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A significant development in the field of agricultural research in India is the formulation of All India Coordinated Research Projects (AICRPs), initially for the improvement of agricultural crops, but later extended to all aspects of crop husbandry.

All India Coordinated Research Projects

1. AICRP on Nematodes, New Delhi

2. AICRP on Maize, New Delhi

3. AICRP Rice, Hyderabad

4. AICRP on Chickpea, Kanpur

COMMON INSECT PESTS AND THEIR CONTROL

Since, insects are the most successful and one among the strongest rivals of man in the competition of existence. Due to their immense tendency of producing numerous viable propagules (eggs) i.e., their high fecundity, their population graph takes a sharp peak in a very short span of time.

A time reaches when the population of an insect type reaches to the level where from it starts causing inconvenience or injury to man, plants, domesticated animals and other human belongings, at such a juncture they are termed as insect pests.

Many, workers are of the view that “insects capable of causing 5 or more than 5% of damage to the crops, stored products, domesticated animals and other human dependences will be termed as pests”. Thus, if an insect causes a loss of less than 5% will not be considered as a pest. Moreover insect pests which cause a damage of 5-10% are said to be minor pests and those which cause a loss of more than 10% of yield are said to be major pests.

12.1. Origin and distribution

• Indigenous to West Indies (Jamaica), Central and South America. Jamaica is the main producer of allspice.

• In India, there are few trees in Maharashtra, Tamil Nadu, Karnataka and Kerala.

• Available in the Mahendragiri hills of Kanniyakumari, and Kallar and Burliar of the Nilgiris of Tamil Nadu; Ambalavayal in Kerala.

12.2. Economic importance

• It combines the odour and flavour of nutmeg, clove, cinnamon and pepper and hence, called all spice.

• Berry, berry oil, oleoresin, leaf oil are the products of economic use.

• Used in food industry (65 to 70%), domestic use (5 to 10%), production of berry oil (20 to 25%), extraction of oleoresin (1 to 2%), and pharmaceutical and perfume industry.

• Has, anti-microbial, insecticidal, nematicidal, anti-oxidant and deodorant properties.

English name : All Spice
Botanical name : Pimento dioica (L.) Merr.
Family : Myrtaceae
Chromosome number : 2n = 22
Centre of origin : West Indies
All spice of commerce is the dry unripe fruits of tree Pimenta dioica (L.) Merr. (Syn P. officinalis Lindi). Allspice, also known as pimento, derives its name from the early misconception of Spanish exporters who mistook the berries for pepper. This led to names such as Jamaica pepper in English and Nalkenpfeffer in German, though it is now officially referred to as “pimenta.” The term “allspice” reflects the belief that the spice combines cloves, nutmeg, black pepper, and cinnamon flavours and aromas. It is available in both whole and ground forms.
The composition of ground allspice berries includes 8.8% moisture, 6.0%protein, 6.6% fat (ether extract), 21.6% fibre, and 52.8% carbohydrates, with 4.2% total ash. Additionally, it contains 0.8% calcium, 0.1% phosphorus, 0.08% sodium, 1.1% potassium, 7.5 mg of iron per 100 g, and vitamins such as 39.2 mg of vitamin C, 0.1 mg of thiamine, 0.06 mg of riboflavin, 2.9 mg of niacin, and 1445 IU of vitamin A. The calorific value is approximately 380 calories per 100 g. Its distinctive aroma comes from the essential oil content (3.3–4.5%) concentrated in the pericarp. The berries also contain tannic acid (over 8%), contributing to their astringency, along with soft resin, fixed oil (5.8%), crude starch (20%), proteins (5.8%), and trace amounts of alkaloids.

Animal Husbandry is a major activity in hilly areas and women contributed the most in maintaining this enterprise. It is of immense importance to conduct study for alleviating drudgery of farm women in hilly areas. Since women’s contribution in animal husbandry is significant to our economy, their technological empowerment is equally important and needs to be given high priority.

