What are the components that cause damage to crops called?

Growing crop plants in monoculture results in ........

Which of the following is not economically useful?

The $IARI$,New Delhi has developed several vegetable crops. What are they enriched with?

Green revolution is related to the increase in

Statement $A$: High-quality disease-free plants and animals are produced.
Reason $R$: Through animal husbandry and tissue culture,food production can be increased to meet the needs of the growing human population.
Which option is correct for Statement $A$ and Reason $R$?