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On March 11, 2024, 11:35 AM

Page No 209: - Chapter 15 Improvement In Food Resources class 9 ncert solutions Science - SaraNextGen [2024]


Question 1:

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

Answer:

Preventive measures and biological control methods should be preferred for protecting crops because excessive use of chemicals leads to environmental problems. These chemicals are also poisonous for plants and animals. Preventive measures include proper soil and seed preparation, timely sowing of seeds, intercropping and mixed cropping, usage of resistant varieties of crops, etc. On the other hand, biological control methods include the usage of bio-pesticides that are less toxic for the environment. An example of bio-pesticides is Bacillus thuringenesis,which is an insect pathogen that kills a wide range of insect larvae. Therefore, both preventive measures and biological control methods are considered eco- friendly methods of crop protection.

 

Question 2:

What factors may be responsible for losses of grains during storage?

Answer:

During the storage of grains, various biotic factors such as insects, rodents, mites, fungi, bacteria, etc. and various abiotic factors such as inappropriate moisture, temperature, lack of sunlight, flood, etc. are responsible for losses of grains. These factors act on stored grains and result in degradation, poor germinability, discolouration, etc.

Also Read : Page-No-210:-Chapter-15-Improvement-In-Food-Resources-class-9-ncert-solutions-Science

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