Which plant is useful as green manure?

The three major crops that contribute most to global food grain production are $........$.

Which one of the following is a disease of poultry?

Statement $S$: $90\%$ of the world's fish production comes from freshwater.
Reason $R$: Hilsa,Sardines,and Major Carps are freshwater fish.

Consider the following statements $(I-IV)$ regarding organic farming:
$I.$ Use of genetically modified crops like $Bt$ cotton.
$II.$ Input of naturally produced compost.
$III.$ No use of urea and pesticides.
$IV.$ Production of vitamin and mineral-rich vegetables.
Which of the above statements are correct?

Which organisms are primarily included as pests?