This chapter covers a study of a project conducted in Udaipur district of Rajasthan. The concerted efforts made under this project through skill training, field demonstration, constant technical support and motivation resulted in acquisition of knowledge and skills in handling various drudgery reducing technologies in animal husbandry. Technological intervention has made farm women aware of new technologies available to assist them in performing the tasks. As a result there is a change in the practices of women and they have begun to adopt new technologies to improve their work efficiency in animal husbandry. By the use of technologies, there is considerable reduction in the drudgery of farmwomen. Equipment like rake, shovel, and wheel barrow and chaff cutter has not only decreased time and energy consumption but have improved work efficiency in terms of output.

Introduction

Livestock development has always been a major concern in the Indian economy along with agriculture. Animal husbandry and Dairy development play a prominent role in the rural economy in supplementing the income of rural household particularly, the landless, small and marginal farmers. It also provides subsidiary occupation in semi-urban areas and more so for people living in hilly, tribal and drought prone areas where crop output may not sustain the family. Animal husbandry output constitutes about 30 percent of the country’s agricultural output. In recent years, animal husbandry has become more indispensable for human kind because of increasing pressure on cultivable land owing to the population explosion.

In the current situation, crop intensification is of topmost importance to increase agricultural production from ever-limiting and degrading resources. In this regard, the potential of agroforestry can be thought that offers ample opportunity to enhance farm output with multifaceted benefits (Xu et al., 2019). Forests are known to maintain ecological balance in many ways with greater ecosystem services; hence, the advantages of forestry can be included in agroecosystem in the form of agroforestry which enables yield of forest products and crops together

The basic points that are to be considered while choosing appropriate enterprise in IFS are:

1. Soil and climatic features of an area/locality.
2. Social status of the family and social customs prevailing in the locality.
3. Economic condition of the farmer (Return/income from the existing farming system).
4. Resource availability at farm and present level of utilization of resources.
5. Economics of proposed IFS and credit facilities.
6. Farmer’s managerial skill.
7. Household demand.
8. Institutional infrastructure and technological knowhow.
9. Market facilities.

Onion

Onion is very popular vegetable crop grown worldwide. Consumption is in the form of fresh, frozen, and dehydrated bulbs and green bunching onion. Origin of Allium cepa is still somewhat mystery. Vavilov (1951) suggested that the onion originated in the area of Pakistan. Others have suggested Pakistan, Iran & the mountain areas to the north (Jone& Mann, 1963). One fact is certain that the onion has been around in its present edible form for thousands of years. Onion recorded in tombs as early as 3200 B.C. It was mentioned as a food in the bible and in the Koran with reference thought to be around 1500 B.C. In addition to being a food considered by people, plant is having certain healing power. Some early drawing indicates that onions were used in spiritual offerings.

1. Introduction

The remains of almond, found in several archeological sites, show the importance of this crop since centuries. Being storable after drying, the fruits can be transported everywhere, this is the reason why, these nutritious nuts have followed the human migration. The easy adaptability of this species to poor soils has favored their spread. It is an elixir for good health and a panacea for all ills. Almonds have long been an integral part of India’s cultural heritage, especially during festive seasons and weddings. In an increasingly health-conscious nation like India, the demand for almonds is ever increasing. However, several problems plague production and limit output which has led to high import.

1.1. Nutritional value

Almonds are good source of fat, in which 80% is in the form of monounsaturated fatty acids (MUFA) which decreases unwanted cholesterol of body. Almonds contain omega-6 fatty acid which is good for heart. The amount of saturated fat is very less in almonds. Almonds have high amount of phosphorus and calcium which is required for bone growth. Magnesium, manganese, vitamin B6 and Vit. E are also available in almonds. Almond oil contains glucosides, minerals, vitamins and is rich in protein. Nutritive value of almond has been presented in Table1.

Green peach aphid/leaf curl aphid : Brachycaudus helichrysi : Aphididae

These are green aphids that suck the sap from growing buds. Leaf buds become weak and result in poor setting and premature fruit fall.

