutions to climate change will not be easy, he added, the more strategies, the better."The huge advantage is that if we can actually deploy many different strategies -- from seaweed farming to renewable energy to energy efficiency and others -- the solution is more resilient," Halpern said.To make it a real option in the United States, policy would need to enable and accelerate seaweed cultivation for carbon sequestration, farmers would need to respond by dramatically scaling up production and the carbon market would need to expand to offer higher prices.In the meantime, research will continue to investigate seaweed cultivation's potential for mitigating climate change."My colleagues and I are now assessing other paths seaweed can take to find the 'best bang for your buck' on carbon mitigation," Froehlich said. Given that farmed seaweed is also subject to climate change effects, a better understanding of how it could be affected would greatly inform how it could be cultivated and managed in the long term.
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Agriculture & Food
| 2,019 |
August 29, 2019
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https://www.sciencedaily.com/releases/2019/08/190829122142.htm
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Getting to the root of how plants tolerate too much iron
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Iron is essential for plant growth, but with heavy rainfall and poor aeration, many acidic soils become toxic with excess iron. In countries with dramatic flood seasons, such as in West Africa and tropical Asia, toxic iron levels can have dire consequences on the availability of staple foods, such as rice.
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Despite dozens of attempts in the last two decades to uncover the genes responsible for iron tolerance, these remained elusive until recently. Now, Salk scientists have found a major genetic regulator of iron tolerance, a gene called GSNOR. The findings, published in "This is the first time that a gene and its natural variants have been identified for iron tolerance," says Associate Professor Wolfgang Busch, senior author on the paper and a member of Salk's Plant Molecular and Cellular Biology Laboratory as well as its Integrative Biology Laboratory. "This work is exciting because we now understand how plants can grow in stressful conditions, such as high levels of iron, which could help us make more stress-resistant crops."In plants such as rice, elevated soil iron levels cause direct cellular damage by harming fats and proteins, decreasing roots' ability to grow. Yet, some plants appear to have inherent tolerance to high iron levels; scientists wanted to understand why."We believed there were genetic mechanisms that underlie this resistance, but it was unclear which genes were responsible," says first author Baohai Li, a postdoctoral fellow in the Busch lab. "To examine this question, we used the power of natural variation of hundreds of different strains of plants to study genetic adaption to high levels of iron."The scientists first tested a number of strains of a small mustard plant (The researchers also found that the iron-tolerance mechanism is, to their surprise, related to the activities of nitric oxide, a gaseous molecule with a variety of roles in plants including responding to stress. High levels of nitric oxide induced cellular stress and impaired the plant roots' tolerance for elevated iron levels. This occurred when plants did not have a functional GSNOR gene. GSNOR likely plays a central role in nitric oxide metabolism and regulates the plants' ability to respond to cellular stress and damage. This nitric oxide mechanism and the GSNOR gene also affected iron tolerance in other species of plants, such as rice ("By identifying this gene and its genetic variants that confer iron tolerance, we hope to help plants, such as rice, become more resistant to iron in regions with toxic iron levels," says Busch. "Since we found that this gene and pathway was conserved in multiple species of plants, we suspect they may be important for iron resistance in all higher plants. Additionally, this gene and pathway may also play a role in humans, and could lead to new treatments for conditions associated with iron overload."Next, Li will be starting his own laboratory at Zhejiang University, in China. He plans to identify the relevant genetic variants in rice and observe if iron-tolerance variants could increase crop yields in flooded Chinese fields.
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Agriculture & Food
| 2,019 |
August 29, 2019
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https://www.sciencedaily.com/releases/2019/08/190829081403.htm
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Food-waste study reveals trends behind discarded items
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Americans throw out a lot more food than they expect they will, food waste that is likely driven in part by ambiguous date labels on packages, a new study has found.
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"People eat a lot less of their refrigerated food than they expect to, and they're likely throwing out perfectly good food because they misunderstand labels," said Brian Roe, the study's senior author and a professor agricultural, environmental and development economics at The Ohio State University.This is the first study to offer a data-driven glimpse into the refrigerators of American homes, and provides an important framework for efforts to decrease food waste, Roe said. It was published online this month and will appear in the November print issue of the journal Survey participants expected to eat 97 percent of the meat in their refrigerators but really finished only about half. They thought they'd eat 94 percent of their vegetables, but consumed just 44 percent. They projected they'd eat about 71 percent of the fruit and 84 percent of the dairy, but finished off just 40 percent and 42 percent, respectively.Top drivers of discarding food included concerns about food safety -- odor, appearance and dates on the labels."No one knows what 'use by' and 'best by' labels mean and people think they are a safety indicator when they are generally a quality indicator," Roe said, adding that there's a proposal currently before Congress to prescribe date labeling rules in an effort to provide some clarity.Under the proposal, "Best if used by" would, as Roe puts it, translate to "Follow your nose," and "Use by" would translate to "Toss it."Other findings from the new study:Household food waste happens at the end of the line of a series of behaviors, said Megan Davenport, who led the study as a graduate student in Ohio State's Department of Agricultural, Environmental and Development Economics."There's the purchasing of food, the management of food within the home and the disposal, and these household routines ultimately increase or decrease waste. We wanted to better understand those relationships, and how individual products -- including their labels -- affect the amount of food waste in a home," Davenport said.The web-based pilot study used data from the State of the American Refrigerator survey and included information about refrigerator contents and practices from 307 initial survey participants and 169 follow-up surveys.The researchers asked about fruits, vegetables, meats and dairy -- in particular how much was there and how much people expected to eat. Then they followed up about a week later to find out what really happened. The surveys also asked about a variety of factors that may have influenced decisions to toss food, including date labels, odor, appearance and cost.An estimated 43 percent of food waste is due to in-home practices -- as opposed to waste that happens in restaurants, grocery stores and on the farm -- making individuals the biggest contributors. They're also the most complicated group in which to drive change, given that practices vary significantly from home to home, Roe said."We wanted to understand how people are using the refrigerator and if it is a destination where half-eaten food goes to die," he said."That's especially important because much of the advice that consumers hear regarding food waste is to refrigerate (and eat) leftovers, and to 'shop' the refrigerator first before ordering out or heading to the store."Roughly one-third of the food produced worldwide for human consumption -- approximately 1.3 billion tons annually -- is lost or wasted, according to the Food and Agriculture Organization of the United Nations. The organization estimates the annual dollar value of that waste at $680 billion in industrialized countries and $310 billion in developing countries.This study looked at refrigerated food because that's where most perishable foods are found in a household and where the bulk of efforts to encourage people to waste less food have been focused. In addition to better understanding food waste patterns, the researchers wanted to help identify opportunities to design policy or public messaging that will work in driving down waste."Our results suggest that strategies to reduce food waste in the U.S. should include limiting and standardizing the number of phrases used on date labels, and education campaigns to help consumers better understand the physical signs of food safety and quality," Davenport said.
