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+{"metadata":{"id":"052513116a5912094fc0c4aced0585c7","source":"gardian_index","url":"https://cgspace.cgiar.org/rest/bitstreams/8a33ce17-be5d-4200-963b-0477398157bf/retrieve"},"pageCount":181,"title":"","keywords":[],"chapters":[{"head":"P REFACE","index":1,"paragraphs":[{"index":1,"size":103,"text":"The pri m ary pur pose of t hi s book i s t o ma ke the duties of a sc i en t i st less fr ustrating. He will f ind i n th is book defin i t ions of commonly used resea r ch terms in hi s di sc ipline and ou tside i t . Thi s gl ossary is also i ntroduced to se rve the needs of under-graduates, gradua t e students , translato rs , interp re ters, specialists, trainees , agr i cult ura l administrators, and extensi on worker s ."},{"index":2,"size":27,"text":"An attemp t ha s been made not on l y to defi ne the some inf orma tion and examples of many of t he terms."},{"index":3,"size":10,"text":"as main examples with mai n emphasis on ri ce."},{"index":4,"size":267,"text":"words but to include Ce real s are used I claimed no original i ty for most of t he terms described . Al l literature cons ulted i s cited in the bibliography . Often when words are direc t l y quoted, the reference so urces are immedi at el y ackn owl edged in the t ext. I sincerel y acknowledge the se aut hors. Ju l y, 1984 I would l ike to express my gratitude t o the ma ny authors whose books and articl es I have use d i n t his gl ossary . Special gratitude goes t o Dr T. T. Chang of IRR I i n t he Ph ilippines f or his thoroug h review and suggestions ; Dr. J . Neil Rutge r of Davi s Ca lifornia; Mr. Jibade Oyekan; Dr. S.V . S. Shas try; Dr. V.T. John of the International Ins t i tute of Tropica l Agricu lture (I ITA) Ibadan, Nigeria; Dr. O.A. Ojomo of the National Ce rea ls Research Inst i t ute, Ibadan, Ni ge ria; Drs M.A. Choudhury, B.A. C. Enyi, O. K. Das Gupta, E.A. Akinsola, A.K. Ko roma, V.A. Awoderu , Dr. Botchey, Mr. T. Asongwede, Mr. N. Bangu ra of the West Africa Ri ce Development Association (WA RDA) who have co ntri buted i n various ways i n edi t i ng thi s glossary . Spec ia l gratitude i s also espressed to Prof. You deowei of Ibada n University for his encou ra geme nt and suggest ions."},{"index":5,"size":68,"text":"I wou ld also li ke t o thank the International Rice Research Institute, Los Banos, Laguna, Phi lippines and Departme nt of Agronomy and Range Sc i ence, University of California, Davis, Cal ifornia for prov i din g me with t he facilities that made the initial attempt to prepare this gl ossa ry possib le during my sabbatical leave there in 1976 to 1977 ."},{"index":6,"size":48,"text":"I am gra t eful to many private typists. Mr. E.K . Apet i, Mr. L. Kamara, Mr. J . O. Larbi, Miss. C. Y. Ogu ndiya and my dau ghter Miss. O. A. Abifarin wh o he lped at vari ous stages of the ma nuscri pt."},{"index":7,"size":49,"text":"I am gratef ul to WARD~ for assistance in mi meog raphing the f inal draft and ~l so g ra~efu l to the Dlrector Ge neral of the International Instit ut e of Troplcal Agr lcult ure who granted m e the sabba t ical l ea ve."},{"index":8,"size":21,"text":"Acquired qualitative or po1igenic characters: Phynotypic changes produced on a plant by the environment during development. Such characters (defined) are uninheritab1e."}]},{"head":"Active ingredient:","index":2,"paragraphs":[{"index":1,"size":30,"text":"The potent portion of a chemical such as fertilizer, insecticide or herbicide that is applied on the soil or plant on which the estimation of the chemical effect is based."},{"index":2,"size":4,"text":"Active vegetative stage: Adapt:"},{"index":3,"size":20,"text":"The stage when there is a profuse or rapid development of leaves, tillers branches or stem elongation of a plant."},{"index":4,"size":16,"text":"Fit or adju~t to or suit a given environment or set of conditions (see adaptability) ."}]},{"head":"Adaptability:","index":3,"paragraphs":[{"index":1,"size":23,"text":"The ability of a plant to change, adjust to or fit into different environments by modifications in the plant's structure or physiological responses."}]},{"head":"Adaptation:","index":4,"paragraphs":[{"index":1,"size":65,"text":"The process by which parts of a plant, a whole plant, a species or population reacts to or fits into new or different environmental conditions by change in form or function. The plant grows and produces satisfactorily despite unfavourable factors that would have made growth and development otherwise impossible. A variety with wide adaptation is one that performs satisfactorily under a wide range of environments."}]},{"head":"Adaptive research:","index":5,"paragraphs":[{"index":1,"size":48,"text":"Research conducted to determine whether a given research result will be suitable in a given area or for a given procedure on a larger scale than when the experiment or research was conducted (see basic and applied research). Example is varietal trial on farmer's field (see on-farm trial)."}]},{"head":"Adaptiveness:","index":6,"paragraphs":[{"index":1,"size":17,"text":"This is the strength, intensity or degree of being adapted to a certain environment or environmental conditions."},{"index":2,"size":4,"text":"Additive effects of genes:"},{"index":3,"size":73,"text":"These are the effects produced by the sum of more th an one pair of genes. The characters or the effects controlled by the ge nes are prodcued by the addition of relatively very small amounts to impart or improve desirable characters or suppress undesirable characters of a plant . There is faste r improvement by selection when dealing with variables controlled by additive gene action than by non-additive actions such as epistasis."}]},{"head":"Additive genes:","index":7,"paragraphs":[{"index":1,"size":10,"text":"Genes that have an additive effect and show no dominance."}]},{"head":"Adopt:","index":8,"paragraphs":[{"index":1,"size":6,"text":"To use another research findi ng."}]},{"head":"Advanced generation :","index":9,"paragraphs":[{"index":1,"size":50,"text":"A generation (see Filian gene ration) later than the f ou rth or fifth (F 4 or F ) in a pedigree systems , i.e. F4 -Fg will be regarded as ad?anced generations. In genera l , most of t he major genes are fixed at the advanced ge neration."}]},{"head":"Adventitious:","index":10,"paragraphs":[{"index":1,"size":60,"text":"Ari s ing from abnormal positi on ; of roots developing f rom the part of a plant other than roots, e.g. f rom stem or leaf ~u tt i ng and buds, sai d of leaf or branch tha t develops from ~ar t of pl ant other than in axil of leaf e . g. from root ."},{"index":2,"size":5,"text":"Aeri a 1 r oots:"},{"index":3,"size":4,"text":"(See noda l roots)."}]},{"head":"Aerial tillers:","index":11,"paragraphs":[{"index":1,"size":3,"text":"Ae robi c:"},{"index":2,"size":6,"text":"(See noda l ti ll ers)."},{"index":3,"size":15,"text":"(1) Havin g mo lecula r oxygen as a part of the enviro nm ent."},{"index":4,"size":18,"text":"(2 ) Grow i ng on ly in t he presence of molecular oxygen , as aerobic organisms."},{"index":5,"size":44,"text":"(3 ) Occ urr i ng only i n the presence of mol ecular oxygen, said of certa i n chemi cal , bi ochemi ca l or mi crobi olog i cal processes such as aerobic decomposition and aerobic respiration (Foth,19 78) ."},{"index":6,"size":4,"text":"African r i ce:"},{"index":7,"size":4,"text":"The After r ipening:"},{"index":8,"size":2,"text":"Agar :"},{"index":9,"size":30,"text":"Bioch emical processes or physical changes that take place in physiologically ma ture fr uit s, seeds, bulbs, tubers, etc., essential in some spec ies for susequent germination (See Dormancy)."},{"index":10,"size":33,"text":"Mucilage derived from a seaw• eed. It forms a gel wi th wa ter . It i s used t o solidify culture media on wh ich mi cro organis ms are grown."},{"index":11,"size":1,"text":"Agriculture:"},{"index":12,"size":3,"text":"Ag ronom y:"},{"index":13,"size":29,"text":"The sc i ence or the practice of cul tivati on, fa rm ing, tillage and horticulture, plant and animal production. It i s app l ied bi ology."},{"index":14,"size":58,"text":"The science in ag riculture that deals with the relationship of soi ls an d plants, their developm ent and improvement f or crop pro ducti on and field ma nageme nt . It is the study of t he management of the land an d the sc i entific cultivation of crops on the la nd ."},{"index":15,"size":27,"text":"In a broad sense , pl ant breedin g and soil sc i ence are incl uded but it includes cultural practices an d weed control mainly."},{"index":16,"size":4,"text":"Ag r onomic characters:"},{"index":17,"size":3,"text":"Al bin o:"},{"index":18,"size":37,"text":"Impo rtant plant characters re l ated to crop processing and product ion usually observed during t he pl ant growth e.g. height, maturity, tiller number, pan icle s ize, qua l ity fa ctors , etc."},{"index":19,"size":15,"text":"A pl ant which l acks chlorophyll; • a de ficiency in norma l pigment."},{"index":20,"size":40,"text":"The lea ves of such plants are yellowish or white and usually the plants die wi t hin a few days of emergence. It occurs when the gene for albinism which is normally recessive is present i n homozygous condition."},{"index":21,"size":3,"text":"Ale urone layer:"},{"index":22,"size":35,"text":"The ou t side layer of endosperm i n a grain below the seed coat. It i s rich in oil, vitamins and protein but lacks starch. It is removed in rice during milling ."}]},{"head":"Al ka l ine soil:","index":12,"paragraphs":[{"index":1,"size":37,"text":"This is a soil that contains among other chemical compounds sodium bicarbonate and sodium carbonate. The soil has a very high PH (defined) ranging from 6.5-9.0. An alkaline soil induces zinc and iron defficiencies in rice fields."}]},{"head":"Allele (allelemorph):","index":13,"paragraphs":[{"index":1,"size":38,"text":"In Mendelian inheritance, one of a pair of alternative contrasting forms of a gene, fn which one may be dominant and the other recessive. The pair occupies the same site or locus in a pair of homologous chromosomes."}]},{"head":"Multiple alleles:","index":14,"paragraphs":[{"index":1,"size":36,"text":"A series of alleles (more than 2) which affect the development of a character. But only one pair of the series will occur at the same locus on a particular pair of chromosomes of an individual."}]},{"head":"Pseudo-alleles:","index":15,"paragraphs":[{"index":1,"size":3,"text":"A 11 ogamous:"},{"index":2,"size":1,"text":"Allogamy:"},{"index":3,"size":23,"text":"Genes that act phonotypically such as mUltiple alleles but are distinguished from one another by crossing over or by independent mutability (Clapper, 1960)."},{"index":4,"size":5,"text":"Capable of cross fertili zation."},{"index":5,"size":5,"text":"Cross-fertilization; oppo site of autogamy."}]},{"head":"Alloplold or allopolyploid:","index":16,"paragraphs":[{"index":1,"size":22,"text":"A plant having more than two sets of non-identical chromosomes in its body cells of each set derived from a different species."},{"index":2,"size":2,"text":"Alluvial soil:"},{"index":3,"size":11,"text":"Soil that has been deposited by any from of running water."},{"index":4,"size":5,"text":"Alte rnate host: Amino acids:"},{"index":5,"size":34,"text":"An individual upon which a parasite (or its spores, eggs, larvae, etc,) lives for a period of time before it finally lives on the main host on which it causes varying levels of damage."},{"index":6,"size":61,"text":"Carboxylic acids that contain the amino group -NH 2 . These acids are the units that link together into polypeptide chains to form proteins. There are twenty different amino acids in nature. There are eight essential ones. Some of these are limited in cereals and very important in nutrition. Some of the aminoacids of importance are lysine, leucine, Iso-leucine and tryptophan."},{"index":7,"size":3,"text":"Amphiploid or Amphidiploid:"},{"index":8,"size":1,"text":"Amylose:"},{"index":9,"size":3,"text":"A m ylopectin:"},{"index":10,"size":2,"text":"Anaerobic :"},{"index":11,"size":1,"text":"Analogous:"},{"index":12,"size":35,"text":"Said of plant resulting from a cross between two different species and having the total chromosome complement of the parent species. It is also usually produced by doubling the chromosome number of the Fl plant."},{"index":13,"size":80,"text":"In the cereal endosperm, it is the starch fraction in which the molecules or residues are made up of straight short chains (see non-waxy endosperm). The non glutinous or non-waxy rice endosperm range from 8-30% in amylose content. Most are 20-25% Low-amylose rice variaties are moist, sticky and glossy after cooking and readily split and break up when over-cooked. But rice with a high-amylose content cooks dry and fluffy and depending on the gel-consistency, it may become hard when cool."},{"index":14,"size":19,"text":"The type of starch in which the molecules or residues are made up of branched long chains (see waxy-endosperm)."},{"index":15,"size":6,"text":"(1) The absence of molecular oxygen."},{"index":16,"size":12,"text":"(2) Growing in the absence of molecular oxygen (such as anaerobic bacteria)."},{"index":17,"size":15,"text":"(3) Occurin9 in the absence of molecular oxygen (as a biochemical process) (Forth, 1978) ."},{"index":18,"size":4,"text":"Similar, e.g. analogous chromosome."}]},{"head":"Analysis of variance:","index":17,"paragraphs":[{"index":1,"size":1,"text":"Anatomy:"},{"index":2,"size":1,"text":"Aneuploids:"},{"index":3,"size":16,"text":"The analysis carried out in statistics that enables one to test the significance of variable sources."},{"index":4,"size":13,"text":"Study of the internal structure of plant parts, e.g. the xylem and phloem."},{"index":5,"size":24,"text":"A plant having a chromosome number that is not an exact multiple of the haploid chromosome complement, e.g. X + 1 or X -1."}]},{"head":"Anisomeric genes:","index":18,"paragraphs":[{"index":1,"size":23,"text":"Several genes that have one directional, cummu1ative, but unequal1 effects. Their expressivity and ,heritability are intermediate between those of major genes and polygenes."},{"index":2,"size":25,"text":"Yearly; used for plants that complete their life cycle (from seed to seed production and death) within a year or single season e.g. cultivated rice."}]},{"head":"Anonymou s:","index":19,"paragraphs":[{"index":1,"size":13,"text":"Nameless; used in scientific publications when the author's name is not given ."}]},{"head":"Antagonistic symbiosis:","index":20,"paragraphs":[{"index":1,"size":3,"text":"Anth esi s:"},{"index":2,"size":23,"text":"A symbiotic (see symbiosis) association which i s disadvantageous or de structive to one of the symbionts or partners involved in the association."},{"index":3,"size":21,"text":"The period when floral pa rts open and pollen is dispersed f rom the anthers The time when fertilization takes place."},{"index":4,"size":1,"text":"Anthocyanin:"},{"index":5,"size":17,"text":"Purple orred pigmentation of different shade in one or more parts of a plant, particularly in rice."}]},{"head":"Antibiotic:","index":21,"paragraphs":[{"index":1,"size":23,"text":"A chemical substance produced by one species of organism that in l ow concentration, will kill or inhibit growth of certain other organisms."},{"index":2,"size":1,"text":"Antibiosis:"},{"index":3,"size":1,"text":"Apiculus:"},{"index":4,"size":93,"text":"An antagonistic assoc ia t ion between two organisms producing detrimental effects on one of them. It co uld also mean an association between one organism and a metabolic product of another. An example i s the phonomenon in which a virus-carrying insect which feeds on a resistant variety of rice has its life span shortened. This adverse effect reduces the insect population density. This also means that there are fewer insects in the rice field to spread the virus the insect i s hosting. Thus t he variety has less infect ion."},{"index":5,"size":15,"text":"A small extension of the lemma and pal ea. It is often coloured in rice."},{"index":6,"size":1,"text":"Apomixis:"},{"index":7,"size":1,"text":"Apparatus:"},{"index":8,"size":42,"text":"\"Reproduction in which sexual organ or related structures take part but fertilization does not occur, so that the resulting seed is vegetatively produced\" (Allard, 1960). In other words, reproduction from an unfertilized egg or from somatic cells associated with the female parent."},{"index":9,"size":28,"text":"Equipment, device or instrument for carryihg out an operation e.g. in rice, clipping to emasu1ate the simple apparatus required consists of a forceps and a pair of scissors."},{"index":10,"size":2,"text":"Application rate:"},{"index":11,"size":22,"text":"The amount applied per unit area or volume of an input in experiments or commercial production, e.g. 60kg of nitrogen per hectare."},{"index":12,"size":2,"text":"Applied research:"},{"index":13,"size":84,"text":"This is the research carried out making use of already available scientific findings in such a way that the results can be used immediately by the consumer in crops or by the farmer. Applied research adapts the results of basic research to the peculiar problems of a country or a region within each country. The research can be focussed from the beginning on meeting particular needs known to be critical now (Mosher, This is a water fern found in warm, temperate and tropical regions."},{"index":14,"size":36,"text":"It is also known as water velvet and mosquito fern. There are over 50 strains of Azolla. Some of the species are Azo11a pinnata, A. fi1iculoides, A. mexicana, A. caro1iniana and A. microphylla TWatanabe, et ~,-1981)."},{"index":15,"size":1,"text":"-"},{"index":16,"size":53,"text":"The importance of Azo11a is due to the association of the blue-green algae, Anoba~na azo11ae (see Blue-green algae) which lives permanently on Azolla s life cycle . In an intensive cropping of Azolla (6 times within 121 days) up to 104 kg of N/ha was produced by the Azolla-Anabaene complex (Watanabe et~, 1981)"},{"index":17,"size":12,"text":"Phosphorus is essential for good growth and deve l opment of Azolla."},{"index":18,"size":9,"text":"Bl, B2 (BC 1 , BC 2 ) :"},{"index":19,"size":11,"text":"The first and second backcro sses or bac kcros s generations."},{"index":20,"size":46,"text":"The first backcross is made by crossing a hybrid with one of its parents; t he second backcross is made by crossing Bl individuals with one of the pa rents, referred to as a recurrent parent whi ch is usually the prefe rred cultivar or line."}]},{"head":"Bac kcross:","index":22,"paragraphs":[{"index":1,"size":40,"text":"A cross of a hyb rid or hete rozygote or an F with one of its parents (recurrent parent) done with th~ aim of transferring a simply inherited trait into an imp roved variety whi ch lac ks the trait."}]},{"head":"Bac kcro ss breed ing:","index":23,"paragraphs":[{"index":1,"size":85,"text":"This is a me t hod for dev eloping a new variety in which a s i mply inher i ted trait is transferred usually fr om an unimproved variety (non-recu rren t or do nor parent) into an imp roved variety which lacks the character from the don or pa rent. Several backcrosses are made to the recurrent parent until the new line resembles the recurrent pa rent except that it has t he new character or cha racter s from the donor parent."},{"index":2,"size":4,"text":"Bac kcross pa rent:"},{"index":3,"size":51,"text":"One of the parents of a hybrid with which the hybrid is repeatedly crossed. It is also known as a recurrent parent. The recu rrent parent has most of the desi rable characters, but l acks one or two trai ts t hat a donor or non-recurre nt parent posse sses."},{"index":4,"size":2,"text":"Backcross ratio:"},{"index":5,"size":2,"text":"Bac teria:"},{"index":6,"size":74,"text":"Th e proportion of heterozygotes to bottom rnce ssives expected in a backcros s ; this is given by calculat i ng 2 where n i s the nu mber of factor s involved, e .g. when n = 1, i t is 1:1 with 2 factors, 2 n = 4 and the expected rat i o is 3:1 with 3 f actors, 2n = 8 and t he expected ratio is 7:1, etc."},{"index":7,"size":39,"text":"Single-celled microscopic organisms. They grow, multiply and may double their number within an hou r under optimal conditions. They are incapable of photosynthesis and depend on various substrates for food. They exist both in the soil and on plants."},{"index":8,"size":41,"text":"They affect plants in various ways, e . g. as pathogens of economic diseases such as bacterial wilt of cassava and as non-pathogens fixing molecular nitrogen in various ways, e. g. module-living Rhizobium spp., blue-green bacteria, Anabaena spp., free-living Azotobacter spp."}]},{"head":"Bacterial bl ight:","index":24,"paragraphs":[{"index":1,"size":75,"text":"A disease caused by bacteria. In rice it is bacterium Xanthomonas oryzae. Lesions may start anywhere on the leaf but usually they start at edges near the tip or leaf margins. The lesions then enlarge and expand downwards in straight lines. Lesions are first pale-green to grayish-green . Later they turn bronze to gray and the leaf tissues die. In very susceptible varieties, lesions may extend over the entire leaf length into the leaf sheath."},{"index":2,"size":4,"text":"Bacterial leaf strea k:"},{"index":3,"size":10,"text":"In rice the causal agent is Xanthomonas translucens f. sp.oryzae."},{"index":4,"size":53,"text":"Infection is usually only on the leaf blade. Lesions first appear as water-soa ked streaks between veins gradually turning yellow or orange. The lesions may develo p side by side, but remain more or les s linear. Hi gh humidity favors i nfection which does no t get trasmitted t o unaffected leaves."},{"index":5,"size":2,"text":"Baggin g:"},{"index":6,"size":25,"text":"The act of covering a plant, especially the reproductive parts to prevent cross pollination or pest damage. This is an important process in cereal breeding."}]},{"head":"Bakana e disease:","index":25,"paragraphs":[{"index":1,"size":116,"text":"A fungal disease in rice caused by Gibberal l a fuji kuroi (Sawada) Ito (Fusarium moni l i f orme shiel d). The m ost cons picuous symptom is the abnormal l eaf elongat i on of affected pla nts which produce tall thin plants in t he seed bed. The young plants are yellowish-green. The disease is seed-borne. In the fiel d, infected pl ants produce ta l l lanky tillers bearing pale-green f l ag l eav es above the general level of the crop. Such plants produce few tillers an d the leaves die one after another. Whitish or pi nk fungal growth may appear on the lower portion of the dying plants."},{"index":2,"size":3,"text":"\"Banta faro\". :"},{"index":3,"size":1,"text":"Bar:"},{"index":4,"size":13,"text":"A local term in the Gambia describing traditional swamp or hydromorphic rice cultivation."},{"index":5,"size":13,"text":"A unit or press ure equal to 1 million dynes per square centimetre."},{"index":6,"size":8,"text":"Basal dressing or basal application of a chemical:"},{"index":7,"size":1,"text":"Base:"},{"index":8,"size":13,"text":"Fertilizer or chemical applied and incorporated into the soil during or before planting."},{"index":9,"size":31,"text":"The lowest portion of the plant to the ground. Height measurement is usually taken from the base of the plant to the tip of the panicle of a mature cereal plant."}]},{"head":"Bas i c Research:","index":26,"paragraphs":[{"index":1,"size":1,"text":"Bias:"},{"index":2,"size":1,"text":"Bimodal:"},{"index":3,"size":45,"text":"Research that deals with fundamental principles of things and organisms. Examples of basic research are: finding the location of a gene on a given chromosome of rice, the replication pattern of DNA of a yellow mottle virus or the mutation frequency of a blast conidium."},{"index":4,"size":15,"text":"Prejudice, favouring one treatment over another or treating a treatment worse or better than others."},{"index":5,"size":14,"text":"A frequency distribution having 2 modes of rainfall, having two peaks in the year."}]},{"head":"Biological control:","index":27,"paragraphs":[{"index":1,"size":1,"text":"Biology:"},{"index":2,"size":29,"text":"Controlling crop pests by using living organisms harmless to the plants but which destroy or reduce the number of the harmful pests. In this process, no chemical is used."},{"index":3,"size":32,"text":"The study or science of living t hings. Main branches are botany and zoology . Other branches are cytology, histology, morphology, physiology, embryology, ecology, genetics and microbiology. Agricultu re is applied biology."}]},{"head":"Biometrics:","index":28,"paragraphs":[{"index":1,"size":15,"text":"The science that deals with the use of statistics to explain biological data or observations."}]},{"head":"Biotic en vironment:","index":29,"paragraphs":[{"index":1,"size":1,"text":"Biotype:"},{"index":2,"size":23,"text":"The insect pests, pl ant pathogens, weeds, other crop plants, small animals and human beings in a habitat make up the biotic environment."},{"index":3,"size":21,"text":"A groupof individuals, e.g . insects with the same or identical phenotype, but having different physiological or bahavioural effects on plants."},{"index":4,"size":1,"text":"Bisexual:"},{"index":5,"size":1,"text":"Bivalent:"},{"index":6,"size":1,"text":"Blast:"},{"index":7,"size":13,"text":"Hermaphroditic possessing both organs in a single individual. pistils in a flower ."},{"index":8,"size":23,"text":"male and female reproducti ve The presence of both stamens and A pair of homologous chromosomes united i n the first mitotic division."},{"index":9,"size":46,"text":"A fungal disease caused by Pyricularia oryzae. A serious disease of rice that may attack one or more of the f ollowing parts of the r ice plant : leaves , ligules neck, nodes, pa nicle, rachi s or in div i dual spi kelets ."}]},{"head":"Bla st nursery :","index":30,"paragraphs":[{"index":1,"size":3,"text":"Bl i ght:"},{"index":2,"size":2,"text":"Block :"},{"index":3,"size":3,"text":"Bl oom :"},{"index":4,"size":63,"text":"A specially pre pared nursery or seedbed where seve r al vari et i es or lines are grown to determine thei r rel ative suscept i bility or resis t an ce to bl ast. The nursery co ns is t s of one or mo re kno wn suscepti ble en t ries t o serve as inocu lum spreade r."},{"index":5,"size":83,"text":"Any age nt cau s in g wi despread bl ac kening necro sis of l eaves and shoo ts. The onl y val i d use i n pl ant pathol ogy is in commo n names of certain di seases charac t er i zed by poten tia ll y ca t as trop hic ep i demic spre ad e.g. pota t o bli ght, f i re bl igh t , bacter ia l l eaf bl ig ht."},{"index":6,"size":119,"text":"In expe riments a bloc k is a grou p of i tems unde r t rea t ment or observat i on. In f i el d experi men t s, it co nsists of a grou p of co ntiguo us plots ass i gned to a pi ece of land. In expe r ime nt al des igns f or stat i st i cal analyses, t here are usu al ly two or ~ore blocks , often cal led rep l icat i ons . Blocking helps remove heterogenei t y. The pl ots or items in a bl ock are suppo sed to be more homoge neous than these in ot her bl ocks."},{"index":7,"size":43,"text":"A f l owe r or flo wers of a seed pl ant; t he powdery coat i ng on cer t ai n parts and f l owers. To produse bl ossom or f l ower (Clappe r , 1960 ) ."},{"index":8,"size":4,"text":"Bl ue -green algae:"},{"index":9,"size":66,"text":"These are al gae th at have bee n reported t o have contr i buted to t he m ain t enanc e of so il fer t ili ty espeC i al ly i n r i ce pa ddy field s . They can f ix fr om 15-45 kg N/ ha (De Datta,198 1) in unfer tili zed ri ce fi elds."},{"index":10,"size":39,"text":"There are in the Tropics many species belonging to the genera Tolypothrix, Nostoc, Schizothrix, Ca lothrix, AnoboenoasiS and Plectonema. Application of phosphatic fertilizers an line -<~ .. L< __ algal growth and nitrogen fixati on (De Datta, 1981) ."}]},{"head":"Bold grain:","index":31,"paragraphs":[{"index":1,"size":15,"text":"Grain as in rice that is broad in shape (see Table 1 under grain characteristics)."},{"index":2,"size":3,"text":"\"Boliland\" rice: Booting:"},{"index":3,"size":38,"text":"A local term is Sierra Leone for the type of rice under an ecology where the land is poorly drained and in depressions which may be flooded for 2-4 months. The soil here is l oW phos phorus."},{"index":4,"size":46,"text":"The characteristic swelling or enlargement at the ba se of the flag sheath in most graminaccous plants pr ior to heading or flowering. In 130-day maturing rice varieti es, about 45 days prior to m aturity . Booting stage becomes visible at 10-15 days before flowering."}]},{"head":"Booting stage:","index":32,"paragraphs":[{"index":1,"size":8,"text":"The growth period when the booting is visible."}]},{"head":"Border effect:","index":33,"paragraphs":[{"index":1,"size":1,"text":"Bran:"}]},{"head":"Breed:","index":34,"paragraphs":[{"index":1,"size":31,"text":"In experiments, especially fie l d ex periments, the better or worse performance of treatments at the edges or borders of a plot when compared with others not on the border."},{"index":2,"size":34,"text":"A product of milling in cereals. It is made up of the pericarp, tegmen or testa, embryo, aleurone layer, and some portion of the endosperm in rice. It is used f or livestock feeding."},{"index":3,"size":13,"text":"To provide offspring, to propagate, to bring about a new type of plant."},{"index":4,"size":22,"text":"Breeder's seed: Th i sis the seed produced by the breeder or hi s agents or association. It is the purest seed."},{"index":5,"size":20,"text":"The seed is used for producing the foundation seed (defined). It is also the source of other certified seed classes."}]},{"head":"Breeder's stock :","index":35,"paragraphs":[{"index":1,"size":42,"text":"This term is used often interchangeably as breeder's seed. However, here it refers to the supply of breeder's seed of a given variety that is available in his store under the breeders or his institution ' s custody. It can be parents."}]},{"head":"Breeder's stock seed:","index":36,"paragraphs":[{"index":1,"size":45,"text":"THis term is also very close to the breeder's seed except here it means that it is the seed harvested from the breeder's seed multiplication under the breeder's supervision. It can also be described as the grain harvested from a nucleus of breeder's seed stock."}]},{"head":"Breeding objectives:","index":37,"paragraphs":[{"index":1,"size":21,"text":"These are sets of goals to be achieved in a breeding program. Examples of breeding objectives: ' (1) High grain yield."},{"index":2,"size":9,"text":"(2 ) Resistance to important diseases and insect pests."},{"index":3,"size":9,"text":"(3) Resistance to drought . (4) Acceptable grain qualities."},{"index":4,"size":6,"text":"(5) Short or medium growth duration."}]},{"head":"Broadcast:","index":38,"paragraphs":[{"index":1,"size":24,"text":"The act of planting by spreading seeds or fertilizer or insecticide at random. Seeds are not usually covered or are incompletely covered by soil."}]},{"head":"Brown p1anthopper:","index":39,"paragraphs":[{"index":1,"size":68,"text":"An important insect of rice especially in Asia. Its scientific name is Ni1aparvata lugens. It causes serious damage, when in large numbers, on the lower portions of the plant. It sucks sap and the leaves turn yellow followed by rapid drying of the whole plant. The term hopper burn is used to describe the resulting damage. The insect also transmits grassy stunt virus and ragged stunt in rice."}]},{"head":"Brown rice:","index":40,"paragraphs":[{"index":1,"size":72,"text":"Rice grain with its hulls removed but not polished. It is also called dehul1ed rice, husked grain, or husked rice. The brown colour is due to pigments in the peri carp and aleurone layer. A common name for the parasitic fungus Helminthosporium oryzae that damages rice leaves. Typical symptoms are small, oval or circular and dark brown lesions. M os t spots have a light yellow hal o around the outer edge."},{"index":2,"size":82,"text":"A term loo sely used for insects. St r ictly refers t o the members of the order Hemi ptera. The order i nc ludes winged and wingless species. The most characteristic feature is the very l ong probos i s adapted for pierc i ng and sucking. The majority bel ong to the sub-order Heteroptera in which most of the plant suckers be l ong. They are very i mporta nt field and storage pests of cereals and ot her crops."},{"index":3,"size":25,"text":"A mod ified shoo t with a muc h shortend stem enclosed by fleshy scale-like leaves usually un de rgro und, e . g. onion."},{"index":4,"size":19,"text":"Noun: A mix ture of different var i et i es of seed s of the same crop species."},{"index":5,"size":67,"text":"Verb: To harvest and mix toge ther seeds from F2 or l ater gen era t i ons for planting the following generation without identify i ng or i so lating individu al plants in the mixt ure. To grow and ma intain genetically differe nt pl ants, usuall y of same species in a population without separating them into pure lines or app lying selection effort."},{"index":6,"size":7,"text":"Bu l k densi ty , soil:"},{"index":7,"size":24,"text":"The mass of dry soil per unit bulk volume. The bulk vo lum e is determined before drying to constant weight at 105°e. (Forth,197B)."}]},{"head":"Bulk method of breeding:","index":41,"paragraphs":[{"index":1,"size":24,"text":"Growing genetically diverse population of self-pollinated crops in a bulk plot with or without selection for 3-7 generations after which single-plant selection is made."}]},{"head":"By-product:","index":42,"paragraphs":[{"index":1,"size":37,"text":"A plant substance obtained incidentally during the manufacture of some other substance of more economic importance. The substance mayor may not be as important as the main substance Hself, e.g. bran is a by-product of milled rice."},{"index":2,"size":6,"text":"CO, Cl, C2 .... Cn :"},{"index":3,"size":60,"text":"In an open pollinated crop such as corn when selection is done on a cycle basis, the cycles are designated by CO, C1, C2 .... Cn. CO denotes the initial population, Cl denotes the population from CO + C2 population derived from Cl, etc. A cycle in corn may cover several seasons and may last several •years (Le Conte, 1973)."}]},{"head":"Calcareous soil:","index":43,"paragraphs":[{"index":1,"size":21,"text":"Soil containing sufficient free calcium carbonate or calcium-magnesium carbonate to effervesce visibly when treated with cold O.l~ hydrochloric acid (Foth, 1978)."},{"index":2,"size":1,"text":"Carbohyrate:"},{"index":3,"size":31,"text":"A chemical compound (CH 2 0) accumulated by plants e.g. sugar, starch, ce llulose. It 1 S essential in the complex chemical grO\\~th and deve10pemnt activities of a 1 iving organism."}]},{"head":"Carbon-nitrogen ratio","index":44,"paragraphs":[{"index":1,"size":36,"text":"The rat i o of the we i ght of organ i c carbon to the weight of tota l ni trogen (mineral plus organic fo rms) in soil or organic materi al (Foth, 1978) ."}]},{"head":"Caryopsis:","index":45,"paragraphs":[{"index":1,"size":2,"text":"Casewo rm:"},{"index":2,"size":77,"text":"A mature fruit , as in grasses, in which the seed coat is f irmly attached to the endosperm. Brown rice is an example of a caryops is. This is the insect Nymphu1a depuncta1is whose larva feeds on leaf tissue leaving only the papery upper epide rmis. The larva has the habit of wrapping itself in a section of the leaf and feeds on another portion of the leaf. It is an important insect pest of rice."}]},{"head":"Catch crop:","index":46,"paragraphs":[{"index":1,"size":48,"text":"This is a crop planted usually very early in the cropping season. It matures early or earlier than the main crop to produce some food before the main crop matures. A catch crop could be a short duration crop grown in between two croppings of a main crop."