Herbicides are chemicals used to manipulate or control undesirable vegetation.

Herbicide application occurs most frequently in row-crop farming, where they are applied before or during planting to maximize crop productivity by minimizing other vegetation.

It is usually a chemical, for killing or inhibiting the growth of unwanted plants, such as residential or agricultural weeds and invasive species.

A great advantage of chemical herbicides over mechanical weed control is the ease of application, which often saves on the cost of labor.

Herbicides are divided into numerous categories:

1. Selective (affecting specific plant species).

2. