What is the advantage of growing crops in a monoculture?

Consider the following statements:
$I$. Solid stem in wheat exhibits non-preference by stem sawfly.
$II$. In cotton,smooth leaf and absence of nectar repel bollworms.
$III$. In maize,high aspartic acid,low nitrogen and sugar content protect them from stem borers.
Which of the statements given above are correct?

The liquid wax is obtained from:

Mulching helps in

Bombykol or gyplure is a

The father of the Green Revolution in India is: