Herbicides

Herbicides are pesticides used to kill or inhibit the growth of unwanted plants (weeds). Commonly known as weed-killers, herbicides are categorized into selective and non-selective. Some of these herbicides act by interfering with the growth of the weed and are often synthetic mimics of natural plant hormones.
They can be foliage-applied or soil herbicides, pre-emergent or post-emergent. Contact herbicides kill only the plant organs with which they are in contact. Translocated herbicides are effective against roots or other organs, to which they are transported from aboveground treated surfaces (soil).

SELECTIVE HERBICIDES: Kill specific weed targets, while leaving the desired crop relatively unharmed.

NON-SELECTIVE: Kill all plant material which they come into contact with.