NCERT Solutions for Class 9 Science Chapter 15

Hybridisation helps to increase the crop production. It involves crossing of inter-variety, inter-specific crossing, inter-generic crossing which give plants of desired characteristics, i.e., high yield of crops which are disease resistant and respond to fertilisers positively, adaptable to the environment, need less water for irrigation and have low maturity periods.

Pasturage is the availability of flowers for nectar and pollen collection for honeybee.
The kind and quality of honey is determined by the kind and quality of pasturage.

Resistant crops variety are useful and give higher yield. Biological control methods are safe, ecofriendly, long lasting and harmless to other forms of life, therefore should be preferred.

The process refers to the transfer of genes from one organism to another, e.g. Bt Cotton is a genetically modified crop which carry bacterial genes, that protects this plant from insects. These are used in rice, maize, brinjal, cabbage, cauliflower to get protection from insects.

Inter-Cropping:
(i) Prevents pests and decreases the chances of spoiling of whole crops, therefore reduce losses and both crops can give better results.
(ii) It can also deal with less monsoon or drought because crop which needs less water can easily survive.
Crop-rotation:
(i) Farmers can grow two or three crops in a year.
(ii) Pulses take nitrogen directly from the atmosphere, and thus needed fewer amounts of fertilisers.
(iii) Vegetables and fruits can be easily grown. It makes best use of land and nutrients present in the soil.

Manure and fertilizers supply nutrients to the soil and increases the fertility of the soil and thus increases the production. They overcome the nutritional deficiency of the soil.