interferons

Proteins secreted by vertebrate cells in response to a wide variety of inducers. They confer resistance against many different viruses, inhibit proliferation of normal and malignant cells, impede multiplication of intracellular parasites, enhance macrophage and granulocyte phagocytosis, augment natural killer cell activity, and show several other immunomodulatory functions.

interrow tillage

Tillage between the rows of growing plants

iodine value

In rendering, a measure of the chemical unsaturation of the fat expressed as the number of grams of iodine absorbed by 100 grams of fat sample.

irrigation

Application of water to soil for the purpose of plant production.

ketone bodies

Chemical substances such as diacetic acid, hydroxybutryric acid and acetone, which are produced in the liver of animals. Excessive amounts in the body result in ketosis. Elimination of ketones in urine is called ketonuria.

latex agglutination test

Agglutination tests in which the antigen is adsorbed onto latex particles before mixing with the antibody specific for the adsorbed antigen

leaf area index

The total area of the upper surface of leaves per unit area of ground that is directly below the plant.

leaf arrangement

The arrangement of leaves on a stem

plant litter

The accumulation of leaves, twigs, bark, needles, stems, fruits, branches and other plant parts on the surface of the soil.

leghemoglobin

A hemoglobin-like oxygen binding heme protein present in the nitrogen fixing root nodules of leguminous plants

light harvesting complex

A pigment-protein complex that harvests light energy and converts it to exciton energy that can migrate to the photosynthetic reaction center where photosynthesis occurs. The light is absorbed by pigment molecules (e.g., chlorophyll, bacteriochlorophyll, carotenoids, phycobilin) that are attached to the protein.

lignin

The second most abundant constituent of wood, located principally in the secondary wall and the middle lamella, which is the thin cementing layer between wood cells.

line planting

Woody perennials in a linear arrangement adjacent to cropland or grassland.

linkage

The co-inheritance of two or more non-allelic genes due to their being located more or less closely on the same chromosome

livestock

Domestic or farmed animals raised for food and fiber such as hogs, sheep, cattle, and horses

Fumigants

These are volatile chemicais applied into confined spaces or into a soil which produce gas that destroys weed seeds and acts as a soil sterilant. The most common soil sterilants are methylne bromide, methane, allyl alcohol, carbon disulphide, chloroprin and tetrachlorocthane. They are packed in particular soild carries suitalble for direct soil application.

Gap Filling

Resowing or replanting or re transplanting in sown ,planted or transplanted field crops where gropping of plants found.

Germination:

Awakening of dormant embryo of seed.

Grains:

The fruit of large seesed grasses .Botanically a grain or kernel is fruit containing seed

Grass:

boanically any plant that is in� the family Gramineae

Green Manure Crops:

Any crops which are grown and burried into the soil for improving the soil condition for addition of organic matter e.g., sunhemp, dhaincha, glyricidia.

Green Manuring

A practice of ploughing or turning into the soil the undecomposed green plant tissue for the purpose of improving physical condition as well as fertility of soil�

Ginning Percentage :

GP quantity of lint generated out of given quantity of cotton expressed in percentage as GP= wt. of lint *100\wt of cotton it is also referred as the ginning out turn(GOT)

Gypsum Block :

An instrument to measure the soil moisture under field condition using the principle of electrical resistance

Glaborous:

Hairlessness of leaf surface is referred to as glaborous nature.

Genetic Purity :

Trueness to the type of any variety of plant which confirms the varietal or characters described by the breeder

Germination

The resumption of the growth of a seed embryo resulting into emergence of ayoung healthy plant. In laboratory conditions, it indicates the ability of a seed to produce a normal and healthy seedling which may develop into a vigorous plant if favourable condition are provided in the soil

Germinator :

It is a machine, sometimes called as germination cabinet, with a perfect control of temperature and humidity, used for gemination test in seed testing laboratories.

Giberellins

These are plant growth stimulating substance used for inducing rapid plant growth breaking seed-dormancy, producing seedless fruits etc.

Glumes:

These are the pair of bracts at the base of a spicklet in the grasses.

Gross Profit:

It refers to the total profit from the farm without deducting expences thereon.

Guard Crops :

Crops grown around the main crop which has to be protected from wild animals, thieves, etc. These crops normally bear spines

habitats

The natural environment where an organism, population or community lives, including biotic and abiotic factors.