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Agriculture & Food
| 2,019 |
August 28, 2019
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https://www.sciencedaily.com/releases/2019/08/190828140052.htm
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New DNA sequencer method achieves early-stage and broad-range detection of wheat diseases
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Plant diseases, especially those caused by fungal pathogens, jeopardize global crop biosecurity and preventing them requires rapid detection and identification of causal agents. Traditional methods for crop disease diagnosis rely on the expertise of pathologists who can identify diseases by eye, but this approach comes with many limitations, including the reliance on physical appearance of disease symptoms.
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Also of note, this traditional method does not allow for the rapid identification of unknown pathogens during an outbreak. This limitation was made obvious recently in Bangladesh, when wheat crops were devastated by an invasion of South American races of wheat blast fungus.As wheat is one of the world's most important crops, a group of Australia-based scientists wanted to address this limitation by developing a new method for analyzing pathogen DNA in wheat leaf samples. Using a portable DNA sequencer, they were able to achieve early-stage and broad-range detection of pathogens in wheat -- and they were also able to characterize all organisms in the wheat and confirmed the presence of an unexpected diseases not previously diagnosed by pathologists.According to the scientists behind this research, "A combination of on-site and centralized sequencing approaches would, in future, revolutionize management of agricultural biosecurity and reduce crop loss." Additionally, these methods can be incorporated into routine field diseases monitoring and biosecurity monitoring at national borders to save time and money and prevent another devastating outbreak like the one seen in Bangladesh.This research, discussed in the open access article "Pathogen Detection and Microbiome Analysis of Infected Wheat Using a Portable DNA Sequencer," also explores the way this new strategy can identify diseases-inhibiting microbes for use in environmentally friendly control of diseases. This research was made available online in May 2019 ahead of final publication in the June issue of the fully open access
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Agriculture & Food
| 2,019 |
August 27, 2019
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https://www.sciencedaily.com/releases/2019/08/190827095045.htm
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How bees live with bacteria
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An apple plantation in spring. The trees are in full bloom. But to ensure that they also yield in autumn, workers have to do a real fluff job for weeks: each individual flower is manually pollinated with brushes -- because there are no bees left to do the job. Not a nice vision of the future. But in some regions of China this is already reality. And the disappearance of the bees is reported all over the world.
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The exact reason for the bee mortality is not known. Pesticides from agriculture, destruction of habitats, pathogens -- probably several factors play together. A research group at Julius-Maximilians-Universität (JMU) Würzburg in Bavaria, Germany, is now focusing on another factor. It is the bacteria that live in and with bees. Many of them are important for the health of bees. If they suffer, so do the bees.The intestines of honeybees, for example, contain bacteria that help digest food and stimulate the immune system of the insects. The beehive also contains useful microbes, some of which produce antibiotics, thus preventing the spread of harmful fungi."Most research in this field is devoted to social bees, especially the western honey bee Apis mellifera," says Dr. Alexander Keller of the JMU Biocenter. Solitary bees would have experienced only little attention. These are pollinators of great ecological importance for the environment and agriculture. More than 90 percent of the 17,500 bee species known worldwide are solitary bees.According to Keller, considerably more research is needed to better understand the relationship between solitary bees and microbes and thus perhaps better combat bee mortality. Many species of solitary bees are threatened or already extinct.Until now, research has been based on the assumption that the knowledge gained from honey bees can be transferred to solitary bees. However, this is only possible to a very limited extent, despite some fundamental similarities. This is the conclusion reached by the JMU research group in a review article published in the journal "Trends in Microbiology." It summarises the current state of research on bees and their microbial associations.The central finding is that solitary bees are much more strongly influenced by environmental factors and human-induced changes than socially organised bees when establishing their relationships with microbes. The consequences of climate change, agricultural changes and habitat degradation, for example, have not yet been clarified and require research specifically adapted to solitary bees.Alexander Keller and his team are currently working with the JMU Chair of Zoology III (Animal Ecology and Tropical Biology) and international partners to investigate the landscape ecological factors that influence the microbial associations of solitary bees.
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Agriculture & Food
| 2,019 |
August 26, 2019
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https://www.sciencedaily.com/releases/2019/08/190826164716.htm
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Wild ground-nesting bees might be exposed to lethal levels of neonics in soil
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In a first-ever study investigating the risk of neonicotinoid insecticides to ground-nesting bees, University of Guelph researchers have discovered at least one species is being exposed to lethal levels of the chemicals in the soil.
