Question

Why should preventive measures and biological control methods be preffered for protecting crops

Answer 1

Preventive measures and biological control methods should be preferred for protection of crops because they are ecological safe target specific and harmless to other life forms.

Some of the preventive measures of pests are the following:

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

Biological control of weeds involves the excessive use of insects or some other organisms which consume and destroy the weed plants.

For e.g
Eradication of opuntia by using the cochineal insects In Maharashtra and Tamilnadu .
Aquatic weeds are controlled by the fish grass carp.

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Hope this will help you.....

Answer 2

Preventive measures and biological control methods are preferred because

I) They are simple.

2) They are economic as they need less money to be invested.

3) They minimise pollution.

4) Minimise the effect on soil fertility.

5) Biological methods control the pests without harming crops and humans.