},{"index":2,"size":2,"text":"Causal organism:"},{"index":3,"size":1,"text":"Cell:"},{"index":4,"size":9,"text":"The organism that produ ces a given plant disease."},{"index":5,"size":21,"text":"The unit of life, a discrete mass of protoplasm bounded by a plasma membrane and a cellulose ,ell wall in plants."},{"index":6,"size":36,"text":"The cell consists of two forms of protoplasm: the nucleus and the cytoplasm. The nucleus contains the nucleic acid which produces the cell's enzymes and the chromosomes. Cytoplasm contains the enzymes that control the cell's metabolism."},{"index":7,"size":4,"text":"Celsius temperature: Centigrade temperature:"},{"index":8,"size":1,"text":"Cereal:"},{"index":9,"size":57,"text":"Temperature measured on a scale origina' l1y devised by Anders Celsius (1701-44) in which the melting point of ice 0° and the boiling point of water is 100°. To convert degree Celsius (OC ) to degree fahrenheit (OF) (defined), multiply by 9, divide by 5 then add 32 to the result. The formula is 9°C + 32."}]},{"head":"5'","index":47,"paragraphs":[{"index":1,"size":10,"text":"Most scientific reports are presented in Celsius or previously Centegrade."},{"index":2,"size":26,"text":"Flowering plants in the grass family (Graminaceae) cultivated mostly for food ' value of their grains e.g. rice, wheat, sorghum, corn, oats, barley, rye and millet."},{"index":3,"size":2,"text":"Certified seed:"},{"index":4,"size":39,"text":"Seed that has met various quality specifications. It is distributed or sold to farmers for food production. It is produced from foundation, registered, or even from certified seed by an approved agency. It could also come from breeder seed."},{"index":5,"size":3,"text":"Character, characteristic, trait:"},{"index":6,"size":1,"text":"Check:"},{"index":7,"size":60,"text":"A distinctive differentiating mark, feature or attribute such as colour, size or behaviour that makes a plant or a group of plants recognizable. It is the phonotypic result of the interaction of one or more genes with the environment. It is the expression of a gene or genes as revealed in the phonotype (see acqui red , discontinous characters )."},{"index":8,"size":29,"text":"A row or plot of a well known variety included in a nursery or test plot for comparison with new introdu ctions, selections or hybrids (see control) (Harrinston, 1952)."},{"index":9,"size":7,"text":"Chi -square (good ness of fit ):"},{"index":10,"size":31,"text":"X 2 -Chi-square is the sum of square of normally distributed independent, variables with zero means and unit vari~nce (Steel and Torrie, 1960). In general a simplified X2 formula used is:"},{"index":11,"size":1,"text":"Chlorosis:"},{"index":12,"size":1,"text":"Chromatid:"}]},{"head":"20","index":48,"paragraphs":[{"index":1,"size":32,"text":"A condition in a plant caused by disease or phisio-chemica1 factors in which the normally green parts of the plant are pale-green or yellow. The condition is due to inhibited chlorophyll formation."},{"index":2,"size":17,"text":"One of the two threadlike structures found during the duplication of a chromosome to form daughter chromosomes."}]},{"head":"Chromosomes:","index":49,"paragraphs":[{"index":1,"size":67,"text":"Microscopic threadlike bodies consisting mostly of DNA and proteins in the cell nuclei. They bear the genes. Their numbers are usually constant in each species and they occur in pairs. They are concerned with the transmission of genetic information from cell to cell and generation to generation. They also control the release of this information to control cellular foundation and deve < lopment. They duplicate themselves easily."}]},{"head":"Ciliate ring:","index":50,"paragraphs":[{"index":1,"size":13,"text":"In rice a ring-like structure at the base of panicle (see panicle base)."}]},{"head":"Classification:","index":51,"paragraphs":[{"index":1,"size":1,"text":"Classify:"},{"index":2,"size":1,"text":"Clay:"},{"index":3,"size":2,"text":"Clay loam:"},{"index":4,"size":1,"text":"Clone:"},{"index":5,"size":30,"text":"The systematic arrangement of plants into groups usually based on natural relationships. In botanical classification, the common categories in diminishing rank are: phylum, class, order, family, genus, species, and variety."},{"index":6,"size":7,"text":"To arrange orderly and systematically into groups."},{"index":7,"size":48,"text":"Fine partici1es of soil less than 0.002 millimeter in diameter m ade up mostly of hydrous aluminium silicates in combination with other minerals. It holds a lot of water. It forms a barrier for water percolation or leaching. A clay soil is referred to as a heavy-textured soil."},{"index":8,"size":15,"text":"A loam soil that consists of 20-30 per cent clay and 20-45 per cent sand."},{"index":9,"size":12,"text":"A name given to progenies resulting from a sexual or vegetative propagation."},{"index":10,"size":27,"text":"Also a group of plants vegetatively produced from the same original stock. Members of a clone are usually the same genetically unless there is mutation among them."}]},{"head":"Cle i stogamy:","index":52,"paragraphs":[{"index":1,"size":1,"text":"Clipping:"},{"index":2,"size":7,"text":"Fertilization taking place in an unopened flower."},{"index":3,"size":28,"text":"To cut of f briskly (with a pair of scissors or ~haverl, the margins, ends, or a sma ll portion of an object, e.g. clipping method of emasculation."}]},{"head":"Cold tolerance:","index":53,"paragraphs":[{"index":1,"size":26,"text":"Said of a plant able to grow and develop under cold conditions (air, water and soil I under which other plants without tolerance cannot survive well."}]},{"head":"Coefficient of variation (Cvl,","index":54,"paragraphs":[{"index":1,"size":129,"text":"A quantity that is used to indicate how precise an experiment i s . It is usually calculated after analysis of variance has been done and found underneath the analysis of variance CV is used to determine the rel iability of an experiment.. When a C.V. is very high, e. g. over 20% for upland rice yield trial in West Africa, the experiment may be considered unreliable. However, how high or low a CV is depends on the type of experiment and the character being observed. For example, insecticide or herbicide trials will have a higher CV than a yield trial. Al so, the CV for t he number of ti ll ers will be much higher than that for plant height which varies less than til ler number."}]},{"head":"Co l eoptile:","index":55,"paragraphs":[{"index":1,"size":19,"text":"The first leaf of a monocotyledon forming a protect ive sheath round the plumule or the embryonic young stem."},{"index":2,"size":1,"text":"Coleorhiza:"},{"index":3,"size":1,"text":"Collar:"},{"index":4,"size":13,"text":"The sheath or covering of the embryonic roots through which the roots burst."},{"index":5,"size":28,"text":"The place or area where especially in grasses. the leaf sheath and the the leaf sheath and leaf blade are joined, It usually differs in pigmentation from blade."},{"index":6,"size":1,"text":"Collection:"},{"index":7,"size":23,"text":"A gathering of different strains, varieties or species. Such a collection is stored in a cold place for preservation until evaluated or multiplied."},{"index":8,"size":2,"text":"Combining ability:"},{"index":9,"size":49,"text":"General -the \"average performance of a line in hybrid combination\" in contrast to specific combining ability used to indicate \"those cases in which certain combinations do relatively better or worse than would be expected on the basis of the average performance of the lines involved\" (Sprague and Tatum, 1942)."}]},{"head":"Commodity-oriented research:","index":56,"paragraphs":[{"index":1,"size":17,"text":"A research focused on a given agricultural product or a crop. It usually involves a multi-disciplinary effort."},{"index":2,"size":1,"text":"Compatible:"},{"index":3,"size":20,"text":"Of plants whose morphologic and genetic traits enable them to cross-pollinate, bud or graft easily and to produce useful progenies."}]},{"head":"Compos He:","index":57,"paragraphs":[{"index":1,"size":17,"text":"In plant breeding, e.g. in maize, a population developed by putting together several individuals with distinct genotypes."}]},{"head":"Competition:","index":58,"paragraphs":[{"index":1,"size":66,"text":"In ecology, genetics and evolution, the endeavour (which may take various forms and have various direct or indirect, deleterious results) of two (or more) organisms of the same or different species to .gain the same particular factor or thing, or to gain the measure each wants from the supply of any factor or thin~ when that supply is not sufficient for both (or all) (Milne, 1961)."},{"index":2,"size":22,"text":"In field crops competition occurs when adjacent plots are planted to varieties differing in plant height, tillering ability, vigour and growth duration."}]},{"head":"Competitive ability:","index":59,"paragraphs":[{"index":1,"size":86,"text":"The success of one species or a variety in a mixture which is generally attributed either to the ability of that species or plant varieties to produce a greater proportion of offspring in the next generation at the expense of other(s} or to its ability to reduce the numbers of the other species without itself changing (the success of one component of the mi xture may depend on its ability to avoid the other (s) without necessarily having any effect on it) (Rieger et ~, 1976)."},{"index":2,"size":1,"text":"Complementary:"},{"index":3,"size":18,"text":"(1) Of two structures, each of which defines the other, e.g., the two strands of DNA double helix."},{"index":4,"size":5,"text":"(2) Of four-strand double crossing-over."},{"index":5,"size":25,"text":"(3 ) Of genes which by interaction produce an effect qualitatively di stinct from the effects of any of them separately (Rieger et ~, 1976)."}]},{"head":"Composite variety;","index":60,"paragraphs":[{"index":1,"size":65,"text":"A variety consisting of a m or e or less high nu mber (over 4) of components, such as inbred lines, all types of hybrids, populations, etc., aimed at obtaining a very diversified pl ant to form a basis for selection. It generally forms a stage in the process of creating new varieties, but the composite varie t y is sometimes suitable for extensio ns."},{"index":2,"size":32,"text":"(I ) In some cases, the components may have common characters, such as similar growth period, similar degrees of resistance to lodging or a pathogenic agent, etc. These composites have specific characters."},{"index":3,"size":24,"text":"(2) With a fa i rl y 1 a rge gene poo 1, the stabil ity of the compos H e variety is limitless."},{"index":4,"size":40,"text":"( 3) It is advisable to use the term \"composite\" whenever the plant involved is not to be extended; but when it is to be grown commercially, \"composite variety\" would be preferable. (Le Conte, 1973) (see synthetic variety ) ."},{"index":5,"size":3,"text":"COn C1IJS1 QI):"},{"index":6,"size":13,"text":"The decision, deducti on or resol ution of an experiment or a report."}]},{"head":"Condition:","index":61,"paragraphs":[{"index":1,"size":12,"text":"Any factor influencing an experiment, e.g. weather, soil, t emperature, site, etc."},{"index":2,"size":1,"text":"Conduct:"},{"index":3,"size":1,"text":"Confirm:"},{"index":4,"size":18,"text":"To put into practice or to carry out, e. g. an experiment or special operation such as measurement"},{"index":5,"size":13,"text":"To verify, strengthen,substantiate, already known fact or a theory e.g. of an experiment."},{"index":6,"size":9,"text":"uphold or to prove an to confirm the result"},{"index":7,"size":29,"text":"An accession, cultivar or a portion of or subdivision of it e.g. strains or pure lines selected for maintaining the accession in a national or international agricultural centEr. Consistent:"},{"index":8,"size":1,"text":"Constant:"},{"index":9,"size":39,"text":"Of a result or performance of a treatment. It means reconciliable, regular, coherent, compatible , e.g. a variety is said to be consistent if it yields highly at all the locations where it has been tested under similar conditions."},{"index":10,"size":26,"text":"Something that does not change, e.g. in various calculations a figure that has been determined and used to solve a particular problem where other factors change."},{"index":11,"size":1,"text":"Constraint:"},{"index":12,"size":40,"text":"Of yield or growth, that factor that adversely affects or prevents the full yield or growth expression. It is also the impediment, factor, pressure, stress, etc. that prevents the expression of the full potential of a crop or a program."}]},{"head":"Contact herbicide:","index":62,"paragraphs":[{"index":1,"size":12,"text":"Herbicide (defined) that is effective mostly when it touches the plant surface."}]},{"head":"Contact insecticide:","index":63,"paragraphs":[{"index":1,"size":12,"text":"Insecticide (defined) that kills insects only when it touches directly the insects."}]},{"head":"Contiguous:","index":64,"paragraphs":[{"index":1,"size":5,"text":"Touching, near, as contiguous plots."},{"index":2,"size":1,"text":"Contribution:"},{"index":3,"size":26,"text":"(1) The role played by an environmental f ac tor or other treatments on a treatment in an experiwent to give the observed or measured result."},{"index":4,"size":11,"text":"(2) A writing for publication especially in a journal or periodical."}]},{"head":"Continuous variation:","index":65,"paragraphs":[{"index":1,"size":2,"text":"(See variation)."}]},{"head":"Con tro I :","index":66,"paragraphs":[{"index":1,"size":17,"text":"Noun: It i s a determined or known check or standard with which other treatments are compared."},{"index":2,"size":18,"text":"Ve rb : To prevent or mlnlmlse the danger of establishment or attack by pests, diseases or weeds."},{"index":3,"size":4,"text":"Convergent im p rov~;r.ent:"},{"index":4,"size":34,"text":"Improvement (see improve) brought about by concent ra ting in bo t h pa rents of a cross, favourable domi nan t genes available i n the lines, and across the two parents together."}]},{"head":"Coordinated tri al:","index":67,"paragraphs":[{"index":1,"size":49,"text":"This i s a trial m~de up of same treatme nts in an expe r iment conducted in ma ny places in and outside of the originating country. Such trials are usually organized by research inst i tutes, associations or other agricultural agencies, e. g. WARDA coordinated trial s."}]},{"head":"Co rrelati on:","index":68,"paragraphs":[{"index":1,"size":59,"text":"A measure of the deg ree to which variables vary to ae ther or a measure of the i nten s ity of associ ation (Steel ahd•. Torrie 1960 ) , e. g. genoty pi c correlation. Correlation can be \"simple\" when there is only one indepe ndent variable and \"multiple\" when there is more than one independent variable."}]},{"head":"Cor relation coefficient\"","index":69,"paragraphs":[{"index":1,"size":3,"text":"Co uplin g:"},{"index":2,"size":38,"text":"A numerical value used to describe the rela tio nsh ip Detween two va ryi ng observations. The value varies from -1 to 1. A ze ro coefficient m eans t ha t there i s no correlation."},{"index":3,"size":20,"text":"Linked recessive alleles occurring in one homologous chromosome and their dominant alternatives occurring in the other homologous chromosome (see repulsion)."}]},{"head":"Co-variance;","index":70,"paragraphs":[{"index":1,"size":13,"text":"Similar to correlation ; measure in statistics of the interrelationship of two variables."}]},{"head":"Cover crop:","index":71,"paragraphs":[{"index":1,"size":17,"text":"A crop planted to prevent soil erosioll and to provide humus . These are generally leguminous crops."},{"index":2,"size":2,"text":"Covered smut:"},{"index":3,"size":1,"text":"Crinkle:"},{"index":4,"size":1,"text":"Crop:"},{"index":5,"size":26,"text":"A smut disease of grains in which the spore masses are held together by the persistent grain membrane and glumes, e.g. Sphaceolotheca cruentia in Sorghum bicolor."},{"index":6,"size":19,"text":"This is a disease whose causal agent is yet unkn own. It causes stunting and chlorotic streaks on rice."},{"index":7,"size":25,"text":"A plant or group of plants that can be grown and harvested for food or other economic purpose. The yield or product from planted plant."},{"index":8,"size":2,"text":"Cropping pattern:"},{"index":9,"size":29,"text":"The yearly sequence and spatial ~rangementof crops or alternating crops and fa ll ow on a given area. The fallow crop may be natural or planted (Ok igbo, 1978)."},{"index":10,"size":2,"text":"Cropping system:"},{"index":11,"size":13,"text":"An organized cropping procedure established fo r a given loca ti on ."},{"index":12,"size":30,"text":"It involves the number of different crops to grow at a time, time of planting, number of crops per year or per season, the rotational scheme and various cultural practices."},{"index":13,"size":2,"text":"Crop rotation:"},{"index":14,"size":2,"text":"(See rotation)."}]},{"head":"Cross:","index":72,"paragraphs":[{"index":1,"size":52,"text":"To affect cross fertilization by the introduction of a male gamete or pollen grains from a different variety or species (usually different genotypes) of plant onto a female part of another plant. The term is also used t o refer to a hy brid or a plant resulting from such a process."},{"index":2,"size":7,"text":"The following types of crosses are possible:"},{"index":3,"size":3,"text":"(1) Backcross (defined)"},{"index":4,"size":4,"text":"(2) Diallel cross (defined)"},{"index":5,"size":6,"text":"(3) Double cross (double cross hybrid):"},{"index":6,"size":13,"text":"The crossing of two different hybrids (F 1 S) (4 ) Multiple cross:"},{"index":7,"size":15,"text":"The crossing of a hybrid with one or more cultivars of diffe re nt origin."},{"index":8,"size":12,"text":"(5) Sing l e cross: (defined) cross involv ing only two parents."},{"index":9,"size":39,"text":"(6) Top cross : A t hree -way cross; a cross between an F] and ano ther parent. A male parent used on many female parents is also called a top cross or tester parent or lin e ."},{"index":10,"size":7,"text":"Cross deSig na t ion s :"},{"index":11,"size":45,"text":"These are the ways that the crosses made are ident i fi ed. Standard practice i s to first list t he fe m ale or pi stillat e pa rent fo llowed by t he male or staminate paren t in a cross ."},{"index":12,"size":35,"text":"Examples of various designations are given below: The CIMMYT system i s easy to read and wri te wh 11 e the USDA sy~. tem is more compatible with computers (Jennings et ~. 1979) ."},{"index":13,"size":1,"text":"Cross-fertilization:"},{"index":14,"size":3,"text":"(See f ertilization)."},{"index":15,"size":2,"text":"Cross numbering:"},{"index":16,"size":92,"text":"This is the consecutiv e numbering that is used to identify a cross. Th e number continues over the years and it is not dup l icated. Therefore, in a given stat i on two or more cro sses never carry the same number. Usua l ly, all cross numbers are preceeded by one or more capital letters identifying t he stat i on, prog ramme or th e crop. For example, IITA uses the pref i x TOX and IRR I , IR f or their rice hybridizati on programme ."},{"index":17,"size":3,"text":"Cross-polli na tion:"},{"index":18,"size":32,"text":"The act of pl ac ing on a s tig ma of a flower the po ll en grains f rom a flowe r of a di ff ere nt pl ant."},{"index":19,"size":6,"text":"Cross ing over (X-over ) :"},{"index":20,"size":52,"text":"An interchange or segment s or port i ons between the chrom atids of two ho~o l og ou s chromoso m es at m eio sis. Crossin g over can be si ngle or multip l e. The poi nt s of exchange ar e call ed chi asm ata ."},{"index":21,"size":4,"text":"Crossover va l ue:"},{"index":22,"size":1,"text":"Culm:"},{"index":23,"size":8,"text":"Culm l engt h: Cult i vat\" :"},{"index":24,"size":3,"text":"Cult i vate:"},{"index":25,"size":24,"text":"The percentag e of cros s i ng ove r in a hybrid populati on, used m ostl y in chromosome ma pping ."},{"index":26,"size":40,"text":"Sten of grass es , espec i all y r i ce and wheat . It i s r ound and smooth and us uall y i t i s th e upr ight axis of the shoo t ."},{"index":27,"size":38,"text":"Thi s i s the di s t an ce of t he cul m (de f i ned ) fro m gro und l evel t o t he base of t ne pani c le ."},{"index":28,"size":83,"text":"A gener al t erm for a ve ri ety , line or cl on e tha t i s widely culti vat ed. It i s now t aken as the interna tional t erm fo r var iety . I t i s said t o be an abb reviated term f or culti va ted var i ety . It i s now use d ge nera lly for a var i ety resulting f rom sel ection work ."},{"index":29,"size":17,"text":"( 1) To prepare the l and in a special way for planti ng or sowin g."},{"index":30,"size":30,"text":"Experiment al growth conducted in the laboratory, the med ium for growi ng plant s experimentally or artific i all y . Also the cult i vation and tillage practices."},{"index":31,"size":5,"text":"CuI tural pract i ces:"},{"index":32,"size":43,"text":"These are the activ itie s or operations that are usually carried out i n raising field crops. Exampl es are pla nting, weed ing, app li cation of chemica l s, irrigat i on , drai ning, tillage, crop rotation, harvesting, etc."},{"index":33,"size":4,"text":"Cummu l ative selection:"},{"index":34,"size":4,"text":"Cur rent: Cut icle:"},{"index":35,"size":25,"text":"A s i mple method of rec urrent select i on in corn with ou t a tester, so that no top-cross is i nvolved."},{"index":36,"size":83,"text":"(a) In i ts s imp l e form {two crops per cycle}, t his met hod may be described as a succession of cycles in which each cyc l e consists of a f irst se l f -ferti li zed crop from which pl ants are selected (according to certain criteria, e. g. r es istance to a patho ge nic agent) and a second crop in which the se l ected sel f-fer ti liz ed progeny i s recoclbined."},{"index":37,"size":15,"text":"{b} In a more complex for m, the cycles have three stages (three crors) :"},{"index":38,"size":12,"text":"1. Pl ants self fertilized without any selection afte r harvesti ng."},{"index":39,"size":9,"text":"2. Ear -to-row sowing with remma nt seed preserved."},{"index":40,"size":15,"text":"3. Recomb in ing t he remma nt seed of the best line s ."},{"index":41,"size":46,"text":"Th e effect of cummulative se l ection, therefore, i s to i ncrease over success ive cycles, the occ urrence of favourable alleles on dis ti nct loci for a desired character, e. g. re s i stance to a pathogenic agent (Le Conte, 1973)."},{"index":42,"size":13,"text":"Of variety, that which is prevalent or bei ng present l y planted."},{"index":43,"size":48,"text":"The superficia l no n-cel lul ar l ayer coveri ng secreted by epide rmis. In most plants, it forms a conti nu ous cover over aerial parts except where there are stomata and lenticels. Functi ons are protecting against injury and preventing excessive water l oss ."},{"index":44,"size":17,"text":"A section of plant capable of developing into a new plant e.g. cassava or sweet potato cutting."},{"index":45,"size":2,"text":"Cy togenetics:"},{"index":46,"size":2,"text":"Cytology :"},{"index":47,"size":2,"text":"Cytoplasm :"},{"index":48,"size":17,"text":"A branch of biology that deals with the study of heredity and variation by cytology and genetics."},{"index":49,"size":18,"text":"A branch of biology that deals with the structure, contents funct ion and mu ltiplicati on of cells."},{"index":50,"size":9,"text":"The protoplasm of a living cell excluding the nucleus."}]},{"head":"Cytoplasmic inheritance:","index":73,"paragraphs":[{"index":1,"size":1,"text":"Damage:"},{"index":2,"size":24,"text":"Extrachromosomal inheritance and plastid inheritance. Non-mendelian inheritance. It is the transmission of hereditary characters through components in the cytoplasm rather t han by chromosomes."},{"index":3,"size":16,"text":"Injury or harm, caused or done by weather, chemical, animals or other plants to a plant."}]},{"head":"Dapog method:","index":74,"paragraphs":[{"index":1,"size":1,"text":"Data:"},{"index":2,"size":55,"text":"A method of ra i s ing seedl in gs i n which pre-germinated seeds are put together on a sheet or other smooth mater i al in a small area . The young seedlings from such a method are lifted li ke a roll of sod and transplanted when they are two weeks old."},{"index":3,"size":12,"text":"Mea sured statistics or col lection of facts usually from experimental treatments."}]},{"head":"Day length (photoperiod) :","index":75,"paragraphs":[{"index":1,"size":13,"text":"This refers to the number of hours there are between sunrise and sunset."},{"index":2,"size":16,"text":"Days to heading, flowering and maturity: A condition of progressive deterioration, e.g. productivity of a variety."},{"index":3,"size":16,"text":"To make less, smaller, to reduce, shrink or substract from e.g. to decrease yield or height."},{"index":4,"size":6,"text":"Dee p water or deep flooded:"},{"index":5,"size":3,"text":"Def i ciency:"},{"index":6,"size":17,"text":"Rice that grows under a water level of 60-100 cm for most parts of its growing period."},{"index":7,"size":13,"text":"(1 ) The absence or deletion of a segment of a chromosom e."},{"index":8,"size":50,"text":"(2) The lack of or inadequacy of a chemical nutrient e.g. Nitrogen, Pho sphorus and Potassium in the soil or plant. It is.~lS? the presence of the chemical in its ynaval ab e form, e.g. ferric form of iron in iron deficiency under uplandwhere iron is in unavailable ferric form."},{"index":9,"size":7,"text":"Dehull, De ~usk (see hull and husk):"},{"index":10,"size":1,"text":"Dehumidify:"},{"index":11,"size":1,"text":"Demonstrate:"},{"index":12,"size":9,"text":"To remove the hulls or husk from a grain."},{"index":13,"size":15,"text":"To remove moisture fro m the air as in a cold storage room for seeds."},{"index":14,"size":25,"text":"To show clearly, to prove or make clear to a large audience by reasoning, evidence, or experiment as in demonstration trial of a new variety."}]},{"head":"Dense panicle:","index":76,"paragraphs":[{"index":1,"size":20,"text":"In cereals especially in rice, it is a panicle that contains a high nu mber of grains per unit area."},{"index":2,"size":77,"text":"Th is type of kernel has a central core of floury st arch, which extends to the apex of the caryopsis and is surrounde d by horny starch. On r i peni ng, th i s floury starch dries and contracts producing a depression at the apex of the kernel, the characteristic indentation of this category of ma ize. Nost of the hybrids in the Co rn Belt (U nited States) are dent corns (Le Conte, 1973)."},{"index":3,"size":1,"text":"Denitrification:"},{"index":4,"size":27,"text":"The release of or escape of nitrogen f rom the soil, organic matter or fertilizer into the air mak ing it unavailable to the growing pl ant."},{"index":5,"size":6,"text":"Deoxyribonucleic (desoxyr ibo senucleic) acid DNA:"},{"index":6,"size":1,"text":"Descriptors:"},{"index":7,"size":117,"text":"Long thread-like molecules found in chromosomes and some viruses, consisting of two interwound helical chains of polynucleQtide s. . The sugar of all the nucleotides i s 2-deoxy-D-ribose, but each nucleotic is characterized by one of the four following nitrogenous bases, adenine, cytosine, guanine and thymine. DNA molecules are reponsible for storing the genetic code by the order of the arrangement of their nitrogenous bases, three bases coding for one amino acid. The st ructure of a DNA molecule has been likened to a twisted rope-ladder, the sides of which consist of sugarphosphate chains, the rungs of linked nitroge nous bases. The rungs consist of complementary base pairs linked by hydrogen bonds (Varov et ~ 1979 )."},{"index":8,"size":49,"text":"These are t he geographical, mo rphological or agronomical features for identi fy ing, characterizing or distinguishing cultivars collected in germplasm programmes. There could be up to 50 or more of these features and detail s on whe re collected. Th e descriptors should adeq uately characterize a cultivar."}]},{"head":"Descriptor-states:","index":77,"paragraphs":[{"index":1,"size":5,"text":"Des i rab 1 e:"},{"index":2,"size":1,"text":"Detassel:"},{"index":3,"size":23,"text":"In cultivar characterization in germplasm work, those features or details under the descriptor, e.g . code s such as 0, 1,2 ... 9."},{"index":4,"size":27,"text":"Of a plant or plant character, that which is preferred, wanted, needed or being sought after e.g. high yield, good grain, hig her protein or sugar content."},{"index":5,"size":13,"text":"To remove the male inflorescence or tassel, as in maize to prevent self-pollination."},{"index":6,"size":4,"text":"Determi na te :"},{"index":7,"size":5,"text":"Deve l op m ent:"},{"index":8,"size":1,"text":"Deviation:"},{"index":9,"size":43,"text":"Of a flower in wh ich t he terminal flower ope ns f i rst. Thi s of t en prevents the elongat i on of other f l oral axi s , e.g. i n some l eg uminous plant s ."},{"index":10,"size":87,"text":"A process of growth an d differen t iati on. It i s a regulated ser i es of pheno typic chan ge s under t emporal , sp at ial and qua nt itative co ntrol whi ch is irreversib l e or re versi bl e wit h difficulty under ordina ry env i ronm ent al condi t i ons. There are fo ur major processes in teracting wit h one another to make up t he comp lex process of deve l opemnt:"},{"index":11,"size":18,"text":"( I ) Genetic rep l i cation, mitosi s and duplicati on of genet ic informat ion."},{"index":12,"size":33,"text":"(2) Growth whic h is increa se i n the m ass of an orga ni sm as a result of vario us cell ul ar metabo li c act i vit ies."},{"index":13,"size":75,"text":"{3} Ce llul ar differentiation wh i ch is t he process by which cel l s of common orig in and ge ne tica ll y i dentica l change and i sola te themselves in stru cture an d fun ct i on. They con seq uen t ly give ri se t o morpho l ogica ll y and phys i ologi ca ll y di st ingui shable cell s ."},{"index":14,"size":55,"text":"{ 4} Tis sue f orma ti ons res ul t ing f r om t he ag gregation of differ enti ated cell s to f orm a uni tary f unc tion. The t i ssue assoc i ate to fo rm orga ns {adapt ed fro m Rieger et ~, 1976} ."},{"index":15,"size":45,"text":"In stati s ti cs it i 5 t he amoun t by which an observation depa r t s fr om the mean , in other words , t he di fference between one set of values and the mean of the set ."},{"index":16,"size":7,"text":"Di a11 e1 cross i ng :"},{"index":17,"size":2,"text":"Di bble:"},{"index":18,"size":118,"text":"H ybr i di zing or crossi ng different va r i eties or l ines togethe r in all poss i bl e combinati ons. With 6 cult i vars, 15 pairs of crosses are possible wit ho ut reci proca l crosse s. The formu l a i s n{n-I } with r eciprocal crosses of the complete se t, and n(n-I }/2 whe re n = the num ber of cu lt ivars when r eciproca l crosses are not involved i n the half dia 11 e1. Thi s method compares t he combini ng ab il i ty of the l ines or va riet i es used for ge net ic studies."},{"index":19,"size":27,"text":"To sow one or more seeds per hole whi ch is ei t her eve nl y or unev enl y spaced fro m t he other."}]},{"head":"Differentiate:","index":78,"paragraphs":[{"index":1,"size":14,"text":"To distinguish between two plants or group of plants, or between characters of plants."},{"index":2,"size":1,"text":"Differentiation:"},{"index":3,"size":1,"text":"Dihybrid:"},{"index":4,"size":1,"text":"Dioecious:"},{"index":5,"size":2,"text":"Diopsis fly:"},{"index":6,"size":2,"text":"Dipl oid:"},{"index":7,"size":9,"text":"The act or process of characterizing or making different."},{"index":8,"size":9,"text":"Changing from general to special characters, e.g. plant cells."},{"index":9,"size":15,"text":"A cross resulting from two parents which are different with respect to two known genes."},{"index":10,"size":21,"text":"A species that has female and male sex organs on different plants, e.g . Carica papaya and some species of Discorea."},{"index":11,"size":31,"text":"Commonly known as stalk-eyed fly, is an insect producing larvae which cause dead heart especially in young ri ce tillers. Three major species are Diopsis (thoracica) macrophthalma Diopsis apicalis Diopsis collaris"},{"index":12,"size":9,"text":"Possessing twice the number of gametic numbers of chromosomes."},{"index":13,"size":19,"text":"The somati c number of chromosomes (2n ) . The gametic number is usual ly half the diploid number."},{"index":14,"size":2,"text":"Direct sowing:"},{"index":15,"size":15,"text":"Sowing of seed directly or \"permanently\" not having to t ransplant, by drilling, broadcase ordibbling."}]},{"head":"Dirty panicle:","index":79,"paragraphs":[{"index":1,"size":2,"text":"Di scard:"},{"index":2,"size":3,"text":"(see glume discoloration)"},{"index":3,"size":21,"text":"A plant, plants or portion of a whole plot in a scientific trial that will not be used for data collection."},{"index":4,"size":1,"text":"Discipline:"},{"index":5,"size":21,"text":"A field of study, e.g. Pathology, Genetics, Agronomy, Entomology that deals in depth only on subjects specific to that particular study."}]},{"head":"Discoloration:","index":80,"paragraphs":[{"index":1,"size":18,"text":"A change to different colour, a stain, e.g. in rice grain caused by insect pests, diseases or weather."}]},{"head":"Discontinuous character:","index":81,"paragraphs":[{"index":1,"size":37,"text":"Character controlled by relatively few major genes. Each of the genes has a large contribution to the development of the character as compared to the environmental factors. Exampl es are colour of flower and smoothness of leaves."}]},{"head":"Disc repancy:","index":82,"paragraphs":[{"index":1,"size":1,"text":"Discrete:"},{"index":2,"size":27,"text":"Disagreement or inconsistency, e.g. of a measurement of a character such as plant height that is unusually different from one replication to another for the same variety."},{"index":3,"size":4,"text":"Distinct, discontinuous (see variation)."},{"index":4,"size":1,"text":"Discussion:"},{"index":5,"size":1,"text":"Disease:"},{"index":6,"size":27,"text":"In reporting writing or experimental results, this is a formal treatment of the experiment, explanation of results in a logical manner leading to conclusions of the trial."},{"index":7,"size":32,"text":"An abnormal condition in which a plant does not function, grow or develop as expected because of fungi, bacteria, viruses, other parasites, or a deficiency or excess of nutrients in the soil."},{"index":8,"size":2,"text":"Disease control:"},{"index":9,"size":17,"text":"The prevention, limiting or eradication of disease on crops. Plant resistance is an economic disease control method."},{"index":10,"size":2,"text":"Disease resistance:"},{"index":11,"size":24,"text":"Ability of a plant to grow and develop relatively well in the presence of a disease with little or no symptoms of the disease."},{"index":12,"size":1,"text":"Dissect:"},{"index":13,"size":47,"text":"To sp lit ope n i n a ca reful manne r for investigation of the co ntent as it is done by the sc ientist looki ng for or study i ng stembo re rs in cereal pla nt s uch as rice or so rghum."},{"index":14,"size":1,"text":"Distribution:"},{"index":15,"size":1,"text":"Divergent:"},{"index":16,"size":1,"text":"Diversity:"},{"index":17,"size":5,"text":"DNA : Domina nce :"},{"index":18,"size":14,"text":"( 1) The act or process of spreading out, e.g. a roo t ."},{"index":19,"size":34,"text":"(2) The position, arrangement or frequency, of occurenc e over an area or throug hout a space or unit of time, e.g. characters of a pl an t i n a give n study."},{"index":20,"size":21,"text":"(3) The natural geographic range of plants, e.g. wide di st r ibution of Oryza glaberri ma in Wes t Africa."