Hybrid Domestic Cats

Food Resources: Crop Production System

Humans depend on plants and animals for food

Humans depend on plants and animals for food - Among all the living organisms, only green plants are autotrophs, i.e., they make their own food. By the process of photosynthesis, in which they use the energy of sunlight, green plants combine carbon dioxide (CO2) and water (h3O) to produce carbohydrates (food).

• In contrast to green plants, animals and human beings are heterotrophs, i.e., they depend on plants and other animals for food.
• All the parts of one or other plant, such as root, stem, leaf, flower and fruit, are consumed by humans in the form of cereals, vegetables, spices and fruits. Animals produce milk, butter, egg, meat, etc., which also supplement our food requirements.
• Since plants are our major source of food, so it becomes necessary to increase the production of crops to meet the food requirement of our population.
• Crops are plants grown in community on larger area.
• Agriculture is an applied science which deals with mass production of plants and animals useful to human beings, involving soil cultivation and breeding and management of crops and livestock.
• Successful crop production depends upon understanding of how crops develop and grow, how various factors affect the growth and development of crops and how each factor can be modified or managed.

• Nutrients as food for plants The food required by plants is composed of certain chemical elements, which are known as nutrients.
• Though plants absorb a large number of elements from its environment only following sixteen of these are found to be essential for the plant nutrition:

Carbon, Oxygen, Hydrogen, Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulphur, Iron, Manganese, Boron, Zinc, Copper, Molybdenum, Chlorine.

• Characteristics of an essential plant nutrient An element must fulfill the following requirements to be an essential plant nutrient:
1. In the absence of the element the plant is not able to complete its life cycle.
2. The deficiency of a particular element can be prevented or corrected only by supplying that nutrient.
3. The element must have a direct influence on the plant nutrition and metabolism.
• Sources of essential plant nutrients: There are three different sources from where a plant gets the 16 essential nutrients. These sources are air, water and soil. Plants get carbon and oxygen from air, hydrogen from water and rest of the nutrients from soil.

• Classification of nutrients On the basis of quantities required, the 13 nutrients needed for plant growth have been grouped into following two classes:
1. Macronutrients The essential elements, which are utilized by plants relatively in large quantities, are called major nutrients or macronutrients. These are Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulphur.

Of these six macronutrients only nitrogen, phosphorus and potassium (i.e., N, P, K) are required by plants in greater amounts, they are called primary elements or primary nutrients.

1. Micronutrients The essential elements which are used by plants in small quantities (or traces) are called minor nutrients or micronutrients. These are Iron, Manganese, Boron, Zinc, Copper, Molybdenum, Chlorine.

• Mode of intake of thirteen essential nutrients by the plants
• The 13 soil nutrients remain dissolved in water. They are absorbed by roots of the plants from the soil. Since soil contains a large number of elements essential for the growth of plants, so soil forms the most important reservoir of plant nutrients. The most important nutrients required for plant growth are nitrogen, phosphorus and potassium (NPK).

• Manures and Fertilizers The deficiency of plant nutrients and organic matter in the soil is made up by adding manures and fertilizers to the soil of crop fields. Both manures and fertilizers are major sources of nutrients of plants, so they are used in crop production.
• Manures Manures are natural fertilizers. They are bulky sources of organic matter which supply nutrients in small quantities but organic matter in large quantities.
• Manures include farmyard manure (FYM), compost, green manures, vermicompost, etc.
• Advantages of manures: Manures affect the soil in following three ways.

1. The manures enrich the soil with nutrients. They replenish the general deficiency of nutrients in the soil. Since manures contain nutrients in small quantities, they are needed to be applied in large quantities.
1. The manures add organic matter (called humus) to the soil which restores the soil texture for better retention of water and for aeration of soil. For example, organic matter present in the manures increases the water holding capacity in sandy soils and drainage in clayey soil.
2. The organic matter of manures provides food for the soil organisms (decomposers such as bacteria, fungi, etc.) which help in making nutrients available to plants.

• Thus, organic manures help to improve the physical properties of soil, reduce soil erosion, increase the moisture holding capacity of soil and above all they are low cost nutrient carriers.

• Disadvantages of manures

1. Manures are bulky with low nutrient content.
1. The nutrients of manures are released slowly, not keeping pace with the high and rapid demand of nutrients by improved high yielding hybrid varieties of crops.
2. Being bulky and voluminous, they are inconvenient to handle, store and transport.
3. Moreover, a manure is not nutrient specific and hence it is not much useful when a particular nutrient is required in the soil for a particular crop.

• Types of manures

1. Farmyard manure (FYM) FYM is the decomposed mixture of cattle excreta (dung) and urine along with litter (i.e. bedding material used in night under cattles) and left over organic matter such as roughage or fodder. These waste materials are collected daily from the cattle shed and stored in a pit for decomposition by the microbes (bacteria, fungi, etc.). FYM contains nitrogen, phosphorus and potassium. Thus, a well decomposed farmyard manure contains about 0.5 per cent nitrogen (N), 0.2 per cent phosphorus pentaoxide (P2O5) and 0.5 per cent potassium monoxide (K2O).
2. Compost Compost is prepared from farm and town refuse such as vegetable and animal refuse (e.g., excreta of domestic animals such as cattle, goat, sheep, horse, donkey, camel, dogs, cats, etc.), faecal matter of human beings, sewage waste, weeds, crop stubble, straw, rice hulls, forest litter, etc. Composting is a biological process in which both aerobic (organisms requiring the presence of oxygen for the respiration) and anaerobic (organisms, in which respiration takes place in the absence of oxygen) microorganisms decompose the organic matter. It takes about 3 to 6 months for decomposition of organic refuse.

Method of preparing compost For the preparation of compost, a trench of suitable size 4 to 5 m long, 1.5 to 1.8 m broad and 1.0 to 1.8 m deep is dug. A layer of well mixed refuse of about 30 cm thickness is spread in the trench. This layer is well moistened by slurry (water paste) of cattle dung and water or earth and water. A second layer of mixed refuse is spread in trench till the heap rises to a height of 45 to 60 cm above ground level. The top of this heap is then covered with a thin layer of moist earth. After three months, the partially decomposed biomass is taken out of the trench and collected in conical heap. This heap is moistened if necessary and covered with earth. After another one or two months, the compost is ready for use in the field.

1. Green manuring The practice of green manuring includes growing, turning or ploughing and mixing of green crops with soil to improve physical structure and soil fertility. Green manures may include both leguminous and non leguminous plants, e.g., Sannhemp (Crotolaria juncea), Egyptian clover (Berseem, Trifolium alexandrium), Sesbania or Dhaincha (Sesbania aculeate) and cluster bean or Guar (Cyamopsis tetragonoloba). These plants are used by Indian farmers to add nitrogen and organic matter to the soil for the improvement of crop yield. The green manure crops are grown in the field for about 6 to 8 weeks and turned into field in the tender stage, i.e., at flowering stage. These crops remain buried for about one to two months. During this period, plants should be completely decomposed before sowing of next crop. Generally the crops which require high nutrient input, are raised in the green manured field. Such crops are rice, maize, sugarcane, cotton, wheat, etc.

• Fertilizers Fertilizers are the sources of plant nutrients, manufactured commercially from chemicals. They contain much higher amount of nutrients in comparison to the manures and are, therefore, used in very small quantities. These fertilizers may supply one or more nutrients. Chemically they may be inorganic compounds (e.g. ammonium sulphate) or organic compounds (e.g. urea).

• On the basis of the availability of nutrients from them, fertilizers are divided into following four groups:

1. Nitrogenous fertilizers These fertilizers supply the macronutrient nitrogen. e.g. Urea, CO(Nh3)2, Ammonium sulphate, (NH4)2SO4, Calcium ammonium nitrate, Sodium nitrate, NaNO3, Ammonium nitrate, NH4NO3.
1. Phosphatic fertilizers They are the source of the macronutrient phosphorus. e.g. Single superphosphate, Triple superphosphate, Dicalcium phosphate.
2. Potassic fertilizers These fertilizers supply potassium to the plants. e.g. Muriate of potash or potassium chloride, KCl, Potassium sulphate, K2SO4, Potassium nitrate, KNO3.
3. Complex fertilizers When a fertilizer contains at least two or more nutrients (N, P2O5 and K2O), it is called complex fertilizer. e.g. Nitrophosphate, Ammonium phosphate, Urea ammonium phosphate.

• Modern agriculture depends greatly on the chemical fertilizers. High doses of these chemicals greatly increase crop yield but then chemicals get washed off through irrigation, rain fall as drainage and reach rivers, lakes, streams and pollute them (by causing toxicity, algal bloom and eutrophication) disturbing the ecosystem. The water of these water bodies becomes unfit for human consumption and even kills the aquatic animals such as fishes. So chemical fertilizers must be used carefully and judiciously.