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Examining the presence of these commonly used pesticides in soil is important given the majority of bee species in Canada make their nests in the ground.This study focused on hoary squash bees, which feed almost exclusively on the nectar and pollen of squash, pumpkin and gourd flowers.Researchers found that the likelihood that squash bees are being chronically exposed to lethal doses of a key neonicotinoid, clothianidin, in soil was 36 per cent or higher in squash fields.That means 36 per cent of the population is probably encountering lethal doses, which is well above the acceptable threshold of 5 per cent, in which 95 per cent of the bees would survive exposure."These findings are applicable to many other wild bee species in Canada that nest on or near farms," said U of G School of Environmental Sciences professor, Nigel Raine, who holds the Rebanks Family Chair in Pollinator Conservation and worked on the study with PhD student and lead author Susan Chan."We don't yet know what effect these pesticides are having on squash bee numbers because wild bees are not yet tracked the same way that honeybee populations are monitored. But we do know that many other wild bee species nest and forage in crop fields, which is why these findings are so concerning."Published in The research comes as Health Canada places new limits on the use of three key neonicotinoids, including clothianidin, while it decides whether to impose a full phase-out of these pesticides. Neonics have been linked to concerns about honeybee colony health, with research showing these bees can ingest dangerous amounts through nectar or pollen."Current risk assessments for insecticide impacts on pollinators revolve around honeybees, a species that rarely comes into contact with soil," said Raine. "However, the majority of bee species live most of their life in soil, so risks of pesticide exposure from soil should be a major factor in these important regulatory decisions.""Until now, no one has examined the risk to bees from neonics in soil despite the fact these pesticides are applied directly to seeds planted into the ground, or sprayed directly onto soil at planting, and can persist for months after application," said Chan."Only about 20 per cent of the neonicotinoid insecticide applied to coated seeds is actually taken up into the crop plant; the rest stays in the soil and can remain there into subsequent seasons."Squash bees are at particular risk because they prefer the already-tilled soil of agricultural fields for their elaborate underground homes. And as they build their nests, they move about 300 times their own body weight worth of soil.Since the bees don't eat soil, it's difficult to know exactly how much pesticide residue enters the bees. But the researchers calculated that even if they are conservative and assume only 25 per cent of the clothianidin enters the bee, the risk of lethal exposure in pumpkin or squash crops is 11 per cent -- still above the widely accepted threshold of 5 per cent.The team also examined the exposure risk in field crops, since many ground-nesting bee species live near corn and soybean fields, which use neonics as well. They found that 58 per cent of ground-nesting bees would be exposed to a lethal dose of clothianidin while building their nests even if only 25 per cent of the clothianidin in the soil enters the bee."Pumpkin and squash farmers face a dilemma in that they want to protect pollinators, such as the squash bee, because they are vital to crop production, but at the same time need to protect their crops from pests," said Chan."New approaches are needed that allow farmers to control pests and protect pollinators simultaneously. My advice to farmers is if you find an aggregation of squash bees nesting on your farm, protect these key pollinators from exposure to neonicotinoids by either not using them at all, or at least not using them near the aggregation. Creating pesticide-free places to nest will help your population of squash bees to grow over time."
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Agriculture & Food
| 2,019 |
August 26, 2019
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https://www.sciencedaily.com/releases/2019/08/190826121942.htm
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The flavor of chocolate is developed during the processing of the cocoa beans
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Just as we have seen an increase in the number of microbreweries making specialty beers, the market for chocolate has also developed, so there are more high-end chocolate manufacturers who are trying to stand out by fine tuning the taste and making several different varietals. Therefore, there is a need to know how you can address this during the processing of the noble cocoa.
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The research was conducted on so-called noble cocoa (the varieties Criollo and Trinitario). Since the vast majority of the world's cocoa production is of the Forastero varietal, much more research has been done on this variety than on the two aforementioned varietals."Criollo cocoa is less bitter than Forastero, but is still more aromatic. You could call it the Pinot Noir of cocoa. But Criollo is a hassle to cultivate and it is difficult to grow in Africa, which is why it is almost exclusively grown in Central America, South America and Madagascar," says Professor with Special Responsibilities at the Department of Food Science at the University of Copenhagen (UCPH FOOD) Dennis Sandris Nielsen and continues:"In this study we have, together with colleagues from Belgium and Nicaragua, examined for the first time how different conditions during fermentation affect the composition and activity of the microorganisms naturally present on the Criollo beans and how this affects the flavour of the finished fermented beans.It has long been known that the processing, including the fermentation and drying of the cocoa, is important in relation to the final quality of the cocoa."Our research confirms this and we have also learned how to fine tune the cocoa by fine tuning the process itself, which means that you can get a higher quality out of your raw materials if you understand these processes," says Dennis Sandris Nielsen.A cocoa fruit is the size of a small honey melon and contains 30-40 cocoa beans, which are surrounded by a pulp. If you take a raw cocoa bean and try to make chocolate from it, it does not taste good -- you need fermentation to release the flavour potential.The fermentation is done by opening the cocoa fruit, removing the beans and allowing them to ferment -- for example, in a box.The pulp surrounding the beans is inoculated with various microorganisms from the surroundings, equipment, etc. The pulp is very acidic (pH 3-3.5) and has a high sugar content (about 10%), and in such an environment only a small number of microorganisms can grow. This is why the fermentation usually goes well, even if it is not inoculated with a starter culture. There is a natural selection of microorganisms that positively affect the taste.Initially, it is mainly yeast that grows and then lactic acid bacteria. The yeast forms alcohol, while the lactic acid bacteria eat some of the citric acid that is naturally present. This means that the pH rises, making the environment more favourable for acetic acid bacteria, which converts some of the alcohol that has been formed into vinegar.The processes generate a lot of heat -- reaching approx. 45-48 degrees. The alcohol and vinegar penetrate the beans and kill the germ in the cocoa beans so that they can no longer germinate. The cell walls are broken down, which means that different substances can react with each other and this is where the flavour development evolves.Flavour development continues as the beans dry in the sun, where they are dried until they are microbially stable. Here ends the process for the cocoa farmers who can now sell the fermented and dried beans on. The producers are responsible for roasting the beans, where the substances formed during fermentation and drying react with each other, leading to the well-known and beloved flavour and aroma of cocoa.In the study, fermentations from different parts of Nicaragua (including highlands and lowlands) as well as fermentations with a variety of oxygen availability were studied."By using a combination of High Throughput Sequencing, chromatography and sensory analysis, we can get an understanding of the quality of the cocoa, particularly in relation to the processing. Overall, our findings show that the treatment the cocoa receives after the harvest is at least as important for the quality and flavour as the genetics of the cocoa. Where the cocoa was grown also has some significance. By varying the conditions during fermentation, we can therefore also reasonably predict the final taste, which provides good opportunities for high-end producers in particular to develop chocolate with different flavours and scents," says Dennis Sandris Nielsen.
