De Man's Values - Refer to the measurements and ratios to express length of nematode, its relative width, relative lengths of esophagus and tail, and position of vulva.

De-Suckering (Tobacco) - Removal of the suckers is known as desuckering.

Dead Furrow - Refers to the open trench which is left in between two adjacent strips of land after finishing the plough.

Dead Seed - Seeds which are not capable of germinating.

Deadstock - The equipment required to operate a fanning enterprise, such as tractors, implements, hay racks, and hurdles etc.

Deadweight - The weight of a dressed carcase.

Dead Water - Standing or still water.

Deassimilation - Refers to the utilization of food by a plant.

Debearder - Preconditioning machine which is used in seed testing laboratory to debeard barley, breakup lucerne seed pods, breakup grass seed doubles, separate and polish vegetable seeds, decorticate sugar beet seeds and remove extra glumes and hulls.

Decalcification - 1. Means the removal of calcium carbonate or calcium ions from soil by leaching, a natural process in soil formation. 2. Also refers to the removal of calcium from the bones of animal in negative calcium balance.

Decarboxylase - An enzyme which is able to liberate carbon dioxide from the carboxyl group of a molecule.
Deciduous - A descriptive term of plants, particularly trees, which shed their leaves annually, usually in the autumn. (Evergreen)

Decidous Teeth - The first teeth to appear in a young animal, later shed and replaced by permanent teeth. Also called milk teeth.

Decortication - The removal of husks from seeds. Oil seeds are frequently decorticated before oil extraction. Cattle Cake derived from oil seeds,(e.g.,Cottonseed Cake) may be either decorticated or undecorticated (the husks having been left on).

Deduplication - Chorisis,i.e.,increase in parts of floral whorl which occurs due to division of its primary members.

Deep Litter - A system of Bedding for cattle or poultry using straw shavings or sawdust.

Deep Percolation - Refers to the moisture which penetrates below the depths from which it may be used by plants. It represents that part of the water absorbed which exceeds the field capacity of the soil within the depth of root development.

Deep Percolation Loss - Water percolating downwards through the soil beyond the reach of plant roots.

Deferred Grazing - Means withholding animals from a pasture beyond the normal beginning of the grazing season.
Deficiency Deseases- Diseases of animals and plants due to an inadequacy of one or more essential food substances, such as a Vitamin, mineral Element, Protein of Amino Acid, etc.,e.g.,Grey Leaf, Brown Heart.
Deflocculation - The dissociation of large particles into smaller ones. Particularly applied to soils and the disintegration of crumbs under wet conditions.

Defoliation - The removal of the leaves of a plant. A defoliant is a chemical which causes this.

Deforestation - The process of clearing forests.

Degras - A fat derived from sheepkins.

Degree Brix - Measure for the sugar content of a solution.

Dehiscent - A descriptive term for fruits which spilt open to release the seeds,e.g.,peas.

Dehorning - The removal of an animal's horns to prevent it wounding others. The best method is to disbud the young animal, but horns can also be removed under anaesthetic by electric saw. Also called dishorning.

Dehulling - Refers to the removal of the outer covering from intact grains of seeds.

Dehydrated Foods - These are the products from which most of the water has been removed in order to improve their stability during storage.

Demography - Refers to the study of numbers of organisms in a population and their variation with time,

Demulcent - Drug having a soothing action especially upon the mucous membrane or inflamed skin surface.

Denaturing - The treatment of wheat grain so as to make it unusable for human consumption either by staining with a suitable dye or by the addition of fish oil to give a smell to it. Wheat, when denatured, can be used in animal feed, but not for flour-milling.

Dendrochronology - Means the dating of trees by observation of annual growth rings in the trunks.

Dendroclimatology - Determination of past climates by studying of relative widths of annual rings.

Denitrification - The breakdown of nitrates and nitrites by denitrifying bacteria in the soil in anaerobic conditions with the release of gaseous nitrogen.

Densitometer - Instrument for measuring photographic density.

Density Crop - Compactness of tree stocking which is expressed as a decimal co-efficient, by taking normal numbers, basal area or volume as unity and assessed by comparison with yield table figures.

Dent Corn - Horticulturally produced variety or com which is characterized by a depression in the end of the dry kernel.