• Differences between manure and fertilizer:

Manure

Fertilizer

A manure is a natural substance. It is obtained by the decomposition of animal wastes such as dung (gobar) of cattle and buffaloes and plant residues. A manure contains small amounts of essential plant nutrients such as nitrogen, phosphorus and potassium. A manure adds a great amount of organic matter in the form of humus in the soil. Nutrients present in the manure are absorbed slowly by the crop plants since manure is not soluble in water. Nutrients exist locked inside the organic compounds of humus. A manure is not nutrient specific and it tends to remove the general deficiency of the soil. A manure is voluminous and bulky so it is inconvenient to store, transport, handle and apply to the crop. A manure is cheap and is prepared in rural homes or fields.

A fertilizer is a human made substance. It is an inorganic salt or an organic compound. Fertilizers are very rich in plant nutrients such as nitrogen, phosphorus and potassium. A fertilizer does not add any humus to the soil. Being soluble in water, a fertilizer is readily absorbed by the crop plants. A fertilizer is nutrient specific. It can provide specifically nitrogen, phosphorus and potassium to the soil according to the need. A fertilizer is compact and concentrated so it is easy to store, transport and apply to the corp. A fertilizer is costly and is prepared in factories.

• Biofertilizers Organisms which enrich the soil with nutrients are called biofertilizers.
• Biofertilizers are used for the specific crop plants such as pulses, legumes, oil seeds and rice.
• Biofertilizers are renewable and non pollutant sources of plant nutrients such as nitrogen. They are not alternatives to chemical fertilizers but can play a supplementary role in supplying nitrogen to specific crops under specific soil conditions.
• Nitrogen fixing micro organisms, i.e., non symbiotic and symbiotic cyanobacteria and phosphate solubilising micro organism, are the main type of biofertilizers that are being used in India. Recently, two biofertilizers, namely Rhizobium cultures and blue green algae (such as Anabaena and Nostoc) have gained popularity amongst farmers cultivating pulses, legumes, oil seeds and wet land rice.

• Water Water is a key input for crop production. Water is one of the most vital substance which supports life of living organisms such as plants, animals and humans.
• The process of supplying water to crop plants of the crop fields by means of canals, reservoirs, wells, etc., is known as irrigation. Irrigation is necessary for the survival and proper development of the crop plants.
• In agriculture irrigation fulfils the following goals:

1. Crop plants are irrigated with freshwater to supply two essential elements to them, hydrogen and oxygen. Both of these elements are present in water molecules and are necessary for growth and development of crop plants.
1. Irrigation of crop fields is necessary to provide sufficient moisture for the germination of seeds. This is because seeds do not germinate in dry soils.
2. Irrigation of crop plants is essential for the growth and elongation of the roots of the crop plants. This is because roots of crop plants fail to develop and elongate in dry soil.
3. Irrigation of crops is necessary to increase the number of aerial branches (called tillers) in crop plants so as to get good crop yield. This is because, the number of tillers (aerial branches in cereals), get reduced in a dry soil which leads to loss in the crop yield.
4. Irrigation is essential for the absorption of nutrient elements by the crop plants from the soil. The irrigation water tends to dissolve the nutrients present in the soil of a crop field to form a solution. This solution of nutrients is then absorbed by the roots of crops for the development of the plants.

• India has enormous surface water resource. Ground water also contributes significantly to total water resources of India. Ground is replenished from the rainfall. In fact, more than 55 per cent of cropped areas of India do not have irrigation facilities and depend on rainfall for crop production.

• Water is a precious natural resource. It should be used in irrigation by exploiting proper techniques of soil and water management.
• By adopting the following methods, the efficiency of irrigation water can be increased:

1. Selection of right crop and cropping
1. Application of optimum quantity of water at correct time
2. Keeping of weeds under control
3. Time table based operation
4. Pest control

• The irrigation or water requirements of crop plants depends on the following two factors:

1. Nature of crop plants Water requirement of different crops is different during the various stages of growth and maturation (ripening). Some crop plants require more water while others requires less water. e.g. paddy is transplanted in standing water and requires continuous water supply whereas wheat, gram, cotton, etc. require less water. For cereals such as wheat, irrigation is required before ploughing the field, at the time of flowering and at the time of development of the grain.