},{"index":21,"size":49,"text":"A se l ection (de fin ed) whi ch is m ade from a single initial pop ul ation or a cross and to produce varieties or lines that greatly differ in character, e .g . late and early maturity, hi gh and l ow prote in conte nt."},{"index":22,"size":39,"text":"The condition of be ing different or having differen ces, variations or varieties, e,g. the great diversity in the sat iva speci es of rice . Plant breeders make use of diversity to produ ce new or improved varieties."},{"index":23,"size":9,"text":"(See deoxy r i bonuc l ei c acid)."},{"index":24,"size":55,"text":"Expre ssion of a chara ct er by one alle le wh i ch completely suppresses expression of the other . For i ns tance, Fl character resemble s that of one dominant pa r ent wit hout any trace of the second recessive parent used i n the cross. Different forms of dominance are:"},{"index":25,"size":31,"text":"(1 ) Incomplete or partial dominance. This i s a case of dominance that i s usually half-way between the characters of t he two parents in the cro ss ."},{"index":26,"size":38,"text":"(2 ) Over-dom inance. The character expressed exceeds that of either of the parents, e.g. an Fl plant may be taller or earl i er than the talle r parent or the earlier parent i n the cross."},{"index":27,"size":5,"text":"D onor Pa rent: Dormancy:"},{"index":28,"size":84,"text":"In grafting it i s the indi vid ual from which tissu es is take n to transfer to another plant. In Geneti cs it is the parent from which one or more gene s were transferred at th e initial cros s of a backcross to the recurrent parent . On ly on e or two cha racters are desirable from a donor parent. The r ecurrent parent which l ack s this character is otherwise an acceptabl e variety (see bac kcross)."},{"index":29,"size":93,"text":"Physiologica l rest or i nac t i ve growth in so me ma t ured seed s buds, bu l bs , etc., that delays germi nat i on or growt h f or some ti me even though there is physiological maturity, e.g. m os t tropical rice var ieties have a dormant per iod of 15 days . The rest period is determined largely by internal factors, certain chemical (oxydiz in g age nts) and phys ical change s (heati ng) whic h are used to brea k dorma ncy."}]},{"head":"Do uble crop pi ng:","index":83,"paragraphs":[{"index":1,"size":47,"text":"Having two crops of the same or differen t var i ety in sequenc e in the same pl ace within a year or cro ppi ng seas on, e .g. tran sp la nt i ng or seeding one after the harvest of the f ormer."}]},{"head":"Dou ble cross:","index":84,"paragraphs":[{"index":1,"size":2,"text":"(See cross)."}]},{"head":"Doug h stage:","index":85,"paragraphs":[{"index":1,"size":23,"text":"Th i s i s the ri pen i ng stage when the grains of a cereal crop ranges from soft to hard."}]},{"head":"Downy mildew:","index":86,"paragraphs":[{"index":1,"size":1,"text":"Dress:"},{"index":2,"size":2,"text":"Dr ift:"},{"index":3,"size":66,"text":"A fungal disease of cerea l s e.g. corn and mill et in whi ch the leaves and stems are attacked. Growth is retarded and often the II I ants di e before reaching t he f lower i ng st age de pending on t i me of inf ection and its severity . Some of the causal agents are Sclerospera macrospora and Sclerophthora macrospora."},{"index":4,"size":27,"text":"Of seeds to apply a chemical such as an i nsec tic ide or fungicide on the seed before pl anting , sending out or st orage."},{"index":5,"size":6,"text":"(see g r \" ~tic drift)."},{"index":6,"size":2,"text":"Drill sowing:"},{"index":7,"size":2,"text":"Droopy :"},{"index":8,"size":1,"text":"Drought:"},{"index":9,"size":35,"text":"To sow seed in shallow furrows or trenches. The seeds are in a continous row and are relatively closed to each other. There may and may not be predetermined spacing wi thin the row ."},{"index":10,"size":32,"text":"(Of l eaves) sagging, hangin g or inclining downward, e.g. rice l eaves. Improved variet ie s usually have non-droopy leaves especially i rr i ga ted va r i eties ."},{"index":11,"size":56,"text":"A prolonged per i od of drynes s during a crop season. Dependi ng on the variety, soil and other environmental conditions, and minimum of five days of no rain could be ragarded as a drought per iod . Upland rice and floating rice during the early stage in some pla ces do suffer from drought."}]},{"head":"Drough t avoidance:","index":87,"paragraphs":[{"index":1,"size":46,"text":"Adaption t o prevent excessi ve water l oss , e.g. ro ll i ng of leaves, stoppage of ac t i ve growth, thick cuti cle, or t o ab sorb more moi sture from the soi l longer and more prolific root sysytem ."}]},{"head":"Drought escape:","index":88,"paragraphs":[{"index":1,"size":36,"text":"Comp l eting a pla nt's essential growth cycle during the period of adeq uate mo i sture. The common escape me chani sm is through ear liness or pho to peri odi c sens itivity."}]},{"head":"Drought recovery:","index":89,"paragraphs":[{"index":1,"size":14,"text":"Resumption of norma l pl ant growth following growth retardation due to drought ."}]},{"head":"Droug ht stress :","index":90,"paragraphs":[{"index":1,"size":23,"text":"The pressure or the undesi r able environmenta l conditions caus ed by l ack of or i nsufficient moisture in the soil."}]},{"head":"Drought tolerance:","index":91,"paragraphs":[{"index":1,"size":30,"text":"Ability of a plant to withstand drough t stress by mea ns of physi olog ical characteristics , e.g. less evapora t ion from pl ants and osmo tic regulation."}]},{"head":"Dryland crop:","index":92,"paragraphs":[{"index":1,"size":60,"text":"Crop that i s grown where there is free wat er drai nage of t he soi l and the cro p depends mainly on the rains. The crop under this condition is rarely or neve r f looded, e. g. dry land or upla nd rice wh ere i rrigatio n is done only under special conditi ons ."},{"index":2,"size":24,"text":"Weight of any part of plant after its moisture content has been removed by any method of drying, e.g. dry weight of rice straw."},{"index":3,"size":4,"text":"Du ncan's mUltilpe-range test:"},{"index":4,"size":17,"text":"This is a test that enables one to m ake valid comparisons between more than two means."}]},{"head":"Duplicate genes:","index":93,"paragraphs":[{"index":1,"size":14,"text":"Two or more pairs of genes that produce identical effects, whether alone or together."}]},{"head":"Duplicate samples:","index":94,"paragraphs":[{"index":1,"size":27,"text":"Collected samples from d~fferent sources whi ch belong to the same variety as indicated by name, site of collection or origin and morpho-agronomic charactel-s (Chang, 1976a )."}]},{"head":"Oupl ication:","index":95,"paragraphs":[{"index":1,"size":1,"text":"Duplex:"},{"index":2,"size":13,"text":"A segment of a chromosome occu r ring twice in the haploid act."},{"index":3,"size":21,"text":"A case i n which a polyploid in recessive in all chromosomes except two loci in respct of a particular gene."}]},{"head":"Durable resistance:","index":96,"paragraphs":[{"index":1,"size":36,"text":"A resistance to disease, insect, physico-chemical factors that lasts throug h the li fe of a plant. The resistance has to be maintained throughout the length of period the variety is used for extensive crop production."}]},{"head":"Dwarf genes:","index":97,"paragraphs":[{"index":1,"size":22,"text":"Genes that are responsible for the small stature of plant parts, especially t he stem internodes. In rice, they are recessive genes:"},{"index":2,"size":1,"text":"dr'"},{"index":3,"size":9,"text":"In most cereals, they often the panicles or ears."},{"index":4,"size":2,"text":"Dwarf variety:"},{"index":5,"size":33,"text":"affect only the internodes below A variety that is shorter or smaller than other varieties of the same genus, e.g. in rice, a dwarf variety is about 50 cm in height (see Semi-dwarf)."},{"index":6,"size":27,"text":"The f ruiting sp i ke of a cereal such as ma ize. It is t he conbination of the seed and the fruit i ng structures."},{"index":7,"size":6,"text":"Ear l y m aturing variety:"},{"index":8,"size":50,"text":"One which completes it s l i fe cyc l e in a shorte r period compared to other va rieties in a given l oca l ity. For example, a rice variety ma turi ng in l ess than 100 days after sowing i s regarded as earl y."},{"index":9,"size":5,"text":"\"Ear-to-row\" select ion (see head-to-row):"},{"index":10,"size":58,"text":"Selection method ba sed on choosing mother plants and then pl an t ing the harvested seed. Sowing may be repeated severa l times on the same site or in different places. A mixt ure of t he original plants is us ed as a check . No artific i al cros sing or s~lfing i s used."},{"index":11,"size":29,"text":"A mixture of remnant seed of the best lines, the check, nay be us ed, or a second choice can be made fro m the best lines observed ."}]},{"head":"compa red wi th of pI ants","index":98,"paragraphs":[{"index":1,"size":61,"text":"This selection meth od consists of several cycles . It is espec iall y effective for improv in g characters such as rate of maturity, s i ze, colour of the ke r nels, position of t he ear, type of plant, etc. (Le Conte, 1973 ) . In mod ification f orms, it i s used in seed prod uction."},{"index":2,"size":5,"text":"Earl y generat ion materials:"},{"index":3,"size":35,"text":"These are the F -F4 lines. In pl ant breeding, especially in the pedigree l sys tem, t he lines that are still segregating for most of their characters are regarded as early generation materilas."},{"index":4,"size":4,"text":"Early yiel d testing:"},{"index":5,"size":2,"text":"Ecology :"},{"index":6,"size":1,"text":"Ecosystem:"},{"index":7,"size":35,"text":"This is estimati ng yi elding abi l ity of lines at F3 or F 4 • The l i nes with hi gher yiel ds are retained for further se l ection or purification."},{"index":8,"size":17,"text":"The science that deals with the rel ation of plants to their environment and to each other."},{"index":9,"size":47,"text":"A collection or community of organism interacting with one another, plus t he environment in which toey live and with which they also interact. A system may consist of green pl ants, ani mals bacteria, fungi, cl imatic and soil conditions and the producers of the crop."},{"index":10,"size":6,"text":"Ecotype, Ecospec i es , Eco-strains:"},{"index":11,"size":75,"text":"Distinct individual s within a species , subspec ies or variety in a given environment that are di ffer en t mo r phologi cally and phys iologi call from others of the same species i n another envi ronment . They cross f reely with other ecot ypes of the same spec i es. They us ually ar i se from re~ea t ed planting and se l ection in disti nc t environment."}]},{"head":"Edaphic conditions:","index":99,"paragraphs":[{"index":1,"size":3,"text":"Effe ct :"},{"index":2,"size":18,"text":"Environmental factors caused by the physical, chemical and bi ol ogica l characteristi cs of the soil ."},{"index":3,"size":66,"text":"In fl uence produced by an environmental fac tor, a plant or plant produ ct that accounts for a cause or a result, e. g. the eff ect of drought i s low yie ld, the effect of heavy or application on a very tall rice plant (150 cm) is lodging. In statist ics, that whi ch i s measured, and analysed e.g. treatment ef fect."},{"index":4,"size":20,"text":"Eli te lines: Supe r ior l i nes t ha t possess most of the characters being sought for."}]},{"head":"Elite germ plasm:","index":100,"paragraphs":[{"index":1,"size":23,"text":"Germpla sm consiting of improved breeding stock i ncluding cultivars and breeding li nes (strains) of hybrids and compos i t e populations."}]},{"head":"El ongat ion genes (Elongation ability ):","index":101,"paragraphs":[{"index":1,"size":44,"text":"These are genes responsible for the unusually rapid in crease in height mostly in rice as water lev el ri ses rapidly in ri ce fields. Th i s rapid growth does not occur where there is no rapid rise i n water level."}]},{"head":"Emascu l atio n:","index":102,"paragraphs":[{"index":1,"size":105,"text":"The process of removing anthers from a hermaphrodite flore t , e.g. ri ce or sorghum before t he anthe rs shed thei r pollen grains on the floret stigma. The plant thus emasculated becomes the f emale parent in hybridization work. There are ma ny met hod s for carrying out emasculation. In self-pollinated cereals t he pop ular methods are (1 ) Clipping of the glumes to remove t he an thers and the air and ho t water methods to force ope n the f loret s to make the remova l of anthers possible or to kil l the pollen grains."}]},{"head":"Embryo:","index":103,"paragraphs":[{"index":1,"size":22,"text":"Emergence: 42 A young non-self-supporting plant arlslng from the union ,of a female and male gametes after fertilization, sometimes without fertil ization."},{"index":2,"size":36,"text":"The act of a germinated seed or the plant parts coming i nto view above the ground surface after sowing or planting. Also other plant parts coming into view from flag leaf, buds, etc. e.g. panicles."}]},{"head":"Empty glumes:","index":104,"paragraphs":[{"index":1,"size":17,"text":"Thes e are sterile rudimentary lemmas found at the lowest part of a sp i kelet (defined)."}]},{"head":"Empty spikelet:","index":105,"paragraphs":[{"index":1,"size":5,"text":"Endemi c: Endosperm: Entry :"},{"index":2,"size":64,"text":"A spikelet not filled or has no grain at maturity. Some of the factors that cause empty spikelets are lack of starch due to disease, lodging or the leaf drying up, lack of fertiliza t ion due to various weather factors or too much nitrogen applied at panicle f ormation stage. Empty spikelets will float when placed in water and can be blown away."},{"index":3,"size":22,"text":"Native to a certain region, indi genous. Said of a disease or plant that is always found in an area (see exotic)."},{"index":4,"size":82,"text":"The nutritive tissue in the seed or fruits of most seed-bearing plants. It is for nutrition and development of the embryo. It is made up of starch, sugar, protein and fats. It is triploid a product of fertilization of two polar nuclei in the embryo sac by one sperm nucleus. It is the food portion of the cereal plant. In rice, it is divided up into non-glutinous (non waxy) glutinous (waxy) and intemediate. In corn, it could be waxy, non-waxy or sugary."},{"index":5,"size":26,"text":"A treatment referring especially to the varieties or lines in an experiment. It also refers to stocking a collection, top cross, multiple cross or comparitive trial."}]},{"head":"Environment:","index":106,"paragraphs":[{"index":1,"size":70,"text":"The collection of factors around a plant that affect its growth and development. Some of these are soil, moisture, light, temperature and other plants and animals. One-c~led layer covering of a plant below the cuticle, e.g. leaf epidermal cells that form the guard cells. This is the action of a nonallelic gene on another gene on a different locus. Epistasis in general terms refers to all non-allelic interaction (see hypostatic)."},{"index":2,"size":16,"text":"Erect growth habit: This is the phenomenon in which the culms are straight and closely grouped."}]},{"head":"Erect leaves: Erosion:","index":107,"paragraphs":[{"index":1,"size":2,"text":"Esca pe:"},{"index":2,"size":14,"text":"Leaves that are straight up witnout drooping e.g. many of the improved rice varieties."},{"index":3,"size":23,"text":"(1) The wearing away of the land surface by running water, wind, ice, or other geological agents including processes such as gravitational creep."},{"index":4,"size":16,"text":"(2) Detachment and movement of soil or rock by water, ,lind, ice, or gravity (Foth, 1978)."},{"index":5,"size":12,"text":"To avoid an undesirable growth condition through early maturity or late maturity."},{"index":6,"size":5,"text":"Essential elements (Essential nutrient elements):"},{"index":7,"size":46,"text":"These are elements that are necessary for growth, development and proper completion of its life cycle. The elements cannot be substituted by another element and are used directly in the plants' nutrition. They are grouped into macro or major (defined) micro. minor or trace elements (de~ined)."},{"index":8,"size":20,"text":"Essential elements are carbon, hydrogen, oxygen, nitrogen,phosphorus, potassium, calcium, magnesium, sulphur, iron, silica, manganese, boron, molybodenum, copper, zinc and chloride."},{"index":9,"size":1,"text":"Etiolation:"},{"index":10,"size":1,"text":"Etiology:"},{"index":11,"size":38,"text":"The phenomenon shown by green plants when grown in dar kness or reduced li ght. The plants become pale-yellow because chlorophyl i s absent, stems are excessively elongated and thin and the leaves are sma ller than normal."},{"index":12,"size":18,"text":"The study of the reasons and explanations for the cause of a symptom, tra it of a disease."},{"index":13,"size":1,"text":"Evapotranspiration:"},{"index":14,"size":30,"text":"Loss of water usually from the soil both directly by changing into vapour or invisible minute particules and by transp iration from plants growing on the soils or in water."},{"index":15,"size":2,"text":"Exchange capacity:"},{"index":16,"size":24,"text":"The total ionic charge of the soil absorption complex that ca n be exchanged. The two types are anion-exchange capac ity and cation-exchange capacity."},{"index":17,"size":1,"text":"Evaporation:"},{"index":18,"size":1,"text":"Exotic:"},{"index":19,"size":27,"text":"The conversion of a li quid into vapo ur without necessarily reaching t he boiling point. An example i s the conversion of soil water to vapour."},{"index":20,"size":10,"text":"Said of variety t hat is introduced from another country."},{"index":21,"size":1,"text":"Expressivity:"},{"index":22,"size":1,"text":"Experiment:"},{"index":23,"size":45,"text":"The deg ree or extent of expression of a given gene. A gene that has low expressivity will not prod uce t he same phenotype under various conditio ns but those that always produce the same pheno type have 100 per cent expressivity (see penetrance)."},{"index":24,"size":26,"text":"A systematic test, or trial specially carried out or a controlled procedure or operation to discove r an unknown effect or to confirm a previous result."}]},{"head":"Experiment farms;","index":108,"paragraphs":[{"index":1,"size":27,"text":"These are carefully prepared field plots with or without provIsIon for irrigation control, well la id ou t plots of known measu rements and uniform growing conditions."}]},{"head":"Experiment Station:","index":109,"paragraphs":[{"index":1,"size":30,"text":"This is a place where various facilities are available for scientific experiments. Some of these facilities are laboratories, green and screen houses, experimental farms, scientific equipment, offices, library, stores, etc."}]},{"head":"Ex perimemn t al error:","index":110,"paragraphs":[{"index":1,"size":52,"text":"A deviation from the true value. The difference between an observed value and true value i . e. Difference due to sampling, management or inherent variability etc. In analysis of variace, the experi mental error is the last undefinable source of variation used to test treatments and rep rese nt differences ."}]},{"head":"Expe rimental site:","index":111,"paragraphs":[{"index":1,"size":56,"text":"This is the location of the piece of land on which field experiments are conducted. The land has met certain criteria, e.g. appropriate size, representative of the environment that the experiment i s aimed tc test, uniformity of land gradient, uniformity or suitabil ity of soil (texture, depth, fertil ity, etc.), accessibility, lack of environmental hazards."},{"index":2,"size":6,"text":"[ xpe ri menta 1 unit:"},{"index":3,"size":4,"text":"A sample (see plot)."},{"index":4,"size":1,"text":"Exploration:"},{"index":5,"size":4,"text":"Exs ert i on:"},{"index":6,"size":1,"text":"Extension:"},{"index":7,"size":17,"text":"The act of searching or loo ki ng for something, such as is done in plant collection."},{"index":8,"size":4,"text":"(See panicle exs~r tion)."},{"index":9,"size":42,"text":"The agricultural activities that deal with popularizing or spreading the value of or any agricultural technology, e.g. varieties, chemical inputs, dates of fa rm operation, special training, etc. to a relatively l arge number of farmers or associated agricultural workers or agents."},{"index":10,"size":3,"text":"Extrachromo somal inheritance:"},{"index":11,"size":5,"text":"(see cytopl asmic inh eritance)."},{"index":12,"size":2,"text":"F2 ratio:"},{"index":13,"size":48,"text":"The first hybrid generation after a cross, us ually unli ke the parents. In a sample or single cross with dominance of ma j or characters, F plants are all uniform except when maternal cy toplas mic etfects are involved. Maximum hetorosis i s expresse d at Fl'"},{"index":14,"size":140,"text":"The second generation selfing of F 1 plants. occu rs in F 2' following a cross. This is the resu lt of M ajor segregating or maxi m um variabil i ty This usually refers t o ratio of the different phenomenon (dominant homozygous, heterozygous, homozygous recessive ) that are ob ta i nable in the F? segregation. It i s determi ned by the number of genes or factor s where there is complete dominance, it is found by calculatinq 4n. Where n = 1, the expected phenotype ratio = 1:2:1 (paren t A; intermedia te ; parent B) or 3:1, three plants will have the dominant character and one will be homozygous recessive. Where n = 2 the expected phenotypic ratio i s 15:1. Where n = 3, the expected phenotypic ratio is 63:1, etc. (see Genotypic number)."}]},{"head":"F2 Population:","index":112,"paragraphs":[{"index":1,"size":1,"text":"F-test:"},{"index":2,"size":89,"text":"This is the assemblance of the F offsprings. In many selections, work begins with F2 ~spec iall y in rice; F Z population is very important. Fai lure or success of breedi ng depends on it. Strict adherence to selection criteria shou ld be followed with the plants in this pop ulat i on. In rice, many characters are fi xed at the F ge nerati on; therefore, any loss may not be recovered in fater generations. Populati on size (defined) i s very critical too in F2 generation."},{"index":3,"size":10,"text":"Progeny obtained by self or sib-fertilization of F2 pl ants."},{"index":4,"size":48,"text":"It is a test used to determine the s i gnificance of a treatment in an experiment. It is essentially a variance r atio . It i s computed by dividing a treatment mean square by erro r mean square calculated in the analysis of variance. Factor :"},{"index":5,"size":1,"text":"Factorial:"},{"index":6,"size":72,"text":"After the observed or calculated F value, one obtai ns the tabular F-val ues from an F table using the degree of freedom for treatment and that of the error. The tabular values for 5% and 1% level of significance is compared with the calculated F-value. If the latter is as large or larger than the former, then the treatment differences are significant at both the 5% and 1% levels of significance."},{"index":7,"size":27,"text":"Thi s is an agent, component, element, part, constituent or condition, e.g. environmental factor which may be tempe ra ture, or another plant that influences the plant."},{"index":8,"size":59,"text":"Said of experiment in which there are two or more treatments at two or more levels producing different interactions. In Mathematics and Statistics, it is the product of a number and all the Consecutive positive whole numbers below it down to 1. Fo r example, factorial 4 written 4! = 4 x 3 x 2 x 1 = 24."},{"index":9,"size":2,"text":"Facultative saprophyte:"},{"index":10,"size":2,"text":"\"Fadama\" :"},{"index":11,"size":45,"text":"An organ ism ordinarily living on other living organisms and may also live on dean tissues of its host. It may live on the dead tis sues during part of its life cycle but not complete its cycle away from a host (see parasite, obligate)."},{"index":12,"size":19,"text":"A loca l term used in Nigeria for the naturally flooded plains where rice or other crops are grown."},{"index":13,"size":4,"text":"Fahrenheit scale of temperature:"},{"index":14,"size":2,"text":"Fa llow:"},{"index":15,"size":88,"text":"The temperature scale in which the melting point of water is taken as 32 °F and the boiling point of water under standard atmosphere pressure (760 mm) as 212°F. 9 Fahrenhei t degrees = 5 Celsi us degrees. To convert degrees Fahrenheit to degrees Ce lsius, substract 32 from F. value, multiply by 5, and divide by 9; to conver t degrees C. to degrees F., mu ltiply by 9, divide by 5, then add 32 to the result. Named after G.D. Fahrenhei t (1686 -1736 ) ."},{"index":16,"size":7,"text":"(Uvarov et~, 1979 ) (See Celsi us)."},{"index":17,"size":74,"text":"The period during wh i ch land not cropped, is left to recover its productivity (reduced by cropping) main ly through accummulation of water, nutrients, attrition of pathogens. Probab ly a combination of all these. During thi s per i od, the land may be bare or covered by natural or planted vegetation. The term fallow may be applied to the land itself or to the crop growin g on it (Okigbo, 1978) ."},{"index":18,"size":3,"text":"False sm ut:"},{"index":19,"size":1,"text":"Family:"},{"index":20,"size":1,"text":"Farm:"},{"index":21,"size":11,"text":"A grain disease such as in rice caused by Ustilaginoidea virens."},{"index":22,"size":13,"text":"The grains are transformed into yellow-greenish or greenish-black spore balls of velvety appearance."},{"index":23,"size":8,"text":"(1) A group of genera, a taxonomic unity."},{"index":24,"size":10,"text":"(2) All closely related lines arising from the same parents."},{"index":25,"size":9,"text":"Their pedigree can be traced to a female line."},{"index":26,"size":2,"text":"(See classification)."},{"index":27,"size":39,"text":"A piece of land • specially prepared and devoted for ralslng agricultural products. Food crops, plants used for industries and animals could be found on a farm. A farm m ay have sorghum, maize, cotton, fibre plants and cattle."},{"index":28,"size":2,"text":"Farming system:"},{"index":29,"size":40,"text":"An agricultural enteprise, .activity or business consisting of a combination inputs (e.g. crop varieties, land, farm practices etc) in numbers, am ounts, sequence and timing to satisfy speci fic objectives of the farmer under a specified environmental setting (Okigbo, 1978)."},{"index":30,"size":2,"text":"Female parent:"},{"index":31,"size":2,"text":"Fe rtile:"},{"index":32,"size":21,"text":"The plant that bears the fruit, with seeds; the plant that possesses the fruiting elements of pistil (ovary, style and stigma)."},{"index":33,"size":32,"text":"Reproductive, can produce fruit or viable seed, can germinate or contain germinable spores or pollen grains. Used also for soil or land that is capable of supporting abundant or luxurious plant growth."},{"index":34,"size":3,"text":"F~rtil i zation:"},{"index":35,"size":15,"text":"The fusion or union of male and female gametes to form a zygote or embryo."},{"index":36,"size":1,"text":"Fertilizers:"},{"index":37,"size":43,"text":"Organic and inorganic substances containing important mineral nutrients needed by the plant used to enrich the soil to increase its productivity. Organic ones are manures, non-organic ones are substance s like sulphate of ammonia, super phosphate etc., which provide nitrogen and phosphorus respectively."},{"index":38,"size":2,"text":"Fertilizer responsiveness;"},{"index":39,"size":23,"text":"This is the trait of a crop for making use of t he applied fertilizer to develop and produce profitable increased yields ."},{"index":40,"size":29,"text":"The yield thus produced is much more than it would have been if the fertilizer were not applied. The increase should be more than the cost for the fertilizer."}]},{"head":"Fi brous root system:","index":113,"paragraphs":[{"index":1,"size":1,"text":"Field:"},{"index":2,"size":22,"text":"Adventitious roots which arise from the base of the stem, bulb, or corn, e.g. in rice or sorghum (see tap root system)."},{"index":3,"size":20,"text":"A piece of cleared land for tillage, pastures, or raislng any economic plant, e.g. food crop or for experimental purposes."},{"index":4,"size":2,"text":"Field/laboratory assistant:"},{"index":5,"size":49,"text":"They are persons with no scientific skill s, they ca r ry ou t routine instructions on field and labo ratory exper iments, e.g. supervi sion of weeding and harves ting of expe ri me nt s and preparation of distilled water or washing of petri-dishes in the laboratory."},{"index":6,"size":2,"text":"Field/laboratory technicians:"},{"index":7,"size":59,"text":"They are persons with some technical skills or training which are much less than the scientists. They carry out instruct i ons fro m the scientists but they are sk ilfu l enough t o carry out their duties with little or no supervision by the scientist,e.g. emasculation and pollination, analysis of nit rog en in crop products etc."}]},{"head":"Field capacity:","index":114,"paragraphs":[{"index":1,"size":2,"text":"Filament :"},{"index":2,"size":47,"text":"This is t he term used to desc r ibe the soil condition when it wi ll no longer absorb moisture. The point whe re the soil ha s been sa turated, additional moisture or water will run off, leach, or accumulate on the so il surface."},{"index":3,"size":16,"text":"The threadlike structure at the end of which an anther i s borne on a flower."}]},{"head":"Filial generations:","index":115,"paragraphs":[{"index":1,"size":10,"text":"Any generation or offspring following the parental generat i on."},{"index":2,"size":47,"text":"A generation resulting from a cross of tloJO parents is called the first filial generation or Fl.  In cooking, the quality of the food that affects the taste and smell. It is usually a sense produced in the mouth through a combination of both taste and smell."},{"index":3,"size":34,"text":"In maize i n which the endosperm consists almost entirely of hard starch. The starch granules are cemented together into a more or less translucent brittle mass by a very thin layer of protein."}]},{"head":"Floating rice:","index":116,"paragraphs":[{"index":1,"size":84,"text":"Rice that grows in a water level of over one metre dee p. The rice plant looks as if it is floating with between one and three leaves usually above the water. The F12 dominance (flint) is not complete and there is also a dosage effect by which 2 fl doses are superior to an fl dose. As a result, the recessive homozygous lines for f12 cannot show xenia as opposed to the phenomenon that occurs in lines homozygous for the opaque-2 gene (02/02)."},{"index":2,"size":44,"text":"There is another floury gene (fl 10 on chromosome 1, ) which also controls t he floury character of the kernel but has no effect on the lysine content. As with the f12 gene, a dosage effect is involved (Le Co nte, 1973) ."}]},{"head":"Floury corn (50ft, starchy corn).","index":117,"paragraphs":[{"index":1,"size":56,"text":"The soft or floury albumen occurs in the form of large starch granules that can easily be separated. This starch is always opaque. The Inca maize from the Cuzco region with very large chalky textured kernels, belong to this category (Le Conte, 1973). Of leaves, e.g. foliar application of chemical is one applied on the leaves."},{"index":2,"size":45,"text":"Any substance or material having or made up of cabohydrates, fats, proteins, minerals, taken in by an organism to maintain growth, repair, carry out vital processes and to supply energy. Inorganic substances absorbed by plants in gaseous form or in water solution are also food."}]},{"head":"Food production:","index":118,"paragraphs":[{"index":1,"size":41,"text":"The growing and making availa~e these agricultural products that are used for food (defined). The number of occurrence of a given type of event, or the number of members of a population falling into a specified class (Kendall and Buckland, 1971)."},{"index":2,"size":64,"text":"The fertilized (sometimes not) ripened ovary with seeds (which may be absent). Usually, many parts of the flower are attached to other structures, e.g. grain of rice is a fruit with the glumes. A trench or groove made by plough or hoe between two ridges. The space between two rows of crops is often also referred to as furrow although no ridging was done."},{"index":3,"size":16,"text":"The union of gametes or reproductive cells to form a new cell or an individual, e.g.zygote."},{"index":4,"size":71,"text":"An excessive or monstrous growth on or in a plant often caused by an insect and in some cases by nematodes. This is the common name of an insect, Orseolia oryzae,formerly known as (Pachydiplisis oryzae) that causes symptoms referred to as onion leaf or silver shoot in rice. The larva of the rice gall midge feeds at the growing point. The feeding results in gall development. Such tillers produce no panicle."},{"index":5,"size":49,"text":"A reproductive cell, usually haploid and sexually differentiated. It is one of the cells produced from meiosis or reduction divis ion. Its ro le is i n fertilization. The female gamete unites with the ma le gamete during fertilization to produce a zygote which develops into an individual plant."}]},{"head":"Gelatinization temperature:","index":119,"paragraphs":[{"index":1,"size":25,"text":"The tempera ture ra ng e in which starch granules start to swell irrevers ibly in hot water. The three general classifications in rice are:"},{"index":2,"size":4,"text":"(1) l ow, 69°C;"},{"index":3,"size":5,"text":"(2) inte rmedia te, 70-74°C;"},{"index":4,"size":6,"text":"(3) high, 75 °C or above."},{"index":5,"size":5,"text":"Gel consistency test: Gene :"},{"index":6,"size":69,"text":"Used to determine which lin e or varieties of rice will remain ha rd or soft on cooli ng after be i ng cooked. In gene ral, rice .Iith le ss than 24 :~ amylose has so ftge1 consistency, i.e . it rema ins soft when cold after cooking. The test is used to differentiate cooki ng behaviour among varieties or li ne s with hig h amylose content."},{"index":7,"size":19,"text":"The scale used for separating hi gh amylose rice into five ca tegor i es are (IRRI, 1980) :"},{"index":8,"size":43,"text":"Gel consistency type: The unit of inheritance passed on to progenies from parents. It i s responsible for expression of heritable characters. The site it occupies on ch romosome is called a locus. A character may be controlled by one or several genes."}]},{"head":"Gene de ployment:","index":120,"paragraphs":[{"index":1,"size":42,"text":"This is growing varieties with several genes for vertical resistance in different geographical regions where the crops is widely grown. The idea is that in case of a breakdown of the resistance yield loss will not be great in all the locations."}]},{"head":"Gene expression:","index":121,"paragraphs":[{"index":1,"size":13,"text":"The manifestation of a gene in a uniform and predictable manne r ."}]},{"head":"Gene frequency:","index":122,"paragraphs":[{"index":1,"size":47,"text":"The proportion of a given type of an alternative allele to the total of all alleles at the genetic locus in a population of plants. It is also defined as the probability of identifying or locating a given gene when it is chosen randomly from the population."}]},{"head":"Gene interaction:","index":123,"paragraphs":[{"index":1,"size":2,"text":"Gene pools:"},{"index":2,"size":16,"text":"Modification of effects of gene action by a nona l leli c ge ne or genes."},{"index":3,"size":11,"text":"Gen~ complexes in a genetically diverse populations (Chang, 1976a ) ."}]},{"head":"Gene ral combining ability:","index":124,"paragraphs":[{"index":1,"size":4,"text":"Generat i on :"},{"index":2,"size":2,"text":"Ge petics:"},{"index":3,"size":3,"text":"(see combining ability)"},{"index":4,"size":81,"text":"An assemblage or group of plants constituting a single step i n the line of descent from an ancestor. Also a single set of progeny in the succession of natural descent. Such set of progeny originated at the same time. It is used t o refer to the average period of ti me between the formation or or i gin of t he parents and that of their offspring. It i s also the act or process of coming into being."