Herbicide

A herbicides are products that kill plants. Herbicides can be grouped by activity, use, chemical family, mode of action, or type of vegetation controlled.

Activity

Contact herbicides destroy only the plant tissue in contact with the chemical. Generally, these are the fastest acting herbicides. They are less effective on perennial plants, which are able to regrow from roots or tubers.

Systemic herbicides are translocated through the plant, either from foliar application down to the roots, or from soil application up to the leaves. They can destroy a greater amount of plant tissue than contact herbicides.

Use

Soil-applied herbicides are applied to the soil and are taken up by the roots of the target plant.

Pre-emergent herbicides are applied to the soil before the crop emerges and prevent germination or early growth of weed seeds. Pre-emergents simply prevent seeds from sprouting.

Post-emergent herbicides are applied after the crop has emerged.