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प्रश्न
Mention three different ways in which insect pests can attack the crop plant.
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उत्तर
Following are the three ways in which an insect pest can attack the crop plants:
1. Chewing insects: They destroy all kinds of crop plants by cutting root, stem, and leaf of plants with their chewing mouth parts. Examples: Locusts, grasshoppers, etc.
2. Sucking insects: They destroy the crop plant by sucking the cell sap from its various parts. Examples: Aphids, leaf hoppers, etc.
3. Internal feeders: They live inside the parts of plants. These are called borers (if they live in twigs or roots) or weevils (if they live in fruits and seeds). Examples: Pod borers and grain weevil.
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संबंधित प्रश्न
Distinguish between micronutrients and macronutrients. Give suitable examples.
How plants get nutrients ?
Define manure. What are different manures and how do they affect the soil ?
Give a short account of biofertilizers.
Distinguish between mixed cropping and intercropping.
What is the advantage of using insect resistant varieties?
Explain what will happen if in a cultivated field only manures are supplied and in another field only fertilizers are supplied, keeping all other conditions similar.
Define irrigation. Why is irrigation of crops essential? Mention the harmful effects of excessive irrigation.
Compare between mixed cropping and intercropping. Write down from advantage of both of these techniques.
Which one is not a source of carbohydrates?
