• Insects in stored grain can cause much damage. The farmer may lose up to a third of the stored grain. 
• Large scale storage of grains is done in silos and granaries to protect them from pests like rats and insects.

• Storage of food crops is an important step of agricultural practices as harvesting because if the grains are not stored properly it may get spoilt or attacked by insects or rats or microorganisms. 
• Large scale storage of grains is done in granaries or silo. Farmers store their dried grains in jute bags or metallic bins. 

Heating of stored grains results due to the high moisture content in the grains. The grains heat up the water content present in the grain due to thier pre existing temperature which attracts more moisture leading to the growth of microbes in the grains or germinate the seeds thus destroying the yield. 

Most important aspect of agriculture is proper storage of harvested grains and other agricultural produce. Proper storage is necessary to get seasonal foods regularly throughout the year. The godowns and stores should be properly clean, storage bags should be fumigated or treated with insecticides or pesticides. In India, the loss due to improper storage of grains is about 9% annually. So, the correct answer is 'All of the above'.

Food can be spoiled when temperatures are not controlled because high temperature give way for the growth of bacteria and excessive heat increases the rate of enzyme reactions. Exposing food to clod temperature also damages the food.

Neem oil is mainly used to prevent the pests at home. Neem leaves help in stopping the growth of pests. It kills larvae and locusts at homes. Mosquitos die when neem extract is sprayed.

The grains are stored in huge stores and warehouses. These stores and warehouses should be regularly and strictly cleaned, disinfected and kept dry to avoid ants, insects, worms or rodents infestations and keep the grains safe and hygienic for consumption at any time. There should be proper space or be disjoining between the grain sacks for fumigation and regular inspection of the grains The grains are stored in mass scale in huge chambers called silos. the silos have a proper outlet to withdraw the desired quantity of grains.The silos have built-in arrangements for aeration, fumigation, protection from rodents, insects and bird etc. Thus all three options strict cleaning, proper disjoining and fumigation is equally important for the storage of grains.

If the freshly harvested grains are not dried, it might contain moisture and moisture provide growth media for various organisms like molds. Drying will delay the spoilage of the grains.
Thus, the correct answer is option A.

Aspergillus consists of several hundred mould species found in various climates worldwide. Aspergillus is highly aerobic and are found in almost all oxygen rich environments. The storage grain produces aflatoxin due to growth of Aspergillus which can cause acute liver damage and cancer.

Eichhornia crassipes (water hyacinth) is the world's most problematic aquatic weed, also called "Terror of Bengal". Because of its very high rate of growth, it can cover the surface of whole water bodies, choke them and cause a threat to other aquatic life forms.

Prey species have evolved various defenses to lessen the impact depredation. For pant, herbivores are the predators plants have evolved an astonishing verity of morphological and chemical defense against herbivores. Calotropis produces highly see any cattle or goat browsing on this plant. A wide variety of chemical substance that we extract from plants on a commercial scale (nicotine, caffeine, quinine, strychnine, opium, etc.) are produced by them actually as defenses against grazers and browsers. So, the correct answer is 'The plant produces cardiac glycosides'.

Native to South America, Lantana camara was brought to India by the British as ornamental plants, possibly as long as 200 years ago. Forest officials in different parts of the country have watched helplessly as the invasive plant has spread, and efforts to contain it have gone largely in vain.

Weeds can be defined as the unwanted plants that grow in the field and harm the desired crops. Parthenium is the flowering plant which can cause an allergy is the most important weed of corn and wheat field. Xanthium is the ruderal weed of maize. Cyperinus is the most invasive weed found throughout the world. It is the weed of rice field. 

Weeds are the unwanted or undesirable plants as they compete with desirable crops in the field for nutrients, sunlight and interfere with the growth of crops.

Herbicides are chemical which control weeds. These are also called as weedicides. Glufosinate ammonium is a broad spectrum herbicides. A 2,4-D (2,4-Dichlorophenoxyacetic acid) is a plant hormone that acts as herbicide. It kills the broadleaf weeds that harm the plants by causing uncontrolled growth in them.

Removal of weed (or weeding) is done before weeds flower because if they flower they will also produce seeds and finally result in the dispersal of the seeds which makes it difficult to control the weeds because each seed will produce a new weed plant.

A weed is a wild plant that grows in an unwanted region and is a competition to cultivated plants. They are also known as invasive plants. Weeds typically produce a large number of seeds and propagate enormously. They are highly competitive, persistent, pernicious and may interfere negatively with human activities. It may have good properties also. But the undesirable properties outweigh the desirable properties at a given place. 

Auxins have a cardinal role in the coordination of many growths and behavioral processes in the plant's life cycle and are essential for plant body development. So the correct option is ' Auxin'.

Weeds are unwanted plants which grow along with the crop plants in the cultivated field. Some common weeds in India are Amaranthus (Chaulai), Parthenium (Gajar ghas), Cyperus rotundus (Motha), Chenopodium (Bathua), Xanthium (Gokhroo). Weeds compete with the crop plants for nutrients, space, light and water. This results in lowering the food grain quality and reduction in crop yield. Weeds may produce toxic substances which may interfere with crop growth. During harvesting, weeds get mixed up with crops to lower down its quality.

So, the correct answer is 'Weeds'.