The pest has a worldwide distribution. In India it is seen in the hills of North India and in nilgiris.

It is a serious pest of peaches, plum, apricot, and almond. The aphids attack the tender portions like new buds, blossoms, petioles, tender fruits and leaves. When the new flushes are attacked, the leaves get curled and crinkled and fruit set is either reduced or  fruits fall off . The infestation starts with the commencement of bud swelling and continues until after flowering. The leaf curl may be confused with that due to the fungal leaf curl by Taphrina deformans.

Genus : Prunus / Amygdalus
Species :  dulcis L. communis, Fritsch.
Family : Rosaceae
Chromosome No. : 2n = 28

Almond tree amongst the deciduous temperate fruits is the first crop to bloom in spring as it responds readily to warm temperature and also for its relatively low chilling requirements. The almond is thought to be one of the oldest nut crop used by man since very long.  However, its specific climatic requirements have greatly restricted its commercial production to limited regions of the world.  The almond blossoms are large attractive pink coloured very sensitive to spring frost, but at the same time the nut require high heat quantum at maturity, cool rainy weather during flowering restricts cross pollination and induces fungal infections. In the mild winter regions almond trees are limited by the fact that distinct chilling requirement for growth and flowering are not met with.

Almond (Prunus dulcis, syn. Prunus amygdalus Batsch.) is an important temperate fruit crop. In India, it is mostly cultivated in Jammu and Kashmir and Himachal Pradesh. Almond is a small deciduous tree, growing to 3–10 m tall, with a trunk up to 30 cm diameter. The young shoots are green at first, becoming purplish where exposed to sunlight, then grey in their second year. The leaves are lanceolate, 4–13 cm long and 1.2–4 cm broad, with a serrated margin and a 2.5cm petiole. The flowers are white or pale pink, 3–5 cm diameter with five petals, produced singly or in pairs before the leaves in early spring. The fruit is a drupe 3.5–6 cm long, with a downy outer coat. The outer covering or exocarp, fleshy in other members of Prunus such as the plum and cherry, is reduced to a leathery grey-green coat called the hull, which contains inside a hard shell the edible kernel, commonly called a nut in culinary terms. Generally, one kernel is present, but occasionally two. However, in botanical terms, an almond is not a true nut. In botanical parlance, the reticulated hard stony shell is called an endocarp. It is mature in the autumn, 7–8 months after flowering. The fruit of the wild forms contains the glycoside amygdalin, “which becomes transformed into deadly prussic acid (hydrogen cyanide) after crushing, chewing, or any other injury to the seed”. However, domesticated almonds are not toxic.(FAO, 2013 and Verma, 2014).

• Recommended no. of beehives for efficient pollination is 5-8 beehives.
• Maturity indices: Change the colour from green to yellowish with cracks.
• Dehulling term is related to Almond.
• Damage to blossom due to early spring frosts is the major constraint in almond cultivation.
• Almond can withstand low temperatures upto -2.2 to -3°C.
• The almond tree becomes productive after 5 years.
• Almond contains oil - 49%, Oleic acid – 62%, Linoleic acid – 24% and Palmitic acid – 6%.
• Almond is a rich source of Vitamin E
• Kernels after blanching, roasting, frying and salting taste very delicious and are in in great demand.
• Green almond kernels are also consumed in the milky stage.
• Almond is cultivated mainly in regions situated between 360 and 450 N latitude.

9.1 Introduction

Almond is one of the major and oldest tree-nut crops of the world. It is a close relative of peach. It was bought to California in the 17th century by Spanish. In India it was first introduced into Kashmir during 16th century by Persian settlers. The tree bears a fruit called a drupe consisting of an outer hull and a hard shell with the seed inside. Almonds are generally cross-pollinated. Therefore, the common honeybee plays a vital role in the production of the nuts. A compound called ‘Amygdaline’ differentiates the bitter almond from the sweet almond. In the presence of water (i.e., on hydrolysis), amygdaline yields glucose and the chemicals, benzaldehyde and hydrocyanic acid (HCN). The salt of HCN known as cyanide is poisonous. The bitter almond is slightly broader and shorter than the sweet. Bitter almonds yield 4-9 mg of hydrogen cyanide per almond. Almonds are cultivated in many parts of the world, with the five leading countries being the U.S., Spain, Australia, Iran and Morocco.