HACCP

A systematic approach to be used in food processing as a means to assure food safety.

halitosis

An offensive, foul breath odor resulting from a variety of causes such as poor oral hygiene, dental or oral infections, or the ingestion of certain foods.

haplotypes

The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the major histocompatibility complex

hardwood

Generally one of the botanical groups of trees that have vessels or pores and broad leaves, in contrast to the conifers or softwoods. The term has no reference to the actual hardness of the wood.

harvest index

Grain weight as a percentage of total above-ground dry weight at maturity.

hard red spring wheat

The wheat class that contains the highest percentage of proteins, making it an excellent bread wheat, with superior milling and baking characteristics; chiefly grown in Montana, North Dakota, South Dakota, and Minnesota; seeded in the spring, and may have a hard or soft endosperm.

hard red winter wheat

The class of wheat used mostly for bread and all-purpose flour; seeded in the fall; ranges from medium to high in protein; may have either a hard or soft endosperm; accounts for more than 40% of the US wheat crop and more than half of US wheat exports; produced in the Great Plains. Wide range of protein, good milling and baking characteristics. Used to produce bread, rolls, and, to a lesser extent, sweet goods and all-purpose flour

heifers

Bovine females that have not given birth to calves

herbicide safeners

Chemicals that selectively protect crops against herbicide injury

heterosis

The adaptive superiority of the heterozygous genotype with respect to one or more characters in comparison with the corresponding homozygote.

home range

The geographic area within which an animal lives and moves and to which it confines its usual activities.

hydrophobins

Hydrophobins are small, cysteine rich proteins secreted by filamentous fungi

hydroponics

The growing of plants in a soilless environment where nutrients are provided by the application of nutrient solutions

hypoxia

Relatively complete absence of oxygen in one or more tissues.

hysteroscopy

Endoscopic examination, therapy or surgery of the interior of the uterus.

hypertrophy

General increase in bulk of a part or organ, due to cell enlargement and accumulation of fluids and secretions, not due to tumor formation, nor to an increase in the number of cells (hyperplasia).

hyperlipidemia

Conditions with excess lipids in the blood.

imino sugars

Sugars in which the oxygen is replaced by a nitrogen atom. This substitution prevents normal metabolism resulting in inhibition of glycosidases and glycosyltransferases.

imitation foods

Products consisting of regular foods and/or chemical formulations that may be used in place of the foods they imitate. Often imitation foods are used by consumers for health or economic reasons.

immunization

Deliberate stimulation of the host's immune response. Active immunization involves administration of antigens or immunologic adjuvants.

in situ conservation

Maintenance or conservation of an organism or gene resource within its native environment.

in situ hybridization

A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.

in vitro culture

Culturing of cells, tissues etc. outside the living organisms or in an artificial environment.

inoculum

Collective term for microorganisms or their parts (spores, mycelial fragments, etc.) which are capable of infection or symbiosis when transferred to a host

insect outbreaks

A marked increase in the population of an insect pest.

insecticide resistance

The development or selection of heritable traits (genes) in an insect population that allow individuals expressing the trait to survive in the presence of levels of an insecticide (biological or chemical control agent) that would otherwise debilitate or kill this species of insect. The presence of such resistant insects makes the insecticide less useful for managing pest populations

insecticides

Pesticides that kill insects.

insectivores

An organism (plant or animal) that mainly feeds on insects.

integrated pest management

A pest management strategy using a systematic approach in which pest populations are monitored to determine if and when control methods are required. Integrated pest management (IPM) uses biological, chemical, physical, cultural and/or genetic control methods in order to minimize pesticide use, reduce production costs, and protect the environment.

intensive farming

A system of raising crops and animals, usually on small parcels of land, where a comparatively large amount of production inputs or labor are used per acre. Compare extensive farming.

intensive forestry

Utilization of a wide variety of forest management and silvicultural techniques in order to maximize the productivity of a unit of forest area.

intercropping

The growing of two or more different species of crops simultaneously, as in alternate rows in the same field or single tract of land.

Defoliant

A chemical or any method of treatment causing falling of leaves or abscise, but fruits remain attached is technically called as defoliant.

Dyes

A colouring chemical used on seed to indicate that the seed is treated so that it may not be consumed. Different dyes make a trade marks of various seed companies.

Drier

A machine fitted with heating system which removes moisture from any object and the process of removal of moisture is called as drying.

Dioecious

Plants bearing only either male or female flowers like papaya.

Dormancy

A chemical condition of seeds which prevents the embryo to initiate germination even after all the favourable conditions for germination are provided and seed remain in resting state.