},{"index":5,"size":35,"text":"The science which studies and explain s he redi tary changes , similarities and differences in plant and anima l s. It deal s with the mechanism of passing the characters from parents to pregeny."}]},{"head":"Genetic advance:","index":125,"paragraphs":[{"index":1,"size":6,"text":"Determined in selection by the formula:"},{"index":2,"size":8,"text":"selection differential phenotypic S.D. of mean heri tability."}]},{"head":"Genetic base:","index":126,"paragraphs":[{"index":1,"size":36,"text":"Available genetic variability among widely grown cultivars in relationship to total variability in a crop species. A cultivar which has a broad genetic base can adapt more readily to changing environments than a narrowly based one."},{"index":2,"size":46,"text":"A group of genotypes with varying characters or resources based on the available number of alleles in the plants considered on a given locus. There is a better chance of selection improvement when there is a wide genetic base, as in composite varieties or complex hybrids."}]},{"head":"Genetic composition:","index":127,"paragraphs":[{"index":1,"size":14,"text":"This refers to the make-up and proportion of genetically different individuals in a population."}]},{"head":"Genetic conservation:","index":128,"paragraphs":[{"index":1,"size":17,"text":"Collection, maintenance and preservation of all types of germplasm in a crop species and its wild relatives."}]},{"head":"Genetic diversity:","index":129,"paragraphs":[{"index":1,"size":27,"text":"The state of being genetically different. This is what plant breeders make use of in their selection work. Farmers depend on genetic diversity to minimize pest damage."}]},{"head":"Genetic drift:","index":130,"paragraphs":[{"index":1,"size":30,"text":"Changes in the gene frequencies of a population when the size of sample chosen for rejuvenation is small. Genetic drift leads to a less of certain genotypes in the population."},{"index":2,"size":2,"text":"Genetic equilibrium:"},{"index":3,"size":14,"text":"Constant nature of phynotype, same frequencies generation after generation in a randomly mating population."}]},{"head":"Genetic potential:","index":131,"paragraphs":[{"index":1,"size":20,"text":"The possibility of genetic material (improved or unimproved cultivar or lines) producing many new combinations (following hybridization) from available variability."}]},{"head":"Genetic resources:","index":132,"paragraphs":[{"index":1,"size":24,"text":"A collection of plants in a species that includes the entire array of cultivars, related wild species in the genes and their various hybrids."}]},{"head":"Genetic resources centre:","index":133,"paragraphs":[{"index":1,"size":18,"text":"A place, agent, institution or association having a strong programme of overrall conservation of one or more crops."}]},{"head":"Genetic stock:","index":134,"paragraphs":[{"index":1,"size":12,"text":"A variety or strain known to possess one or more specific traits."},{"index":2,"size":17,"text":"The genettc inheritance or such traits may not be clearly understood unlike those of a genetic tester."}]},{"head":"Genetic tester:","index":135,"paragraphs":[{"index":1,"size":30,"text":"A plant known to carry one or more genes clearly expressing themselves in morphological or physiological features. The mode of inheritance of such traits is known by previous genetic experiments."}]},{"head":"Genetic variability:","index":136,"paragraphs":[{"index":1,"size":8,"text":"The act of being different or changeable genetically."}]},{"head":"Genetic Vulnerability:","index":137,"paragraphs":[{"index":1,"size":1,"text":"Genetics:"},{"index":2,"size":50,"text":"It is used to refer to the potential danger of disease and pest epidemics on a crop which is currently resistant to such a disease or insect pest. This is recently used to emphasize the incidents of breaking down of a genetic resistance to a disease or an insect pest."},{"index":3,"size":28,"text":"The science which studies and explains hereditary changes, similarities and differences in plants and animals. It deals with the mechanism of passing the characters from parents to pregeny."},{"index":4,"size":1,"text":"Genotype:"},{"index":5,"size":38,"text":"The genetic constitution on make-up of a plantl It may be expressed or unexpressed, depending on environmental effects on the plant in a given location. Also refers to a group of plants having a common or specific make-up."},{"index":6,"size":3,"text":"Genotype, number of:"},{"index":7,"size":1,"text":"Genus:"},{"index":8,"size":23,"text":"The number of different types of genetypes that can be obtained in an F2 population. It is calculated by using the formular 3n"},{"index":9,"size":40,"text":"where n 2 = number of genes involved. In a backcross where n = 2, e.g. in an F2 resulting from a cross with two different pairs of alleles there will be 9 g~notypes. The backcross will have four genotypes."},{"index":10,"size":74,"text":"A taxonomic group comprlslng one or more species that are of common origin and are different from other taxonomic groups. Similar genera (plr of genus) are grouped in a family. It is a group above the species. In binominal nomenclature, it is the first word of the scientific name and it begins with a capital. The second word is the trivial or specific name and it does not begin with a capital (see classification)."},{"index":11,"size":1,"text":"Germination:"},{"index":12,"size":24,"text":"Initial growth of the embryo from a seed or spore in which the radicle and shoot or hypha protrude from the seed or spore."},{"index":13,"size":1,"text":"Germinator:"},{"index":14,"size":12,"text":"Equipment used for seed germination inside which temperature is usually controlled Germplasm:"},{"index":15,"size":16,"text":"A collection of many different varieties or lines which represent the diverse genotypes of the species."},{"index":16,"size":33,"text":"It is a bearer of all hereditary factors in a species. It is sometimes referred to as the gene bank of the species or the sum total of genetic material in a species."}]},{"head":"Germplasm bank:","index":138,"paragraphs":[{"index":1,"size":46,"text":"A special building where germp1asm is carefully kept and preserved for a period of time. The tempe rature, and often the relative humidity also, i s controlled. Cold seed storage is another commonly used ex pression. The three types of co l d seed storage are:"},{"index":2,"size":19,"text":"Short-term with temperature at 18°-21°C, 45 -75% R.H. or uncontrolled. Seed can be conserved he re fore 2-5 years."},{"index":3,"size":13,"text":"Medium-term-temperature 0°_5 °C, 20-70% R.H., seed can be co nse rved 25-30 years."},{"index":4,"size":20,"text":"Long-term-temperature -20 to -lO ce, 15-30% R. H. or controlled. Seed can be conserved \"p to 50 years or more."},{"index":5,"size":1,"text":"Gibberel1ins:"},{"index":6,"size":21,"text":"A grou p of plant hormones that promotes stem elongation of certain plants and growth of fruits and other beneficial effects."},{"index":7,"size":2,"text":"Glaberrima rice:"},{"index":8,"size":1,"text":"Glabrous:"},{"index":9,"size":6,"text":"(see Oryza glaberrima and African rice)."},{"index":10,"size":36,"text":"A plant or plant part that is smooth or divoid of hai rs or any projection. Sometimes some hairs may be found and not have to be completely absent to be described as ql ab rous."}]},{"head":"Glassine envelope of bag:","index":139,"paragraphs":[{"index":1,"size":1,"text":"G1ume:"},{"index":2,"size":29,"text":"A long, narrow envelope made of thin transparent paper and opening at one end. It is frequently used for bagg lng in hybridasation work or sometimes for seed storage."},{"index":3,"size":40,"text":"The two chaffy structures in the inflorescence of grasses. It is made up of the lemma and palea which usually cover the floret before blooming and often remain attached to the ripened \"fruit\" or grain of some cereals, e.g. rice."},{"index":4,"size":6,"text":"Glume discoloration (Grain discoloration, dirty panicles):"},{"index":5,"size":70,"text":"This is the result of staining or masking the original • colour of the glumes. The glumes dark giving a dirty and unattrative appearance. In rice and other cereals, discoloration is caused either by sucking insects or one or more fungi species such as Pyricularia, He1minthos orium, Corcos ora, Rh nchos orium, ternar1a, crocy 1n r1um, usar1um, oma and curvularia. The discoloration may and may not affect the grain endosperm."}]},{"head":"G1ume discoloration:","index":140,"paragraphs":[{"index":1,"size":3,"text":"(See grain discoloration)."}]},{"head":"Glutinous endosperm:","index":141,"paragraphs":[{"index":1,"size":4,"text":"(See waxy endosperm) ."}]},{"head":"Goodness of fit:","index":142,"paragraphs":[{"index":1,"size":1,"text":"Grade:"},{"index":2,"size":1,"text":"Grain:"},{"index":3,"size":3,"text":"(See Chi-square test)."},{"index":4,"size":21,"text":"The separation of milled or unmilled grains into different sizes or categories, e.g. broken and whole grain, short and long ."},{"index":5,"size":100,"text":"Botanically a caryopsis with its hulls, a \"fruit\" of grasses. It is the receptacle in which the single embryo and endosperm are found. The peri carp or ovary wall and testa or seed coat are often fused. In some cereals the testa may be absent. The grain's main components are the hull and caryopsis coat, (pericarp, seed coat, nucleus). Endosperm and embryo: In rice, the lemma, pa1ea, rachi11a, sterile lemma and the awn if present, firmly adhere to the grain. In some cereals, e.g. maize, the lemma and palea are not present and in sorghu, they are not firmly attached."}]},{"head":"Grain chemical quality:","index":143,"paragraphs":[{"index":1,"size":21,"text":"This is the proportion of various important chemical compounds or elements usually of nutritional importance, e.g. protein and its ac; ds."}]},{"head":"Grain charac ter istics","index":144,"paragraphs":[{"index":1,"size":82,"text":"The se are the various di mens ion s , s ha pes, weight, seed coat colour endosperm type, scent, amylose content, t ran slucency. chalkiness, milling yields, gelatinization temperature. gel co nsistency, brown rice protein, lysine content. elongation ratio and sensory factors of the grain s . Most of these characteristics have been described under different heading in the glossary. Table 1 shows t he three desc r i pt ive sca les widely used fo r rice length and shape."},{"index":2,"size":3,"text":"Tab le 1:"},{"index":3,"size":68,"text":"Three decriptive scales widely used for r i ce len gth and sha pe (adapted from IBPGR -IRRI, 1980). This is the longitudinal distance in mil li metres from the base of the lowermost sterile lemma to the ti p or spiculus of the lemma or palea whichever is longer. disregarding awns. Long grains in I'ice are over 6.6 mm and short grains are less than 5.5 mm."}]},{"head":"Grain milli ng qua lity:","index":145,"paragraphs":[{"index":1,"size":23,"text":"In rice, charactristics or status of grain on milling. In determination of the milling quality the following constituents or t erms are considered:"},{"index":2,"size":43,"text":"Brown rice (per cent) -weight of dehul1ed (brown) rice to weight of grain in the sample at 14% moisture; expressed in per cent to one decimal pl ace. The complement of br own rice pe rcen tage i s t he percentage hulls."},{"index":3,"size":26,"text":"Total milled r ice (per cent ) -weight of mill ed ri ce (who le and broken kernels) to wei ght of grain in the sample."},{"index":4,"size":46,"text":"Head ti ce (per cent) -weight of whole ke rnel s of mi 11 ed rice to weight of grain in the sample; sepa ration of head r i ce from broken kernels is done by a sizing device often refe rred t o as grading."},{"index":5,"size":4,"text":"Gr a in number:"},{"index":6,"size":18,"text":"Th i s i n cereals ref ers t o quantity of grain s per cob or panicle."},{"index":7,"size":28,"text":"In rice this nu m ber var ies from 80 -170 depending on the intera cti on of various environme nt al factors with var ietal characteris tics."},{"index":8,"size":3,"text":"Grain sha pe:"},{"index":9,"size":2,"text":"Grain size:"},{"index":10,"size":57,"text":"This refers to how the grain looks like phys icall y . The grain length-width (LjW) r atio influences the shape . The descriptive terms f or grain shape ana t he L/W are: slender L/W = 3.04; med ium L/W = 2.1 -3.0; bold L/W = 1. 1-2. 0, round = -1. 1 (See table 1)."},{"index":11,"size":18,"text":"The proport ionate dimension of the grai n, grain size is re l ated to gra in weight."},{"index":12,"size":5,"text":"Grain/St raw rat i o:"},{"index":13,"size":45,"text":"Propo rtion of grain weig ht to straw weight recorded in rice from 6 plants or 2 sq . metres for broadcast rice, ou t at grou nd level and dried to the same moisture co ntent. Also see ha rves t i nde x."},{"index":14,"size":2,"text":"Grain translucency:"},{"index":15,"size":27,"text":"In rice, t he property of grain that after dehul1 i ng or mill ing l ig ht can pass throu gh the endos pe r m."},{"index":16,"size":17,"text":"The grain is devoid of a chalky spot (white centre, white belly or ~Ihite back ) ."},{"index":17,"size":2,"text":"Grain weight:"},{"index":18,"size":46,"text":"This is the heaviness of grain. Usually given per number of grain, e.g. in rice it is on the basis of one thousand grain. The weight ranges from 16 to 50 g, with 25-35g being common. It is an important yield component of most cereal crops."},{"index":19,"size":2,"text":"Grain width:"},{"index":20,"size":28,"text":"The dorsi ventral (underneath to top) diameter ~easurement from 10 grains. In rice it is the distance across the lemma and the palea at the widest pOi nt."},{"index":21,"size":2,"text":"Grain yield:"},{"index":22,"size":30,"text":"The harvested grain per unit area often expressed in kilogram per hectare and at a given seed moisture content. In rice, yields are calculated at a moisture content of 14%."},{"index":23,"size":3,"text":"Gras s cutter:"},{"index":24,"size":2,"text":"(see rodent)."}]},{"head":"Grassy stunt:","index":146,"paragraphs":[{"index":1,"size":1,"text":"Greenhouse:"},{"index":2,"size":23,"text":"A virus disease in rice generally in Asia in which the plants are strikingly shortened and tiller profusely. The vector is Nilaparvata lugens."},{"index":3,"size":43,"text":"A construction (usually roofed with glass) in which pla nts are grown under controlled humid •and temperature conditions. The plants are th us protected from rain and a few other environme ntal ha~rds. Glasshouse is the term used in Great Britain for greenhouse."},{"index":4,"size":5,"text":"Green 1 ea fhoPJ:€ r:"},{"index":5,"size":3,"text":"Green smut :"},{"index":6,"size":49,"text":"An important rice pest especially in Asia. It is known as Nephotettix.-m.. It causes partial to pronounced yellOl•ling and increas i ng severity of stunting which may kill the plants. It also transmits the yellow dwarf diseas e of rice. The insect i s found mostly on the leaves."},{"index":7,"size":3,"text":"(See false smut)."}]},{"head":"Green re vol uti on:","index":147,"paragraphs":[{"index":1,"size":117,"text":"This i s a t er m coined f oll owi ng the success of IRRI wi t h r i ce and CI MMYT with whea t when the newl y de veloped hi gh-yieldi ng var i eties ma de big str i ki ng changes in cro p production in it s var i ous ra mi fication s . There \\;ere cha nge s in res earch pr i nci pl es production practices an d other agro economic and socia-political decis i ons on food crop . Cu rrently the express i on i s use d to r efer to bi g Go vernmen t campai gns for food product ion."},{"index":2,"size":11,"text":"Gro und hog (Grass cutter or cutti ng gra ss) :"},{"index":3,"size":40,"text":"In West Africa , an ani ma l (T hryonornys sViinderianus) that causes a l ot of damag e to ce r ea l crop s es pec ially rice, by che wi ng t he s t em ."}]},{"head":"Ground wa t e r:","index":148,"paragraphs":[{"index":1,"size":1,"text":"Grow:"},{"index":2,"size":101,"text":"Th e port ion of t he total preci pitation tha t at any pa rticula r ti me is ei ther passi ng t hrou gh or standing i n t he so il and t he under lying strata and is free to mo ve under t he i nflu ence of gra vi ty ( Fot h, 1978) . This gro und water l eve l or table is important f or hydromo rphic r i ce . The higher t he water t able the les s t he rice Vl i ll suffer f rom drought."},{"index":3,"size":27,"text":"To come t o life or t o become l arger may al so l ead to deve l opme nt of complex and simple st ructures."}]},{"head":"GroViing season:","index":149,"paragraphs":[{"index":1,"size":2,"text":"Gr owth:"},{"index":2,"size":129,"text":"A per iod i n the year wh en t emperature , 1 i ght , rainf all, et c . ena bles a crop t o grow well and prod uce economic yields. In general term s , i t is an i ncrease in size and us ua l ly in mos t plants include s di fferen t iati on of ce lls. It i s an irreversible change in a pl ant which is foll owed by ut ili za t ion of mat eria l and usually result in increased vo l ume, dry weight or pro t ei n content. It may re sult in in crease in popu l atio n or colony of a cu l ture of micro-organi sm ."}]},{"head":"Growth dura t io n:","index":150,"paragraphs":[{"index":1,"size":38,"text":"Gene rally, the length of ti me the crop takes t o mature, i. E. days fro m planting till it pro duces m ature seeds or other product s . In ri ce this varies from 100-140."}]},{"head":"Growth habit:","index":151,"paragraphs":[{"index":1,"size":3,"text":"(see habi t)."}]},{"head":"Growth inhibitors:","index":152,"paragraphs":[{"index":1,"size":13,"text":"Hormones or chemicals that suppress growth, e.g. abscisic acid, morphactins and maleic hydrazide."}]},{"head":"Growth regulators:","index":153,"paragraphs":[{"index":1,"size":4,"text":"Chemicals that control growth."}]},{"head":"Growth reterdants:","index":154,"paragraphs":[{"index":1,"size":15,"text":"These are chemicals that delay or slow down growth, e.g. chlormequat, daminozide, gametocides and a11e10pathin."}]},{"head":"Growth stages:","index":155,"paragraphs":[{"index":1,"size":14,"text":"Distinct periods in the life cycle of a plant, e.g. seedling, ti11ering, reproductive stages."}]},{"head":"Growth stimulators:","index":156,"paragraphs":[{"index":1,"size":40,"text":"Hormones or chemicals that promote or accelerate the rate of growth, e.g. auxins, Gibbere11ins, Cytokinins and ethylene. The general appearance of a plant, the way it grows, whether erect, prostrate, climbing, twin i ng, spreading, etc. or annual vs. perennial."},{"index":2,"size":45,"text":"Plants having only one common pa rent. A group of half sibs is obtained by fertilizing a series of ears or panicles with po l len from the same panicle or by fertilizing an ear or panicle of a line with a mixture of pollen."},{"index":3,"size":25,"text":"Having the basic numbe r of chromosomes in a somat ic cell, e.g. in gametes or reproductive cells. A plant with gametic chromosome number (n)."}]},{"head":"Hard dough stage:","index":157,"paragraphs":[{"index":1,"size":58,"text":"The reproductive stage when the grain filling stage has been completed and the grain is almost fully ripe It is hard to dent but not as hard as a fully ripe grain . The hard dough stage in rice, on the average, is about 7 days to full maturity or 21 days after anthesis of a fertilized spikelet."},{"index":2,"size":45,"text":"A hardened soil layer below a soft upper layer. It is caused by cementation of soil pa rticles with organic matter or with materials such as silica or calcium carbonate. An example of hard pan is the hard layer beneath a puddled rice paddy soil."},{"index":3,"size":10,"text":"Plant being able to endure severe climatic conditions although unprotected."},{"index":4,"size":18,"text":"(1) A special farm implement or device for breaking up soil during land preparation for planting or sowing."},{"index":5,"size":9,"text":"(2) The process of using such device or implement."},{"index":6,"size":23,"text":"The removal or ga thering (or that which is removed) of the economic parts of the plant for food or for other products."},{"index":7,"size":6,"text":"The person or machine that harvests."},{"index":8,"size":2,"text":"Harvest index:"},{"index":9,"size":1,"text":"Head:"},{"index":10,"size":13,"text":"The percentage of grain to whole plant at harvest given by the formula:"},{"index":11,"size":8,"text":"where g = dry grain weight and G"},{"index":12,"size":10,"text":"= grain weight plus dry weight of plant at harvest."},{"index":13,"size":14,"text":"The higher the index the greater the efficiency of the plant to produce grain."},{"index":14,"size":19,"text":"An inflorescence, e.g. the capitulum of composites. It also refers to panicles of cereals such as sorghum and rice."},{"index":15,"size":3,"text":"Head i ng:"},{"index":16,"size":3,"text":"Hea'd ri ce:"},{"index":17,"size":42,"text":"Br ing out the rep rodu ctive part s or infloresce nce of a plant. Used m ainl y for grami naceous crops . Also defi ned as the emergence of the panicl e out of the fla g l eaf sheath."},{"index":18,"size":6,"text":"(see gra in milli ng) ."},{"index":19,"size":4,"text":"H eadi ng stage:"},{"index":20,"size":10,"text":"The growth per iod when heading beings, Head-to -row :"},{"index":21,"size":1,"text":"Hectare:"},{"index":22,"size":4,"text":"H erbici de :"},{"index":23,"size":2,"text":"Heredity :"},{"index":24,"size":1,"text":"Heritable:"},{"index":25,"size":66,"text":"The proces s of growing seed from a pa ni cle or ea r t o one or more rows , This i s done to determ i ne or main ta in seed purity of a var iety bei ng st udu ed or multi pli ed. In maiz e i t is a spec ial breeding procedure called ear-to-rO\\; method (defi ned ) ."},{"index":26,"size":26,"text":"In r i ce , th i s method i s used to devel op a homogeneo us varie ty from a heterogeneous var iety ."},{"index":27,"size":46,"text":"A metr i c unit (see Table 2) of area measurement t ha t which is 10,000 squa re meters of land or 2. 47105 acres. In sc i en t i fic repo rting yie l ds are usuall y expressed in weight per hectare."},{"index":28,"size":85,"text":"A chemical used for killing weeds or retarding their growth. Herbi cides can be applied in solution or granular form. They may be app lied before weeds germinate (pre-emergence herbicide ) or after ge rminat i on (post-emet'gence herbicides. Selective herbicides affect only a partic1 Jl ar plant type withou t damage on others, It is the pro cess by which similarity i s brought about be tween parents an d pregeny . Transmission of genetic characters of parents t o t he ir progeny."},{"index":29,"size":20,"text":"The passi ng on or transmission t o progeny of genetic characters of parents (expre ssed or unex pressed )."},{"index":30,"size":14,"text":"A plant that has six sets (genomes) of chromosomes, i.e. chromosome number of 6n."},{"index":31,"size":2,"text":"High-yielding variety:"},{"index":32,"size":3,"text":"Hi 11 :"},{"index":33,"size":2,"text":"Hill rice:"},{"index":34,"size":1,"text":"Hoeing:"},{"index":35,"size":17,"text":"A variety that produces relatively more yields than traditional varieties of same crop in a given area."},{"index":36,"size":21,"text":"A heap or mound of earth so prepared for planting. of plants growing closely together, separated by a from another group."}]},{"head":"A grou p given distance","index":158,"paragraphs":[{"index":1,"size":15,"text":"Upland r ice grown on steep sl opes usually in areas with high rainf all."},{"index":2,"size":12,"text":"In general, it is the act of removing weeds with a hoe."}]},{"head":"Homogeneo us :","index":159,"paragraphs":[{"index":1,"size":14,"text":"Similar in kind, qualities or nature. and similar in genetic composition due common ancester."}]},{"head":"Uniform i n appearance to descent from a","index":160,"paragraphs":[{"index":1,"size":3,"text":"Hom ologous chromosome:"},{"index":2,"size":1,"text":"Homozygote:"},{"index":3,"size":1,"text":"Hormones:"},{"index":4,"size":40,"text":"Chromosomes that are alike and synapse or pair at the first division (prephase) in meiosis. In a pair of homo l ogous chromosomes, each member has a corresponding sequence of gene lo ci and is derived from a different parent."},{"index":5,"size":17,"text":"Having one or more genes that are al ike at correspond ing lo ci on homologous chromosomes."},{"index":6,"size":32,"text":"In plants, these are growth regulatory chemical substances su ch as gibberellic acid, auxin (defi ned), kinins produced by plants for vari ous physiological processes (see growth i nhibit ors, stimulators etc.)."},{"index":7,"size":2,"text":"Horizontal resistance:"},{"index":8,"size":13,"text":"A moderate .~. ~l of stable resistance controlled by many minor Host plant:"},{"index":9,"size":60,"text":"genes. It is also referred to as field resistance. It is polygenic, non-specific to any type of a given strain of pathogen and it is generally graded in expression, only exceptionaliy approaching immUnity. It is expressed as varying combinations of restriction of infection and/or reproduction of pathogen. It is said to be responsible for durable disease resistance of many crops."},{"index":10,"size":12,"text":"This is a plant which nourishes or supports a pest or disease."},{"index":11,"size":2,"text":"Host resistance:"},{"index":12,"size":40,"text":"The mechanism in which a plant or animal having a given parasite on it is able to avoid, tolerate or recover from attacks of the parasites or pathogens. They are able to do this by evolving morphological and physiological modifications."},{"index":13,"size":3,"text":"Hot air emasculation:"},{"index":14,"size":39,"text":"In cereal using hot air to open by force a floret to remove the anther. The air temperature for such an operation is between 30-40°C and the time of exposure co uld vary from two t o five minutes."},{"index":15,"size":4,"text":"Hot water emasc ulation:"},{"index":16,"size":25,"text":"As in hot air masculation, but the panicle is ammersed in hot water. In thi s method, pollen grains can get killed in some plants."},{"index":17,"size":3,"text":"Hot water treatment:"},{"index":18,"size":28,"text":"Steeping bulbs, seeds and other plant parts in a wa t er bath at a temperature lethal to the infecting nematodes, fungi, insects, etc. without damaging plant material."}]},{"head":"Hull (husk):","index":161,"paragraphs":[{"index":1,"size":45,"text":"In general hull and husk are used interchangeably. It is the dry or membraneous ou t er covering of seed or fruit, e.g. rice hull or corn husk. In r ice and sorQhum for example, it is made up of the lemma and palae ."},{"index":2,"size":3,"text":"Hulling (huski ng):"},{"index":3,"size":10,"text":"The process of removing husks or hulls from the grain."},{"index":4,"size":1,"text":"Humus:"},{"index":5,"size":2,"text":"Hybri d:"},{"index":6,"size":59,"text":"Dark-brown colloidal matter present in soil as a result of animal and vegetable decomposition. It is an important source of mineral nutrients for plants. Also described by Foth (1978) as: That more or less stable fraction of the soil organic matter remaining after the major portion of added plant and animal residues have decomposed. Usually, it is dark coloured."},{"index":7,"size":24,"text":"A product of crossing two genetically dissimilar parents. The first generation offspring of a cross between two plants differing in one or more genes."},{"index":8,"size":4,"text":"Hybrid maize, hybrid rice:"},{"index":9,"size":11,"text":"Fl hybrids of single (maize and rice) or double crosses (maize)."},{"index":10,"size":1,"text":"Hybridisation:"},{"index":11,"size":20,"text":"Crossing individuals that differ in genetic constitution. A method of breeding new varieties which utilize crossing to obtain genetic recombination."}]},{"head":"Hybridisation block:","index":162,"paragraphs":[{"index":1,"size":24,"text":"A block or a piece of land set aside for making crosses. The parents for these crosses are usually planted in a hybridisation block."}]},{"head":"Hybrid variety:","index":163,"paragraphs":[{"index":1,"size":45,"text":"In general, a variety derived by hybridization; developed from repeated crossing, having male sterile and restorer genes. It is generally higher yielder due to hybrid vigour, e.g. in maize, sugarbeet, onion etc. Formerly, a variety developed by hybridization was referred to as a hybrid variety."},{"index":2,"size":2,"text":"Hybrid vigour:"},{"index":3,"size":2,"text":"(see heterosis)."}]},{"head":"Hydrogen ion concentration (pH)","index":164,"paragraphs":[{"index":1,"size":11,"text":"The number of grams of hydrogen ions per litre of solution."},{"index":2,"size":24,"text":"It is useful as a measure of acidity of a solution and in this context is usually expressed in terms of pH = 1091Bl/10[H+],"},{"index":3,"size":61,"text":"where [H+] is the hydrogen ion concentration. As ure water at ordinary temperatures dissociates slightly into hydrogen ions and hydroxyl ions (H 0 = H+ + OH-), the concentration of each type of ion 6eing 10-7 mole per litre, the pH of pure water will be 109101/10-7 = 7; this figure is accordingly taken to represent neutrality on the pH scale."},{"index":4,"size":31,"text":"If acid is added to water, its hydrogen ion concentration will increase and its pH will therefore, decrease. Thus a pH in excess of 7 indicates alkalinity (Uuarov et ~ 1979)."},{"index":5,"size":2,"text":"Hydromorphic rice:"},{"index":6,"size":12,"text":"Rice grown where the water table is very near the soil surface."},{"index":7,"size":50,"text":"Water may even 1 ie on the soil surface for 2-6 weeks during the growing period. Rice grown under this condition usually suffers from drought only when it does not rain for 4-8 weeks during the growing season. Many so-called upland rice areas are ecologically under hydromorphic conditions in Africa."}]},{"head":"Hydromorphic soil:","index":165,"paragraphs":[{"index":1,"size":1,"text":"Hydroponic:"},{"index":2,"size":1,"text":"Hypostatic:"},{"index":3,"size":1,"text":"Hypothesis:"},{"index":4,"size":1,"text":"Ideotype:"},{"index":5,"size":8,"text":"Soil that can be permanently or periodically flooded."},{"index":6,"size":20,"text":"A method of ra151ng a crop e.g. vegetables by supplying all the nutrients the plant needs through a nutrient solution."},{"index":7,"size":27,"text":"A gene that is suppressed by a nonallelic dominant gene. This is a theory or postulate that is yet to be proven. An unproven bel i ef."},{"index":8,"size":2,"text":"13 etc:"},{"index":9,"size":11,"text":"Symbols used to designate the first, second, third inbred generations etc."},{"index":10,"size":34,"text":"A new plant model which assumes that when such a plant is produced and grown, it will be more efficient in the utilization of light, water, and chemical unputs, more resistant to In1' lune:"},{"index":11,"size":56,"text":"unfavourab l e envi ro nme ntal fac t ors. The features of such an ideotype ar e those that are used as guide for selection work and related to plant type characters, e.g. height, s i ze and angle of leaves, ty pe, shape and position of pa ni cl es or ears etc ."},{"index":12,"size":29,"text":"Fr ee of or comp letely resis tant t o a disea se or a pes t that i s in the enviro nmen t of a plant ."}]},{"head":"Im perfect fl ower:","index":166,"paragraphs":[{"index":1,"size":20,"text":"A fl oVie r devoid of either pi stil or stamen, i .e. it i s un i sexua 1."}]},{"head":"Imp rove ( Impro ved variety ) :","index":167,"paragraphs":[{"index":1,"size":41,"text":"To make better, rectify or co rrect, e. g. i m proved seed or i mproved va ri ety i s one t hat i s better in one or more characte rs than t he prev ious ly used ones."}]},{"head":"Imp ro ved pl ant type:","index":168,"paragraphs":[{"index":1,"size":1,"text":"Inbred:"},{"index":2,"size":124,"text":"A plant ty pe (def ined ) who se morpho -phys iol og i cal fe at ur es have been changed or m odified in such a way t hat has produce d more eff i c i en t or higher yielding pl an t. In r i ce it means shorter pl ant height, wit h a stiff and sturdy culm res i stant to l odging, erect leaves more eff ic ient for photosynthe s is, heav i er ti l leri~g , nit r ogen fertilizer respo ns ive and sometimes photope r i od in se nsi tive . IR 8 wa s the first rel eased variety to m eet t hese qua l it ies ."},{"index":3,"size":12,"text":"The progeny afte r cross ing two re l ated plants ."}]},{"head":"Inbred line:","index":169,"paragraphs":[{"index":1,"size":107,"text":"Inbreed ing: Any l ine whic h is m ore or l ess homo zygous deri ved from a cross pop ul ation by repeated (a t l east for five success ive generat 'o ns) inbreed i ng (se lf-fertil i zat i on, s ibi ng cross ing. etc.) of an individual and it s proge ny . A population i n whic h i nbreed ing i s i nevi table beca use of the li mited po pulation s i ze (bree ding size) t he reby forcing relatives to i nterc r oss i s equ i valent to an inbreeding line."},{"index":2,"size":47,"text":"A fertilizat io n system whi ch. in co ntras t to o ut or cross breedi ng i nvolves the breeding together of i ndiv i dual s. more cl ose ly I'e l ated than pa re nts at ran dom from a populatlOn ."},{"index":3,"size":15,"text":"The closest form of inbreeding is sefl-fertilization, other forms are sib crossing and half-sib crossing."},{"index":4,"size":100,"text":"A 11 forms of inbreed i ng result in an increase of homozygos ity, i.e. lead to genetic fi xa tion. When inbreeding i s imposed on a normally outbreeding population, the population i s broken up into smaller groups accompanied by a decrease in total heterozygosi ty as fixation occurs in t he sub-groups. If no selection for particular homozyqotes occurs, genetic variance as a whole is increased in t he population (transformation of potential into free genetic variation). Inbreedi ng in normall y outbreeding populations generally leads to a loss of fitness referred to as i nbreeding depression."},{"index":5,"size":51,"text":"In plants, morphological and phisiological mechanism favouring inbreed ing are common, e. g. fai l ure of flowers to open (cleistqgamy ) or opening of flowers only after the pollen has been shed. The relative restriction of outbreeding mediated by these and other mechanisms ranges from facultative self-pollination to obligate self-fertilization."}]},{"head":"Incompatible:","index":170,"paragraphs":[{"index":1,"size":23,"text":"Unable to set seed or units when se1fed, crossed or grafted because of structural, physiological, or o ~t oge nic reaso ns ."}]},{"head":"Incomplete dominance:","index":171,"paragraphs":[{"index":1,"size":27,"text":"Two different alleles (e .g. a dominant and reces s i ve gene ) producing an intermediate effect compared to the effect of the domi nant alleles."}]},{"head":"Incomplete flower:","index":172,"paragraphs":[{"index":1,"size":1,"text":"Incubation:"},{"index":2,"size":18,"text":"A flower that lacks one or more of the acce ss orial parts, e.g. corolla or the calyx."},{"index":3,"size":63,"text":"The process of keeping plants, disease pathogens or seed under a cel'tain temperature to hasten growth. In seed incubation, e.g. rice after soaking for 24 hours, water is removed and the seeds are washed, placed on a clean surface, e.g. floor and covered with sack for 24 hours. Incubation keeps the seeds \\•!arm to increase the embryo growth for uniform germi nat ion."}]},{"head":"Independent assortm ent:","index":173,"paragraphs":[{"index":1,"size":38,"text":"The assortment of rearrangements of two or more pairs of segregating genes to the gametes that is due only to chance. The distribution of the genes to the gametes is not influenced by each other, i.e. not linked."