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Agriculture & Food
| 2,019 |
August 26, 2019
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https://www.sciencedaily.com/releases/2019/08/190826092336.htm
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Monster tumbleweed: Invasive new species is here to stay
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A new species of gigantic tumbleweed once predicted to go extinct is not only here to stay -- it's likely to expand its territory.
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The species, Findings from the study are detailed in a new paper published in the Oxford University-produced journal "Humans are diploid organisms, with one set of chromosomes donated by the mother and one set from the father. Sometimes a mother's egg contains two sets of chromosomes rather than just the one she is meant to pass on. If this egg is fertilized, the offspring would be triploid, with three sets of chromosomes. Most humans do not survive this.Plants with parents closely related enough to mate can produce triploid offspring that survive but are unable to reproduce themselves. However, a hybrid plant that manages to get two copies from the mother and two from the father will be fertile. Some species can have more than four sets of chromosomes. They can even have "hexaploidy," with six sets of chromosomes.Scientists have long assumed there must be some kind of evolutionary advantage to polyploidy, the term for hybrids that have multiple sets of chromosomes, since it poses some immediate difficulties for the new hybrids."Typically, when something is new, and it's the only one of its kind, that's a disadvantage. There's nobody exactly like you to mate with," said study co-author Shana Welles, the graduate student in Ellstrand's laboratory that conducted the study as part of her Ph.D. research. She is now a postdoctoral fellow at Chapman University.The advantage to having multiple sets of chromosomes, according to the study, is that the hybrid plant grows more vigorously than either of its parents. This has been suggested as the reason polyploidy is so common in plants. However, it has not, until now, been demonstrated experimentally.Polyploidy is associated with our favorite crops; domesticated peanuts have four sets of chromosomes, and the wheat we eat has six.Though tumbleweeds are often seen as symbols of America's old West, they are also invasive plants that cause traffic accidents, damage agricultural operations, and cause millions in property damage every year. Last year, the desert town of Victorville, California, was buried in them, piling up to the second story of some homes.Currently, Though this tumbleweed is an annual, it tends to grow on the later side of winter."It's one of the only things that's still green in late summer," Welles said. "They may be well positioned to take advantage of summer rains if climate changes make those more prevalent."Given its potential for damage, the knowledge now available about "An ounce of prevention is a pound of cure," he said.
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Agriculture & Food
| 2,019 |
August 26, 2019
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https://www.sciencedaily.com/releases/2019/08/190826092328.htm
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New way to bump off ticks: Dry up their saliva
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Saliva from a tick's bite can transmit pathogens that cause serious illnesses, such as Lyme disease, and significant agricultural losses. Current insecticides have drawbacks, so scientists have been seeking new ways to prevent these pesky arachnids from spreading pathogens. Now, researchers report that compounds they previously identified can dry up ticks' saliva by upsetting the balance of ions in the salivary gland, reducing feeding and potentially limiting pathogen transmission.
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The researchers will present their results today at the American Chemical Society (ACS) Fall 2019 National Meeting & Exposition."Lyme disease is exploding in the northeastern U.S.," says Daniel Swale, Ph.D., the project's principal investigator. "Most methods to kill ticks in the agricultural sector involve the use of neurotoxic insecticides, but it's difficult to effectively use these insecticides to control ticks in residential areas. So we wanted to identify a new way to control these disease-carrying ticks.""We knew that the salivary gland is critical to the biological success of ticks, suggesting it had potential as a target for a pesticide that works through a new mechanism," Zhilin Li, a doctoral student who is presenting the work at the meeting, says. The researchers, who are at Louisiana State University, reasoned that if they could stop ticks from producing saliva, then they could prevent them from feeding -- a situation that would be incompatible with sustaining life.Li and Swale focused on a potassium ion channel, known as a Kir channel, which has been shown to be important for the excretory systems of arthropods -- a classification of animals that includes mosquitoes, as well as ticks. These microscopic channels allow potassium to move in and out of cells in the salivary gland and elsewhere in the ticks, maintaining an ionic balance essential to saliva secretion and the ticks' health.In their current work, they fed ticks blood laced with two compounds known to act on the Kir channels. Two of the molecules -- known as VU0071063 and pinacidil, a human hypertension drug -- were effective, reducing saliva secretion by 95% or more and reducing blood ingestion by approximately 15-fold. Importantly, ticks that fed on bovine blood infused with either of these compounds were dead within 12 hours. That timeframe is significant because transmission of pathogens via ticks' saliva into their human or animal hosts typically takes at least 12 hours and sometimes as many as 40 hours. These initial studies were conducted in artificial host feeding systems that contained a blood meal. Next, the researchers plan to test whether their treatment can in fact prevent pathogen transmission when ticks feed on rodents.Ticks removed from the blood meal before they died were obviously sick, the researchers report. The ticks were uncoordinated and lethargic, and they couldn't walk well. The researchers attribute this behavior to an imbalance of potassium, sodium and chloride ions in the ticks. Normally, when a tick feeds, its saliva returns excess water and ions from human or animal blood back into the host. But the treated ticks were spitting out more ions despite producing much less saliva, disrupting their biological functions. "We think their nervous system wasn't working normally, and we suspect that's why we saw high mortality in the treated ticks," Li says.Li and Swale will follow up on initial results suggesting that the ion channel is expressed in the salivary gland only during blood feeding and then disappears. And the researchers are zeroing in on the exact type of cells in which the ion channels are produced within the salivary gland. Once they have a more complete understanding of the reliance of blood feeding and pathogen transmission on Kir channel function, they hope industry can use their findings to create a commercial product such as a spray for gardens, or an injection or oral treatment for the agricultural industry for those animals at risk of getting tick bites. Swale notes that the method also seems to reduce saliva production and feeding in aphids and fruit flies, so it could potentially be used to control these agricultural pests, too.