Diaphanoscope

It is a dark work-board with glass top through which light passes from below and helps in determining the presence of caryopsis within the glumes of graminacious seeds

Degeneration

It is a process of regular and progressive decrease in vigour of successivegeneration of plants which may happen due to unfavourable growing conditions attack of disease or cross pollination

Deflocculate

To separate the individual components of compound particles by chemical and/or physical means

Double Cropping

Refers to the practice of growing two crops in a year as in case of dryland areas

Duoculture :

Practice of growing only two type of crops in a year

Dry Land Crops

It refers to all such crops which are drought resistant and can complete their life cycle without irrigation in areas which receive an annual rainfall of 50 cm. or less.

Dryland Agriculture

Scientific management of soil and crops under drylands without irrigation is called as dry land agriculture

Dry Lands

These are the areas which use to receive an annual rainfall of 50 cm. or less and there is no irrigation facility for raising crops.

Diara Lands

These are the areas which are located in river basins that get submerged during rainy season and the soil is used for crop production only during rabi or/and sometimes during zaid season. It is also known as Kachhar lands.

Diffusion

The upward or downward movement of solube salts in a profile without movement of water is known as diffusion.

Drought

It is a condition of insufficient moisture supply under which they fail to develop and mature properly. It may be caused by soil, atmosphere and/or both.

Dry Farming

lt is practice of raising successful and profitable rained crops in areas which receive an annual rainfall of 50 cm. or less Sometimes it is also called as dry land agriculture

Drought Resistance :

It is a capacity of plants to endure the drought conditions without suffering any irrecoverable injury to plant like leaf or death of tissue etc

Directed Spray

It refers to the post-emergence spraying of herbicides in the inter-row spaces by covering the spray nozzle under a hood or shield. It is mostly done in case on non-selective and contact herbicides

Ecofallow System

It is also called as chemical fallow system which is a type of reduced tillage practice made possible by herbicides which kill weeds of a fallow area.

Enforced Dormancy

change in environment conditions , especially temperature restricts germination which is called as enforced dormancy

Emulsifiable Concentrates

These materials from stable emulsion, when diluted with water, become suitable for spraying over the plant surfaces Emulsifiable materials at the same active ingredient are better than suspensions. These are of two types like concentrated emulsions which prepared mechanically by despersing an aqueous solution of the herbicides inwater-immiscible solvent by means of a colloid mill. The another type of emulsifiable material ismiscible oil consists of herbicides, solvent and emulsifier

Eksali Planting of Sugarcane

It is common is South India and takes about one year or 12 months for harvesting. The planting is done in January-February

Elluviation:

It is a part of the soil formation process in which removal of materials in solution, solution or even in suspension form in vertical direction forced by downward movement of water form one horizon to another.

Erosion

Detachment and transportation of soil particles from their original places through water, wind , ice or any other geological agent is called as erosion

Evapotranspiration :

It is an additive or cumulative volume/quantity of water lost due to both evaporation and transpiration from the soil surface, when it becomes difficult to separate out boththe losses from one another then an additive value is expressed and term evapotranspiration is used. It is often referred as consumptive use of water of crops

Ear

An ear is large, dense or heavy spike like inflorescence in graminacious plants especially in cereal like wheat ,barley�

Epigeal

A type of germination in which the cotyledons appear above the soil surface.

Embryo

The rudimentary seedling within the seed which gives out a palnt after sprouting when�provided with favourable conditions.

Epicotyl

A part of the embryo which produces shoot or the above ground part of the plant.

Endosperm

The food storage for nourishing the embryo in a seed which develops from fertilization of the polar nuclei of the ovule by a second male nucleus.

Essential Plant Nutrients:

These are the nutrients without which plants cannot grow and develop and they fail to cumplete their life-cycle.

Exchangeable Sodium Percentage

The extent to which the adsorption complex of soil is occupied by sodium and it may be calculated by using following equation: Exchangeable sodium (ineq/100 g of soil)ES.Px 100?/Cation exchange capacity (meq/100g) of soil

Earthing Up

The raise the soil at the base of plant e.g., surgarcane.

Ephemerals:

The weed which completes its seed to seed cycle within two or four weeks eg niruri.

Emulsifying Agent

A surface active material which facilitates the suspension of one liquid to another

Endozoochory Mechanism :

The ingested weed seeds are passes in variable from 0.2% to 9.0% with the animals excreata which is dropped wherever the animal moves eg., fox-ber.