Dental Formula - A formula indicating the number of each kind of teeth for a given animal species. The teeth are shown in the order incisors (i), canines (c), premolars (p) and molars (m), with teeth numbers for one side of the upper jaw shown above those for the lower jaw. The formula for a pig for example is. 3/3, 1/1,p4/4, m3/3

Dentition - The cutting or growing of teeth. Also the arrangement and number of teeth.

Depreciation - A figure included in the annual farm accounts as an expense indicating the amount by which various assets such as machinery and implements, etc, have lost value with ageing.

Depth Wheel - A wheel on an implement used to control the depth of working.

Dermatitis - An inflammation of the skin.

Dermatology - Refers to the scientific study of the structure and function of skin, diseases of skin, and the treatment of skin diseases.

Derris - An insecticide powder from the root of the tropical plant, Derris elliptica.Used against fleas, lice and Warbles.

Designated Diseases- Plant diseases which have been specified for seed certification of a given kind and in those regard certification standards must be met.

Designated Weeds - Species of weeds have been specified for seed certification of a given kind and in those regard certification standards must be met.

Dessicant - A chemical applied to a crop causing the foliage to dry up so that harvesting can commence.

Detassel - Means the removal of young tassels in maize plants so as to render the plants fully female, specially in hybrid maize seed production.

Detoxicants - Agents which are used to neutralize the action of poisonous substances.

Detritus Food Chain - Food chain in which microorganisms are able to absorb and break down the energy-rich compounds synthesized by the primary producers.

Dew-claw - The rudimentary fifth digit protruding from the heel of cattle, pigs and dogs.

Dewlap - 1. The losse flesh which hangs from the throat of oxen and cows. 2. The fleshy wattle of the turkey.

Dextrins - Refer to the products which are obtained by the partial chemical breakdown of starch by the action of heat, acids, enzymes, or a combination of these agents.

Dhaincha (Ind.) - Sesbania cannabina(Retz.) pers.(S. acu/eataPers var.cannabillaBaker). Family Papionaceae. Ranks next to sannhemp as green manure crop; a legume which has been adapted to a wide range of soil and climatic conditions, growing well on soils too wet, too dry, or too salty for most green manure crops. It is grown as green manure mostly in low lands, and planted on paddy bunds or in high lands for seed production.

Diallel Crossing - Means type of crossing in which each of a number of males is made to cross to each of a number of females so as to compare the breeding value of males.

Diamond Tup - A shearling male lamb. Also called a dinmont, particularly in the borders.

Diaphragm Pump - A type of pump in which a flexible diaphragm, generally of rubber is the operating part.

Diarrhoea - Waterly faeces which are caused by internal parasites, bacterial infection, excessive feeding of green succulent or other feed. Simple diarrhoea could be treated with catharitics like castor oil.

Diastase - An enzyme produced in germinating seeds and by the pancreas which converts starch to sugar.
Dib - A small bone in a sheep's leg.

Dibber, Dibble - A pointed hand tool used to make holes in the ground for seeds or plants.

Dibble, To - To sow seeds, or plant seedlings, in holes made with a planting peg.

Dibbling - Refers to the method of sowing the crops by using manual labour or a dibbler where in specific spacing and number of plants are maintained between the rows and within the rows.

2, 4-Dichlorophenoxyacetic Acid (2, 4-D) - A synthetic auxin which is used as an herbicide and defoliant.

Dieldrin - An insecticide ten times more powerful than D.D.T. A Chlorinated Hydrocarbon, highly poisonous to birds and fish, banned from use in sheep Dips in 1966 and as a winter wheat dressing in 1975. Its use is now limited under the Pesticides Safety Precautions Scheme to specified circumstances where no suitable alternative exists.

Diet - Food or feed of an animal, which is having implications of amounts consumed, or offered, in any given time.

Dietary Diseases - Diseases caused if the animal needs for nutrients and vitamins are not satisfied.

Dietetics - Deals with the application of the science of nutrition to the feeding of individuals and group of people.

Digestibility (Indicator Method) - A quick method which is used for determining the digestibility of animal feed without measuring either the feed intake or faces output. This is carried out by using an indicator with the feed to be tested and then finding out the ratio of the concentration of the indiator to that of a given nutrient in the feed and also in the faces resulting from feed, as shown below:

Digestibility =
100-[100 × % indicatorinfeed/% indicator in faeces × % nutrient in faeces/ % nutrient in feed]