Question

a farmer needs to spray 2, 4D in his crop field. this indicates that..

Answer 1

There is weeds in his plants  

2,4D is one of the most common weedicide

Answer 2

2,4-Dichlorophenoxyacetic acid was introduced as a plant growth-regulator. It is widely used as  herbicide in the United States .It is used as a herbicide to control broadleaf plants and as a plant growth-regulator.It is also used to control weeds in crop field. This herbicide mimics the action of auxin and results in uncontrolled growth of broadleaf which leads to death of the susceptible plant.The derivatives of 2,4-D including esters, amines, and salts.