Fouling Crops

Whose cultural practices allow the infestation of weeds intensively eg., direct seeded upland.rice.

Flooding

A method of irrigation, where the land is supplied with sufficient water enough to stand above the surface.

Flye Curing

A method of curring cigarette tabacco, wherein the leaves are.

Facuitative Weed

Weed of wild community origin, escaping sometimes to crop yield eg., cactus.

Fillar��

it is the inert inactive substance used to dilute the chemical for herbicide, insecticide or fungicide etc.

Forage Crop:

Crop grown primarily for livestock feed harvesting either'hay, silage, green fodder grazing e.g., lucerne.

Field Heat :

It refers to the heat of anything like seed, packing material, bags etc. put in the storage in excess of the heat at the storage temperature.

Foundation Seed

A second category of seed, in order of genetic purity, multiplied by breeder's seed under strict supervision and complete enforcement of seed production technique. The seed production may be done by the seed agencies directly or by the certified growers

Free-Flowing Seed

A smooth surfaced non-chaffy seed which moves freely through seed sampler or seed mixing machines�

Furnigation

It is a process of using chemical like celphos, E.D.B. etc., in a leak proof container used for seed storage which produces texic fumes and kills all the storage pests.

Field Capacily :

The percentage of water remaining in soil two or three days after having been saturated and after free drainage has practically ceased.

Farm Forestry:

Refers to the practice of growing raising forest trees on the waste land of the farm like around the buildings, all along the fences or the roads with a view to utilize the waste land in a purposeful manner.

Foliage Applied Herbicides:

Herbicides when applied over the foliage are known as foliage applied herbicides. They are always post-emergence herbicides.

daptomycin

A cyclic lipopeptide antibiotic that inhibits gram-positive bacteria.

data deficient species

A taxon that is not evaluated for its risk of extinction by the International Union for Conservation of Nature due to lack of sufficient information.

deacidification

To raise the pH of a substance or material to above 7.0

dead wood

Dead branches or completely dead standing trees resulting from natural processes or anthropogenic activity such as logging

decontamination

The removal of contaminants or contaminating material from a product, a person, an object or an environment.

defect action levels

Levels of natural or unavoidable defects in foods that present no health hazards for humans.

deficiency diseases

Diseases caused by an insufficient intake of essential nutrients, i.e., protein (or amino acids), vitamins, and minerals or inadequacy intake of calories.

delignification

Removal of part or all of the lignin from wood by chemical treatment

demeclocycline

A tetracycline analog having a 7-chloro and a 6-methyl. Because it is excreted more slowly than tetracycline, it maintains effective blood levels for longer periods of time.

demonstration forests

Forests which provide models of forest ecology and exhibitions of various forest management techniques and silvicultural practices.

dendrochronology

The study of annual growth rings of a tree in order to determine the historical date of their formation and the age of the tree.

dendroclimatology

The study of the annual growth rings of a tree to determine historical patterns of climate variation.

dendroecology

The use of tree ring data to investigate the past histories of ecological processes such as, forest dynamics with precise spatial and temporal resolution.

dermis

A layer of vascular connective tissue underneath the epidermis.

determinate growth

Plant growth in which the growth of the main axis is terminated. Typically applied to inflorescences, where the terminal flower is the first to mature along the inflorescence.

detoxification

The removal or inactivation of a poison or toxic substances from a nonliving substance or product.

diffuse solar radiation

Diffuse solar radiation is that fraction of the solar radiation that is reaching Earth's surface after been scattered downwards by the molecules or particulates in the atmosphere.

digestible dry matter

Amount of digestible fibre in a feed or forage.

disease resistance

Describing any organism which has low susceptibility or has the ability to withstand a disease caused by infectious agents (i.e., viruses, bacteria, fungi) or by parasitic nematodes, protozoa and helminths.

disease susceptibility

A constitution or condition of the body which makes the tissues react in special ways to certain extrinsic stimuli and thus tends to make the individual more than usually susceptible to certain diseases.

DNA

he chemical substance from which genes are made. DNA is a long, double-stranded helical molecule made up of nucleotides which are themselves composed of sugars, phosphates, and derivatives of the four bases adenine (A), guanine (G), cytosine (C), and thymine (T). The sequence order of the four bases in the DNA strands determines the genetic information contained.

domestication

The process of breeding for one or more desirable characteristics in plants�

double cropping

Two different crops grown on the same area in one growing season.

draft animals

Animals used to supply power to pull farming implements, carts, vehicles, heavy loads, etc.

drainage system

Manmade systems of furrows, ditches, tile drains, pipes, etc. which collect and remove water from a central location.

dried milk

Dairy product made from milk by the removal of 95-98% of the water.

dried skim milk

The product obtained by removing water from pasteurized skim milk. It contains not more than 5% moisture and not more than 1.5% milk fat unless otherwise indicated.

