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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
What are fertilizers ? Classify fertilizers.
Why is irrigation essential ?
Why water should be used judiciously ?
Define intercropping. How does it differ with mixed cropping?
Write about three main criteria which should be considered while selecting the crops for rotation?
Why are leguminous crops desirable in crop rotation?
Give two examples each of
(a) Narrow leaved rabi season weed.
(b) Broad leaved kharif season weed.
Distinguish between fertilizer and manure. Give suitable examples. What are advantages and disadvantages of using fertilizer?
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.