Abstract

Health benefits of aloe vera include its application in wound healing, treating burns, protection against skin damage, lung cancer, intestinal problems, increasing high density lipoprotein (HDL), reducing low density lipoprotein (LDL), reducing blood sugar in diabetics, fighting acquired immune deficiency syndrome (AIDS), allergies and improving immune system. Phytochemistry of aloe vera gel has revealed the presence of more than 200 bioactive compounds. Aloe vera gel is extracted from its leaves and appropriate processing techniques are needed for stabilization and preparation of the food products. Aloe vera gel products have become available in our country for internal consumption as a tonic and diversification in its products is on progress. The use of aloe vera has gained popularity because of herbal movement initiated by naturopaths, yog gurus, alternative medicine promoters and holistic healers. A recent market analysis report indicates that Americans have spent almost 40 billion dollars on functional foods, drinks and supplements for the improvement of their appearance as well as to provide energy and added nutrition to handle health issues such as hypercholesterolemia and diabetes.

8.1. Origin and distribution

• Indigenous to Eastern and Southern Africa, the Canary Islands and Spain.

• Spread to Mediterranean basin, West Indies, India, China.

• Also cultivated in India. It is the miracle plant.

8.2. Economic importance

• Source of drug aloe; aloe gel is a mixture of glucoside aloin, main constituent of atom is barbation.

• Commercially important species - A. barbadensis, A. ferox, A. africana and A. spicata

• Yellow bitter juice from leaves consists of aloin and gel.

• Other products - dehydrated aloe powder, concentrates.

Morphological characteristics

This plant is a large evergreen tree about 20 meters tall and 1.5–2.4 meters in girth with somewhat straight and fluted bole. Leaves are alternate 0.5-10 cm by 2-5 cm, oblong, lanceolate or elliptic, caudate, acuminate and glabrous with slender nerves. Venation is parallel. Petiole is 0.3-0.5 cm long. It is commercially used as fragrant and in prepation of drugs. The tree contains plenty of oleoresin and has irregular dark patches. The wood burns with a bright flame giving off pleasant smell.

Floral characteristics

Flowers are bisexual, white in colour, pedicillate, in both axillary and terminal umbellate cymes, shortly pedunculed, perianth, companulate, lobes 5 spreading and densely pilose. Pedicels is 0.5-0.8 cm long, slender. Perianth remains persistent in fruit and 1.3-1.5 cm long, silky densely villous, connate at the base. Stamens are 10, anthers 10 with subsessile disc. Ovary is subsessile, villous and two-celled. Stigma is large, subsessile. Fruit is capsular, 3-5 cm long, obovoid, pericarp coriaceous and densely tomentose. Seeds are ovoid with a long tail.

Distribution

The crop is found in parts of Bengal and North-Eastern States of India covering Assam, Meghalaya, Manipur, Mizoram, Arunachal Pradesh and Nagaland.

“Age and Area”: The hypothesis (by Willis) that the older a species is, the wider will be its geographical distribution.

A-Without; lacking.

A.I.: See active ingredient.

A.O.U. Code: A code of nomenclature published in 1885 (revised 1908) by the American Ornithologists’ Union for the standardization of bird nomenclature.

Ab-Away from; off.

Abnormal combustion: Combustion that does not proceed in the normal way, in which knock, pre-ignition, run-on or surface ignition occurs. Refer knock.

Abrasion: It is the surface discontinuity brought to any solid by the process of removal of surface material through friction of another solid, liquid or gas or combined thereof.

Absolute or specific humidity: It is the mass of water vapour present in a unit mass of dry air. It is also called as humidity ratio.