• The correct timing of irrigation is very important for getting a good crop yield. For example, if the irrigation of wheat is done when the wheat crop is fully matured or if there is heavy rain during the harvesting season, then the wheat plants remain unable to resist strong winds and they fall on the ground. The falling of mature crop plants in the field which have been affected by untimely irrigation or rain, due to the action of strong winds is called lodging. Lodging reduces both, the quality and quantity of wheat grains as well as that of straw. In such drastic situations, the excess of water present in the field should be drained off immediately through a proper drainage system to save the crop from damage. Excessive irrigation results in wastage of precious irrigation water, water logging and increment of soil salinity.

1. Nature of soil Irrigation also depends on the nature of the soil in which crop is grown. The crops grown in a sandy soil need irrigation more frequently, whereas the frequency of irrigation is comparatively less for crops grown in a clayey soil. Sandy soil is highly porous having high permeability. When the crop plants standing in a sandy soil are irrigated, then water quickly percolates down the soil and the crop plants are not able to absorb adequate amounts of water. So, due to poor water retaining capacity of the sandy soil the crops cultivated in sandy soil need more frequent irrigation. In contrast to sandy soil, clayey soil is much less permeable, so it can retain water for a much longer time. So, when the crops grown in a clayey soil are irrigated, the water persists in the soil for a longer time and as a consequence plants grown in clayey soil can absorb this water in adequate amount. Thus, due to good water retaining capacity of the clayey soil, the crops cultivated in clayey soil need irrigation less frequently.

• Harms of excessive irrigation: Crop fields should be irrigated with just the right amounts of water, since, excessive irrigation water may cause the following type of damages:

1. Too much water in soil retards the process of germination of seeds. If it rains soon after the sowing of seeds in the field, due to presence of excess water the seeds fail to germinate. This occurs because seeds which are submerged in water fail to get sufficient atmospheric oxygen for their respiration.
2. Except the roots of paddy, roots of crop plants do not grow properly when there is standing water in the field, as they fail to get sufficient air for breathing.
3. Excess of irrigation water cause salinisation of soils of crop fields and result in destruction of standing crop. Prolonged water logging (i.e., standing water) in the crop field increases the amount of salt on the surface of soil due to excessive evaporation. Such accumulation of salt (carbonates and bicarbonates of sodium having high pH) damages the soil fertility and reduces the crop growth.

• Irrigation systems Some most commonly used irrigation systems are:

1. Canal system In canal system the human made canals receive water from one or two reservoirs or from rivers. This is usually an elaborate and extensive irrigation system. Thus, main canal is distributed into branch canals and branch canals further have distributaries or field channels. Finally these unlined field channels may serve individual fields or a group of field. Each field or group of fields are given water by rotation.
2. Tanks Tanks are small storage reservoirs, which catch and store the runoff of smaller catchment areas. Small dams are built below the higher elevations of the catchment areas. In the tanks, outflows are controlled according to the availability of water. Otherwise it causes an uneven distribution of water. The main drawback of uneven distribution of irrigation water is that it causes shortage of water at tail end and excessive use at the top.
3. Wells Wells are constructed wherever exploitable ground water is present. Wells are of two types:

1. Dug wells In the dug wells, the water is collected from water bearing strata. The dug wells have their bottom below the ground water table. The water from the shallow strata slowly accumulates in the pit. From these wells, water is lifted by mechanical means, e.g., bullock operated devices.

1. Tube wells A tube well can tap water from the deeper strata. From these wells, water is lifted by diesel or electricity run pumps. Deep bore tube well can supply water continuously for many years.
1. River valley system In southern part of India, particularly in Western Ghats in Karnataka and Kerala, many steep and narrow riverine valleys are found. In these parts of India, the rainfall is heavy but concentrated in four or five months period of the year. This is followed by drying up during the rabi reason. On the slopes of these valleys and in the valleys perennial plants such as coconuts, areca nuts (supari), coffee, rubber and tapioca are cultivated. The bottom lands of the valleys are used for growing a single rice crop.
2. River lift system In the areas where canal flow is inadequate or irregular due to insufficient reservoir release, the lift system of irrigation is used. In lift system, water is directly drawn from the river for supplementing irrigation in the area near to rivers.