}]},{"head":"Independent variable:","index":174,"paragraphs":[{"index":1,"size":9,"text":"A variable not influenced or affected by another variable. "}]},{"head":"Indicator plant:","index":175,"paragraphs":[{"index":1,"size":17,"text":"A suitable suscept plant used to signify the survival or reproduction of plant parasitic nematodes. (Caveness, 1974)."}]},{"head":"Indica rice:","index":176,"paragraphs":[{"index":1,"size":3,"text":"Infect: Infection: Infest:"},{"index":2,"size":71,"text":"(See Japonica and Javanica or Bulbus). A subspecies of rice varieties based on geographical distribution, plant and grain morphology, hybrid sterility and serological reaction. The indica rice varieties are those from Ceylon, Southern and Central China, India, Java, Pakistan, Phillippines, most African countries and other tropical areas. They are characterized by having broad, light-green leaves, slender and somewhat flat grains, profuse tillering and tall plant stature, and amylose content above 20%."},{"index":3,"size":18,"text":"To contaminate with a pathogen or disease-producing substance. To invade and establish a parasitic relationship within the host."},{"index":4,"size":33,"text":"The result of affecting injuriously. The process of establishment of a pathogen in its host after invasion. The state produced by the establishment of an infective agent in or on a suitable host."},{"index":5,"size":21,"text":"To attack externally, e.g. insect pests, attack on a plant's part such as grain of rice. Also to contain the parasite."}]},{"head":"Infl orescence:","index":177,"paragraphs":[{"index":1,"size":1,"text":"Influence:"},{"index":2,"size":1,"text":"Inherit:"},{"index":3,"size":18,"text":"A flowering shoot on which flowers are arranged on the floral axis, e.g. as in sorghum or rice."},{"index":4,"size":17,"text":"To control, dominate, affect, induce or modify the growth and development of a plant in any way."},{"index":5,"size":5,"text":"To receive genes form parents."}]},{"head":"Inheritance:","index":178,"paragraphs":[{"index":1,"size":15,"text":"The transmission of genetic information (characters, triats, chromosomes genes) from parents and ancestors to progeny."}]},{"head":"Inhibitor gene:","index":179,"paragraphs":[{"index":1,"size":11,"text":"The gene that prevents or inhibits the expression of another gene."}]},{"head":"Initial evaluation trial:","index":180,"paragraphs":[{"index":1,"size":28,"text":"This is a first stage trial conducted to determine which of the several varieties or lines (100-400) could be retained either for future detailed trial or for hybridization."}]},{"head":"Inland swamps:","index":181,"paragraphs":[{"index":1,"size":3,"text":"Inoculate: Inoculum: Inorganic:"},{"index":2,"size":18,"text":"These are swamps or poorly drained land found in the interior, far from the coast in any country."},{"index":3,"size":24,"text":"To introduce micro-organisms into another organism or a medium. Spores, bacteria, eggs of insects or fragments of mycelium of pathogens which can infect plants."},{"index":4,"size":14,"text":"Of mineral orlgln not a carbon compound or not from living tissue or compounds."},{"index":5,"size":22,"text":"Materials provided to the soil or plant or both to support or improve plant production. Examples are fertilizers, herbicides and insecticides (defined)."}]},{"head":"Insecticide:","index":182,"paragraphs":[{"index":1,"size":2,"text":"In situ:"},{"index":2,"size":1,"text":"Inspection:"},{"index":3,"size":7,"text":"A substance used to kill insect pests."},{"index":4,"size":20,"text":"In natural or original position, not removing a plant from its original position for study or for any other operation."},{"index":5,"size":21,"text":"The act of examlnlng thoroughly with the idea of discovering someting unsual or substandard as in field inspection of seed fields."}]},{"head":"Integrated pest management:","index":183,"paragraphs":[{"index":1,"size":60,"text":"This is a term used to describe crop pest (insects, diseases, weeds and animals) control techniques that include the use of one or more of the following, biological control, physical and mechanical control, autocidal insect control, chernical behavioural insect control and selective chemical control (Bottrell,19BO). The techniques involved are to be cheap and easily adaptable and free from environmental hazards."}]},{"head":"Interaction:","index":184,"paragraphs":[{"index":1,"size":46,"text":"The act of two or more variables affecting the expression or performance of each other. At different levels or locations, e.g. a trial involving different plant populations at different nitrogen levels. The populations will behave differently under the various levels of nitrogen (Steel and Torrie, 1960)."}]},{"head":"Interallelic:","index":185,"paragraphs":[{"index":1,"size":19,"text":"Between two different alleles of a gene, e.g. interallellic action is one which is influenced by two different alleles."}]},{"head":"Interbreeding:","index":186,"paragraphs":[{"index":1,"size":14,"text":"Said of plants that are capable of actual or potential gene exchange by hybridization."}]},{"head":"Intercropping:","index":187,"paragraphs":[{"index":1,"size":12,"text":"Growing more than one crop in a rield at the same time."}]},{"head":"Interference:","index":188,"paragraphs":[{"index":1,"size":14,"text":"The restriction or influence of a crossover on another probable crossover close to it."}]},{"head":"Intermediate:","index":189,"paragraphs":[{"index":1,"size":24,"text":"A triat or character falling between the level of two different plants or two groups of plants. In rice the intermediate height is lOO-140cm."}]},{"head":"Intermediate host:","index":190,"paragraphs":[{"index":1,"size":17,"text":"The host in which the sexual stages of a parasitic life cycle of an organism take place."}]},{"head":"International Rice Testing Programme (IRTP):","index":191,"paragraphs":[{"index":1,"size":1,"text":"Internode:"},{"index":2,"size":44,"text":"A rice testing programme in which several countries participate in the nomination of entries and conduct of the field trials. In the case of rice, the programme is being coordinated by IRRI founded by UNDP. There are many types of nurseries in the programme."},{"index":3,"size":29,"text":"The part of a plant stem or culm between two successive nodes. There are normally four to six elongated (more than lcm) internodes in a mature rice (Vergara, 1979)."}]},{"head":"Interspecific :","index":192,"paragraphs":[{"index":1,"size":20,"text":"Between two different species. An interspecific cross for example in rice will be one between Oryza sativa and Oryza glaberrima."}]},{"head":"Intrnduction:","index":193,"paragraphs":[{"index":1,"size":94,"text":"The procedure of bringing into a location a cultivar or mixture of cultivars that is not normally available there. Such cultivar may be from another part of the country though often it is from another country. The cultivar is used directly as a variety, assessed for its potentials or utilized in hybridization work contributing a character or genes not available in the local or existing cultivars. This is the incorporation of a slightly different character from a very related plant by repeated crossing or backcrossing, e.g. introgressive hybridization may occur when similar parents hybridize."},{"index":2,"size":7,"text":"To get flooded or put under water."},{"index":3,"size":17,"text":"Growth or movement of an infectious agent into a host with its susequent establishment as a disease."},{"index":4,"size":30,"text":"The arrangement of a piece or segment of a chromosome so that its genes are no\\, in reversed 1 inear order as compared to how they were before the rearrangement."}]},{"head":"Investigation: in vitro: in vivo:","index":194,"paragraphs":[{"index":1,"size":20,"text":"Examining, searching, probing or looking with the idea of proving a theory or making a discovery as in an experiment."},{"index":2,"size":73,"text":"It means in glass by deviation. The general use refers to biological or biochemical processes or experiments that occur or that are carried out in a laboratory container after which the cells or tissues in which the cells or process occur are isolated from the whole living organisms, e.g. the growing or culturing of anthers into a plant in a special culture medium. Biological process occuring in the body of a living organism."}]},{"head":"Iron deficiency symptoms:","index":195,"paragraphs":[{"index":1,"size":44,"text":"High soil pH is one of the causal factors of iron deficiency in soil. The symptom on the plant, e.g. in rice is yellowing of newly emerged leaf. The next leaf becomes more yellow or chlorotic, then turns white if conditions are not improved."},{"index":2,"size":151,"text":"The symptoms are di st i nguishab l e f rom t hose of ni troge n de fi ci ency (def ined) in that , i n ni t ro aen defic i ency. the new leave~ are pa e green f i rst an d t urn ye l low later on. The older l eaves are more ye ll Ol•lish . In i ron def i ci ency as explained above, all l eaves are yellOl-l both youn g and old. Iro n def i ciency is more cOllno n in up l and r ice t han i n irrigated rice. [t can be correc ted by fo l iar applicat i on of a so l ut ion conta i ninq i ron (Kang et aI, 1974) and al so by so il appl i cation of fe r r ous su l pha t e."}]},{"head":"Iron toxic i ty :","index":196,"paragraphs":[{"index":1,"size":218,"text":"Thi s is the prob l e~ bro ug llt abo ut whe n there is too much of iron i n the soil. This occurs e.g. in rise paddies or other soil unde r redu ced condi t ion wi th l ow pH . There are varieties of r i ce symp t oms on affected plants . Leaves may have fel\" sma ll brOl-In spots on the green l eaves sta r t i ng f rom the tips and spreading to the leaf base . If cond i t i on i s severe, the whol e l eaf m ay become pur pl e , brown or bronze. Leaves of some var i eti es become ye ll ow. These sy~ptoms are most ly seen on t he leaves betv/ee n t he i r veins. High iron con t ent is as soc iated wi th def i ciency of other element s . e.g . po t assi um or phosp horus. Proper drai nage, time ly ap plication on some so il us i ng urea i nstead of sulphate of ammo nia fertil i zer apply i ng potassium or phosp horus wi ll r emo ve or reduce iron tox i ci ty pr ob l em ."}]},{"head":"I rradiat i on:","index":197,"paragraphs":[{"index":1,"size":38,"text":"Irr i ga ted : Expos ure of pl ants or t hei r parts t o mutagens or agents such as X-rays, gamma rays or chemi ca 1 mutage ns t o cause i ncreased mutation ."},{"index":2,"size":24,"text":"To ap ply v/ater ar tificia ll y other than by rain or river for t he be nefit of grow i ng crops."}]},{"head":"Irr i gated ri ce : I soa ll el es:","index":198,"paragraphs":[{"index":1,"size":134,"text":"Ri ce grown under ar t i f ic ial ly wate re d co ndit i ons i n wh i ch t he so il i s usua ll y l eve l led and pU dd l ed wi t h bunds or l eeves that give sorne water contro l. Irr i gated r i ce us uall y does not suffer frorn l ack of or too much of water as water control i s best under this condi ti on. Up l and rice can be irr i gated too under certa i n c;o ndi t ion s . All el es occu py i ng a l ocus that ca nnot be different i ated from eac h othe r exce pt by specia l test."},{"index":2,"size":26,"text":"Gametes or sexual cell s t ha t are the same in size and app earance but they conj uga te and produce a zy gote."},{"index":3,"size":18,"text":"The fus i on of gametes or sexual cel l s that are simi lar i n size."},{"index":4,"size":22,"text":"Of pla nt s that possess the same genotype and differ in only one gene controlli ng a given cha rac ter."}]},{"head":"Isoge ni c l i nes:","index":199,"paragraphs":[{"index":1,"size":21,"text":"Isol ate : Two or more lines that are ge neticall y different at only a si ngle 1 oeus ."},{"index":2,"size":80,"text":"To sepa r at e a group of plants or i ndividual pl ants from other group s or plan t s with which th ey could othe rw i se f r eely i nterc ross . This i s to prevent cro ss -f ertiliza t i on between the .;epara ted plants or groups of pl ants , e . q. ma i ze va r i et\"i es or fungal or bac terial cu lture ."}]},{"head":"Japonica rice:","index":200,"paragraphs":[{"index":1,"size":142,"text":"A sub-speci es of O. sat i va,group of rice variet i es from northern and ea stern Ch ina: Japan and Korea. In gen era l, most of the mo rph ol og ic al and phys i ological var i ations of these gro ups of r i ce are al so fou nd in ot he r group s of rice such as Indi ca and Ja vani ca . However, the Ja ponica vari eties are chara cter ized by havi ng narrow, dark-gr ee n leaves , short ro und is h grains, mediu m til l er in g, short pl ant natu r e and low amy lose content. A mo re appropri ate t erm i s Sinica r i ce si nc e t he Japanese acquired t heir rices f rom China."}]},{"head":"Java nica rice (Bulu rice):","index":201,"paragraphs":[{"index":1,"size":55,"text":"A gro up of rice var i etie s from Indone si a; also a sub -species of O. sat iva. They are the bulu and gundil va r i et i es . They have broad thic k grains, l ow t ill ering , ta ll plant stature and long panic l es."},{"index":2,"size":36,"text":"Juven il e stage: Period of immaturity or young growth; or the immature or young growth period. This is a stage in most crops before flowering or active accummulation of carbohydrates in parts that are harvestable."}]},{"head":"Kneeing abil ity:","index":202,"paragraphs":[{"index":1,"size":52,"text":"Kerne I : This is an important characteristics of a deep-water variety with elongation ability. This is the capability of some cereals especially rice to be able to raise the panicles up after lodging following flood water receding. This occurs after a deep-water variety has elongated during appreciable rise in water level."},{"index":2,"size":8,"text":"In rice, it generally refers to milled rice."}]},{"head":"Kernel smut:","index":203,"paragraphs":[{"index":1,"size":3,"text":"Kil ogram: Kresek:"},{"index":2,"size":3,"text":"Labe I ;"},{"index":3,"size":17,"text":"A smut or fungus disease that affects the kernel, e.g. in rice, Tilletia barclayana or Nevossia horrida."},{"index":4,"size":102,"text":"A metric weight unit equivalent to 2.2046 pounds. It is 1,000 grams, used commonly in experimental measurements. This is the Indonesia name given to a stage of the systemic disease called bacterial blight (defined). The bacteria attacks the young rice plant through wounds on the roots or leaves, and the leaves wilt and die rapidly as the pathogen becomes systemic. Symptoms resembles those from dead heart, iron deficiency, cricket or rat damage when the affected leaves are out and squeezed, a yellowish to yellow-white, shiny, bacterial fluid oozes from the vascular bundles. This oozing is absent in other sources of plant damage."},{"index":5,"size":10,"text":"Any written or a piece of material for identification purposes."},{"index":6,"size":25,"text":"In field trial, it is a tag or a piece of cardboard, stakes, etc. giving the identity of entry with its row or plot number."}]},{"head":"Labile genes:","index":204,"paragraphs":[{"index":1,"size":6,"text":"Genes that are unsteady (always mutating)."}]},{"head":"Lag phase:","index":205,"paragraphs":[{"index":1,"size":3,"text":"Land ri ce:"},{"index":2,"size":9,"text":"Vegetative stage of a plant in a photoperiod-sensitive genotype."},{"index":3,"size":35,"text":"A locally grOlvn cultivar or an unimproved traditional variety in a given location. It is always found in the area in pure or mixed types and it is well adapted to the environmental conditions there."}]},{"head":"Larva (pl. larvae):","index":206,"paragraphs":[{"index":1,"size":1,"text":"Latent:"},{"index":2,"size":30,"text":"A stage in the life cycle of most insects. The larva hatches out of the egg. In some insects, it is also known as a caterpillar, maggot, grub or worm."},{"index":3,"size":14,"text":"An unexpressed condition of a gene or disease even though present in a plant."},{"index":4,"size":4,"text":"Latin square (LS) design:"},{"index":5,"size":36,"text":"An experimental design used mostly in field experiments where there is a bi-directiona1 fertility gradient. In this design the number of replications is equal to the number of treatments. It is generally used for 4-8 treatments."},{"index":6,"size":2,"text":"Lattice designs:"},{"index":7,"size":66,"text":"Special designs used in incomplete block designs. Treatments in lattice designs are large' 2 Balance lattice -number of treatments is a square number, e.g. K , number of replication is K + 1, K ~ number of plots per block. Partially ba1an 2 ed latticenumber of treatments is a square number, e.g. K , number of replication is possible. Number of plots per block is K."}]},{"head":"Lax panicle:","index":207,"paragraphs":[{"index":1,"size":1,"text":"Leaching:"},{"index":2,"size":13,"text":"A panicle with few lateral spike1ets on the branches. is open or loose."},{"index":3,"size":11,"text":"branches and sparsely distributed It also refers to a panicle that"},{"index":4,"size":15,"text":"The removal of useful chemicals or other materials in solution from the soil through percolation."},{"index":5,"size":1,"text":"Leaf:"},{"index":6,"size":2,"text":"Leaf angle:"},{"index":7,"size":36,"text":"A lateral organ borne on the stem or axis of most plants. It is the major organ used for photosynthesis by plant to accumulate carbohydrates and for many other physiological processes such as respiration and transpiration."},{"index":8,"size":40,"text":"In cereal crops, it refers to the distance of the leaf blade from the stem. It determines the openess or closeness of the leaf. The general descriptive terms often used are erect (angle of 0-30°) intermediate (31-60°), horizontal (61-90 0"},{"index":9,"size":37,"text":") , descending (over 91°). In rice, the angle of the flag leaf is important. Erect flag leaf discourages the attack of birds as the grains on the panicles are less showy and more difficult to reach."}]},{"head":"Leaf-area index (LAI):","index":208,"paragraphs":[{"index":1,"size":2,"text":"Leaf blade:"},{"index":2,"size":2,"text":"Leaf blast:"},{"index":3,"size":104,"text":"The area of the leaf surface per unit of land surface. It is the total leaf surface to the area of land it covers. A general formula is: LAI = Sum of leaf area of all plants in an area Area of land covered by the plants Generally, the thin, flattened, conspicuous portion of the leaf (see lamina) joined to the leaf sheath, leaf petiole or directly to the stem in some plants. It is the major part of the plant responsible for photosynthesis. It may be simple (one piece) as in rice or compound (divided into separate parts or leaflets) as in cassava."},{"index":4,"size":14,"text":"The blast disease that affects the leaf as differentiated from other forms of blast."}]},{"head":"Leaf curling:","index":209,"paragraphs":[{"index":1,"size":10,"text":"The characteristic rollinq of leaves due to control water loss."}]},{"head":"Leaf folder:","index":210,"paragraphs":[{"index":1,"size":38,"text":"An important insect on cereal especially rice. The insect is Caphalecrosis medinalis. The larva which causes the damage creates a leafy tube as it gets bigger and feeds within the tube consuming the leaf tissues except the epidermis."},{"index":2,"size":2,"text":"Leaf rolling:"},{"index":3,"size":2,"text":"Leaf scald:"},{"index":4,"size":28,"text":"The moving of leaf by revolving inwardly or outwordly due to decrease in the leaf tissue water potential as affected by atmospheric moisture content and soil moisture supply."},{"index":5,"size":84,"text":"A type of leaf disease by a fun9us in rice known as Rhynchosporium oryzae. The lesion occurs very often on the tip of the leaf. It may also start at the margin of leaf blade. The typical lesions form characteristic zonations or bands as they spread and enlarge on leaves of susceptible varieties. The lesions thus develop into large ellipsoid areas encircled by grayish dark brown bands, accompanied by light-brown halo. Rice varieties with broad leaves appear to be more susceptible to leaf scald."},{"index":6,"size":2,"text":"Leaf senescence:"},{"index":7,"size":2,"text":"(See senescence)."},{"index":8,"size":2,"text":"Leaf sheath:"},{"index":9,"size":24,"text":"The lower part of the leaf which is modified to invest, enclose or wrap around the stem and young leaves in grasses or sedges."},{"index":10,"size":21,"text":"A good basal wrapping of the leaf sheath is an important feature for lodging resistance in cereal crops such as rice."},{"index":11,"size":4,"text":"Least significant difference (LSD):"},{"index":12,"size":1,"text":"Legume:"},{"index":13,"size":1,"text":"Lemma:"},{"index":14,"size":35,"text":"A computed value used for comparing p1anned paired means arising from analysis of variance. Any two means whose difference exceeds this value are declared significantly different. A 5% or 1% probability level is often used."},{"index":15,"size":59,"text":"The pod produced by a group of plants in the order Leguminosae (peas, beans, etc.) The term is used for a particular group of plants that produce these pods. They are important in cropping system for their ability to enrich the soil with their high nitrogen content. Most of them fix nitrogen in association with bacteria in root nodules."},{"index":16,"size":22,"text":"One of the two members (lemma and palea) of the parts referred to collectively as glumes in the flower of a grass."},{"index":17,"size":2,"text":"Lesi on:"},{"index":18,"size":3,"text":"Le vee :"},{"index":19,"size":1,"text":"86"},{"index":20,"size":30,"text":"In rice, it is bigger th an palea. The al'in ex tends from lema i n r i ce. It encloses the palea ( See sterile l emma ) ."},{"index":21,"size":36,"text":"An unusual change in form, colour s truc t ure and devel opme nt of a ce ll, tissue, org an or any part of a plant due t o i njury or di sease ."},{"index":22,"size":15,"text":"A paddy bund or the hig h side of a main irr i gation channel."}]},{"head":"Letha l gene:","index":211,"paragraphs":[{"index":1,"size":3,"text":"Life cycle :"},{"index":2,"size":3,"text":"Ligu l e:"},{"index":3,"size":7,"text":"Life cyc l e : Line :"},{"index":4,"size":29,"text":"Gene whose effec t is suf fic i ent ly dra st i c t o ki l l t he bearer of cer ta i n genotypes ."},{"index":5,"size":30,"text":"The success i ve se ri es of changes t hrough wh i ch an orga ni sm oasses in t he cou r se of it s developeme nt."},{"index":6,"size":166,"text":"p, po inted 1 eafy st ru cture that proj ects upward fro m the t op of the l eaf shea th, cl ose ly pressed t o the culm in m ost grasses. It i s red uced Dr abse nt i n some grasses . It i s used a l so to cesc r i be some pa rts of a fl ower. O. sa t iva has l ong 1 i gu l e , Q. gl abeni ma, s hort , Progressive se r ies of cha nges und e rgone by a pl ant from fe rtil izat i on to death or t o the per i od when the pl ant al so produces gametes whi ch begi n an i denti ca l series of chan ges. It i s also agro -nomi ca l ly r eferred to as the per i od from seeding t o m atur i ty of the crop ."},{"index":7,"size":22,"text":"A fa mi ly of pl ants or i gi nat i ng fr om a commo n cross or pa rents."},{"index":8,"size":55,"text":"A pl an t t ha t i s st ill undergoin g se l ect i on, i mproveme nt, or unrecommended indi vidu al s. After severa l generati ons and de sc r i ptions, a lin e becomes a var i ety and i s given a varieta l name ."},{"index":9,"size":13,"text":"The line or proge ny derived from usually self-pollinating homozy go us plants."},{"index":10,"size":2,"text":"Line sowing:"},{"index":11,"size":11,"text":"To sow in line rather than broadcasting or ha pzard dibbling."},{"index":12,"size":2,"text":"Linear model:"},{"index":13,"size":11,"text":"A model with linear equations for the varia~e s invol ved."},{"index":14,"size":5,"text":"Linear regre ss i on:"},{"index":15,"size":3,"text":"Lin kage :"},{"index":16,"size":4,"text":"(See regress ion )."},{"index":17,"size":54,"text":"The associat i on of one or more genes on a chrom osome . They are found almost always toge t her unless the linkages ane broken in me i os is . The closer the gen es are , t he t ig hter the lin kage and more diff icult their separation."}]},{"head":"Linkage grou p:","index":212,"paragraphs":[{"index":1,"size":15,"text":"A group of genes arra nged i n a linear order on a chromo some."},{"index":2,"size":4,"text":"Lin kage ma p:"},{"index":3,"size":2,"text":"Litre :"},{"index":4,"size":1,"text":"Loam:"},{"index":5,"size":21,"text":"A diagram of linkage groups showing th e rel at ive positi on of the genes on a gi ven chromosome."},{"index":6,"size":32,"text":"Unit of volume i n met ric sys tem. It i s equa l to 1000 ml. A place or site where a plant is found or an experiment is carried out."}]},{"head":"Locus (pl. loci):","index":213,"paragraphs":[{"index":1,"size":1,"text":"Lodge:"},{"index":2,"size":1,"text":"Lodicule:"},{"index":3,"size":2,"text":"Long smut:"},{"index":4,"size":2,"text":"Loose smut:"},{"index":5,"size":12,"text":"The site or position on a chromosome where a gene is located."},{"index":6,"size":36,"text":"Of plants, to fall over due to wind, rain, and pest damage or due to the character of the plant which is too tall or weak to stand erect, especially after or during the grain-filling stage."},{"index":7,"size":26,"text":"Lodging often causes yield loss. Lodging is increased by high soil fertility and poor leaf sheath wrapping. Potassium unlike nitrogen prevents or reduces lodging in rice."},{"index":8,"size":16,"text":"A small structure, scaly or hairy, often associated with the stamens in the flowers of grasses."},{"index":9,"size":11,"text":"A common name for a sorghum grain smut called Tolyposporium erhenbergii."},{"index":10,"size":14,"text":"A fungus disease in cereals such as wheat or barley of genus Ust ilace."},{"index":11,"size":4,"text":"Lowland r i ce:"},{"index":12,"size":3,"text":"Lys i ne:"},{"index":13,"size":49,"text":"Rice grown i n swamps and in deep and shallow f l ooded conditlon or irrigated cond ition. In contras t to up land r ice , the so il is i nundated duri ng a cons i de rab l e pa r t of rice growt h."},{"index":14,"size":11,"text":"One of the es senti al amino acids in seed protein."},{"index":15,"size":17,"text":"li mitin g i n m any ce real s such as sorghu m or mai ze."},{"index":16,"size":6,"text":"Vel\"y impo rtant nutritionall y ."},{"index":17,"size":3,"text":"It is often"},{"index":18,"size":20,"text":"Firs t , second and thi rd ge nera t i ons follOloJin g exposure to d mutagenic age nt."}]},{"head":"Main effects:","index":214,"paragraphs":[{"index":1,"size":16,"text":"The average effect of t he majo r factor in f ac t oria l experiments."},{"index":2,"size":12,"text":"Major elements, mac r o el ements or mac ronutrient s :"},{"index":3,"size":89,"text":"These are chemical elements essential for hi gher pl ant growth and deve l opemnt in relatively la rge amounts (usual l y ove r 500 parts per mill ion in the plant) see essential el ements ) . The re are nine of these nut r ient elements. The three mostly f rom air and wate r are Carbon, Hyd rogen and Oxyge n. Ot he rs from the so il are Nitrogen , Phospho rus, Potas s ium, Ca l sium, 1 1agnesi um and Sulphur ."}]},{"head":"M ajor genes:","index":215,"paragraphs":[{"index":1,"size":63,"text":"Mendelian ge nes t ha t contro l di scont i nuous character ( see character) . They operate in fewer nu mbe rs , e. g. one or two pairs. They indi vi dua ll y produ ce pronoun ced phenoty pe effec ts . They segrega te clearl y an d can be analysed as mendel ian rat i os ."},{"index":2,"size":5,"text":"I~a 1 e pa rent;"},{"index":3,"size":21,"text":"The pl ant t hat possesses the stame ns from whi ch po llen i s gathered f or crossing ."}]},{"head":"Male steri le:","index":216,"paragraphs":[{"index":1,"size":44,"text":"A pl ant de void of pollen grains or wit h inv iab l e po ll en and therefo re un ab le t o fer t ili se the female, e.g . non-dehl scence of antller and genic or cytoplasmic male sterility."},{"index":2,"size":2,"text":"Mangrnve swa~~s:"},{"index":3,"size":33,"text":"'o10/d::,P5 \"hc\"e ilI:ln9rove trees, e.g. Rhizllphol'J racenlosa or .c;viccennic, nitlda grow. c1angrove S'>'IdlllpS-arc typified by salir,Jcyan-d--il-cidity. The soil contJins sulfur and sulfur C[lII:~ounds \"Ich as ferrous sulfide (FRS) dnd pyrite (FeS 2 )."},{"index":4,"size":13,"text":"Groljing I icp on land generally cleared of mangrove forest. (see mangrove sllamp)."},{"index":5,"size":3,"text":"~1a rker gene:"},{"index":6,"size":19,"text":"A qene of known function and usually also of a known location o~ Vie chr'olfosomes; used in genetic studies."},{"index":7,"size":2,"text":"~ldSS selection:"},{"index":8,"size":58,"text":"A form of breeding in which the new variety to be bred consists of selecting several single plants and bulking them together. This selection method is used mainly to preserve genetic purity of already established variety of land variety. The new variety is a mixture of different but rather homogeneous or uniform for most of the plant characters."}]},{"head":"Mature grain stage:","index":217,"paragraphs":[{"index":1,"size":2,"text":"Maturi ty:"},{"index":2,"size":1,"text":"Mean:"},{"index":3,"size":34,"text":"The stage when individual grain is mature, fully developed in size and is hard. In rice, it is clear and free from green tint. It is when the grain has reached maximum dry weight."},{"index":4,"size":69,"text":"A growing stage when seeds are ripe, or capable of being harvested or util ized in other ways. In crop such as rice \"days to maturity\" is the number of days from seeding to ripening of more than 85 per cent of the grains on the panicle. During this stage most of the grains have turned yellow or straw colour. Also refers to the growth duration, e.g. maturity groups."},{"index":5,"size":16,"text":"Average; the total of observations, measurements, scores, etc., being divided by the number of such observations."},{"index":6,"size":2,"text":"Mean square:"},{"index":7,"size":18,"text":"The sum of the squares of a set of treatments or replications divided by its degree of freedom."},{"index":8,"size":1,"text":"Measure~ent:"}]},{"head":"Median:","index":218,"paragraphs":[{"index":1,"size":1,"text":"Mediu~:"},{"index":2,"size":1,"text":"Meiocyte:"},{"index":3,"size":1,"text":"Meiosis:"},{"index":4,"size":26,"text":"The determining of the quantity, size, length, value or amount of a treatment or a plant (various units are used for this operation (see Table 2)."},{"index":5,"size":20,"text":"The value of the variable on each side of which there is an equal number of larger and smaller variables."},{"index":6,"size":54,"text":"Statistically, the figure that represents the middle position of 2 or more sets of figures, it is a mean or average. In general term, it is in between two things or extremes, e.g. medium height, medium duration. The surrounding or environment in which a plant grows, especially in the laboratory or other controlled places."},{"index":7,"size":5,"text":"Diploid cell to undergo meiosis."},{"index":8,"size":40,"text":"It is also referred to as reduction division. Meiosis is genetically controlled and genetical changes take place during the process. It is the process responsible for heredity and a basis for sexuality of higher plants. It serves two major functions:"},{"index":9,"size":18,"text":"(1) Provision for the random assortment of paired chromosomes and halving of the somatic or diploid chromosome number."},{"index":10,"size":25,"text":"(2) Determination of accurate segregation of different alleles and random recombination of unlinked genes and non random recombination of linked genes (Rieger et al, 1976)."},{"index":11,"size":2,"text":"Mendelian Character:"},{"index":12,"size":68,"text":"Expressed character (defined) due to one or few pairs of genes which have major effect. The expressed character can be dominant or recessive or intermediate. The following table shows factors for coverting non-S1 units to acceptab SI units. Parenthetic reference to SI base units does not mean that onl base units can be used, but shows the equivalent base unit. All units in this column are acceptable. Metabolism:"}]},{"head":"Non-Sl Units","index":219,"paragraphs":[{"index":1,"size":2,"text":"Mi crobe:"},{"index":2,"size":29,"text":"The summation of the building-up and breaking down processes that take place in a living organism in maintaining growth, development and reproduction. Both physical and chemical processes are involved."},{"index":3,"size":12,"text":"A small organism, usually used to describe a bacterium, fungus, virus, etc."},{"index":4,"size":2,"text":"Microcl imate:"},{"index":5,"size":24,"text":"(1) The climatic condition of a small area resulting from the modification of the general climatic conditions by local differences in elevation or exposure."},{"index":6,"size":16,"text":"(2) The sequence of atmosphere changes within a very small region, e.g. a plant (Foth, 1978)."},{"index":7,"size":5,"text":"Micro elements, micronutrients, trace elements:"},{"index":8,"size":58,"text":"These are important or essential nutrient elements (defined) that are required in the plant for proper growth and development in only very small amount; less than 50 parts per million in the plant. The seven elements which make up this group are found mostly in the soil. They are Iron, 5il ica, Boron, Mo1ybodenum, Copper, Zinc and Chloride."}]},{"head":"Micro organism: Mill ing:","index":220,"paragraphs":[{"index":1,"size":10,"text":"A small organism that is often visible only through microscopes."},{"index":2,"size":52,"text":"In rice, the process of removing the glumes or hull and removal of testa or seed coat, the embryo, the aleurone often some portion of the endosperm of the rice grain. milled or polished rice is mainly the starchy endosperm kerne 1 . further 1 ayer, and Thus, of the ri ce"},{"index":3,"size":2,"text":"Milling recovery:"},{"index":4,"size":58,"text":"This refers to the percenta~e of the actual amount of milled rice obtained after the milling process. It usually refers to total milled rice, i.e. broken and whole kernel. Recovery varies from 50-80 per cent depending on the grain quality and whether or not the rice is parboiled, the harvest and storage conditions, etc. (see grain milling quality)."},{"index":5,"size":6,"text":"Milk stage or milk grain stage:"},{"index":6,"size":12,"text":"The reproductive phase when the grains are just being filled with carbohydrates."},{"index":7,"size":1,"text":"Mineralization:"},{"index":8,"size":19,"text":"The conversion of an element from an organic form to an inorganic state as a result of microbial decomposition."}]},{"head":"Minor genes:","index":221,"paragraphs":[{"index":1,"size":17,"text":"Genes which individually produce very little effect but in combination may produce a marked effect (see polygenes)."}]},{"head":"Minikit trial:","index":222,"paragraphs":[{"index":1,"size":31,"text":"A trial in which the entries are small in number and in plot unit. The entries with all the inputs per plot are put in a small container or a box."}]},{"head":"Minimum tillage:","index":223,"paragraphs":[{"index":1,"size":64,"text":"A reduced or limited land preparation. There are many variation~ depending on soil type or crop involved. In a light textured soil, it may mean ploughing plus one harrowing or one of these operations before planting. It could mean only one rotavating without ploughing. Full tillage is a full or deep ploughing with at least two harrowirg before planting, e.g. for upland rice cultivation."},{"index":2,"size":2,"text":"Missing data:"},{"index":3,"size":33,"text":"Data that are not available, lost or cannot be used because of some reasons, e.g. mechanical errors, loss of sample after harvest, removal by theft, destruction by rodent, bird or insects, drought, etc."