Question

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

Answer 1

Hint: Crops are highly affected or destroyed by weeds, insects, pests and diseases. Effective measures should be preferred to avoid these factors and for higher crop yield.

Farmers should consider two important aspects:
Ecological safety and the extent of harm to other organisms while selecting methods for protecting crops. Based on this aspect, preventive measures and biological control methods should be preferred for protecting crops. The excessive use of chemicals as manures and pesticides can lead to many environmental problems and cause pollution. They can also enter the food chain and cause serious health hazards. So, these measures are simple, economic and minimize pollution.

Complete answer:
Some of the preventive measures are as follows:
1. Proper soil and seed preparation,
2. Timely sowing of seeds,
3. Inter cropping and mixed cropping,
4. Usage of resistant varieties of crops, etc. for protecting crops.

On the other hand, biological control methods involve the use of biological organisms and biopesticides which are less toxic and are completely safe for other life forms.
Example:
1. Cochineal insects were used in Maharashtra and Tamilnadu for the eradication of opuntia.
2. Fish grass carp controls aquatic weeds.
3. Bacillus thuringiensis, which is an insect pathogen, kills a wide range of insect larvae thus considered as a bio-pesticide.

Note: The preventive measures and biological control methods adopted by the farmers are usually eco-friendly methods of crop protection. Also, these methods minimize the effect on the fertility of soil. These provide farmers with better yield and reduce the chances of damage.