• Crop protection Field crops are infested with a variety of pests. A pest is any destructive organism which causes great economic loss by destroying crop plants or products obtained from them.
• Pests of crop plants include weeds, insects, mites, nematodes, rodents, fungi, bacteria and viruses.
• There are various methods by which insects and diseases can be controlled. One of the most common and effective methods is the use of pesticides or biocides which include insecticides (for killing the insects), weedicides (for killing the weeds) and fungicides (for killing the fungi). Thus, chemicals used to kill pests, e.g., weeds, insects, mites, rodents and fungi are called pesticides. The pesticides are sprayed on crop plants or used for treating seed and soil.
• It would be far better if we adopt the preventive measures rather than allowing the crops to be infested by pests and then control them by pesticides.
• Some of the preventive measures of pests are:

1. Use of resistant varieties of crop plants
1. Selection of optimum time of sowing the crops
2. Crop rotation and multiple cropping
3. Clean cultivation
4. Summer ploughing

• Insect pest control Many insects are serious pests of plants. They attack all stages, parts and products of plants. Insects attack the crop plants in the following three ways:

1. The chewing insects destroy all sort of crop plants. They cut root, stem and leaf of crop plants by the help of their chewing mouth parts. e.g., locusts, grasshoppers, caterpillars, etc.
2. The sucking insects suck the cell sap from various parts of the plant. e.g. aphids, leaf hoppers, plant bugs, etc.
3. The internal feeders live inside the plant part and destroy them, e.g. pod borers make holes in pods of chick pea and feed on developing grain.

• Infestation of different types of insect pests can be controlled by the following methods:

1. Root cutting types of insect pests can be controlled by mixing insecticide in soil.
2. Stem and leaf cutting and boring type of insects are controlled by dusting or spraying the contact insecticides, e.g., malathion, lindane and thiodan.
3. All sap sucking insects can be controlled by spraying systemic insecticides e.g., dimethoate.

• Disease control Our environment contains a variety of pathogens. When they get favourable conditions for their growth and propagation, they spread and infest the crop plants causing diseases. Depending upon their mode of occurrence, crop diseases are of four main types:

1. Seed borne diseases are spread through seed.
2. Soil borne diseases are spread through the soil and mostly affects roots and stems of crop plants.
3. Air borne diseases are transmitted by the air and attack all the aerial parts of the plant.
4. Water borne diseases are transmitted by the water.

• Control of crop diseases All the seed and soil borne diseases can be controlled by treating the seed or soil. Air borne diseases are controlled by spraying fungicide solution on infested parts.

• Weed control The small sized unwanted plants which grow with a cultivated crop in a field are called weeds
• The growth of weeds in the crop fields is harmful because they consume a great amount of nutrients, water, sunlight and space which are meant for the crop plants.
• Growth of weeds tends to reduce the crop yield and lower the quality of food grains.
• The weed may be a crop plant or plant of another variety of same crop. Thus, barley or mustard plant in wheat field and plants of tall variety of wheat in the field of dwarf variety are also regarded weeds because they have grown out of place.
• The weeds also harbour pests and spread crop pests and crop diseases, since they act as alternate host to insects and microorganisms.
• Infestation of weeds is more during kharif season than in rabi season.
• Some types of weeds produce toxic substances which may interfere with crop growth or which may poison the crop produce.

• Types of weeds Based on the morphology of plants, weeds can be classified into narrow leaf weeds and broad leaf weeds.

1. Important kharif season weeds are:

1. Narrow leaf: nutrgrass, wild sorghum.
2. Broad leaf: chaulai, saathi.

1. Important rabi season weeds are:

1. Narrow leaf: mandoosi, jangli jau.

1. Broad leaf: bathua, hirankhuri.

• Methods of weed control Weeds can be controlled by following methods:
1. Mechanical methods These include uprooting, weeding with trowel or khurpi or harrow (a comb like implement), hand hoeing (scraping), interculture, ploughing, burning and flooding.
• The process of removing the weeds from crop field is called weeding.
• Weeding can be done by the following methods: (a) Weeds may be pulled out with hand. Ploughing helps in removing large number of the weeds because it uproots majority of them. (b) Before sowing or transplantation, weeds are removed by using a big comb like harrow. Harrow cannot be used in standing crops because it will also uproot the crop plants. The weeds which appear during the growth of crop plants are removed manually by using a trowel (khurpa).
2. Cultural methods They include proper bed preparation, timely sowing of crops, intercropping and crop rotation.
3. Chemical methods In this, chemical weed killers, called herbicides or weedicides, are sprayed on weeds to destroy them. Some common examples of weedicides are 2, 4 D (2, 4 Dichlorophenoxy acetic acid), atrazine, fluchloralin, isoproturon, etc.
4. Biological methods Biological control of weeds involves the deliberate use of insects or some other organisms which consume and specifically destroy the weed plants. The best Indian example of biological control is eradication of prickly pear cactus (Opuntia) by using the cochineal insects in Maharashtra and Tamil Nadu. Aquatic weeds are controlled by the fish grass carp.
• Generally, a combination of one or more of these weed control methods are employed to get good results.