},{"index":4,"size":30,"text":"In rice, when over 20% of hills are unavailable due to any of the above reasons, the plot yield is treated as missing data in statistical analysis (Gomez and Chang)."}]},{"head":"Missing hill:","index":224,"paragraphs":[{"index":1,"size":13,"text":"In transplanted rice it is the spot where transplanted seedlings died before maturing."}]},{"head":"Missing plot:","index":225,"paragraphs":[{"index":1,"size":1,"text":"Mitosis:"},{"index":2,"size":22,"text":"In field experiment when an experimental unit is completely absent at maturity due to lack of germination, disease, animal damage, drought etc."},{"index":3,"size":28,"text":"A process of somatic cell division which produces daughter nuclei which are identical genetically with one another and to the parent nucleus. They contain same number of chromosomes."},{"index":4,"size":45,"text":"Mitosis produces genetically equivalent cells in the growing somatic region of organisms. It is a process by which the diploid stage of a cell is maintained, i.e. there is no reduction of the chromosome number. The five main staqes are prophase, prometaphase, metaphase,anaphase and telophase."},{"index":5,"size":2,"text":"Mixed cropping:"},{"index":6,"size":17,"text":"A farming system in which more than one crop is grown concurrently on a piece of land."}]},{"head":"Mixed farming:","index":226,"paragraphs":[{"index":1,"size":1,"text":"Mixture:"},{"index":2,"size":1,"text":"Mode:"}]},{"head":"Agriculture animals for integration","index":227,"paragraphs":[{"index":1,"size":23,"text":"involving growing of crops associated with rearinq work or other purposes. In short, it is an of crop and animal production (Okiqbo, 1978)."},{"index":2,"size":8,"text":"Seeds made up of more than one variety."},{"index":3,"size":12,"text":"In observation or sets of data, the value which is most frequent."},{"index":4,"size":22,"text":"(1) A formalized expression of theory or the causal situation which is regarded as having generated observed data (Kendall and Buckland, 1971)."},{"index":5,"size":72,"text":"(2) In statistics, it is a set of symbols in the form of equation on which interpretation of the analysis is based. The model expresses a linear additive of the components. There are fixed random or mixed models in statistics. Fixed means that the interpretation will be valid only for the treatment in the given experiments, random means that it will be good for similar treatments not used in the particular experiment."}]},{"head":"Modifying genes (modifying;factors):","index":228,"paragraphs":[{"index":1,"size":37,"text":"Genes whose main role is to influence the expression of other genets) or nonallelic genes. They affect phynotipic expression of those genes being modified even though nonallelic. They may enhance or reduce the expression of the characters."},{"index":2,"size":3,"text":"~1oi sture content:"},{"index":3,"size":23,"text":"The amount of water in a plant or soil. Grain yield in rice is usually reported on 13-14 per cent moisture content basis."}]},{"head":"Moisture stress:","index":229,"paragraphs":[{"index":1,"size":17,"text":"Said of plant when it is suffering from lack of soil moisture for good growth and developement."}]},{"head":"Moisture tester:","index":230,"paragraphs":[{"index":1,"size":16,"text":"An instrument for testing the moisture content of any part of the plant, especially the seed."},{"index":2,"size":1,"text":"Monoculture:"},{"index":3,"size":1,"text":"Monocious:"},{"index":4,"size":18,"text":"The repetitive growing of the same crop (annual, biennual or perennial) crop on the same land (Okigbo, 1978)."},{"index":5,"size":24,"text":"Having flowers with only one sex, i.e. either female or male flowers on different parts of the same plant. An example is Zea mays."}]},{"head":"Monogenic:","index":231,"paragraphs":[{"index":1,"size":29,"text":"Having a type of inheritance on which the difference between the genotypic difference between two cultivars is due to only a difference of one pair of alleles (1 gene)."}]},{"head":"Monohybrid cross:","index":232,"paragraphs":[{"index":1,"size":10,"text":"A cross resulting from two parents differing in pne gene."}]},{"head":"Monomoda1 rainfall distribution:","index":233,"paragraphs":[{"index":1,"size":13,"text":"The type of rainfall in which there is only one peak a year."}]},{"head":"Monoploid (Haploid):","index":234,"paragraphs":[{"index":1,"size":12,"text":"A plant or organism having only one set of chromosome (n) Monosonic:"},{"index":2,"size":12,"text":"Lacking one chromosome of the normal chromosone complement, thus it has 2n-l."}]},{"head":"Morphology:","index":235,"paragraphs":[{"index":1,"size":1,"text":"Mosaic:"},{"index":2,"size":1,"text":"Mould:"},{"index":3,"size":1,"text":"Mulch:"},{"index":4,"size":8,"text":"Study of the form and structure of organisms"},{"index":5,"size":26,"text":"The way leaves arranged so that upper leaves do not shade those below. The characteristic patchy or mottled yellowing of leaves usually caused by a virus."},{"index":6,"size":17,"text":"Applied to microscopic saprophitic fungi that affect grains or fruits, e.g. Aspergillus f1avus and Pennicillum spp. etc."},{"index":7,"size":47,"text":"Spread on the soil surface straw sawdust, leaves, plastic film, loose soil etc to protect the soil and plant roots from effects of raindrops, soil crushing, freezing, evaporation, etc. Any material used for such a protection. Mulch also adds organic matter and mineral nutrients into the soil."}]},{"head":"Multicellular:","index":236,"paragraphs":[{"index":1,"size":15,"text":"Consisting of more than one cell. Most plants are made up of millions of cLi's"},{"index":2,"size":29,"text":"(5 ) Relay intercropping: Growing two (or more) crops in sequence, seeding or transplanting the succeeding one before the harvest but several weeks after the emergence of the former."}]},{"head":"Multiple cross:","index":237,"paragraphs":[{"index":1,"size":39,"text":"A cross involving an Fl and another parent other than either of its parents. A cross between two or more F s or two or more different hybrids. Two or more selfed varieti~s crossed with an open pollinated variety."},{"index":2,"size":2,"text":"Multiple-range test:"},{"index":3,"size":2,"text":"(See Duncan's)."},{"index":4,"size":8,"text":"M ult i pl i cat i on:"},{"index":5,"size":1,"text":"Mutagen:"},{"index":6,"size":27,"text":"The proces s of increasing the planting material of a plant such as seed or cutting for wide di stribution for increased planting at a given site."},{"index":7,"size":6,"text":"A substance used to induce mutation."}]},{"head":"Mutageni c:","index":238,"paragraphs":[{"index":1,"size":4,"text":"Mutant: Ca using mutations."},{"index":2,"size":16,"text":"A plant which has acquired a heritable chara cter or variation as a result of mutation."}]},{"head":"Mutant tra it:","index":239,"paragraphs":[{"index":1,"size":1,"text":"Mutation:"},{"index":2,"size":44,"text":"A variant that is relatively different from the normal or parental type and it is inherited in a simple Mendelian manner. The mutant traits are variants of a mo re extreme nature than those commonly observed in a small grou p of cultivated varieties."},{"index":3,"size":42,"text":"A sudden heritable change in chromosomal DNA. This may be a change in form, number of genes, or chromosomes. It could be natural or artificial in origin. Natural mutation is a normally infrequent event, though it is happening all the time Muton:"},{"index":4,"size":1,"text":"Mycelium:"},{"index":5,"size":29,"text":"102 its effects are masked by heterozygosity, lethality and so are unobserved. It is speeded up artificially through irradiation with X-rays, gamma-rays, neutrons , etc. and by some chemicals."}]},{"head":"Smallest length of DNA capable of mutation change","index":240,"paragraphs":[{"index":1,"size":23,"text":"Collective term for a mass of hyphae that ma ke up the vegetative pa r t of a fungus N 2n: , 103"},{"index":2,"size":21,"text":"The notations for the ganetic and zygotic (diploid) or somatic chromosome number of a plant, e.g. 2n = 24 in rice."},{"index":3,"size":6,"text":"Narrow brown leaf spo t :"},{"index":4,"size":53,"text":"A fungal disease caused in rice by Cercospo ra oryzae. The symptoms on the leaves are very narrow, short, redish-brown spots. The long axis of the spots are parallel with the veins of the leaf. The linear appearance differentiates these spo ts from those of the oval brown spots of Helmintho sperium oryzae."}]},{"head":"Narrow cross:","index":241,"paragraphs":[{"index":1,"size":18,"text":"A cross between two parents that differ only in a few genes. They have many genes in common."}]},{"head":"Natural cross pollination:","index":242,"paragraphs":[{"index":1,"size":24,"text":"Cross pollination occurring without m an's effort. Pollination could be by insect, wi nd or floral parts making di rect contact with each other."},{"index":2,"size":2,"text":"Natural selection:"},{"index":3,"size":1,"text":"Neck:"},{"index":4,"size":20,"text":"The retention or survival of a plant in a given locality under natural conditions and not influenced by human action."},{"index":5,"size":13,"text":"In panicles, it refers to the upermost internode just below the panicle base."}]},{"head":"Neck blast:","index":243,"paragraphs":[{"index":1,"size":1,"text":"Nematode:"},{"index":2,"size":1,"text":"Nitrogen:"},{"index":3,"size":9,"text":"Blast attacking the neck of panicles, e.g. in rice."},{"index":4,"size":35,"text":"A term for any individual of the phylum nematoda. A member of a group of minute worms with long cylindrical unsegm ented bodies. The parasitic forms adversely affect plant growth and development in various ways."},{"index":5,"size":16,"text":"A gaseous element which makes up about 4/5th of the air. The chemical symbol is N."},{"index":6,"size":21,"text":"It is one of the major or essential elements for plant growth and supplied to the plant in various nitrogenous fertilizers."},{"index":7,"size":3,"text":"Nitrogen defficiency symptoms:"},{"index":8,"size":74,"text":"These are signs that a plant exhibits to show that nitrogen is absent or insufficient. In rice, the indications are stunted growth, reduced ti1lering erect and yellow leaves. When there is inadequate nitrogen in the early growth stage, generally yellowing occurs first on the older leaves and later extends to the young leaves which first turn pale green starting from the tip. This is a distinguished feature between nitrogen deficiency and iron deficiency (defined)."},{"index":9,"size":2,"text":"Nitrogen fixation:"},{"index":10,"size":15,"text":"Biological conversion of molecular dinitrogen (N2) to organic combinations or to forms utilizable by plants."},{"index":11,"size":2,"text":"Nitrogen response:"},{"index":12,"size":2,"text":"Modal roots:"},{"index":13,"size":7,"text":"Nitrogen response of a cu1tivar refers to:"},{"index":14,"size":12,"text":"(1) The general increased growth of the plant due to nitrogen intake."},{"index":15,"size":14,"text":"(2) The rate of increase in crop yield per unit measure of nitrogen fertilizer."},{"index":16,"size":20,"text":"(3) In economic terms, the ratio of crop value from increase in yield to the cost of the nitrogen fertilizer."},{"index":17,"size":11,"text":"Roots formed on the upper nodes when deep-water rice is flooded."},{"index":18,"size":8,"text":"Noda 1 t i 11 e rs :"},{"index":19,"size":1,"text":"Node:"},{"index":20,"size":15,"text":"Tillers formed on the upper nodes at the end of flooding deep water rice ."},{"index":21,"size":34,"text":"Relatively hardened and sometimes bulging part of a cereal culm where one or more leaves, tillers, branches or adventitious roots may arise. A node separates two internodes. Branches or spike1ets arise from panicle nodes."},{"index":22,"size":2,"text":"Node blast:"},{"index":23,"size":1,"text":"Nodules:"},{"index":24,"size":7,"text":"Bl ast t hat attacks the nodes."},{"index":25,"size":90,"text":"These are swe llings or pounded lumps on most l eguminous roots. They contain bacteria, e.g. Rhizob i um spp which l ive on t he root s. They f i x molec ular air ni trogen i n this nodules. The nitrogen fixed is available for the plant and enr iches the so il for t he following crops as the nodules get incorporated i nto the soil at the end of t he ho st plant's life cyc l e and deat h (see Symbios i s) ."},{"index":26,"size":7,"text":"No n-alle li c interact i on:"},{"index":27,"size":9,"text":"Interaction that is be tween different genes (see epistasis)."},{"index":28,"size":4,"text":"Non -recurrent pa rent:"},{"index":29,"size":21,"text":"The donor parent in a backc ross . It i s used on ly once in a backc ross (see backcross)."},{"index":30,"size":7,"text":"Non -waxy endosperm: (non glu tinous) :"},{"index":31,"size":78,"text":"A common no n-glutinous endosperm, e .g. in rice. The starch fraction of the endosperm ha s both amylose and amy l opectin. A characteristic of non-wa xy endosperm is i t s dark -blue sta i ni ng with we ak potassium i odi de-iodine sol ution. In rice, the non -waxy endosperm is popul ar among peopl e who prefer to eat a dry or non sticky and fluffy r i ce (see amy l ose)."}]},{"head":"Normal distribution:","index":244,"paragraphs":[{"index":1,"size":3,"text":"Nuc l eus:"},{"index":2,"size":45,"text":"The sp r ead of data assumed t o be a continous frequency dis tribut i on of in f i nite range. \"hen such data are rep r esented by grap h, th e graph is called a normal curve, laplacian or gaussian curve."},{"index":3,"size":5,"text":"The curve is bel l-shaped."},{"index":4,"size":31,"text":"The chromat ic and the most constant part of a ce ll, found in the ce ll cytopl asm. It has its own membrane. Chromosomes are i n the nucleu s."}]},{"head":"Nucleus seed:","index":245,"paragraphs":[{"index":1,"size":16,"text":"A class of pure seed produced by a breeder f or raising breeder ' s seed."},{"index":2,"size":2,"text":"Null hypothesis:"},{"index":3,"size":1,"text":"Nullipla.x:"},{"index":4,"size":29,"text":"In statistics, it is a hypothesis stating that there is no difference between observed information or measured data and those expected. This hypothesis is the basis for significance tests."},{"index":5,"size":19,"text":"The condition in which a polyploid is recessive in all chromosomes in respect to a particular qene (Allard, 1960)."},{"index":6,"size":5,"text":"Null i somi c: Nursery:"},{"index":7,"size":17,"text":"The condition in which a pair of chromosomes is absent resulting in a chromosome number of 2n-2."},{"index":8,"size":75,"text":"A piece of prepared land ~/here crop seedl ings are raised for a short time pending their planting in permanent sites. A place where a large number of introduced or breedin~ varieties or lines are first looked at or screened under field conditions. Such 1urseries consist of plots of 1-4 rows, unreplicated . In some countries, nursery refers to coordinated trials sent to various locations and involving 1 arge numbers with or ~/ithout repl ication."},{"index":9,"size":2,"text":"Nutritional disorders:"},{"index":10,"size":53,"text":"These are irregular or abnormal growth and development in plants due to inbalanced availability of one or more of the essential elements (defined) . The elements may be lacking or excessive causing deficiency, toxicity or salt injury symptoms . The disorders occur under various soil conditions . (see al so physiological di seases)."}]},{"head":"Objectives :","index":246,"paragraphs":[{"index":1,"size":1,"text":"Obligate:"},{"index":2,"size":23,"text":"A set of goals or aims to be achived The main purpose of the experiment. objectives (defined). in carrying out an experiment ."}]},{"head":"Examples are breeding","index":247,"paragraphs":[{"index":1,"size":38,"text":"The characteristics of an organism or parasite that enable it to survive only under certain conditions, e.g. an obligate parasite can live only on living things in contrast to an obligate saprophyte which lives only on dead materials."}]},{"head":"Observation:","index":248,"paragraphs":[{"index":1,"size":17,"text":"Information for scientific studies collected by noting facts or occurrences. One measurement or count constitutes one observation."}]},{"head":"Observation yield trial:","index":249,"paragraphs":[{"index":1,"size":16,"text":"A preliminary yield trial that has several entries ~tth small plots. It may have 1-3 replications."}]},{"head":"Obsolete types:","index":250,"paragraphs":[{"index":1,"size":18,"text":"Varieties that used to be very important but are at present little or no longer used for cultivation."}]},{"head":"Off-season crop:","index":251,"paragraphs":[{"index":1,"size":1,"text":"Off-shoot:"},{"index":2,"size":1,"text":"Off-type:"},{"index":3,"size":13,"text":"Crop that is planted outside the regular period or main season of planting."},{"index":4,"size":13,"text":"A lateral young growing branch which mayor may not be used for propagation."},{"index":5,"size":28,"text":"A plant havi ng a di fferent phonotype among many others. It mi ght have arisen from unpurified seed from volunteer plants or seeds from prev ious crops."}]},{"head":"Oligegenic gene:","index":252,"paragraphs":[{"index":1,"size":21,"text":"A m ajor gene of good expressivity and high heritabil ity. Mendel ia:n analysis of discontinuous traits generally involves major genes."}]},{"head":"On-farm tria l:","index":253,"paragraphs":[{"index":1,"size":62,"text":"This is a trial of va r ieties, of chemicals, operational methods or a package of these evaluated under the farmers' conditions to assess the local adaptability of the applied research results. It helps also to find additional areas where experi rrent station results would be useful. In on-farm trials, non-uniformity of land, weedy plots and untimely operations have to be accepted."}]},{"head":"Opaque-2 gene:","index":254,"paragraphs":[{"index":1,"size":27,"text":"In corn, it is the gene located on chromosome 7, which has great effect on the amino acid distribution in the endosperm especially lysine and tripto phen."},{"index":2,"size":58,"text":"In the homozygous recessive state, lysine content varies from 3.8-5.0% protein in contrast to that of a normal corn which varies from 2.4 to 3%. The endosperm of kernels with the Opaque-2 gene has a floury texture. The weight of the kernel is reduced by about 10% which leads to a similar drop in yield (Le Conte, 1973)."}]},{"head":"Open pollination:","index":255,"paragraphs":[{"index":1,"size":3,"text":"Optimum: Organ: Organic:"},{"index":2,"size":3,"text":"(see cross pollination)."},{"index":3,"size":32,"text":"A condition that deve 1 opment. is most satisfactory for a plant's growth and A group of one or more tissues on a plant specialized for performing a particular function, e.g. leaf."},{"index":4,"size":7,"text":"Originating from living substances, chemicals containing carbon."}]},{"head":"Organic soil:","index":256,"paragraphs":[{"index":1,"size":1,"text":"Oryza:"},{"index":2,"size":15,"text":"A soil that contains a high percentage (15 or 20 per cent) of organic matter."},{"index":3,"size":65,"text":"The generic name for rice. There are several species in the genus. (see Table 3). The two cultivated species are Oryza sativa and Oryza glaberrima. The former is of Asian origin while the later is of African origin. Their characteristics overlap but the two major distinguishing characters are the reduced ligule and the lack of secondary panicle branches of glaberrima as compared to sativa. Osmosis:"},{"index":4,"size":17,"text":"The tendency of two solutions to be equalized by diffusion through a selectively permeable or semipermeable membrane."},{"index":5,"size":2,"text":"Osmotic pressure:"},{"index":6,"size":20,"text":"Pressure exerted in living bodies as a result of unequal concentration of salts separated by a cell wall or membrane."},{"index":7,"size":1,"text":"Out-breeding:"},{"index":8,"size":8,"text":"A breeding system that involves relatively unrelated parents."}]},{"head":"Out-crossing:","index":257,"paragraphs":[{"index":1,"size":1,"text":"Ovary:"},{"index":2,"size":13,"text":"A cross of unrelated plants or of different genotypes, usually under natural conditions."},{"index":3,"size":19,"text":"In seed-bearing plants, the relatively enlarged bottom portion of the pistil containing the ovules. The ovary becomes the fruit."},{"index":4,"size":1,"text":"Overdominance:"},{"index":5,"size":17,"text":"The act of heterezygote expressing a character more than when the dominant genes are in homozygous state."},{"index":6,"size":21,"text":"The structure containing the developed or developing egg or female gamete. It develops into a seed upon successful fertilization and maturity."},{"index":7,"size":7,"text":"Unfertilized egg cell containing a haploid nucleus."},{"index":8,"size":29,"text":"Often used to designate the parental generation from which breeding begins. Used also to designate the parent or parents of crosses. PI = female parent; P2 = male parent."},{"index":9,"size":12,"text":"An irrigated field that is bunded, puddled and wet for rice growing."},{"index":10,"size":8,"text":"The rough rice is also called paddy ."},{"index":11,"size":17,"text":"The smaller or inner member of bracts that forms the glumes of grass florests (see lemma) ."}]},{"head":"Pale yellow mottle:","index":258,"paragraphs":[{"index":1,"size":2,"text":"Panic le:"},{"index":2,"size":53,"text":"This is a disease in rice caused by pale yellow mottle virus. Symptoms are light-green to pale yellow streak on the lea f blade and sheath. The typical mottling is present. Chloro sis sets at a later stage. Stunting may occur, panicle and grain develo pment are adversely affected causing steri lity ."},{"index":3,"size":24,"text":"A branched raceme with each branch bearing a stalked flower. The harvested portion containing grains of most economic cereal crops. e.g. rice and sorghum."},{"index":4,"size":3,"text":"Pan icle axis:"},{"index":5,"size":18,"text":"The main axis of the panicle. It is often distinctively grooved extending from the base to the apex."},{"index":6,"size":4,"text":"Pani c1 e base:"},{"index":7,"size":22,"text":"The nearly solid node between the uppermost in cereal and the main axis of the panicle. panicle branches originate from this node."},{"index":8,"size":9,"text":"internode of the culm The first primary Panicle exsertion:"},{"index":9,"size":53,"text":"The extension of the panicle above the flag leaf of a cereal plant. A well exserted panicle is one in which panicle base is clearly above the flag leaf sheath, partly exserted panicle is one in which the panicle base appears at the same level as the top of the flag leaf sheath."}]},{"head":"Panicle initiation:","index":259,"paragraphs":[{"index":1,"size":28,"text":"A growth stage when the panicle primordium is formed. It is the stage when the young panicle starts its development. In rice, it OCGurs 30-35 days before heading."},{"index":2,"size":2,"text":"Panicle length:"},{"index":3,"size":14,"text":"The length of the panicle from the panicle base to its tip in rice."},{"index":4,"size":4,"text":"Pani c1 e type:"},{"index":5,"size":30,"text":"This term is used in rice and sorghum to describe the mode of panicle branching, angle of primary branches and spikelet density. Three general classifications are compact, intermediate and open."}]},{"head":"Panicle shattering:","index":260,"paragraphs":[{"index":1,"size":12,"text":"In rice, this is the act of grain shedding from the panicle."}]},{"head":"Panicle threshability:","index":261,"paragraphs":[{"index":1,"size":1,"text":"Parameter:"},{"index":2,"size":15,"text":"This is the ease or difficulty of removing grain from a mature panicle. (see characters)."},{"index":3,"size":12,"text":"A numerical quantity which specifies a population in respect to some characters."}]},{"head":"Paras i te:","index":262,"paragraphs":[{"index":1,"size":64,"text":"A relatively smaller organism living in or on another bigger organism. The parasite ob ta i ns its f ood from its host wholly or in part. Facultative parasite is a parasite that can live on both dead and living organism. Obligate parasite is one that can live only on other living plants. Parasite s mayor may not be harmfu l to the host."}]},{"head":"Parboiled rice:","index":263,"paragraphs":[{"index":1,"size":2,"text":"Parent :"},{"index":2,"size":118,"text":"Rough rice or ~illed rice subjected to steaming or hotwater treatme nt before milling. The rough rice may be soaked in cold or ~/arm water for a given ti me and put in boil ina Vlater f or another period, e.g. soaking at 70°C for two hours and putting in boiling water for 5-10 minutes and dryi ng first ra pidly to 20 per cent m oi sture content and slowly to about 14 per cent before mill ing There i s a higher milling recovery and higher proport ion of head rice or whole kernel to broken rice in parboiled than unparboiled rice. Parboiling also increases the vitamin content of milled rice and improves its storage ability."},{"index":3,"size":76,"text":"One of the two sexually opposite individuals involved in fertili za tion. Th e female is denoted by ~ and a male by d'. In hermaphrodite (defined) plants, one plant is called a ma le parent when only the male gametes or pollen grains are used in a given cross. Similarly a female parent is one in which the male parts have been removed during emasculation and the stigma is fertilized by pollen from another plant."},{"index":4,"size":3,"text":"Pa rthenoca rpy:"},{"index":5,"size":26,"text":"Formation of an organism from a sex cell or a qamete but without the f usi on of another di ssimil ar gamete, e.g. no fertilization."}]},{"head":"Partial dominance ( incomplete dominance):","index":264,"paragraphs":[{"index":1,"size":1,"text":"Pathogen:"},{"index":2,"size":34,"text":"When dominance is incomplete. The F or hybrid is intermediate betVleen the two parents; one which i~ partially dominant and the other t'eces s ive for the charac ter in question (see incomplete doiminance)."},{"index":3,"size":38,"text":"A microorganisln which lives and feeds parasitically on or in a la rge organism (its host) and causes disease ( Van den Bosch and Mensenger, 1973 ). The ability of an organism to start or cause a disease."}]},{"head":"Study of disease or diseased tissues:","index":265,"paragraphs":[{"index":1,"size":45,"text":"An organic soil containing more than 50 per cent organic matter. Used in the United States to refer to the stage of decomposition of the organic matter. \"peat\" referring to the slightly decomposed or undecomposed deposits and \"muck\" to the highly decomposed materials (Foth, 1978)."}]},{"head":"Record of origin of family or","index":266,"paragraphs":[{"index":1,"size":20,"text":"ancestors in a linear form to show the sequential aline. A record of the ancestry of an individual plant, strain."}]},{"head":"Pedigree breeding:","index":267,"paragraphs":[{"index":1,"size":136,"text":"A breeding method in which individual plants are selected in the segregating generations from a cross ba5ed on their individual desirability and on the basis of a pedigree record. Selection usually commences at F generation when there would be 3000-10,000 seqregatiohs to choose from. T~e most desirable plant meeting one's objectives are selected. During the F -F generation, selection is based on characters controlled b § ofigogenes or few major genes. The seeds from F?, plants selected are grown in separate progeny rows. Selection are none among progenies and within progenies. The procedures continue for 5 or more generations until the desirable line becomes fixed or uniform in most of the major characters. Yield trials usually follow after F~ generation -could be later or earlier. In this system, pedigree name and numbers record (defined) are important."}]},{"head":"Pedigree name or number:","index":268,"paragraphs":[{"index":1,"size":64,"text":"A set or numbers assigned to a line that gives ancestral numbers and often its own generation or the generation reached when the number is assigned, e.g. TOX 7-2-4-5 is the 5th plant selection in a F population. Its ancestor of the F3 plant was the 2nd selectad plant in an F2 population which originated from the 7th cross of F1 of that station."}]},{"head":"Pedigree record:","index":269,"paragraphs":[{"index":1,"size":23,"text":"A series of notes which give the relationships amonq the families that are grown. The records also show distinguishing characters of the families."}]},{"head":"Pedigree sel ection:","index":270,"paragraphs":[{"index":1,"size":21,"text":"Selection carried on by obtaining lines and families of lines from which the best desirable ones are chosen (see pedigree breeding)."}]},{"head":"Penetrance (expressivity):","index":271,"paragraphs":[{"index":1,"size":3,"text":"Pentap l oid:"},{"index":2,"size":2,"text":"Peri carp:"},{"index":3,"size":48,"text":"The ability or frequency of a gene to be expressed in an individual that carried the gene. For instance, a dominant penetrant gene in homozyg~us condition produce the expected phe notype -100 per cent of the plants in a given population, weaker penetrance gives a lower percentage ."},{"index":4,"size":11,"text":"Said of a plant that has five sets of chromosomes ."},{"index":5,"size":18,"text":"Wall of an ovary after it has matured into a fruit; m ay be dry, membraneous, or hard."}]},{"head":"Perfect flower:","index":272,"paragraphs":[{"index":1,"size":9,"text":"A f l ower possessing both stamens and pistils."}]},{"head":"Permanent hybrid:","index":273,"paragraphs":[{"index":1,"size":1,"text":"Pest:"},{"index":2,"size":41,"text":"A hybrid or heterozygous plant that breeds true to type or fixed heterozygotes which do not segregate because some letha l genes prevent expression of other types in the offspring. In some cases, the condit ion is maintained by vegetative propagation."},{"index":3,"size":92,"text":"In the narrow sense, any insect that destroys crops. In the broad sense, any insect, rode nt, weed, bacterium, or f un gus that is damagi ng to a crop . Pests unlike parasite mayor may no t be smaller than the plant being attacked. Pest association with the plant is usually relatively shorter than that of pal-asite which may live on the hos t throughout its l ife cyc l e . Limiting the population of pest, or their damage eradication of the pest or preventing them from damaging the crop."},{"index":4,"size":12,"text":"Chemical or any agent used to kill a pest, especially insect pest."},{"index":5,"size":18,"text":"A shallow flat-bottomed circular glass dish, which may have a fitting cover used in laboratories for various purposes."},{"index":6,"size":39,"text":"The visible characteristics (structural and functional) of a plant as opposed to its genotype or genetic make-up. The phenotype of an individual is the sum total of the interaction between various environmental factors and the effect of the genes."},{"index":7,"size":4,"text":"(see hydrogen ion concentration)."}]},{"head":"Phenotype acceptability:","index":274,"paragraphs":[{"index":1,"size":63,"text":".llcceptabil ity based on visible characters. Phenotipic acceptability score (acceptability score): Score 1-9 or other scale used to assess in the field the general traits of a plant based on its phenotype and on the set objectives for the selection or trial. The score is visual and subjective; it is a quick way to compare many lines or varieties before weights are taken."},{"index":2,"size":3,"text":"Phenotypic ratio: Phosphorus:"},{"index":3,"size":3,"text":"(see F2 ratio)."},{"index":4,"size":16,"text":"An element occurring in many forms. plant growth and proper development. many forms as a salt."}]},{"head":"It is an essential element in","index":275,"paragraphs":[{"index":1,"size":9,"text":"It is appl ied to soil in Photoperiodism :"},{"index":2,"size":49,"text":"Flowering response of a plant to photoperiod or length of sunlight hours with 24 hours period. Plant reaction s to a defi nite numbe r of hours of day-light per day for flowering. Some f l ower only when days are shorter than nights. These are called shortday-length plants."},{"index":3,"size":8,"text":"Pho toper iod i c sens it ivity:"},{"index":4,"size":26,"text":"Thi s is a state where some plants are insens iti ve; others are strongly sensitive, and there are many intermedi ate react ion s ."}]},{"head":"Photo synthesis:","index":276,"paragraphs":[{"index":1,"size":38,"text":"Thi s i s a proce ss by which gree n plants manufacture organic comp ou nds, e.g. car bo hydra t~s from water and carbon dio xide using energy absorbed from sunlight. By-product is oxygen and water."},{"index":2,"size":7,"text":"Phys i ol ogical disea ses :"},{"index":3,"size":1,"text":"Physiology:"},{"index":4,"size":47,"text":"These are di sea ses (defined) t hat occur as a result of nutritional disorders (defined) caused by submerged soil conditions . The essential elem ent s (defi ned), inbalance causing these diseases are asso ci ated to reduced or anaerobic (defined) soil conditi on s ."},{"index":5,"size":24,"text":"The sc ience that deals with how living things function, thei r life processes, and developme nt of the individual or parts of them."}]},{"head":"Physiological races:","index":277,"paragraphs":[{"index":1,"size":24,"text":"Pathogen s of the same species that are inse parabl e morphologically but differ in their attack, virulence, development, etc. on their hosts ."}]},{"head":"Phytosanitary regula t i ons:","index":278,"paragraphs":[{"index":1,"size":58,"text":"Regulations imposed on importation and exportation of plant material. These regulations deal with the health or presence or absence of certain pathogen on or in the plant materials, e.g. seed, cuttings, tubers, bulbs etc. Dista nc e i n centimetres from the ground l evel to t he top of the panic l e of a mature plant."},{"index":2,"size":5,"text":"Pl ant i ng board:"},{"index":3,"size":49,"text":"~his is a piece of wood marked at a given di st ance often with nails or peg s for sowing or transplanting i n a regular pattern. It m ay al so mean a board with spaced ho l es for dropping seeds i nto the soil ."}]},{"head":"Planti ng date :","index":279,"paragraphs":[{"index":1,"size":6,"text":"Date when a crop is sown."}]},{"head":"Pl ant popu l at i on:","index":280,"paragraphs":[{"index":1,"size":18,"text":"A group of plants i nh ab iti ng a particular area or grown from one sample ."},{"index":2,"size":3,"text":"Pl ant quarantine:"},{"index":3,"size":91,"text":"The process of restricting a foreign plant or any of its parts into direct entry in a country, in order to in spect or observe the pla nt part to determine whether or not it possesses any i nsec t or disease pathogen that i s not already in the country. This is to prevent the spread os diseases or pests. Quarantine process can be asshort as two wee ks or as long as a year when growth of the plant material is done un der special conditions for careful observation."},{"index":4,"size":9,"text":"A silvery-white soft highly reactive alkali me tal element."},{"index":5,"size":10,"text":"It is essenti al to plant growth and proper development."},{"index":6,"size":13,"text":"Potassium is applied to soil in various salt f orms of potassium fertilizer."}]},{"head":"Potential yield:","index":281,"paragraphs":[{"index":1,"size":3,"text":"Preda tor :"},{"index":2,"size":25,"text":"Theoretical ly, a poss ibl e yield based either on t heoretical calcul ations or previous performance under same or di fferent condit i ons."},{"index":3,"size":37,"text":"An animal which feeds upon other anima ls (its prey) which are smaller or weaker than itself. A predator may feed on the egg, larva, nymph of its prey with or witho ut harming the adult prey."},{"index":4,"size":2,"text":"Pre-emergen ce:"},{"index":5,"size":22,"text":"Before emergence; the period after sowing or planting until emergence, e .g . pre-emergence herbicide is one applied before emergence (see emergence)."