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Agriculture & Food
| 2,019 |
August 22, 2019
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https://www.sciencedaily.com/releases/2019/08/190822141927.htm
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Cell suicide could hold key for brain health and food security
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Research into the self-destruction of cells in humans and plants could lead to treatments for neurodegenerative brain diseases and the development of disease-resistant plants.
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A study co-led by The University of Queensland's Professor Bostjan Kobe identified the role certain proteins play in cellular suicide."To sustain life, diverse organisms like humans and plants have cells that commit suicide for the benefit of the rest of the organism," Professor Kobe said."This is a key part of our own immune response -- infected cells will often commit suicide, so the greater organism can live."Surprisingly though, studying proteins involved in the cell death process in human neurons has led us to discover how cell death also occurs in plants."We've found common ways human and plant cells bring about cell suicide."The team used a combination of structural biology, biochemistry, neurobiology and plant science to analyse cells and proteins, laying the foundation for some potentially ground-breaking innovations."Neurodegenerative diseases affect millions of people worldwide, and come about for different reasons, but what connects them is the breakdown of brain cells," Professor Kobe said."A particular protein -- SARM1 -- is essential for this brain cell breakdown across different neurodegenerative diseases."We've provided crucial information about this protein -- revealing its three-dimensional structure -- that will accelerate the development of drugs that could delay or stop this breakdown."A better understanding of cell death processes may also lead to the development of disease-resistant plants, helping boost yields, minimise waste and bolster food security."Food security is similarly an increasingly relevant problem worldwide," Professor Kobe said."Plant diseases account for more than 15 per cent of crops losses per year, before they're even harvested."Specific plant resistance genes can protect plants from disease, but how the products of these genes work has been poorly understood."Part of this resistance is that -- similar to human neurons -- infected cells self-destruct."Knowing how this process happens in neurons, we were able to find how resistance comes about in plants."This takes us a step closer to making effective synthetic resistance genes that can be used to provide additional protection in Australia and worldwide from crop diseases."
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Agriculture & Food
| 2,019 |
August 22, 2019
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https://www.sciencedaily.com/releases/2019/08/190822141903.htm
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Experiments illuminate key component of plants' immune systems
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Plants, like humans and animals, have over millions of years evolved complex immune systems that fend off invading pathogens. But unlike many animals, plants lack adaptive immunity conferred by antibodies. This means each plant cell must defend itself against all potential pathogens -- a daunting task.
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Hiding inside each plant cell, protein complexes encoded by disease resistance genes are like sleeping armies, waking up and activating defenses when harmful pathogens such as fungi or bacteria are detected. Such genes encode traits used by agricultural biotechnologists to generate disease-resistant crops, and plant biologists are striving to illuminate every aspect of how they work -- much of which remains shrouded in mystery.In new research published in the journal The research team was led by Nishimura, Jeff Dangl of the University of North Carolina at Chapel Hill, and Jeffrey Milbrandt of the Washington University School of Medicine. Nishimura started the work as a research scientist in the lab of Erin Osborne Nishimura, CSU assistant professor in the Department of Biochemistry and Molecular Biology.Together with colleagues, Nishimura identified the mechanism of one little-understood domain of plant resistance proteins called a "toll-interleukin-1 receptor," or TIR domain. The team showed that during the plant immune response, the TIR domain is an enzyme that degrades a molecule called NAD+, which is essential for metabolism in all organisms. By cleaving NAD+, the plant self-destructs infected cells while leaving others unharmed.Scientists had previously surmised that plant TIR domains might act like physical scaffolds, building a structure that attaches to the cell's plasma membrane and recruiting other proteins to the area to begin an immune response. This is how these domains work in animal cells, including in humans.But in 2017, Nishimura's collaborators at Washington University School of Medicine observed an unusual animal TIR domain, found in a protein called SARM1, that doesn't work like other TIR signaling scaffolds in animal cells. Rather, it functions as an enzyme. Nishimura and colleagues set out to probe whether this domain could have a similar function in plant immunity.Nishimura and colleagues' new work in "For 25 years, we didn't know what TIR domains did in plants," Nishimura said. "So these results were very interesting in terms of advancing our understanding of how TIR domains actually trigger immunity."Uncovering individual biochemical pathways in the plant immune response may be crucially important to how plant systems are manipulated to protect food crops, particularly as new pathogens emerge and global food supplies become vulnerable, Nishimura said."Hopefully, really mechanistically understanding immune receptors will help us transfer existing receptors while retaining function, and ultimately let us rationally engineer new receptors to recognize emerging pathogens," he said.