• Scientific storage of grains Most crops are harvested only once a year. Thus, they are available in plenty during a selective time. For getting seasonal foods regularly throughout the year, they are stored in safe storage.
• Cereals or food grains are stored at following three levels:

(a) at producer (farmer) level (called rural storage),

(b) at traders level (this is done by keeping food grains in gunny bags),

(c) at FCI (Food Corporation of India) level, (This is done by storing grains in silos).

• During storage damage of grains can take place by following two main types of factors:

1. Biotic factors such as insects, rodents, birds, mites and bacteria.
2. Abiotic factors such as moisture content and temperature.
1. Effect of temperature As the maximum growth rate of insects and activity of microorganisms and enzymes is at higher temperatures (30 - 40C), the food grains / materials should be stored at lower temperature (below 30C). Then, the insects, microorganisms and enzymes will become less active and the damage of materials will be minimized.
1. Effect of moisture The greater amount of moisture present in food grains increases the rate of decay of food materials caused by microorganisms and enzymes and increases the population of insects. More moisture also increases the size of food grains due to which they require more space.
2. Effect of humidity Humidity promotes the growth of moulds on the stored food materials. It also initiates the germination process of stored seeds.

• Combination of biotic and abiotic factors causes infestation of insects, degradation in quality, loss in weight, poor germinability, discolouration of produce, poor marketability and economic loss. Therefore stored grains must be protected from all types of losses and damages.

• Preventive measures Following preventive measures are taken before grains are stored for future use:
1. Drying At the time of harvesting of the crops, moisture content in grains and seeds varies from 15 to 35 per cent. In addition, grains and seeds have the tendency of absorbing moisture from the atmosphere. Moisture content in the grains and seeds play a vital role in determining their fate:

1. When there is a greater amount of moisture in grains, it tends to increase the rate of decay of food materials. The decay is caused by microorganisms (fungi) and enzymes present in grains.
2. High moisture content of grains promotes infestation of pests (fungi, insects) and decreases the quality of the product.

• Therefore, it is recommended that for safe storage of seeds and grains their moisture content should be brought below 9 per cent. This can be achieved by proper drying of the produce in sun followed by drying in shade. For drying, seeds and grains should be spread in thin layer on cemented floor. On commercial scale, however, mechanical drier with hot air blowing process can also be used.

1. Maintenance of hygiene This involves the following measures:
1. Godowns, warehouses and stores should be properly cleaned. All types of dust, dirt, rubbish, webbing or refuse of the previous grain should be swept.
2. Cracks and holes in the wall, floor or ceiling of stores should be sealed.
3. If possible, new gunny bags should be used for storing grains because old dirty gunny bags may carry some insects, pests or microorganisms which can spoil fresh stock of grains.
4. If old gunny bags are being used, then clean them properly. Turn them inside out, wash with boiled water and expose to bright sunlight for drying. Such old bags may be fumigated.
5. Earthen pots should be cleaned and properly exposed to sun before using them for grain storage.
6. The grain should be clean, cool and dry.
7. After filling, the mouth of gunny bags should be stitched tightly.
8. The grain filled gunny bags should be kept in godowns in such a way that they should not touch the walls of godowns. They should have some gap from the walls, otherwise they will catch the moisture.
9. Pathways should be provided between the stacks of grain filled bags, for the periodic inspection, for spraying or for fumigation.
2. Prophylactic treatment Warehouse or godowns should be treated with chemical spray, dust or fumigation. Bags should be treated with suitable insecticide. Grains to be used for seed purpose can be mixed with insecticide and fungicide.
3. Improved storage structures Improved storage structures should be used for safe storage of grains and seeds. In these structures, moisture, temperature, oxygen and carbon dioxide can be manipulated for protecting the produce. Various research organizations have developed a variety of improved storage structures such as Pusa bin, Pusa cubicle, Pusa kothar and Pant kuthala. All these structures are air tight, moisture impervious, thermally insulated and rodent proof. In fact, in these storage structures, the produce is not affected by change in weather outside them.
• For the large scale storage of grains, the grain silos are also used. The silos are big and tall cylindrical structures. They store different stocks of food items at different levels. Silos are provided with outlets at different levels to withdraw the desired stock of grains. They have built in arrangement for aeration, temperature control, protection from insects, rats, birds and mammals, fumigation and inspection of its grain stocks.
• Other advantages of storing grains in bulk (in silos) are greater storage capacity per unit of volume of space, lesser difficulty in loading and unloading, involvement of no cost for purchasing the gunny bags and infestation is comparatively less.

