Classification of Herbicides

• According to mode of action of herbicides

Contact - When the chemicals kill the plants by coming in contact with them they are called contact herbicides.

Translocated -The systemic or translocated herbicides are chemicals that kill the plants after their absorption by accelerating or retarding the metabolic activities of plants.

• According to their relative time of application to weed emergence

Pre-plant herbicides -Are applied on the field before planting the crop.

Pre-plant emergence herbicides - Are applied before emergence of weeds.

Past-emergence herbicides - Are applied after the emergence of weeds.

• Chemical classification of herbicides

It refers to grouping of various herbicides according to their chemical composition.