Absolute instrument: It is an instrument, which measures a quantity (such as pressure, temperature etc.) in absolute units by means of simple physical measurements on the instrument.

Absolute pressure: It is the actual pressure at a given position and it is measured relative to absolute vacuum (i.e., absolute zero pressure). Absolute pressure = pressure shown on the pressure gauge + atmospheric pressure. At sea level, atmospheric pressure is 14.7 psi (1.033kg/cm²).

Abattoir : An establishment where animals are butchered is known as abattoir. It is also known as slaughterhouse. 
Abiotic : Abiotic means any factor which is not biological / abiological and especially there is no involvement of the organisms in synthesis of certain compounds.

Abnormal milk: It is milk that is not smooth and homogenous but is flaky, ropy, stringy, slimy, watery, discoloured or bad flavoured.
 
Abrassive peeler: It is equipment comprising a rotating drum lined with carborandum (an abrasive material) in which certain vegetables like potato and ginger are tumbled and exposed to the abrasive action of the carborandum lining, thereby facilitating separation of peel from the vegetables (Plate 1).

Absinthe: It is green liquor which is flavored with wormwood, anise, and other aromatic herbs. Its commercial production is banned in many countries for health concerns.

A horizon: i) The surface soil horizon of a mineral soil having maximum organic matter accumulation, maximum biological activity or eluviation of materials such as iron, aluminium oxides and silicate clays. ii) A mineral horizon that formed at the surface or below an O horizon, obliterating all or much of the original rock structure and (a) characterized by an accumulation of humified organic matter intimately mixed with the mineral fraction and not dominated by properties characteristic of E horizon or B horizon. See also B horizon, C horizon.

Abatement: Refers to reducing the degree or intensity of greenhouse-gas emissions.

(+)sense RNA (plus-sense RNA)     :    A virus with a single-stranded RNA genome of the same polarity (‘sense’) as mrna.

Abiotic Factors : These are physical, chemical and other non-living components of the environment such as light, temperature, moisture, nutrients and other edaphic factors.
 
Absolute Drought : It is defined as a period of consecutive days none of which had rainfall of 2.5 mm or more OR when actual rainfall is less than twice the mean deviation OR actual rainfall is less than half the normal weekly rainfall.
 
Absolute Growth Rate : The rate of increase in size of a growing plant (or part of it) in a given time under specific growing conditions.

Absolute Humidity : Absolute humidity is defined as the actual mass of water vapour present in the given volume of air. It is measured in grams per cubic meter or in terms of partial pressure of water vapour in air in mb or mm.

Bacillus thuringiensis (Bt): Soil-inhabiting bacterium that produces an insecticide effective against larval stages of many species of Lepidoptera, although some strains are effective against various beetle, mosquito, and blackfly larvae.

Backcross: A cross between a hybrid and one of its parents; a cross between a heterozygote and a homozygote (cf. Hybridization, Heterozygous, Homozygous).

Bacterial insecticide: Bacteria pathogenic to insects (e.g., Bt or B. popilliae). Applied using application techniques also used for chemical pesticides.

Bacterium (pl. bacteria): Microscopic, prokaryotic, single-celled organisms having cell walls but lacking membrane-bound organelles. Important in decomposition, nitrogen fixation and other symbiosis, and as pathogens. A significant component of soil food webs.

Bait (B): A pesticide formulation that combines an edible or attractive substance with a small amount of toxic active ingredient (usually about 5%). Baits containing poisonous chemical and food stuffs are primarily offered to pests as food for control of animal pests like mollusks, cutworms, and rodents.

Babbitt: 1. A tin base alloy containing 88% tin, 8% antimony and 4% copper. 2. In machinery, to line, bush, fill or face with Babbitt metal, e.g. to babbit a bearing.

Back furrow: A raised ridge left at the centre of the strip of land when ploughing is started from centre to side. See Fig. 1B.