}]},{"head":"Pregerminated seeds:","index":282,"paragraphs":[{"index":1,"size":10,"text":"Seeds that have germinated or sprouted before sowing or broadcast."},{"index":2,"size":4,"text":"Preliminary trial or experiment:"},{"index":3,"size":1,"text":"Prepotency:"},{"index":4,"size":1,"text":"Primary:"},{"index":5,"size":31,"text":"A trial or experiment that is f irst ca n' ied out to find out initial information that will be used in more detailed or critical expe r iments later on."},{"index":6,"size":22,"text":"The capacity of a parent to impress characteristics on its offspring so that they are more alike than they would have been."},{"index":7,"size":11,"text":"First form or the most important plant, tiller, objectives, leaves etc."},{"index":8,"size":4,"text":"Primary leaf (\"Second leaf\"):"},{"index":9,"size":15,"text":"In cereals, the first seedling leaf without a blade that emerges next to the coleoptile."},{"index":10,"size":3,"text":"Pr imitive forms:"},{"index":11,"size":42,"text":"Pl ants having primit ive f ea tures I,hi ch are akin to its wild relatives in ri ce, pigmented pl ant pa rts, long awns, la x panicles, extreme shattering and perennia l growth habit are pri mitive traits (Chang, 1976a)."},{"index":12,"size":4,"text":"Primitive ge rmp lasm:"},{"index":13,"size":1,"text":"Probability:"},{"index":14,"size":1,"text":"Progeny:"},{"index":15,"size":32,"text":"A germplasm made up of unimproved stock (land races) often consisting of a mi xture of related genotypes. Primitive variety is a similar term used to de scr ibe the unimproved variety."},{"index":16,"size":59,"text":"The proportion of times in .which an event occurs i n an infinitely large and hypothetical series of cases, each capable of producing the event (Allard, 1960) . A mathema tical definition is given below: P = Number of success or occurrence Total number of even t s (Su ccess or occurrence + failure or no n-occur rence ."},{"index":17,"size":4,"text":"An offspring or descendant."}]},{"head":"Progeny se lection:","index":283,"paragraphs":[{"index":1,"size":5,"text":"Selection based on progeny performance."}]},{"head":"Progeny test:","index":284,"paragraphs":[{"index":1,"size":1,"text":"Propagate:"},{"index":2,"size":31,"text":"To determine the genetic characters or to evaluate the genotype of a var i ety or parent based on the performa nce of i ts progeny un der a controlled condition."},{"index":3,"size":17,"text":"To continue or multipl y by sexual and asexual reprod uct i on through seeds, cuttings, etc."}]},{"head":"Propag u1e:","index":285,"paragraphs":[{"index":1,"size":2,"text":"Protoqy ny:"},{"index":2,"size":3,"text":"Prote in s:"},{"index":3,"size":27,"text":"125 Any part of a plant, sexua l or asexual that ca n be used to ?~opagate the plant, e.g. seed , cuttin~, buds, tube rs, bUlbs."},{"index":4,"size":7,"text":"Matu~ation of the pistils before the stamen."},{"index":5,"size":37,"text":"A comp l ex nitrogenous organic compo und of high mo le cu lar weight. It is composed of numerous amino acids. There are 20 different kinds of amino acids common ly f ou nd in proteins."},{"index":6,"size":21,"text":"Proteins are of great importance to all 1ivinq matters. Prote in s conta in nitrogen, carbon, hydrogen and usually su lfur."},{"index":7,"size":2,"text":"Protein content:"},{"index":8,"size":3,"text":"Protop la sm:"},{"index":9,"size":1,"text":"Pubescence:"},{"index":10,"size":1,"text":"Puddling:"},{"index":11,"size":2,"text":"Pure line:"},{"index":12,"size":29,"text":"The amou nt of protei n in any part of the plant, e.q. in seeds. In r i ce, it ranges from 7-1 5%. Most are however, between 8-10%."},{"index":13,"size":13,"text":"The basic substance of which all li ving matter i s made ."},{"index":14,"size":16,"text":"Being covered with hairs which may be fine, soft and short or hard and l ong."},{"index":15,"size":76,"text":"The act of land preparat ion of a water•saturated soi l for rice transplanting or direct seeding. The soi l agqregates are destroyed during puddling. The process enhances formation of a traffi c or p 1 ClNpa n. I t reduces water los ses tha t may occur by water percolation (Moorma n and Van Breemen, 1978). Chemical inputs are made more ava il ab le to the rice crop and in efficie nt amount ."},{"index":16,"size":20,"text":"A line or strain that i s completely or almost completely homozygous at all loci. It is genetica lly pure."},{"index":17,"size":51,"text":"It is derived by repeated self pollination and selection of a specific type from a single individual (or by the removal of off-types). A pure line should breed true except for occasional mutation or environmental varieties. However, there is no absolute pure line existing in nature when all loci are considered."}]},{"head":"Pure line selection:","index":286,"paragraphs":[{"index":1,"size":2,"text":"Pure seed:"},{"index":2,"size":94,"text":"This is a method of breeding in which individual plants are selected from a land variety or other cultivar. The grains from selected plants are planted separately unlike in mass selection (defined) where all grains from desirable plants are bulked. The single plant progeny are assessed for their qualities. The best progeny are retained, multiplied, and beconle a pure 1 i ne vari ety. Thus, in pure 1 i ne breedi ng the bred variety consists of the progeny of a single pure line which is homozygous and uniform, its descendants are genetically similar."},{"index":3,"size":25,"text":"Seed that possesses a high level of purity, it has little or no contaminants or seed of other varieties of the same or different species."},{"index":4,"size":4,"text":"Pyramiding ge nes :"},{"index":5,"size":40,"text":"Transfering several major genes known to control vertical resistance into a single variety. It is assumed by so doing having all these major genes in same background, they will produce stable resi stance to a given disease, e.g. rice blast."}]},{"head":"Pyricularia oryzae:","index":287,"paragraphs":[{"index":1,"size":1,"text":"Quadriplex:"},{"index":2,"size":2,"text":"Qual itative:"},{"index":3,"size":11,"text":"A fungus causing an economic disease of rice (see bla st)."},{"index":4,"size":2,"text":"(see Nulliplex)."},{"index":5,"size":12,"text":"Dealing with the nature, and not the amounts of a given substance."},{"index":6,"size":33,"text":"A shoot or stem that g'rows from either the base or roots of a stump whose main stems from a previous growth have been out as when harvested, e.g. rice or sorghum ratoons."}]},{"head":"Ratoon cropping:","index":288,"paragraphs":[{"index":1,"size":2,"text":"Raw rice:"},{"index":2,"size":1,"text":"Receptive:"},{"index":3,"size":3,"text":"Recess i ve:"},{"index":4,"size":19,"text":"Regrowth from stumps following a harvest not necessarily for grain, e.g. sugarcane, sorghum, rice, mi llet, etc. (Okigbo, 1978)."},{"index":5,"size":10,"text":"Rice mil led without having been steamed or parboiled ."},{"index":6,"size":2,"text":"(see parboil)."},{"index":7,"size":32,"text":"A stage in a plant organ, e.g. stigma, when it is physiologically and physically mature or ripe to allow the entrance or growth of a foreig\" body e.g. pollen grain on it."},{"index":8,"size":39,"text":"The gene that is not expressed in the character of the plant even though present in the genotype, because of the presence of the other allele that is dominant. It is expressed only when both alleles are present (homozygous)."}]},{"head":"Reciproca l cross:","index":289,"paragraphs":[{"index":1,"size":58,"text":"A set of crosses involving two pa rents in which either is used as male and female parents, e.g. A x Band B x A. In other words, the sources of male and female gametes are reversed. With similar cytoplasm, the F! phenotype will be the same irrespective of which parent 1S used as the male or female."}]},{"head":"Recombination:","index":290,"paragraphs":[{"index":1,"size":13,"text":"The occurrence of new gene combinations in the offsprin g of a cross."}]},{"head":"Recommended variety:","index":291,"paragraphs":[{"index":1,"size":22,"text":"A variety that possesses some attributes which make it more desirable than others; it i s officia lly approved for commercial planting."},{"index":2,"size":1,"text":"Recovery:"},{"index":3,"size":2,"text":"Red ,ice:"},{"index":4,"size":54,"text":"130 That which i s go t back again after a certain process, or experiment (s ee grain milling recovery or milling recovery). Also the ability of pl ants to surv ive in spite of unfavourable physical, chemical, pathogenical co ndi tjons, e.g. pl ants recovering from drou gh t or bla st effect."},{"index":5,"size":37,"text":"Any r i ce kerne l having red seed coat. Red rice i s f reque ntly found in \"African r ice\" (defined), Oryzae ala be r r ima and some Oryzae sa ti va cultivars ."},{"index":6,"size":6,"text":"Recu rren t pa ren t:"},{"index":7,"size":18,"text":"The parent to which successi ve backcrosses are ma de in backcross br eeding (def i ned) ."},{"index":8,"size":2,"text":"Recurrent selection:"},{"index":9,"size":85,"text":"A breeding system used to increase th e fr eq uency of favour able or des ired genes for yield or other cha r ac te r s. The se lection i s done among the progeny produced by cros sin g art i fi cially or naturally of the selected i ndi vidua ls (or t hei r se l fed progeny) of t he previous generation . There are several repeated cycl es of such crossing and selection. The different forms ar e:"},{"index":10,"size":19,"text":"(a) Simple recurrent se lection (of cummu l ative selection) without using a tester or t op cros s."},{"index":11,"size":67,"text":"(b) Recu rrent se l ection for speci fic combi ning abiTity, ba sed on crossing a series of lines with a tester with a narrow genetic bas e (pure li ne or sing l e cros s hy brid ) fo ll owed by test ing the top crosses (single or three-way crosses) obtained in this way , and r ecombining the best line s ."},{"index":12,"size":54,"text":"(c ) Recurrent sel ection for gene ra l combinin~ abil ity based on crossing a serie s of lines with a tes t er wi th a wide genetic base (e.g . a synthetic variety) foll owed by tes ting the top crosses obtained, and recombi nin a the best l i nes."},{"index":13,"size":82,"text":"(d) Reciprocal recurrent selection wit h two sources, A and B whi ch m ay be hybrids, varieties or pop ulat i ons, with source B used as t he tester for A, and vice versa. Two new strains, Al and S1, are obtained which, when crossed, sho uld give better result t han A x B. Thi s type of select i on ma kes use of the effects of both specific and genera l combining ab ility )Le Conte, 1973)."},{"index":14,"size":3,"text":"Regional conservation centre:"},{"index":15,"size":52,"text":"A national or international centre located in broad georaphic area that assumes the responsibility for conserving germplasm in that area through collection, rejuvenation, and storage. The regional centre also handles the distribution of conserved stocks. It cooperates with the genetic resources centre in overall preservation of a crop or crops (Chang, 1976a)."},{"index":16,"size":4,"text":"Regional trials (zonal trials):"},{"index":17,"size":77,"text":"These are trials usually of improved varieties and also sometimes of cultural practices developed in a given region in one or more countries. Average number of entries varies from 10-15 with one or two check varieties. Sites are at experiment stations and farmers' fields. The objective of regional trial is mainly to evaluate the potential of new varieties or a newly developed package of cultural practices. Zonal trials are used interchangeably with regional trial in some countries."},{"index":18,"size":1,"text":"Registration:"},{"index":19,"size":34,"text":"The act of entering into an officially recognised record the existence of a line, variety, clone or seed stock in a given area. The character and qualities of such a plant are usually recorded."}]},{"head":"Reduction division:","index":292,"paragraphs":[{"index":1,"size":18,"text":"A nuclear division in which the chromosomes are reduced from the diploid to the haploid number (see meiosis)."},{"index":2,"size":2,"text":"Registered seed:"},{"index":3,"size":2,"text":"Regress ion:"},{"index":4,"size":33,"text":"Seed which has met a set of standards and purity. It is produced in a clearly defined manner and usually from a foundation seed stock. It is normally grown to produce certified seed."},{"index":5,"size":38,"text":"In general, a situation in which the offspring of two different parents (tall or short) appear to be average. In biometrics, it is the dependance crf a variable called dependent on another variable called independednt variable or variate."}]},{"head":"Regression coefficient:","index":293,"paragraphs":[{"index":1,"size":16,"text":"The numerical measure of the rate of change of the independent variable on the dependent variable."},{"index":2,"size":2,"text":"Re production:"},{"index":3,"size":27,"text":"The sex ual Ot' asex ua l process or mecha ni sm by which an indiv idual mu l tipl i es and ma intains its species."},{"index":4,"size":3,"text":"Repro ductive system:"},{"index":5,"size":27,"text":"All the organs and s t ructures in vo lved i n the product i on of and delivery of ga metes or re productive cel ls."},{"index":6,"size":6,"text":"Reproduct i ve pha se :"},{"index":7,"size":5,"text":"Rep ul s i on:"},{"index":8,"size":2,"text":"Resea rch:"},{"index":9,"size":35,"text":"The stage when the reproductive parts start to deve l op , e.g . i n r i ce , it is fr om panicle initiation to flowering (see ri pe ni ng stage )."},{"index":10,"size":30,"text":"Linked genes i n whi ch one domina nt and one r ecessive are l inked in each m ember of the pair of homo l ogo us chromosomes ."},{"index":11,"size":104,"text":"As in sc i entifi c researc ~ I~ean s a carefu l an d thorough systema ti c investiga t io n, a diligent investigatio n, inquiry or experimen t ation ai med at the di scovery, i nterpretation of fact s , revisi on of accepted theories or laws in t he l ig ht of ne w fac ts or for pract ical ap pli cation as in produc i ng new plant var i etie s whic h ar e more productive or devel opment of new operat i ng procedure s which are IIlore efficient Dr cheape r ."},{"index":12,"size":4,"text":"Research eq ui pment:"},{"index":13,"size":1,"text":"Residue:"},{"index":14,"size":79,"text":"The se are different types of scienti fic equipment t hat are essent i al for sc i enti f ic invest igat i ons. Exampl es are we ighing inst ru ments , microscopes, data proce ss ing machi nes , weath er an d su nl i ght mo nitor ing instruments, t hermometers, re l ative humidity instrument s, ca l cu lators, l ength an d height measur ing tapes and rul e rs etc."},{"index":15,"size":32,"text":"In plan t , t he part t ha t remai ns aft er t he eco nomi ca ll y useful par t or pa r t s have been taken"},{"index":16,"size":46,"text":"Remainder after some quantity has been subtracted from the original quantity. In statistics, e.g. in analysis of variance when all true values are subtracted from observed or calculated values or values due to known sources of variation the remainder is called residual (frequency called an error)."},{"index":17,"size":2,"text":"Residual effect:"},{"index":18,"size":1,"text":"Respiration:"},{"index":19,"size":1,"text":"Response:"},{"index":20,"size":1,"text":"Resistance:"},{"index":21,"size":26,"text":"Effect of chemical, e.g. fertilizers, herbicides, in secticides, whose effect or action is still noticeable in the following crop season without fresh application of the chemical."},{"index":22,"size":41,"text":"The act of taking oxygen (sometimes no oxygen is involved) from the environment, using the oxygen in a chemical reaction i n the body to re lease needed energy from substrates, e.g. glucose Carbon dioxide is a by-product of more respiration."},{"index":23,"size":26,"text":"The reaction of a plant or group of plants to some form of treatment or stimulus, e.g. reaction of plants to the application of nitrogen fertilizer."},{"index":24,"size":73,"text":"Refer s gene rally to the physiologic, structural and morphologic, conditions of a plant that allow it to tolerate, avoid, be immune to, or recover from an adverse effect of a pathogen , weather or soi l problem. A resistant variety suppresses or reta rds the development of a pa thogen or other injurious factors. Development of resistant varieties is the most economic method for controlling disease, insect and other undesirable environmental factors."}]},{"head":"Restorer gene:","index":294,"paragraphs":[{"index":1,"size":16,"text":"A gene, when present, restores fertility to an indi vi dual th at is otherwise sterile."}]},{"head":"Rever mutation:","index":295,"paragraphs":[{"index":1,"size":25,"text":"This is a heritable change in a mutant gene or chromosome. It i s a process whereby the ori gi nal state is res tored."}]},{"head":"Root nodules;","index":296,"paragraphs":[{"index":1,"size":1,"text":"Rotation:"},{"index":2,"size":2,"text":"Rough rice:"},{"index":3,"size":1,"text":"Row:"},{"index":4,"size":2,"text":"Row marker:"},{"index":5,"size":50,"text":"Sma 11 s~/e 11 i ng on roots of 1 egumi nous plants (pea, bean, etc.) produced as a result of infection by nitrogen-fixing bacteria. These nodules are rich in notrogen which is made available either to the plant carrying the nodules or the plant that succeeds the leguminous plant."},{"index":6,"size":100,"text":"A cropping system in which the same plant species is not planted continously on a given piece of land. In a rotational system, a piece of land may be divided up into 3 or more parts each part having a different crop gro~m. The following year each crop changes position. This continues for 3 or more cycles . It may take up to 4 or more years before a given plant species returns to its original site. It is also defined as systematic growing of different kinds of crops in recurrent succession on the same piece of land (Okigbo, 1978)."},{"index":7,"size":13,"text":"The harvested threshed unmilled grains or caryopsis. It is also called paddy rice."},{"index":8,"size":28,"text":"A number of plants in orderly sequence or series. A continous prepared strip of land or opening on the soil running horizontal or parallel to a base line."},{"index":9,"size":11,"text":"Any device for marking the soil surface for seeding in rows."},{"index":10,"size":33,"text":"It could be hand or tractor-drawn. The marking spikes or boards are spaced to correspond to the desired row space. In upland rice work, the rOl'ls are 30-40 cm in most breeding plots."}]},{"head":"Row seeding or sO~/ing:","index":297,"paragraphs":[{"index":1,"size":1,"text":"Rudimentary:"},{"index":2,"size":14,"text":"To sow seed in a rOl'/ as opposed to a haphazard sO~/ing or broadcasting."},{"index":3,"size":64,"text":"Development on a primitive level or development which was stopped or arrested at an early stage. In general, said of part of a plant that is imperfectly developed, underdeveloped or so deficient in size or structure as to entirely prevent its performing its normal function when compared to non-rudimentary ones, e.g. rudimentary glumes in cereals. Verb; To sow seed, to bear or shed seed."},{"index":4,"size":29,"text":"Noun: The fertilized and matured ovule. It is made up of embryo, testa, or seed coat formed from the integument(s) and endosperm which mayor may not contain food reserves."},{"index":5,"size":9,"text":"Seed is frequently the vehicle to perpetuate a genotype."},{"index":6,"size":26,"text":"Raised tilled flat-topped soil prepared specially for planting seed or raising cuttings. There is usually a shallow drainage trench around the piece of land so prepared."},{"index":7,"size":2,"text":"Seed-borne disease:"},{"index":8,"size":2,"text":"Seed box:"},{"index":9,"size":2,"text":"Seed coat:"},{"index":10,"size":16,"text":"A disease whose pathogen is already present in or on the seed or its associated structures."},{"index":11,"size":26,"text":"A specially constructed box usually rectangular with an open top filled with soil for germinating seeds, the seedlings of which are later transplanted into the field."},{"index":12,"size":26,"text":"The outer protective covering of the seed derived from the integument(s). In rice, the seed coat or testa is firmly adhered to the maternal peri carp."}]},{"head":"Seed dressing:","index":298,"paragraphs":[{"index":1,"size":46,"text":"A chemical for seed treatment protecting seed from parasites or pathogens that can establish themselves on the seed or in the soil to cause some damage on the seed or seedling. Generally, seed dressing substances are various types of fungicides which could be systemic or non-systemic."},{"index":2,"size":2,"text":"Seed emergence:"},{"index":3,"size":2,"text":"(see emergence)."},{"index":4,"size":8,"text":"percentage, shape, purity (defined) etc. of the seed."},{"index":5,"size":2,"text":"Seeding rate:"},{"index":6,"size":21,"text":"A quantity or amount of seed planted in a unit area of land, e.g. 60 kg of rice per 1 hectare."},{"index":7,"size":2,"text":"Seed setting:"},{"index":8,"size":2,"text":"Seed source:"},{"index":9,"size":18,"text":"The process of a fertilized ovule developing into seed, the development and enlargement of young seed, seed formation."},{"index":10,"size":5,"text":"The source supplying the seed."}]},{"head":"Seed vi abil Hy","index":299,"paragraphs":[{"index":1,"size":1,"text":"Segregant:"},{"index":2,"size":2,"text":"(see viable)."},{"index":3,"size":15,"text":"Any plant derived from a segregating population, e. g. in the F2 or F4 generations."}]},{"head":"Segregation:","index":300,"paragraphs":[{"index":1,"size":1,"text":"Selection:"},{"index":2,"size":49,"text":"The separation of allele pairs and homologous chromosomes from one another an• -j their distribution to the resulting different cells usually at meiosis. On the field, the actual phenotypic separation of plant characters wherever population of F 2 , F 3 , F4 etc. of disimilar parents are grown."},{"index":3,"size":43,"text":"Any natural or artificial process which permits an increase in the proportion of certain genotypes or groups of genotypes in succeeding generation in preference to the other genotypes, The process involves retention (select;ng) and discarding (elimination). Often, the selected plants possess desirable traits."}]},{"head":"Artificial selection:","index":301,"paragraphs":[{"index":1,"size":10,"text":"A choice among plants, as made or influenced by man."}]},{"head":"Sheath blotch:","index":302,"paragraphs":[{"index":1,"size":60,"text":"This is a disease caused by a fungus especially in rice. The fungus is Pyrenochaeta orfzae. Symptoms are grayish brown to brown blotches on theeaf sheath. They may be found also on the leaf blade and glumes. With age the lesion turns gray dotted with black fruiting bodies and the margins usually remain brown. Infected stems become light and shrivelled."}]},{"head":"Sheath pulvinus:","index":303,"paragraphs":[{"index":1,"size":3,"text":"Sheath rot; Shed:"},{"index":2,"size":27,"text":"It is the swelling at the base of the leaf sheath just above the node; it is frequently mistermed the node in rice (Chang & Bardenas, 1964)."},{"index":3,"size":9,"text":"A fungus disease caused by Acrocylindrium oryzae in rice."},{"index":4,"size":40,"text":"The symptoms are oblong or irregular brown to grey lesions the lipper part of the leaf sheath near panicle. The lesions may coalesce to cover the entire leaf sheath. Panicle emergence is often impeded or completely chocked without panicle exsertion."},{"index":5,"size":15,"text":"To distribute, disperse, disconnect from the main body, e.g. pollen grains and unharvested rice grains."}]},{"head":"Shifting cultivation:","index":304,"paragraphs":[{"index":1,"size":1,"text":"Shoot:"},{"index":2,"size":44,"text":"A farming system in which crops are planted on a piece of land for two or more years and the land is left fallow for several years to regain soil fertility while farming is continued on another piece of land at a different location."},{"index":3,"size":13,"text":"A young growing branch or usually above the ground. plumule of the embryo."},{"index":4,"size":16,"text":"twig. The part of the plant that is The part that develops from the Short-day plant:"},{"index":5,"size":1,"text":"Shrub:"},{"index":6,"size":2,"text":"(see photoperiodism)."},{"index":7,"size":23,"text":"A woody perennial tree with no main trunk on smaller structure than a tree. There are usually many well developed side shoots, Sibs:"},{"index":8,"size":6,"text":"usually not taller than 10 metres."},{"index":9,"size":10,"text":"Progeny from same parents, i.e. they have two common parents."},{"index":10,"size":7,"text":"Half-sibs have only one parent in common."},{"index":11,"size":1,"text":"Sib-crossing,sibbing:"},{"index":12,"size":10,"text":"Crossing lines derived from the same two parents (sister-brother mating)."}]},{"head":"Side dressing:","index":305,"paragraphs":[{"index":1,"size":1,"text":"Sign:"},{"index":2,"size":21,"text":"To apply an input usually fertilizer near, or beside or in-between the planted seed or plants in bands or continous application."},{"index":3,"size":46,"text":"Something that serves to indicate the presence or existence of another thing in a plant, e.g. dead heart in rice shows the presence of stemborer, blast lesions indicate the presence of blast pathogen, the swelling of the flag leaf base indicates the development of the panicle."},{"index":4,"size":1,"text":"Significance:"},{"index":5,"size":13,"text":"The reliability (or otherwise) of a difference between that observe and that expected."}]},{"head":"Significant difference: Si 1 t:","index":306,"paragraphs":[{"index":1,"size":58,"text":"A difference which is statistically real. The statistics usea for determining whether or not differences between or among two or more planned comparisons are real or large enough to accept that the means are different. The difference is usually expressed as having a certain level of probability of being wrong or due to chance. (see least significant difference)."},{"index":2,"size":34,"text":"A soil separate consisting of particles between 0.05 and 0.002 millimetres in equivalent diameter. Soil of the textural class silt contains 80 per cent or more silt and less than 12 per cent clay."},{"index":3,"size":2,"text":"Silver Shoot:"},{"index":4,"size":3,"text":"(See gall midge)."},{"index":5,"size":2,"text":"Single cropping:"},{"index":6,"size":20,"text":"The growing (planting to harvest) of only one crop in a given piece of land in one year (Okigbo, 1978)."}]},{"head":"Single cross:","index":307,"paragraphs":[{"index":1,"size":2,"text":"Sister cell:"},{"index":2,"size":19,"text":"A cross (defined) involving a variety or line and another variety ,or line. Only two different genotypes are involved."},{"index":3,"size":11,"text":"One of the cells formed from an original or pre-existin9 cell."},{"index":4,"size":4,"text":"Slow-release fertil izer: Smut:"},{"index":5,"size":1,"text":"Soak:"},{"index":6,"size":2,"text":"Soil :"},{"index":7,"size":14,"text":"Fertilizer (defined) that give up its wanted element, e.g. nitrogen at a slow rate."},{"index":8,"size":31,"text":"The name given to a disease especially in cereals caused by a fungus of the order Ustilagnales . Individual grain or the ~Ihole panicle is replaced by black masses of spores."},{"index":9,"size":31,"text":"To place in water which completely cover the seed for a determined length of time. Rice is usually soaked in ~Iater for about 24 hours before incubating for seed bed planting."},{"index":10,"size":28,"text":"The upper layer of the earth. The medium which upholds majority of plants. The surface is tilled or cultivated to produce loose aggregates for plant growth and development."},{"index":11,"size":32,"text":"It is also the place where numerous microorganisms are found. Its physical nature is made up of its texture, structure, water content and atmosphere. The chemical nature are the soil mineral solutions."}]},{"head":"Soil fumigation:","index":308,"paragraphs":[{"index":1,"size":15,"text":"The use of chemical that kill mainly nematodes to disinfest soil for plant parasitic nematodes."}]},{"head":"Soil heterogeneity:","index":309,"paragraphs":[{"index":1,"size":38,"text":"Soil map: This is the case where soil in a relatively small area varies greatly in texture, fertility, topography, moisture content and drainage. It contributes to experimental error and lowers the precision of experimental results in field experiments."},{"index":2,"size":13,"text":"It introduces a degree of uncertainty into conclusions made from crop yield data."},{"index":3,"size":28,"text":"A map showing the distribution of soil types or other soil mapping units in relation to the prominent physical and cultural features of the earth's surface (Foth, 1978)."},{"index":4,"size":2,"text":"Soil moisture:"},{"index":5,"size":57,"text":"Soi 1 pores: This is the term that describes the state of water in the soil. It may be in saturation condition or completely absent. Osmotic and capillary effect are the two forces that are responsible for the holding and movement of water in the soil. Soil moisture may contain plant nutrients such as nitrogen, phosphorus, potassium."},{"index":6,"size":49,"text":"These are spaces between the assemblage of soil aggregates. The spores are filled by air and soil water or solution of minerals the proportion of air and water depending on various biological and environmental and tillage conditions. Microorganisms can be found in the pore spaces and withing the aggregates."},{"index":7,"size":2,"text":"Soil science:"},{"index":8,"size":46,"text":"The science dealing with soils as a natural resource on the surface of the earth, including soil formation, classification and mapping. and the physical, chemical, biological and fertility properties of soils, per se; and these properties in relation to their management for crop production (Foth, 1978)."},{"index":9,"size":2,"text":"Soil structure:"},{"index":10,"size":38,"text":"This is the visible arrangement of soil particles or aggregates that make up the granular or crumb formations that are suitable for plant growth. The aggregates vary in size and make up a system with soil pores (defined)."},{"index":11,"size":45,"text":"Soil texture: This is the term which describes the particles of varying sizes that constitute the soil. The sizes of the particles vary from gravel, coarse sand, fine sand and silt down to clay. These in varying proportion form the mechanical aspect of the soil."}]},{"head":"Somatic cell:","index":310,"paragraphs":[{"index":1,"size":28,"text":"A body cell that has a 2n chromosome complement. It is different from a germ cell that has In. The somatic cell divides to form tissues, organs, etc."}]},{"head":"Somatic cell hybridization:","index":311,"paragraphs":[{"index":1,"size":19,"text":"The fusion of non-germ cells in cell culture under certain other treatments and the formation of viable hybrid cells."}]},{"head":"Sorghum vulgare:","index":312,"paragraphs":[{"index":1,"size":1,"text":"SO~/:"},{"index":2,"size":2,"text":"Sowing date:"},{"index":3,"size":1,"text":"Spacing:"},{"index":4,"size":19,"text":"A botamical name for a cereal crop commonly called sorghum or guinea corn which is a drought tolerant crop."},{"index":5,"size":5,"text":"To plant or scatter seed."},{"index":6,"size":10,"text":"The time or day in the month when sowing occurs."},{"index":7,"size":16,"text":"A fixed distance between plants or seed planted or between two rO~/s • Species (pl. Species):"},{"index":8,"size":31,"text":"In taxonomy a unit below the genus; a group of plants that interbreed freely or can interbreed. They possess similar characters that differentiate them from other species in the same genus."}]},{"head":"Specific combining ability:","index":313,"paragraphs":[{"index":1,"size":1,"text":"Spike:"},{"index":2,"size":1,"text":"Spikelet:"},{"index":3,"size":3,"text":"(see combining ability)."},{"index":4,"size":20,"text":"An inflorescence with a fairly elongated axis along which the flowers are sessile or nearly so, e.g. a wheat spike."},{"index":5,"size":39,"text":"A unit of inflorescence (e.g. in rice) consisting of the two sterile lemmas, the rachilla and the floret. The two rudimentary glumes are considered to be part of the spikelet. Spikelet is commonly taken to be synonymous with floret."}]},{"head":"Spikelet sterility:","index":314,"paragraphs":[{"index":1,"size":15,"text":"The condition in which there is no grain within the glumes (see sterile and sterility)."}]},{"head":"Split-application:","index":315,"paragraphs":[{"index":1,"size":29,"text":"Said of chemical, e.g. fertili zer when the whole rate per unit area is divided into two or more doses and applied at two or more given intervals ."},{"index":2,"size":2,"text":"Split-plot design:"},{"index":3,"size":1,"text":"Spore:"},{"index":4,"size":1,"text":"Spreader:"},{"index":5,"size":19,"text":"Design used for factorial experiments, involving at least two factors not equally important and divided into main and subplots."},{"index":6,"size":25,"text":"Single-celled or several celled reproductive body (e.g. seed) that becomes detached from the parent and gives rise either directly or indirectly to a new individual."},{"index":7,"size":33,"text":"An implement that is used to disperse seed, straw, etc, on the field. Susceptible plants that are used to propagate and extend over other plant disease inoculum, pathogen or insects into test line."},{"index":8,"size":14,"text":"A shoot or germinated seed. To gro~1 from a seed or other plant parts."},{"index":9,"size":2,"text":"Stable resistance:"},{"index":10,"size":2,"text":"Stable line:"},{"index":11,"size":17,"text":"Resistance (defined) that holds up under various conditions for an appreciable length of time (see durable resistance)."},{"index":12,"size":3,"text":"(See fixed line)."}]},{"head":"Staggered planting:","index":316,"paragraphs":[{"index":1,"size":24,"text":"The planting of some varieties or lines at different planting days, e.g. every two weeks. Usual for hybridization, agronomic studies, storage or marketing purposes."}]},{"head":"Stained grain:","index":317,"paragraphs":[{"index":1,"size":2,"text":"Stake :"},{"index":2,"size":2,"text":"Staple crop:"},{"index":3,"size":1,"text":"Stamen:"},{"index":4,"size":1,"text":"Stand:"},{"index":5,"size":3,"text":"(See grain discoloration)."},{"index":6,"size":31,"text":"A wooden or metal marker placed at the end of a row or plot and bearing the identity of the material, or having an identifying label attached to it (Harrington, 1978)."},{"index":7,"size":42,"text":"A term used for a crop that is used, enjoyed or needed constantly by many people in a given area or country. It is provided or imported in large quantity into the area, examples are corn in Kenya and rice in Liberia."},{"index":8,"size":19,"text":"The part of the flower conslslng of the filament and anther. It is the pollen-bearing organ in the flower."},{"index":9,"size":10,"text":"A group of plants growing together in a given area."}]},{"head":"Standard deviation:","index":318,"paragraphs":[{"index":1,"size":74,"text":"A measure of variability. It gives in mJthematical terms how much an observation differs from the means of the set of observations. It could also be defined as the square root of the average of the squares of the differences from their mean of a number, n of observations. A branch of mathematics which deals with the analysis and interpretation of numerical data. An orderly arrangement of facts collection for study or general information."},{"index":2,"size":23,"text":"The main axis or shaft of a plant, may be creeping, underground or upright. It possesses the ability to produce buds either Stemborers:"},{"index":3,"size":9,"text":"for vegetative or reproductive parts and usually, adventitious roots."