• Control measures against pests attacking stored grains The grains, which are meant for human or animal consumption, should be exposed to sun or fumigated. For them, mixing of insecticide is not proper. However, seeds should be treated with insecticides for avoiding any chance of their insect infestation.
• Following techniques of chemical control are used for checking pest infestation of stored produce:

1. Chemical control Insecticides can be applied by spraying method on the stored grains. In spraying method, the solution of insecticides is sprayed over the gummy bags containing food grains by manual sprayer or mechanical sprayer. In this method only the outer layer of grains (which is packed in the gunny bags) gets sprayed. Thus, spray of gammaxene or benzene hexachloride wettable powder (BHC WP), pyrethrum and malathion at 3 weeks interval may be done for the treatment of the surface area of the store house.
2. Fumigation Chemicals which can exist in gaseous state in sufficient concentration to be lethal against the pest are known as fumigants. In fumigation method the insecticide solution is converted into fumes to kill the insects. These fumigants occur in following three states:

1. Liquid, e.g., ethylene dibromide (EDB), ethylene dichloride plus carbon tetrachloride (E.D.C.T.)

1. Solid, e.g., aluminium phosphide (AlP)
2. Gaseous, e.g., methyl bromide (CH3Br)

1. Plant products The practice of adding a small quantity of vegetable oil or mineral oil to grains of legumes to protect them from insects is very common. The treatment prevents laying of eggs, reduction in egg hatching, interference with larvae development, so that only a few insects are able to hatch to become adults. Mixing of neem kernel powder, crushed dried fruit of black pepper or cloves is also effective in controlling insects.

• Precautions for handling pesticides All the pesticides are poisonous to some extent to human beings, domestic animals and pets. So, a great care should be taken in the storage, application and disposing off the left overs.
1. Precautions for storage of pesticides:
1. A pesticide should always be stored under lock and key, away from the living rooms and reach of the children.
2. Pesticides should never be kept in the kitchen or near any other food item.
3. Pesticide container should be clearly labeled and their lid should be tightly closed.
4. Pesticides should be stored in a cool, dry and dark place.
2. Precautions for applying pesticides:
1. Before using the pesticides, one should always wear gloves.
2. One should open the pesticide container carefully, keeping his/her face away.
3. One should check the spraying equipment or machine, etc.
4. One should not blow, suck, or apply mouth to any sprinkler, nozzle or other equipment.
5. If possible, ones face should be covered with a suitable mask, arms and legs should be covered with proper clothes, e.g., gloves, rubber boots, etc.
6. There should not be smoking, drinking or eating during the spraying of pesticides to minimize the inhalation of mist or dust of pesticide.
7. One should not spray pesticides against the wind in open fields.
8. Only required amount of pesticide should be used.
9. If, by mistake, the pesticide solution spills on ones clothes, then the clothes should be changed immediately.
10. If at any time, the pesticide spray happens to get into the eyes, then one should flush the eyes with plenty of fresh water and he/she should consult the doctor.
11. In case pesticides are inhaled or consumed accidently, a doctor should be called and proper care should be taken against the patient at once.
12. One should always keep ready the first aid box.
3. Precautions after spraying stage:
1. After spraying a pesticide, its empty container should be destroyed.
2. Before the use of vessels such as buckets, mugs, etc. which have been used for preparing pesticide solution should be washed thoroughly 3 or 4 times with soap and water.
3. After the spraying is over one should have a bath, if not possible, wash face and hands properly.
4. The clothes worn during the spraying should be well washed with soap and water before using again.
5. If a person feels headache, nausea and vomiting after the spraying, he should immediately rush to a doctor.