Backfire: The accidental explosion of an overly rich mixture in the exhaust manifold of a spark-ignition engine. Backfire conditions can also develop if the premature ignition occurs near the fuel intake valve and the resultant flame travels back into the induction system.

Backlash: The clearance or play between two parts, such as meshed gears.

B cell : It is one of the lymphocytes that have antigen-binding antibody molecules on the surface, that comprise the antibody-secreting plasma cells when mature, and that in mammals differentiate in the bone marrow. It is also called B lymphocyte.

B.T.U. : It stands for British thermal unit. The heat required to raise the temperature of one pond of the water through 1oF is called BTU.

Baby back ribs : Meaty pork ribs cut from the lower back rib section.

B.T.U.: It stands for British thermal unit. The heat required to raise the temperature of one pond of the water through 1^° F is called BTU.
Baby back ribs: Meaty pork ribs cut from the lower back rib section.

Bacitracin: A polypeptide antibiotic isolated from a bacillus (Bacillus subtilis or B. licheniformis) and usually used against gram-positive bacteria.

Back Bacon / Canadian bacon: Bacon cut from the loin that has little fat and is cut into round or oblong slices.

B horizon: i) A soil horizon that formed below an A horizon, E horizon, or O horizon, dominated by obliteration of all or much of the original rock structure and showing one or more of the following: a) illuvial concentration of silicate clay, iron, aluminium, humus, carbonates, gypsum, or silica, alone or in combination; b) evidence of removal of carbonates; c) residual concentration of sesquioxides; d) coatings of sesquioxides that make the horizon conspicuously lower in value, higher in chroma, or redder in hue than the overlying or underlying horizons without apparent illuviation of iron; e) alteration that forms silicate clay or liberates oxides, or both, that forms granular, blocky, or prismatic structure if volume changes accompany changes in moisture content; or f) brittleness. ii) A soil horizon usually beneath the a horizon that is characterized by one or more of the following: a) A concentration of silicate clays, iron and aluminium oxides, and humus, alone or in combination; b) a blocky or prismatic structure, and  c) coatings of iron and aluminium oxides that give darker, stronger or redder colour.

B    :    Born.     
B cell, also known as a B lymphocyte      :    One of the major types of cells in the immune system. B cells can differentiate to form memory cells or antibody-forming cells. OR A type of lymphocyte derived from bone marrow stem cells that matures into an immunologically competent cell under the influence of the bursa of Fabricius in the chicken and bone marrow in nonavian species. Following interaction with antigen, it becomes a plasma cell, which synthesizes and secretes antibody molecules involved in humoral immunity.

Back-Door Cold Front : A front moving south or southwest along the Atlantic seaboard of the United States.

Backing : A change in wind direction in a counterclockwise manner in the Northern Hemisphere and a clockwise manner in the Southern Hemisphere.
 
Ball Lightning : A rare form of lightning that may consist of a reddish, luminous ball of electricity or charged air.
 
Banner Cloud : A cloud extending downwind from an isolated mountain peak, often on an otherwise cloud-free day.
 
Bar : A unit of pressure, (usually the atmospheric pressure on) one is equivalent to a pressure of one million dynes per centimeter square one hundred kilopascals; 29.53 inches or 750 millimeters of mercury at zero degree Celsius.

Caecae: Saclike or tubular structures open at only one end (blind), often opening from the mid-intestine (Fig. 41).

Caecum (pl. caeca): A blind-ending tube or sac or pouch sac of the alimentary canal (L. caecus= blind) e.g., haepatic caecae in the alimentary canal of insects (Fig. 41).

Calamistrum: One or two rows of curved spines on the metatarsus of the hind legs (spiders; fig. 608, clm).

Calibration: The adujustment of application equipment so that a defined quantity of chemical or other material is applied per unit time or area.

Calling: A vergin female moth releasing sex pheromones to attract males for the purpose of mating.

Calliphorin: A protein produced in the fat body and stored in the haemolymph of larval Calliphoridae (Diptera).

Cable conveyor: A power conveyor in which a trolley runs on a flexible, torque transmitting cable that has helical threads.