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Agriculture & Food
| 2,019 |
August 22, 2019
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https://www.sciencedaily.com/releases/2019/08/190822130441.htm
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Adaptation to life in cattle may be driving E. coli to develop harmful features
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A large-scale study of the genetic differences and similarities among
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While "To develop the most effective preventive measures, we need a deep understanding of the source and living conditions of the bacteria," says Yoshitoshi Ogura, associate professor at Kyushu University's Department of Bacteriology, who led the research."Although cattle have long been thought to be a main source of Ogura's group, in collaboration with researchers across Japan and in France, Belgium, and the United States, set out to help answer this question by investigating the genetics of "To date, there have been only a limited number of reports of the genome sequences of While the largest number of samples was from Japan, strains from other regions exhibited characteristics that were well distributed among those from Japan, indicating a good diversity of the set of samples.Based on the genetic features of the bacteria, the researchers could generally separate the different strains of Applying the same analysis to clinically obtained Furthermore, many of the samples from cattle exhibited features similar to those causing food poisoning, such as the production of Shiga toxin. While these features generally appear not to cause illness in cattle, their prevalence in the investigated samples suggests that such characteristics are beneficial for life in a cattle's intestine."As long as there is pressure to maintain or strengthen these illness-producing characteristics to better adapt to living in a cattle's intestine, new variants of The researchers speculate that these characteristics may help
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Agriculture & Food
| 2,019 |
August 22, 2019
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https://www.sciencedaily.com/releases/2019/08/190822124834.htm
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Scientists successfully inoculate, grow crops in salt-damaged soil
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A group of researchers may have found a way to reverse falling crop yields caused by increasingly salty farmlands throughout the world.
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Led by Brent Nielsen, professor of microbiology and molecular biology at Brigham Young University, scientists have used bacteria found in the roots of salt-tolerant plants to successfully inoculate alfalfa plants against overly salty soil."We take the roots of these salt-tolerant plants (called halophytes), grind them up and grow the bacteria in a petri dish in the lab," Nielsen said. "Doing this, we isolated over 40 different bacteria isolates, some of which can tolerate ocean-level salt content."The team then applied the bacteria isolates to alfalfa seeds through a solution and tested the alfalfa's ability to grow in high-saline conditions. They saw significant growth of the alfalfa both in their lab and in greenhouse experiments carried out by collaborators at the Institute for Advanced Learning and Research in Virginia.The study identifies two specific bacteria isolates -- Halomonas and Bacillus -- that worked to stimulate plant growth in the presence of 1 percent sodium chloride (salt), a level that significantly inhibits growth of uninoculated plants. This discovery is significant since soils throughout areas of China, Australia and the Middle East have grown increasingly salty, as well as major farmland in the southwest United States."As an area of land is repeatedly used for farming, the salinity rises; the irrigation water has salt in it and when it evaporates or is taken up by the plants, the salt is left behind," said student Caitlyn McNary, one of six BYU undergraduate co-authors on the paper. "With what we've found, lands that are now unable to sustain plant life due to high salinity could once again be used for crops."In addition to the work on alfalfa, America's No. 4 crop, the research team has already started to conduct lab and greenhouse experiments on rice, green beans and lettuce. The next step is to carry out field trials on the inoculated crops.The lab work for the research, recently published online in "We've long wondered if increasingly salty land was just a losing battle or if there was something we could do about it," Nielsen said. "Now we have shown there is something we can do about it."
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Agriculture & Food
| 2,019 |
August 21, 2019
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https://www.sciencedaily.com/releases/2019/08/190821163820.htm
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Shift to more intense rains threatens historic Italian winery
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Wine lovers may appreciate a dry white, but a lack of steady rainfall brought on by a changing climate is threatening a centuries old winemaking tradition in Italy, according to an international team of scientists.
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Researchers found a shift from steady, gentle rains to more intense storms over the past several decades has led to earlier grape harvests, even when seasonal rainfall totals are similar. Early harvests can prevent grapes from fully developing the complex flavors found in wines.Intense precipitation events represent the second most important factor, behind temperature, in predicting when grapes were ready at one vineyard that's been producing wine using traditional methods since the 1650s and recording harvest dates for 200 years, the scientists said."Our results are consistent with the hypothesis that the increasing tendency of precipitation intensity could exacerbate the effect of global warming on some premium wines that have been produced for almost 400 years," said Piero Di Carlo, associate professor of atmospheric sciences at D'Annunzio University of Chieti-Pescara in Italy.Because the winery doesn't use irrigation or other modern techniques, its harvest records more accurately reflect what was happening with the climate each year. Scientists gathered local meteorological data and used models to simulate what factors likely most influenced grape readiness. They recently reported their findings in the journal "Because they haven't changed their techniques, a lot of other variables that may have changed harvest date are taken out of the picture," said William Brune, distinguished professor of meteorology at Penn State. "It makes it cleaner statistically to look at things like precipitation intensity and temperature, and I think that's one reason why we were able to tease these findings out."Previous studies have established a link between higher temperatures and earlier grape harvest dates at other European wineries. Higher rainfall totals can help offset advances in harvest dates caused by rising temperatures, but the impact of rain intensity was not well understood, the scientists said.Steady rains are better for agriculture because heavy storms cause water runoff, and plants and soils can absorb less moisture.The findings indicate a feedback in the climate system -- the increase in temperature precipitates more intense rainfall, which further advances the grape harvest date, according to the researchers. Three wine barrels in a row"We really need to think more broadly about how increases in temperature may have an influence on other variables and how that amplification can affect not only this winery, but all wineries, and in fact all agriculture," Brune said. "I think it's a cautionary tale in that regard."The winery in the study faces particularly difficult challenges because mitigation strategies like irrigation would change the way the vineyard has cultivated its grapes for hundreds of years. Moving to higher elevations may be an option, but land is limited, and such a change could have other, unforeseen impacts on the wine, the scientists said."If we would like to keep our excellence in terms of production of wine, but also in other agricultural sectors, we have to be careful about climate change," said Di Carlo, lead author on the study. "Even if we can use some strategies to adapt, we don't know if we can compensate for all of the effects. We could lose a valuable part of our local economy and tradition."