The growth of weeds can be controlled by the following methods:

Weeding is necessary since weeds compete with the crop plants for water, nutrients, space and light. Thus, they affect the growth of the crop. Some weeds interfere even in harvesting and may be poisonous for animals and human beings. 

Any plant not sown in the field by the farmer and grow where it is not wanted is called a weed. 

• A weed can be defined as any plant that requires some form of action to reduce its effect on the economy, the environment, human health, and amenity. 
• Weeds compete with crops for space, nutrients, water, and light. Smaller, slower-growing seedlings are more susceptible than those that are larger and more vigorous. 

Weeds are the undesirable plants that are not cultivated. They are the plants at the wrong place. They compete with the crop for nutrients and space. Hence, they are harmful to the crop. These weeds can be controlled by using weedicides.

The unwanted plants which grow in field along with the crop plants are termed as weed. They are harmful for the crops as they compete for nutrients with them.

Insecticides and pesticides are used to kill the insects and the pest that harm the crops . While biofetilizers are the manure (contains living microorganisms) . On the other hand , weedicides are used to kill the weeds .

The unwanted plants in a crop field are known as weeds. These compete with the crop plants in the field for nutrition, hence hampering their growth. 

Some seeds are capable of withstanding exposure to low temperature (-10C to -20C). Some of properly dried seeds can withstand low temperature of even liquid nitrogen (- 196C). This reduces respiration and enzymatic activity to bare minimum which is required for sustaining the living of the seeds. Samples of the seeds are periodically tested for germination ability.

Malathion is an organophosphate and an acetyl cholinestrase inhibitor that is strictly used as a topical pediculicide.

Eichhornia crassipes , commonly known as water hyacinth , is an aquatic plant native to Amazon basin, known for it's highly problematic invasion outside it's native range. It forms dense mats in the water bodies, which causes the reduction in the oxygen for other organisms in the water body .

Weeds can be defined as the unwanted plants that are grown in the field and harm the desired crops. Cyperinus is the most invasive weed found throughout the world. It is the weed of rice field. This is the weed which is commonly found in the temperate regions. 

When the invasive species prickly pear was introduced it possessed a threat to the native species. The growth Opuntia is then controlled by the introduction of the species of the cochineal insect.

A carbamate is an organic compound which is derived from carbamic acid (NH$ _{2}$COOH). 

Weeds are unwanted plants in the cultivated field. They compete with the crop plants for food, space and light. They take up the nutrients and reduce the growth of the  crop.

Parthenium is most common weed which grows anywhere on the land like roadsides, war footings etc.  It releases chemicals to supress the growth of plants and allergents toxic to other livestock. Thus it is important to supress  this weed first. Thus the correct answer is 'Parthenium'. 

Eichhornia crassipes also known with the common name of water hyacinth is a free-floating aquatic plant native to America. It is often considered a highly problematic invasive species outside its native range. E. crassipes reproduces both vegetatively and sexually, but the vegetative reproduction is responsible for the plant’s rapid spread and colonization of water bodies. It occurs through the formation of stolons, which produce daughter plants. This is generally very rapid, if the temperature is high and nutrients are available, it often invades bodies of water that have been impacted by human activities as they often receive large amounts of nutrients. One plant can multiply to cover one acre in a single growing season forming a dense strand. So, with the combination of its free-floating habit, rapid vegetative propagation, and ability to survive on mud during periods of low water levels, E. crassipes has been able to naturalize in a wide variety of aquatic habitats.

Weeds are nothing but unwanted crops that grow along with the main crop. Thus, they compete with the main crop for sunlight, water, nutrients, and space and thus reduce the resources available to them. In this way, they hamper the growth of the main crop.

• Rotating crops with ones that kill weeds by choking them out, such as hemp and other crops, can be a very effective method of weed control. 
• It is a way to avoid the use of herbicides and to gain the benefits of crop rotation. 

The unwanted plants which grow in field along with the crop plants are termed as weed. They are harmful for the crops as they compete for nutrients, space and sunlight with them.

The unwanted plants which grow in field along with the crop plants are termed as weed. They are harmful for the crops as they compete for nutrients with them.

The  Eichhornia , commonly known as common water hyacinth, is an aquatic plant native to the Amazon basin, and is often a highly problematic invasive species outside its native range . It grows at an alarming rate and spreads on the surface of the water body. This cut out of the light and it also causes an increase in the oxygen demand. Thus, causing the death of fishes and other aquatic organisms. 

Congress grass is the common name for Parthenium hysterophorus . It is a species of flowering plant in the aster family, Asteraceae. 

Parthenium hysterophorus is commonly called as congress grass or gajar ghass .It is a species of flowering plant in the aster family, Asteraceae. It is native to the American tropics. This weed is equally dangerous for all flora and fauna. It is highly dangerous for humans. It utilizes most of  the nutritious substances from soils, thus converting fertile ground into unfertile ones.

• Agent Orange refers to a herbicide mixture which was used by the U.S. military during the Vietnam War and it contained a dangerous chemical contaminant called dioxin. 
• The active ingredient of Agent Orange was an equal mixture of two phenoxy herbicides – 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5 trichlorophenoxyacetic acid (2,4,5-T) and it also contained traces of the dioxin 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).
  
• So the correct option is ' All of the above'.