},{"index":4,"size":32,"text":"Insects whose larvae cause economic damage to plants, e.g. in rice, sorghum and maize by boring into their stem, feeding on the soft tissues of the stem and the plants' growing points."}]},{"head":"Stem or stalk rot:","index":319,"paragraphs":[{"index":1,"size":100,"text":"This is a fungus disease found in most cereal crops such as corn, rice and sorghum. Infection •occurs through a break or injury on the stem. The fungus having penetrated into the stem causes • dark:•lesions which gradually enlarge depending on the susceptibility of the plant. The inner plant tissues and leaf .sheath become rotten and the weakened plant lodges usuallY,before maturity. Burning the straw and stubble helps to reduce the level of viable fungus in the field. Stem or stalk rot is caused by many pathogens. The most common are fungi belonging to the genera Fusarium, Diplodia and Macrophomina."}]},{"head":"Stem elongation:","index":320,"paragraphs":[{"index":1,"size":1,"text":"Sterile:"},{"index":2,"size":2,"text":"Steril ity:"},{"index":3,"size":29,"text":"In cereals, it is the rapid increase in length of the internodes• In rice, the stem elongation starts between the latter part of tillering stage and panicle initiation stage."},{"index":4,"size":35,"text":"Absence of micro-organisms, incapable of producing spores as in some fungi. In flowers, unproductive for lack of or a defect in the ovules or stamen, with no viable pollen, also due to adverse environmental factors."},{"index":5,"size":11,"text":"The act of possessing no fruit, or grain in a plant."},{"index":6,"size":4,"text":"Sterile glumes (Sterile lemmas):"},{"index":7,"size":1,"text":"Stigma:"},{"index":8,"size":19,"text":"One pair of the glumes, e.g. in grass, a spikelet (as in rice) which does not subtend a flower."},{"index":9,"size":6,"text":"In f1o~ters, of a style. etc."},{"index":10,"size":51,"text":"the pollen receptive structure, usually at the end It may be bifurcated, lobular, This is the act of a stigma capable or allowing the germination of pollen on its surface. The period of receptivity may vary from two days to over two weeks depending on the crop and environmental condition •"},{"index":11,"size":66,"text":"The main stem of a plant. The rooted stem on which a scion is grafted. Cultivated plants grown for profit. Special purified seed in storage for future multiplication. An available amount of seed . This is the seed which forms the nucleus for all future seed increase or large multiplication. It is the seed from the breeder's plot. It is often referred to as breeder's seed."},{"index":12,"size":27,"text":"In general terms, stock seed sometimes means any type of seed e.g. foundation seed that is from a recommended variety and has met a certain standard purity."},{"index":13,"size":26,"text":"A horizontally growing stem, runner or creeping stem that can produce adventitious roots and scale leaves . It can also produce new upright shoots or tubers."}]},{"head":"Stomata (Stomates):","index":321,"paragraphs":[{"index":1,"size":1,"text":"Strain:"},{"index":2,"size":1,"text":"Straw:"},{"index":3,"size":29,"text":"Pores in the epidermis of plants, present in large numbers, especially on leaves, through which gaseous excha~ge takes place. Guard cells regulate the opening and closlng of a stoma."},{"index":4,"size":52,"text":"A group of plants within a variety or species which differ from related groups mostly in physiological rather than morphological characteristics, as having exceptional productivity, disease resistant, or other quality. A group of individuals from a common origin or progeny of a single plant• Strain may include several lines with similar features."},{"index":5,"size":33,"text":"Dried stems along with some leaves. Remnants of a small grain crop after threshing. The likelihood that a plant will be affected adversely in development or growth by micro-organisms, insects, or environmental conditions."},{"index":6,"size":41,"text":"Rice grown under usually continous wet or flooded soil conditions without water control. Under normal rainfall, it does not suffer from drought. The soil is usually poorly drained, which mayor may not be toxic, and usually high in organic matter content."},{"index":7,"size":60,"text":"This maize is a recessive mutation from field corn. Two genes are known for this character. \"su 1\" on chromosome 4 and \"su 2\" on chromosome 6. The sugar content of the kernel increases right from the milky stage. On maturing, the sweet kernel shrinks and becomes wrinkled, so that its appearance is very different from that of ordinary kernels."},{"index":8,"size":14,"text":"This food crop must be harvested at the milky stage (Le Conte, 1973) ."},{"index":9,"size":55,"text":"Parasitic association for mutually benefit association of dissimilar organisms to their mutual advantage, e.g . association of nitrogen fixing bacteria ~Iith leguminous plants. The bacteri.a inhabiting nodules on roots manufacture nitrogen compounds from nitrogen of the air which become available to the plant. The bacteria obtain carbohydrates and other food materials from the plant ."},{"index":10,"size":20,"text":"The clue, sign or evidence which leads to the detection of a disease or a physiochemical disorder on a plant."},{"index":11,"size":8,"text":"Conjugation at pachytene and zygotene of homologous chromosomes."},{"index":12,"size":1,"text":"Synchronization:"},{"index":13,"size":1,"text":"Syngamy:"},{"index":14,"size":18,"text":"Simultaneous occurence of two or more events, e.g. the follo~Jing of two different varieties at the same time."},{"index":15,"size":10,"text":"Union of gametes or sex cells to form a zygote."}]},{"head":"Synthetic variety:","index":322,"paragraphs":[{"index":1,"size":1,"text":"Systemic:"},{"index":2,"size":41,"text":"A variety developed (usually in an open-pollinated crop) by first crossing, in all possible combinations, many (at least five) genotypes or lines that have good combining ability, then all are mixed together and the variety is maintained by open poll ination."},{"index":3,"size":10,"text":"Common to a plant system, generally distributed throughout an organism."}]},{"head":"Systemic fungicide:","index":323,"paragraphs":[{"index":1,"size":36,"text":"It is a substance that is absorbed by the plant and remains within the developing plant tissues harmless to the plant and yet protects the entire plant against fungus attack for a reasonable length of time."}]},{"head":"Systemic infection:","index":324,"paragraphs":[{"index":1,"size":9,"text":"The general presence of pathogen within the plant tissues."},{"index":2,"size":27,"text":"The pathogen multiplies rapidly throughout the plant structures favourable for its establishment. Such pathogen causes devastating damage to the plant in contrast to that of local infection."}]},{"head":"Systemic insecticides:","index":325,"paragraphs":[{"index":1,"size":1,"text":"Tag:"},{"index":2,"size":28,"text":"A substance which is absorbed by the plant tissues and affording protection for a reasonable length of time against insect pests without any appreciable harm to the plant."},{"index":3,"size":19,"text":"A cardboard, plastic, paper or metal marker used for identification or classification of a plot, varieties, treatments or collection."},{"index":4,"size":1,"text":"Tassel:"},{"index":5,"size":1,"text":"Tensiometer:"},{"index":6,"size":1,"text":"Tertiary:"},{"index":7,"size":1,"text":"Testa:"},{"index":8,"size":2,"text":"Test cross:"},{"index":9,"size":1,"text":"159"},{"index":10,"size":9,"text":"The terminal male inflorescence of some plants, e.g. corn."},{"index":11,"size":6,"text":"An apparatus for measuring soil moisture."},{"index":12,"size":15,"text":"Third rank produced by the plant, e.g. tartiary tillers are the third group of tillers."},{"index":13,"size":23,"text":"Seed coat, formed from the integuments, a protective covering of embryo of seed plants, it is usually dry, could be hard or leathery."},{"index":14,"size":55,"text":"In general, a cross between a plant dominant for a character and another recessove for the character. It refers also to a cross between a double or multiple heterozygote to a corr\"esponding double or multiple recessive. It is used for determinning I\"hether the dominant character is homozygous. It is used also to study gene linkages."},{"index":15,"size":2,"text":"Tester strain:"},{"index":16,"size":1,"text":"Tetraploid:"},{"index":17,"size":1,"text":"Thallus:"},{"index":18,"size":64,"text":"A strain with a dominant gene whose ~xpression is unaffected in the progeny of a particular parent that is being progeny-tested (lush, 1943). Its contribution to the offspring ~'ill not hide the inheritance being received from the parent being progenytested . A common parent (generally male) used in crosses ~lith a series of lines in order to analyse the combining ability of the lines."},{"index":19,"size":39,"text":"An organism with four sets (genomes) of chromosome. The act of reducing the number of plants, especially at seedling stage. To reduce the plant number per stand or per unit area of land. Also of fruits on a tree."},{"index":20,"size":2,"text":"Three-way cross:"},{"index":21,"size":4,"text":"(see cross, top cross)."},{"index":22,"size":1,"text":"Thresh:"},{"index":23,"size":12,"text":"The act of removing grains from panicles or ears of cereal crops."},{"index":24,"size":1,"text":"Threshability:"},{"index":25,"size":2,"text":"Thresholds: Tillage:"},{"index":26,"size":1,"text":"Tiller:"},{"index":27,"size":14,"text":"The relative ease of removing grains from the panicles or ears of cereal crops."},{"index":28,"size":7,"text":"Phenomenon that can obscure the gene-character relationship."},{"index":29,"size":11,"text":"Also economically, safe level as in the case of insect attack."},{"index":30,"size":12,"text":"The act of preparing the soil by mechanical manipulations for crop production."},{"index":31,"size":30,"text":"A side shoot produced at the base of a stem of grasses, e.g. rice tillers. It is a shoot which includes the roots, stem and leaves with or without panicle."},{"index":32,"size":90,"text":"Tiller number: This is the quantity of tillers as in rice produced by a rice plant. The number os affected by spacing , season and soil fertility. Under irrigated condition, tiller number varies from 3-33 per plant with a spacing of 10 x 10 cm, there will be 3 tillers per plant, 100 plants per sq. metre or 300 tillers per sq. metre. When plants are spaced 50 x 50 em, these are 33 tillers per plant, 4 plants per sq. metre and 122 tillers per sq. metre (Vergara, 1979)."}]},{"head":"Tillering ability:","index":326,"paragraphs":[{"index":1,"size":1,"text":"Tolerance:"},{"index":2,"size":1,"text":"Topcross:"},{"index":3,"size":26,"text":"The capacity to produce tillers. In rice the full number capacity can be obtained by wide spacing of about 50 by 30 cm in rich soil."},{"index":4,"size":38,"text":"The ability of a plant to withstand adverse environmental factors without excessive damage. The ability of plant to grow and develop relatively well without showing serious symptoms or damage from diseases or insect pests which have attacked it."},{"index":5,"size":60,"text":"A three-way cross or a cross of an F to a variety or line A cross between a selection, line, c~one, etc., and a common pollen parent which may be a variety, inbred line, single cross, etc. (Allard, 1960). The common pollen parent is called the top-cross or tester parent. In maize, a topcross is commonly an inbred variety cross."},{"index":6,"size":2,"text":"To dressing:"},{"index":7,"size":34,"text":"As in chemical application, especially nitr0genous fertilizer, when a dose in applied by braodcasting on top of the sailor water surface where the crop is being grown, rather than by incorporating into the soil."},{"index":8,"size":1,"text":"Toposcequence:"},{"index":9,"size":2,"text":"Top soil:"},{"index":10,"size":65,"text":"A continous or connected series of related soils that differ one from the other primarily because of their relative height from a given base level, e.g. a stream. The water table of the different series will vary and so will the crops react to this water table. In rice, it i.s used for studing drought tolerance and effect of nutrients, e.g. nitrogen at different level."},{"index":11,"size":29,"text":"The layer of soil nearest to the soil surface. The superficial layer. It is usually the richest in organic matter. It is the soil that is moved in cultivation."},{"index":12,"size":3,"text":"Total milled rice:"},{"index":13,"size":6,"text":"(See grain quality and milling quality)."},{"index":14,"size":1,"text":"Toxicity:"},{"index":15,"size":1,"text":"Trait:"},{"index":16,"size":1,"text":"162"},{"index":17,"size":30,"text":"The presence of a toxic or poison in a level that can adversely affect plants that are not tolerant to the toxin in the •plants' growing environment, e.g. iron toxicity."},{"index":18,"size":10,"text":"A character or distinguishing quality of a plant (see character)."},{"index":19,"size":2,"text":"Transgressive segregation:"},{"index":20,"size":47,"text":"Possession by an individual segregant of a more extreme development of a character than either of the parents involved in the cross. This can be found in the F? later generations of a cross, e.g. PI = 10 cm, P 2 = 15 cm segregant = 20•cm."},{"index":21,"size":1,"text":"Translocation:"},{"index":22,"size":1,"text":"Translucent:"},{"index":23,"size":35,"text":"Transfer of part of a chromosome into a different part of a homologous, or a non-homologous chromosome. Also the transfer of food from the site of manufacture (leaves) to the site of storage (roots\"grains, etc.)."},{"index":24,"size":3,"text":"(see grain translucency)."},{"index":25,"size":1,"text":"Transpiration:"},{"index":26,"size":1,"text":"Transplant:"},{"index":27,"size":2,"text":"Trap crop:"},{"index":28,"size":1,"text":"Treatment:"},{"index":29,"size":8,"text":"Loss of water by plants, mainly through leaves."},{"index":30,"size":31,"text":"To remove a plant from a temporary site (e.g. seedlings from nursery) and establish it in an area where they will complete the rest or more of its life cycle ."},{"index":31,"size":20,"text":"A crop planted to attract pests, rodents, nematodes and birds before the main crop reaches the sensitive stage for attack."},{"index":32,"size":31,"text":"In experiment, that ~Ihich is given to an experimental unit (plot or variety) whose effect will be determined or measured and compared with other. treatments, e.g. a level of fertilizer Tree:"},{"index":33,"size":1,"text":"Trial:"},{"index":34,"size":6,"text":"Trihybrid: 163 or herbicides or variety."},{"index":35,"size":8,"text":"A perennial wood plant with an evident trunk."},{"index":36,"size":32,"text":"A test or an experiment, e.g. field trial to determine or test the quality, value, performance or usefulness of given varieties, lines, chemicals, date and time of planting, spacing and populations, etc."},{"index":37,"size":14,"text":"A hybrid resulting from a cross between parents differing in three specific genes ."},{"index":38,"size":2,"text":"Triple crossing:"},{"index":39,"size":1,"text":"Triplex:"},{"index":40,"size":2,"text":"Triploid :"},{"index":41,"size":2,"text":"Trisomic :"},{"index":42,"size":1,"text":"Tuber:"},{"index":43,"size":25,"text":"Sequential crossing of three cultivars, e.g. A, Band C: A x B, AB x C, ABC x A, ABCA x B, etc (Rice et~, 1953)."},{"index":44,"size":14,"text":"A polyploid recessive of all loci except three in respect to a particular gene."},{"index":45,"size":9,"text":"A plant with three basic sets of chromosomes, 3n."},{"index":46,"size":23,"text":"A cell or a plant with one of the chromosomes represented three times (2n + 1). The rest of the chromosomes are duplicates."},{"index":47,"size":28,"text":"A swollen underground stem and root specialized for storing food reserve. Moist stem tubers can give rise to a new plant, e .g. the common or Irish potato."}]},{"head":"Udbatta d'isease:","index":327,"paragraphs":[{"index":1,"size":21,"text":"A disease 1n rice caused by Ephelis pallida Pat. in which the panicles emerge as small cylinders covered with white mycelium."},{"index":2,"size":4,"text":"Unfi 11 ed grain:"},{"index":3,"size":1,"text":"Uniform:"},{"index":4,"size":19,"text":"A grain that is either completely devoid of endosperm or it is very much-developed due to adverse environmental factors."},{"index":5,"size":17,"text":"Variety or line in which the main characters vary little or none from one plant to another."},{"index":6,"size":4,"text":"Uniformity trial (blank test):"},{"index":7,"size":22,"text":"An experiment in which all the operations and treatments are the same but different sampling sizes are taken to evaluate soil heterogeneity."},{"index":8,"size":3,"text":"Unimproved plant type:"},{"index":9,"size":1,"text":"Univalent:"},{"index":10,"size":2,"text":"Upland rice:"},{"index":11,"size":55,"text":"This is a traditional plant type (defined) that has not been changed or affected by the process of breeding to produce more efficient plant. The plant is very close to th~ wild form having many undesirable characters deterimental to yeild increases, e.g . too tall, low til1ering, lodging, non nitrogen fertilizer responsive, 10~1 yield, etc."},{"index":12,"size":5,"text":"An unpaired chromosome in meiosis."},{"index":13,"size":55,"text":"Rice grown in an unpudd1ed and unbunded soil condition, depending only on rain ~/ater. The soil is under an aerobic or the crop is directly seeded, mostly without bunds, nonreduced condition for the greater part of the grol1ing season . The term \"upland\", defined as above, would cover \"rainfed\", \"pluvial\", \"dry1and\", and \"hydromorphic\" rice (defined)."},{"index":14,"size":2,"text":"Varietal improvement:"},{"index":15,"size":1,"text":"Variety:"},{"index":16,"size":18,"text":"Improvement or desirable changes made within a given species that have resulted in a new or improved variety."},{"index":17,"size":55,"text":"A group of strains or a single strain or like which is morphologically or physiologically different from another group within the species. It is described as an agronomic unit familiar to breeders and farmers alike. (Pcehlman, 1959) A described and released clone or line of plants resulting from direct or indirect breeding work (see cultivar)."},{"index":18,"size":2,"text":"Variety group:"},{"index":19,"size":43,"text":"In rice germplasm work, this is the classification of accessions into groups based mainly on the morphological features of the adult plant and on grain appearance to some extent. The four major groups are indica, sinica, (Japonica), Javanica and intermediates (hybrids) (IBPGR-IRRI, 1980)."}]},{"head":"Variety trial:","index":328,"paragraphs":[{"index":1,"size":1,"text":"Vector:"},{"index":2,"size":18,"text":"A trial or experiment in which treatments are only different in varieties and all other factors are uniform."},{"index":3,"size":22,"text":"In biology, a carrier of a pathogen, e.g. an insect transmitting a viral bacterial or fungal disease from one host to another."},{"index":4,"size":2,"text":"Vegetative vigour:"},{"index":5,"size":73,"text":"In general, refer to the vigour (defined) expressed during the vegetative phase (defined) of a plant. In rice, it refers to the combination of various factors such as rapid seedling emer~ence and development, early and high tillering, moderately, long and initially droopy leaves and early and rapid increase in seedling height. It refers to that ability of plants to rapidly fill in the space between plants and rows (Jennings et ~, 1979) Vernalisation:"},{"index":6,"size":26,"text":"Exposure of germinated seedlings to conditions (usually cold) which slow down growth. Later grown under normal conditions they ~Jill flower earl ier than unvernal ised plants."},{"index":7,"size":18,"text":"A plant growing from an unintentionally included seed, e.g. seed shed or dropped by a previous crop ."},{"index":8,"size":2,"text":"Water control:"},{"index":9,"size":2,"text":"Water table:"},{"index":10,"size":1,"text":"Weathering:"},{"index":11,"size":36,"text":"The management of water in such a way that water can be applied to and removed from the field. Partial water control could be inability to drain the field or insufficient water in the field ."},{"index":12,"size":17,"text":"The upper .surface of ground water or that level below which the soil is saturated with water."},{"index":13,"size":17,"text":"All physical and chemical changes produced in rocks, at or near the earth's surface by atmospheric agents."}]},{"head":"Wa xy endosperm:","index":329,"paragraphs":[{"index":1,"size":2,"text":"~Jeeds :"},{"index":2,"size":68,"text":"The portion of the endosperm in which the starch fraction is composed mainly of amylopectin. It is stained, reddish-brown by a weak potassium iodide-iodine solution; has an opaque appearance; is glutinous in rice, i.e. becomes pasty anJ sticky when cooked. In rice, the waxy type of endosperm does not contain gluten,. Rice pastries and high quality rice wine are made from milled waxy rice (Chang and Bardemas, 1965)."},{"index":3,"size":55,"text":"Any plant growing in an unwanted place. A foreign variety or a wild relative is also a weed. Weeds are injurious to food crops in that they compete for space, light, nutrients and moisture. They are reservoirs for pests and diseases. They cause yield loss if uncontrolled and expensive to control mechanically, manually or chemically."},{"index":4,"size":3,"text":"Heed control (weedin~):"},{"index":5,"size":27,"text":"Prevention of or limiting the effect of weeds, eradication of weeds or their removal or limiting their growth by mechanical or chemical means or by hand ."},{"index":6,"size":1,"text":"Weedicide:"},{"index":7,"size":4,"text":"Weight: 169 (See herbicide)."},{"index":8,"size":58,"text":"The standard for determining how heavy a substance is. The standar~or established amount that has been acertained for the heaviness of any plant produce or parts, e.g. grain, straw, lOOO-grain, ear, panicle, etc. In most scientific experiments, metric (defined) measurements are used. (See Table 2). Weight units commonly used are grams (gm) and kilograms (defined) abbreviated as kg."},{"index":9,"size":4,"text":"White belly (White Core):"},{"index":10,"size":16,"text":"In rice, the white or chalky layer found in the ventral part of the rice caryopsis."},{"index":11,"size":2,"text":"White core:"},{"index":12,"size":27,"text":"In rice, the white or chalky portion in the centre of the caryopsis. It may also extend to the edge of the central side of the caryopsis."}]},{"head":"White head:","index":330,"paragraphs":[{"index":1,"size":2,"text":"White tip:"},{"index":2,"size":2,"text":"Wide cross:"},{"index":3,"size":25,"text":"In cereals, especially in rice, the characteristic white panicle as it dries due to stemborer damage at flowering. Rat damage can also produce white head."},{"index":4,"size":17,"text":"A nematode symptom on rice leaves, caused by the nematode Aphelenchoides besseyi . Leaf tips become white."},{"index":5,"size":47,"text":"A cross in which parental varieties differ greatly in their g:nes. The pa~ents may belong to the same species or to dlfferent specles of t~e same chromosome number. If the pare~ts belong to specles of different genera the cross is consldered to be very wide (Harrington, 1978)."}]}],"figures":[{"text":" Spec ial ack nowl edgemen t and gratitudes go to t he Crop Sc i ence Socie ty of America an d the Internationa l Rice Resea rch In stit ute f or al l owi ng me t o use their ta bl es in thi s gl ossa ry A. O. ABIFARI N I ITA/WARDA Liaison Sc i entist P. O. Box 1019 Mon rovia -Libe r i a. "},{"text":" term refers only t o the cul t ivated 0 glaberr im a. Other wild speci es t hat ar e believed to be indigenous to Africa are C. barthii A. Chev. (fo rmerly known as O. bre viligu1ata A. Chev. et Roc hr.) ~. brachyantha A. Chev. et Roehr., O. eichingeri A. Peter, ~ longistaminata A. Chev . et Rochr (formerly~nown as Q barthii A. Chev) and~. puntata, Kot schy ox Stoud. "},{"text":" und cross ((C[ (AxB)xC]xDxE) )xF [(A-BxC/D)E]F A/B //C///D/4/E/5/F "},{"text":" Dead heart: Number of days fromplanting to heading, flowering and maturity. The remains of a tiller of a cereal plant in which the growi ng point has been destroyed by the l arva of a stem bor er of Decline: Decrease: the diopsis fly. It is caused by insect damage before flowering. "},{"text":" of proteins produced by living cells. They act like catalysts in essential chemical reactions in living tissues. The enzyme itself is unchanged in such chemical reactions. Examples of enzymes are amylase, dehydrogenase, pepsin and try psin. "},{"text":"Fixative: 50 A generation from selfing or crossing Fl plants is the second fil ial genel\"ation F 2 . The progeny of F Z make up the third f ili al generation F 3 , etc.Chemical in which plant parts are preserved for subsequent study. "},{"text":" has become unchanged, stable and relatively homo zygous. A line (defined) derived fro m a cross through 6 or more generations of selection. The line is self-pollinated (if an open poll inated crop) for each generation. It thus has a highe r degree of homozygosity. The characters are repronducible as long as selfing is maintained. The line continues to breed tr ue to type. In cereal plants such as leaf below the pa nicle . sheath specially wrapped boofing stage. rice or sorghum, the last or topmost The panicle emerges through its leaf around the young panicle at the Flatland rice : Fla vour: Fl int corn: Upland rice grown on a relatively gentle slope in contrast to hill rice. "},{"text":" usually kept above the water level. Plant heig ht could be up to five metres or more.A si ngle small flower often among many ot~ers in a head or pan icle of floVlel'.A structure in higher plants that contain modified parts for sexual reproduction and insect attraction for pollination. The essential sex ual reproduction parts are the pistils and stamens which mayor may not be found in the same flower. The important accessory parts are petals, sepals, peduncle or pedicel and receptacle. They are variously modified, and one or more may be absent.The act of a plant bringing forth flowers with their floral parts visible.The floury-2 gene (symbolized by f12) has been known since 1935 (work by MUMM in Illinois). Located on chromosome 4, it gives the kernel a floury character in the double recessive state. In 1965, Nelson recognized its effect on lysine and tryptophan co ntent, rather similar to that of opaque. "},{"text":" of growth or watering within a short time . "},{"text":" is the seed produced from breeder's seed. Usually, it is produced or multiplied at an experiment station or other sites controlled by a station. Seed produced from foundation seed becomes registered seed, which also becomes certified seed. "},{"text":" Full sibs:Plants having both parents in common. Full sib mating is the most extreme form of in-breeding.Fumigation:The destruction of bacteria, insects and other plant pests by exposure to poison gas or smoke.Fungicides:Organic and inorganic chemicals that are effective in killing fungi.Fungus (pl. fungi): unicellular or multicellular and primitive plants devoid of chlorophyll. They depend on living or dead plants for their food.Being parasitic on living things, they are responsible for many plant diseases. "},{"text":"FAD  "},{"text":" (especially in Africa) for Sorghum bico1our a cereal crop. "},{"text":" or inflorescence in which no flower bud ends the axis of the flower cluster. The inflorescence produces flower over a long period. The terminal flower is last to open. "},{"text":" irat io n) inch mi crOm Ole(H?O) per sq ua re ce nt i meter second (appa r ent photosyn thes i s) cubic meter, Mg m milligram per ~q uale me!rr -2 seco nd , m g m 5-(10 gm millimeter, m m( 10-3 m) 5-1 ) milli gra m (H 2 ) 2De ~ls qua~~ mAt~s -1 second, n19 m-5 (10 g nl 5 ) microme t er , pm (10-6 m) kilome te r , km (10 3 m) per hecta re , kg ha-1 megagram per hecta re, Mg ha-1kilogram per cubic meter, kg m-cells found at the growing tips of stems or roots that are actively dividing and are undifferentiated. Later, they become differentiated into different parts of the plants. "},{"text":" discover plants that are resistant or subscepttble to diseases, pests, or other environmental factors. "},{"text":" has been recommended by breeders and widely grown by farmers in an area.An important reserve food or storage form of carbohydrates of green plants. It is found in storage tissues.A single datum or term in a collection of statistics. It is an estimate of a parameter made from a sample, with the quantity computed from a sample. Statistic is to sample what parameter is to population. "},{"text":" ability to resist disease or other harmful environmental hazards. It is the state of being vulnerable to the harmful effects of a chemical, pathogen, or physical and edaphic "},{"text":" Simple, vegetative, plant-body, showing no differentiation into root, stem and leaf. Unicellular or multicellular, consisting of branched or unbranched filaments or is more or less flattened and ribbon-shaped (Abercombie et al. 1975). "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":"  "},{"text":" It endeavours to find on an indepth basis the 'why, how, where, when and what' of things or organisms. The findings of basic research form the basis of applied research. They are often too fundamental for direct use by the farmers or other intended users of the research. Basic research may and may not yield any immediate useful result. (see applied and adaptive research).  "},{"text":" It is the process by which a nucleus halves its chromosome number from original diploid state to the haploid state. It takes place by having two successive divisions of the nucleus preceding the formation of gametes. In one division, there is no prior longitudinal splitting, the homologous chromosomes pair separate resulting in half of the original diploid number in each resulting in daughter nucleus. The second division is essentially mitotic in character. Four haploid cells are thus produced by the two divisions. The two nuclear divisions of a normal meiosis are called first (Meiosis 1) and second meiosis division (Meiosis II). Meiosis I consists of Leptotene, zygotene, pachytene, diplotene, Meiosis I consists of Leptotene, zygotene, pachytene, diplotene, Diakinesis, Prophase I, Metaphase I, Ana phase I and Telophase I. Diakinesis, Prophase I, Metaphase I, Ana phase I and Telophase I. Meiosis II consists of Prophase II, Metaphase II, Anaphase II and Meiosis II consists of Prophase II, Metaphase II, Anaphase II and Telophase II. Telophase II.  "},{"text":"Table 2 : Coversion Table for 51 Units (adapted from Crop Science)  "},{"text":"Table 3 : Chromosome numbe rs, genome symbols, and geographycal dist r ibution of Oryza species (adapted fromChang, 1976b & c). Species name Synonym (x = 12 ) Genome 2n= group Distribution Species name Synonym(x = 12 ) Genome 2n= groupDistribution O. alta 48 CCOO Central & Sou th Ameri ca O. alta48CCOOCentral & Sou th Ameri ca O. australiensis 24 EE Australia O. australiensis24EEAustralia O. barthi i (0. breviligulata) 24 AgAg West Africa O. barthi i (0. breviligulata)24AgAgWest Africa O. brachyant ha 24 FF West and Ce ntral Afr i ca O. brachyant ha24FFWest and Ce ntral Afr i ca O. eichingeri 24 , 48 CC, BBCC East and Central Afri ca O. eichingeri24 , 48CC, BBCCEast and Central Afri ca O. gl aberrima 24 AgAg West Af rica O. gl aberrima24AgAgWest Af rica O. gra ndi gl umi s 48 CCOD South Ame r i ca O. gra ndi gl umi s48CCODSouth Ame r i ca O. gra nu 1 ata 24  South & South eas t Asia O. gra nu 1 ata24South & South eas t Asia O. latifolia 48 CCDD Central & South Amer ica O. latifolia48CCDDCentral & South Amer ica O. longiglumis 48  Nelv Guinea (I r ian Jaya) O. longiglumis48Nelv Guinea (I r ian Jaya) ~. longi stam inata 24 AlAI Africa ~. longi stam inata24AlAIAfrica O. meridionalis 24 AA Australia O. meridionalis24AAAustralia O. meyeri ana 24  Southeast Asia, Southern China O. meyeri ana24Southeast Asia, Southern China ....n. minuta 48 BBCC Southeast Asia, New Guinea ....n. minuta48BBCCSoutheast Asia, New Guinea  "},{"text":" This i s an ins trument used to measure pressure associated with water. It i s generally used in crop resea rch to monitor t he gro und water le vel, e . g. in a rice toposequence study or up l and rice exper i me nt.A collective name for the female parts of a flower.Any living organism belongi ng to the ki ng dom Plantae characterized by lack of locomotive movement for most part of their adult lives, l acking obvious nervous or sensory organs, and possessing cel lul ose cell walls. Example s are gra s ses, young trees, vines , shrubs or herb planted or sui table for pl anti ng and vi sible and invisible fu ng i . Physio l ogical ly, they are nourished by gases or li quids and generally do no t ingest so l i d part i cl es of fo od and usually have the capac ity for indef i nite growth. To put or set in the soi l; to grow any part of a pl ant, e.g. stem, seeds or bul bs. Breeding methods for cross-pollinated crops are: Breeding methods for cross-pollinated crops are: Mass selection Mass selection Progeny sel ec tion and line breedi ng Progeny sel ec tion and line breedi ng Hybrid varieties develo pment Recurrent sel ection and Hybrid varieties develo pment Recurrent sel ection and Synthetic var iet ies development. Synthetic var iet ies development. Plant density: Plant density: Number of plants on a given plot of land. Number of plants on a given plot of land. Pla nt height: Pla nt height: Plant breeder: Plant breeder: One who applies t he genet ical princip l es to devel op new varieties of One who applies t he genet ical princip l es to devel op new varieties of pl ant (see Breeding ) . He i s actively i nvolved in the breeding and pl ant (see Breeding ) . He i s actively i nvolved in the breeding and ma i ntenance of variet i es of plants . A tra ined pla nt breeder ma i ntenance of variet i es of plants . A tra ined pla nt breeder possesses some knowledge on Bo tany, Genetics, Cytogenetics, possesses some knowledge on Bo tany, Genetics, Cytogenetics, Pri ncipl es of Plant Breed ing, Statistics, Ag ronomy and other Pri ncipl es of Plant Breed ing, Statistics, Ag ronomy and other associated disci plines such as Pathology and Entomol ogy . associated disci plines such as Pathology and Entomol ogy . Other intrinsicr qualit ie s of a plant breeder are kee n observational Other intrinsicr qualit ie s of a plant breeder are kee n observational power, great interest i n field work, s i ncerity in his decisi ons, power, great interest i n field work, s i ncerity in his decisi ons, consistent and sou nd judgement, and hi gh organizat i on. consistent and sou nd judgement, and hi gh organizat i on. Plant breeding methods: Plant breeding methods: These are the different scientific procedures for imrpoving These are the different scientific procedures for imrpoving plant characters and functions. For se lf-poll inated crops the plant characters and functions. For se lf-poll inated crops the commonly used methods are: commonly used methods are: Mass select i on Mass select i on Pure-line breeding Pure-line breeding Pedigree method Pedigree method Bulk-popu lat io n me thod Bulk-popu lat io n me thod Backcross me thod. Backcross me thod.  "}],"sieverID":"e519c573-b50c-4b8a-a547-b8d523359aa5","abstract":"The lavae of an insect pest Spodopptera spp. The larvae feed forociously on cereal crops consuming the upper portions of the plant. The leaf midribs and stems are not attacked.Fragrance, usually a pleasing smell of plant parts or of cooked food. The term is used in cooking quality tests e.g. in rice.Without involving sex or two dissimilar gametes."}
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