Drip loss

The loss in weight of food products owing to extruding and dripping away of tissue juices, such as meat juices lost during the thawing of frozen meat.

dry period (lactation)

The time in late pregnancy when a cow (or other lactating animal) ceases to give milk. Commonly, U.S. dairy cows are dried off 60 days before calving.

durum wheat

The hardest of all U.S. wheats, seeded in the spring, and contains a high amount of protein, which is good for pasta products (macaroni, spaghetti, and other noodles), grown in the same northern area as Hard Red Spring wheat--mainly in North Dakota.

Deep Tillage

When soils tilled from 25 cm to 45 cm. It is carried out in root crops.

Dry farming

� Crops The crop which are grown under natural precipitation eg, sorghum,

Dockage Sample

usually refers to a representative sample of seed used to determine the amountof Inert method and other crops seed etc.

Detergent

� A chemical having abiity to remove soil.

Defoliant

A chemical which causes the lealf or follage to drop from the plant.

Dessicant�

A chemical which promotes the dehydration of plant tissue.

Dibbling

it is method of sowing the crop with the help of manual labour or dibber when specific spacing and� number of plants are maintained between rowa� and with in row�

Dip irrigation

A method of irrigation where water is supplied to plant by small tubus of pipes, through which water trickles drop by drop.

Detasseling

Proces of� removing the tassel in maize,

Drainage

Removal of excess surface or ground waler from the land.

durdgery to Labourers�

Wariness� or operational difficulties felt by the body of the labourers while doing a field operation

Dead Heart

The condition of plant where the central axis is dried up or rotten, is called dead heart.

Duly of Waler

Refers to the area irrigated by discharge of one causec of water during the crop period.

Diploid

Plant having two sets of chromosomes.

Drenching

A method to soak the root zone by using particular solution to control the spread of a particular disease.

Dredging

An operation to remove the accumulated silt in a dam.

Dibbling:

System of placing the seed in the soil by hand.

Defoculation

Action to separate or break down soil aggregates of clay into their individual particles.

Damping-off :

Death of seedling caused ty the attack of somePyhium spp. This normally occur under high condition and over crowding of seedlings.�

Desiccate

The process of drying of any object so as the moisture fall below the normal level.

waxy corn

Rice with 0-2% amylose or mainly amylopectin in the endosperm and pollen starch.

wetland plants

Plants adapted for survival in soils frequently saturated with surface or groundwater.

wheat allergy

A malabsorption syndrome that is precipitated by the ingestion of foods containing gluten, such as wheat, rye, and barley. It is characterized by inflammation of the small intestine, loss of microvilli structure, failed intestinal absorption, and malnutrition.

white tea

Tea made from the dried leaves and buds of the Camellia sinensis plant.

whole farm planning

An approach to farm management which addresses environmental considerations within the farm enterprise, such as water supply, waste management, runoff, etc. Best management practices may also be considered in the whole farm plan for sustainability of farm operations.

wide hybridization

interspecific and intergeneric hybridization which is a first step to introduce alien variation and to transfer desirable genes and traits from wild species into cultivated species

white-rot fungi

A group of decay fungi that are able to degrade cellulose, hemicellulose and lignin in wood. Compare with brown rot fungi.

wines

All alcoholic beverages made from the fermentation of grape juice, other fruits or vegetative parts. Wine may be sparkling or carbonated, made from condensed grape must, made from agricultural products other than the juice of grapes, and includes products sold as wine such as imitation wine, cider and sake

yield tables

A table showing, for one or more species in a fully stocked stand, the growth pattern of a managed even-aged stand derived from measurements at regular intervals covering its useful life. It includes mean d.b.h. and height, number of stems, and standing volume per unit area. The table may also contain a variety of other useful data