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Agriculture & Food
| 2,019 |
August 21, 2019
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https://www.sciencedaily.com/releases/2019/08/190821082231.htm
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Optimizing fertilizer source and rate to avoid root death
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Fertilizer is used worldwide in farming. It's used to give plants a boost, increasing yield and ultimately farmers' profits.
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But, as the old adage goes: the dose makes the poison. Similar effects are seen in over-the-counter medicines. They need to take the right dose, at the right intervals, to be safe and effective. Fertilizer works the same way.In particular, the rate and source of the fertilizer can make the difference, especially in a method called banding. It's a method where the fertilizer is placed in a band in the soil below the seed. While banding has many advantages, it can also cause damage to the plant roots if used incorrectly."While banding below and to the side is the recommended practice, banding directly below the seed continues to be a common practice used in dryland systems," says Isaac Madsen. "It can reduce the number of passes across the field required in a growing season. Banding also allows you to put on all or most of your fertilizer at one time. This generally causes less disturbance in a minimum or no-till system." Madsen is a postdoctoral research associate at Washington State University.Researchers like Madsen are trying to find the ideal rate and source that will help the plants without damaging the roots. Madsen and his team studied canola in particular. New imaging and analysis techniques allowed them to see canola roots interacting with fertilizer in a way never previously done."In this study, we imaged canola roots growing into a fertilizer band and measured the damage to the canola tap root," Madsen explains. "Using scanner-based rhizoboxes (glass boxes filled with soil), we were able to collect a series of root images over time. This allowed us to look at the effect of fertilizer rate and source on the seedling root systems."The reason the root damage is of such concern in canola is because it has a long tap root. These larger roots are especially affected by fertilizer. If the tap root is damaged, the plant can't properly take up nutrients and water.The team's end goal was to determine what is called a dose-response curve. This will help farmers better apply their fertilizer and know if it will harm their crops' roots or not. They used the data they collected from the root images to develop these curves for the different fertilizer sources."A dose-response curve helps determine the amount or dose of a substance that will result in a specific response," Madsen says. "In this instance we modeled tap root survival, depth, and distance from fertilizer band."They used three sources of nitrogen fertilizer in their study: urea, ammonium sulfate, and urea ammonium nitrate. Each one reacts differently in the soil, and the researchers thought they would cause different amounts of damage to the roots.Madsen says their results show that banding urea ammonium nitrate rather than urea, along with keeping the rates low, is the best option for canola. He adds that this research is important for canola growers in the Pacific Northwest area. It helps establish guidelines for them to apply nitrogen fertilizers."I think banding is, indeed, frequently the best practice," says Madsen. "But we need to be careful with our rates and sources. Banding of fertilizers will not cause problems as long as the rates used are low enough and the sources used are safe enough. My research goal is to develop rate and source guidelines that growers can use to minimize damage and maximize fertility."Madsen says the imaging techniques used in this study were unique and very useful. Getting a glimpse at the roots can be valuable. It allows something usually hidden beneath the soil and important for plant health to be studied in real time."I really like taking pictures and making videos of roots," Madsen adds. "There is something immensely satisfying about making videos of phenomena which have not been imaged before."
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Agriculture & Food
| 2,019 |
August 20, 2019
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https://www.sciencedaily.com/releases/2019/08/190820130954.htm
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Queen bees face increased chance of execution if they mate with two males rather than one
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Queen stingless bees face an increased risk of being executed by worker bees if they mate with two males rather than one, according to new research by the University of Sussex and the University of São Paulo.
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A colony may kill their queen because of the quality of offspring, according to the paper by Professor Francis Ratnieks, from the University of Sussex, along with colleagues Ayrton Vollet-Neto and Vera Imperatriz-Fonseca from the University of São Paulo, published in a leading evolutionary journal, the Professor of Apiculture Francis Ratnieks said: "By studying test colonies, we found that queen stingless bees will have an increased chance of being executed by the workers in their colony if they mate with two males instead of the one male they normally mate with.""The reasons for this are fairly complex but, in short, it's due to the genetics of sex determination in bees and the risk of what's known as 'matched mating'."Queen stingless bees are closely related to honeybees and bumblebees but are only found in tropical countries like Brazil.While a queen honeybee might mate with ten to twenty males, queen stingless bees normally only mate with one male. According to this new paper, that may be to reduce the chance of execution.In bees whether an individual egg becomes a male or a female depends on a single genetic locus, known as the sex determination locus. Normal males arise from an unfertilized egg and have only one set of chromosomes, from the mother, and so only one sex allele.If the egg is fertilized it will have two sets of chromosomes, one from the mother and one from the father. The two sex alleles can be different, in which case it is female, or the same, in which case it will be a diploid male -- males who are a genetic dead end as they cannot reproduce and serve no useful function to the colony. What should have become a female worker, who will benefit the colony, is instead a useless diploid male.When diploid males are produced, the worker bees in the colony can tell that things are not right and they generally execute the queen soon after adult diploid males emerge from their cells.Diploid males are produced by 'matched mating' where the sex allele of a male the queen mates with is the same as one of the queen's two, different, alleles. In a matched mating, 50% of the fertilized eggs from that male's sperm will be diploid males.If a queen bee mates with two males, although her chances of making a matched mating are doubled, the number of diploid males that could be produced decreases from 50% to 25%.It turns out, however, that worker bees are just as likely to execute a queen who produces 25% diploid males as one who produces 50%.Professor Ratnieks said: "If a queen mates with two males instead of one, her chance of being executed double. As a result, natural selection favours queens to mate with a single male in stingless bees."Interestingly, the researchers found that if a queen were to mate with four males, this would actually reduce her chance of being executed.If a queen were to mate with four males and there was a matched mating, only 12.5% of the offspring would be diploid males. This low proportion is not enough to cause the workers to execute the queen.The researchers point out that for stingless bees to evolve from single mating to multiple mating, with 4 or more males, there would need to be an intermediate stage of double mating. As double mating causes higher queen execution, natural selection does not allow this first stage to occur. Stingless bee queens seem to be stuck on single mating.