Cable: 1. A general term applied to rope or chain used for engineering purposes. 2. The standard wire with insulating cover used for conducting electrical current.

Cage harrow: A rolling harrow with horizontal shafts each fitted with star shaped tines joined by rods forming the lines of cylinder.

C - enamel can : The sulphur resistant lacquer is golden coloured and the can coated with it are called C-enamel can or sulphure resistant can, used for packing non acid products.

CA storage : Storage of commodities under gaseous atmosphere like gas storage, where the composition of atmosphere is controlled accurately. MA and CA differ only in degree of control and CA is more exact. These storage methods in combination with refrigeration markedly enhance storage life of fruit and vegetables.

C - enamel can: The sulphur resistant lacquer is golden coloured and the can coated with it are called C-enamel can or sulphure resistant can, used for packing non acid products (Plate 35).

CA storage: Storage of commodities under gaseous atmosphere like gas storage, where the composition of atmosphere is controlled accurately. MA and CA differ only in degree of control and CA is more exact. These storage methods in combination with refrigeration markedly enhance storage life of fruit and vegetables (Plate 36).

C horizon: i) A horizon or layer, excluding hard bedrock, that is little affected by pedogenic processes and lacks properties of O, A, E, or B horizons —note the material of C horizons may be either like or unlike that from which the solum presumably formed. ii) A mineral horizon generally beneath the soil solum that is relatively unaffected by biological activity and pedogenesis and is lacking properties diagnostic of an a horizon or a b horizon. See also Soil horizon.

C    :    Cytosine.
C domains    :    The constant regions of the polypeptide chains of immunoglobulin molecules are made up of one or more constant domains or C domains of similar structure; each immunoglobulin chain also has a single variable or V domain.

C3 Plant : A plant in which the first product of CO₂ fixation is the 3-carbon compound; phosphoglyceric acid and is comparatively photosynthetically less efficient than C4 plants e.g. wheat, rice, barley etc. 
C4 Plant : A plant in which the first product of CO₂ fixation is the 4-carbon compound oxalo acetic acid (OAA) and is photosynthetically more efficient than C3 plants e.g. sugarcane, maize etc.
Calibration : Calibration with respect to models refers to the adjustments made to model parameters so as to give the most accurate comparison between simulated results and results obtained from field measurements. 
Calm : Absence of appreciable wind : On the Beaufort Scale of wind force calm is accorded the figure 0 and has a wind speed equivalent or less than 1 knot.

Dall code: A code of nomenclature prepared by W.H. Dall at the direction of the American Association for the Advancement of Science (1877).

Damage boundary: The level of injury where damage can be measured.

Damage threshold: Pest population above which crop loss occurs.

Damage: Measurable reduction in crop growth or yield; or a measurable loss of host utility, most often including yield quantity, quality, or aesthetic appeal.

Damping off: Infection of newly formed roots and stems of young seedlings by fungi or bacteria, typically at soil level, resulting in decay or seedling death.

Danger: A signal word used on pesticide labels to inform the user that the pesticide is highly toxic, as defined by FIFRA. The word poison and the skull and crossbones symbol always accompany the signal word danger.

Dah: A metal with handle used for cutting trees and cleaning jungle growth. See Fig.1D.

Dead axle (tractor trolley): An axle beam, which does not drive the road wheels. Usually refers to a rear axle which does not have any rotating parts within it, but on which the rear wheels are mounted with antifriction bearing.

Dead centre: 1. The centre, which is fitted into the tailstock of a lathe and does not rotate with the work. 2. The extreme top or bottom position of the crankshaft throw at which the piston is not moving in either direction.

Dead furrow: An open trench left in between two adjacent strips of land after finishing the ploughing operation. See Fig.1B

Dead weight: The weight of a vehicle or carrier itself as distinguished from carried or live load.