Z-DNA

A less common "zig-zag" conformation of double-stranded DNA with a left-handed double helix which requires alternating GC sequences. It is favored by high salt concentration, but may occur in cells and may have regulatory functions

zearalenone

(S-(E))-3,4,5,6,8,10-Hexahydro-14,16-dihydroxy-3-methyl-1H-2-benzoxacyclotetradecin-1,7(8H)-dione. One of a group of compounds known under the general designation of resorcylic acid lactones. Cis, trans, dextro and levo forms have been isolated from the fungus Gibberella zeae (formerly Fusarium graminearum). They have estrogenic activity, cause toxicity in livestock as feed contaminant, and have been used as anabolic or estrogen substitutes.

zein

A group of alcohol soluble seed storage proteins from protein bodies in endoplasmic reticulum of corn endosperm

zero wastes

Waste management objective in which industrial outputs are reused as inputs and products are recycled to eliminate waste

zinc finger motif

Motifs in DNA- and RNA-binding proteins whose amino acids are folded into a single structural unit around a zinc atom. In the classic zinc finger, one zinc atom is bound to two cysteines and two histidines. In between the cysteines and histidines are 12 residues which form a DNA binding fingertip. By variations in the composition of the sequences in the fingertip and the number and spacing of tandem repeats of the motif, zinc fingers can form a large number of different sequence specific binding sites.

zero emissions

Pollution abatement objective in which industrial processes or energy source emissions contribute no waste products, such as greenhouse gases, that pollute the environment or effect climate change; actual emissions may be offset through recycling, carbon sequestration or environmental credit trading

zoning

In general, the demarcation of a planning area by ordinance into zones and the establishment of regulations to govern the use of the land (commercial, industrial, residential, type of residential, etc.) and the location, bulk, height, shape, use, and coverage of structures within each zone

zoonoses

Diseases of non-human animals that may be transmitted to humans or may be transmitted from humans to non-human animals

zooplankton

Free-floating, minute, often microscopic, animals of aquatic systems. They include protozoa, rotifers, crustaceans, and larvae of larger animals, such as annelids and fish, that feed on other plankton.

zygospores

A thick-walled resting cell or spore formed by the fusion of gametangia (or specialized haploid hyphae) of different mating types during the sexual reproduction, as seen in some species of fungi, algae, protists etc

technical crops

Those crops that are not specifically grown for foodstuffs (such as fruit crops, vegetable crops and grain crops), but are specifically grown to yield a useful product for man or industrial processes, such as fiber, oils, rubber, chemicals, resions, energy, waxes, or dyes

tension wood

Abnormal wood found in leaning trees of some hardwood species and characterized by the presence of gelatinous fibers and excessive longitudinal shrinkage. Tension wood may cause warping

terraces

Natural or manmade landforms which run perpendicular to the slope and are bordered on one side by a steep ascending slope and on the other side by a steep descending slope.

terracing

In agronomic practice, the construction of ridges of earth built across a slope with a flat or graded channel to stop soil erosion and control the runoff of water.

testcrosses

A cross between an organism exhibiting the dominant phenotype for a certain trait, but whose genotype for that trait is unknown and an organism that is homozygous recessive for the trait so that the unknown genotype can be determined from that of the offspring.

tetraploidy

A cell, tissue, or organism having four sets of chromosomes.

The Nature Conservancy

An international conservation organization that purchases lands in order to preserve plants, animals and natural communities.

thigmonastic movement

The movement of plant parts in response to non-directional stimuli. The stimulus may be external, such as the movement of Mimosa leaves when touch (thigmonasty), or internal, such as the sudden movement of plant parts due to changes in turgor pressure (seismonasty). Nyctinasty is the movement of organs, such as the opening of flowers during the day and closing at night, in response to the diurnal cycle.

thinning (in forests)

The silvicultural practice of removing excess, diseased or poor quality trees and underbrush to improve the growth, health and value of the standing timber crop.

thinning (plants)

The practice of reducing the number of plants in an area or the quantity of vegetative or reproductive structures on individual plants.

threatened species

Any species which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range and which has been designated in the Federal Register by the Secretary of Interior as a threatened species. (Endangered Species Act of 1973) This includes species categorized as rare, very rare, or depleted.

tissue-cultured meat

Meat produced from the skeletal muscle or muscle cells or stem cells in laboratory conditions by using tissue engineering techniques.

tissue banks

Centers for acquiring, characterizing, and storing organs or tissue for future use.

tissue culture

A method of maintaining or growing tissues, organ primordia, whole or parts of organs, in a manner to preserve their structure and/or function.

top dressings

The application of compost or fertilizer on top of the soil during plant growth.

topping (pruning)

The practice of removing the top branches of a tree or shrub.