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Agriculture & Food
| 2,019 |
August 20, 2019
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https://www.sciencedaily.com/releases/2019/08/190820130915.htm
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Connected forest networks on oil palm plantations key to protecting endangered species
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Connected areas of high-quality forest running through oil palm plantations could help support increased levels of biodiversity, new research suggests.
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There is growing pressure to reduce the consumption of palm oil due to concerns over deforestation. However, the research team, led by the University of York, says promoting more sustainable palm oil is a better alternative.For palm oil to be certified as sustainable, the Roundtable on Sustainable Palm Oil (RSPO) requires oil palm growers to identify and conserve areas within a plantation that support high conservation values.If these patches contain high-quality forest, they may help protect species like orangutans, as well as various species of insects, birds and bats -- many of which are threatened with extinction in areas of Indonesia and Malaysia, where 85% of the world's palm oil is produced.Connections between forest fragments in oil palm plantations to other areas of forest and remaining natural habitat are essential for species to be able to move freely -- something that is increasingly important as species face growing pressure to seek out alternative habitat due to continued land-use and climate change.The researchers suggest that current criteria for the sustainable production of palm oil should incorporate clearer guidance for plantation companies to ensure connectivity between set-aside areas of forest.Lead author of the research, Dr Sarah Scriven, who is working in Professor Jane Hill's lab within the Department of Biology at the University of York, said: "Palm is the world's most-productive major vegetable oil crop and yields six to 10 times as much oil per hectare as crops like soy or rapeseed. Switching to alternative sources of vegetable oil wouldn't enable producers to provide enough oil for the world's growing population and has the potential to do even more environmental damage."With demand for crop land set to increase, coming up with new ways to conserve biodiversity within agricultural landscapes is of critical importance."However, the researchers found that even large areas of set-aside forest provide few benefits to forest species movement if they are isolated from other forested areas in the wider landscape.In addition, set-aside areas frequently contain degraded forest. If plantation companies were to reforest these patches, the researchers calculate that set-asides within plantations in the lowlands of Borneo would be 16% better connected for forest species.Dr Scriven added: "There is a pressing need to restore previously forested habitats. Rapid expansion of commodity agriculture has resulted in widespread loss and fragmentation of forest and in many areas of Indonesia and Malaysia, formerly extensive forests now persist as isolated remnants scattered across vast agricultural landscapes."Current RSPO guidelines are not prescriptive about strategies for maximising the connectivity of forest set-asides in oil palm landscapes. We therefore recommend that large, isolated areas of forest should be identified and reconnected with forested areas in the wider landscape."Future revisions to the RSPO guidelines should also ensure that plantation companies improve the quality of previously forested set-asides so that they can support high levels of biodiversity and contribute to landscape connectivity."
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Agriculture & Food
| 2,019 |
August 19, 2019
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https://www.sciencedaily.com/releases/2019/08/190819132127.htm
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Burning invasive western juniper maintains sagebrush dominance longer
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Burning invasive western juniper increases the time -- post-fire -- that native mountain sagebrush will remain the dominant woody vegetation in the plant community by at least 44 percent compared to cutting juniper back, according to a new study in
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It is important to maintain sagebrush as the dominant woody vegetation in sagebrush steppe communities in the northwestern U.S. where western juniper (Juniperus occidentalis Hook) is encroaching on and replacing sagebrush. Among the benefits are providing endangered sage-grouse better long-term habitat. However, as soon as juniper cover reaches 3 percent, sage-grouse stop using the area. In addition, juniper encroachment greatly increases erosion risks, and reduces forage production by 2- to 10-fold, depending on the specific site.A team of scientists from the ARS Range and Meadow Forage Management Research Laboratory in Burns, Oregon, Oregon State University and The Nature Conservancy compared the results of prescribed burns with areas where cutting down juniper was employed as the control method at 77 sagebrush steppe locations in Southeastern and Southcentral Oregon, Northern California and Southwestern Idaho.The researchers looked at ecological data for as long as 33 years after either fire or cutting down juniper was used to control junipers."Counter to commonly held beliefs, what we found was prescribed burns were a better conservation practice for encouraging long-term sagebrush dominance in areas that had been encroached upon by western juniper compared to mechanically cutting," ARS rangeland scientist Kirk W. Davies said.Previously, shorter term studies had suggested that cutting was a more effective practice."If we need to restore immediate sagebrush dominance in an area that is a mix of juniper and sagebrush, cutting will achieve that," Davies pointed out. "But if we want longer term sagebrush dominance, prescribed burning of encroaching juniper can be a logical choice." Both fire and cutting have critical roles in the conservation of sagebrush communities."Removing juniper by cutting is significantly more expensive than using prescribed fires. But cutting does not result in any immediate loss of sagebrush and sage-grouse habitat as prescribed burning does.Evaluating cutting and prescribed burn effects over an extended time not only provided evidence that prescribed burns provided extended juniper control, it also validated the ecological model that had predicted this outcome."We wanted to evaluate the effectiveness of cutting versus prescribed burns because we thought we were observing more young juniper trees in areas that had been cut in the last decade or so compared to burned areas," Davies explained.With this research, federal and state land management agencies and private landowners will be able to make better decisions about selecting control methods."In the end, if you burn, in the long run you will have a lot more sagebrush habitat," Davies said.The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.
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Agriculture & Food
| 2,019 |
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