Dahi : It is the product obtained from pasteurized or boiled milk by souring, natural or by harmless lactic acid or other bacterial culture. It is also called Curd.
Daidzein : These are the substance from which daidzein is derived and are isoflavone C₁₅H₁₀O₄ found chiefly in legumes and esp. soybeans.
Dairy : It is a farm building often a single room in which milk is cooled and temporarily stored prior to collection for transportation to the commercial diary. Here the milk is treated and made into cream, butter and cheese. Or

Dahi: It is the product obtained from pasteurized or boiled milk by souring, natural or by harmless lactic acid or other bacterial culture. It is also called Curd (Plate 68)

Dairy: It is a room, building, or establishment where milk is kept and butter / cheese is made or it is the department of farming / farm that is concerned with the production of milk, butter, and cheese or an establishment for the sale / and distribution of milk and milk products.

Dabbling ducks: Duck species that principally feed in shallow water by “tipping up” or dabbling on the surface.
 
Damping off: i) The wilting of young seedlings by certain fungi that cause decay of stem, or roots. The major diseases of germinating seeds are grouped under the single name ‘damping off’. It is caused by a number of separate fungi, mainly species of Pythium, Rhizoctonia and Phytophthora. The disease is expressed either by the failure of seedling to emerge or by the death of the seedling shortly after emergence. Protection from this is to allow the surface of the soil to dry before doing additional watering. Sphagnum moss spread thinly over the soil surface is also effective in reducing damping off. ii) A term used to describe the action of parasitic soil fungi, which cause rotting of seedlings before or soon after germination. This can sometimes be avoided by adding sand to the soil mixture to improve drainage, thus preventing the fungi from multiplying rapidly, or by using fungicides. Eucalypts and pine species are particularly susceptible to damping off.

D gene segments, diversity gene segments     :    D gene segments, or diversity gene segments, are short DNA sequences that join the V and J gene segments in rearranged immunoglobulin heavy-chain genes and in T-cell receptor â and ä chain genes. See gene segments.    
D loop    :    An extended loop of single-stranded DNA displaced from a duplex structure by an oligonucleotide.

Daily Maximum Temperature : As per the IMD guidelines, the maximum temperature recorded in a 24 hour period at any given place or location.

Daily Mean Temperature : The average of the values observed during a day (at any regular intervals or maximum and minimum) of temperature.

Daily Minimum Temperature : As per the IMD guidelines, the minimum temperature recorded in a 24 hour period at any given place or location.

Daily Range of Temperature : The range of temperature (between maximum and minimum) recorded as per IMD guidelines in 24 hour period.

Early postemergence: The application of herbicide after plant emergence and during the initial growth phases of crop or weed seedlings.

EC: See emulsifiable concertrate.

Ecdysial cleavage lines: Preformed lines of weakness along which the shed cuticle of the cranium splits during ecdysis; cuticle in the region of these lines lacks the exocuticle (Fig. 100).

Ear plug: A device made of a pliable substance, which fits into the ear opening; used to protect an ear from excessive noise or from water.

Ear protector: A device, such as a plug or ear muff, used to protect the human ear from loud noise that may be injurious to hearing, such as that of jet engines.

Earned value: The budgeted cost of the work performed for a given project.

Earth moving: Tillage action and transport operations utilized to loosen, load, carry and unload the soil.

Earthmover: A machine used to excavate, transport, or push earth.

E numbers : Each food additive used in the food industry has been given a specific number code for their identification. These numbers are called as E numbers. These E numbers are used within the European Union. The word prefix “E” stands for Europe. They are commonly used on the food label through out the European Union. These are not used in Australia and New Zealand. The different food additives are given different E numbers depending upon the type of food additive like E100-E199 (food colours), E200-E299 (preservative), E300-E399 (antioxidants), E400-E499 (thickners, stabilizers, emulsifier), E500-E599 (pH regulator, anticaking agent), E600- E699 (flavour enhancers), E700-E799 (antibiotics), E900-E999 (miscellaneous like waxes, synthetic glazes, packaging gases, sweetners, foaming agents), and E1000-E1099 (additional chemicals).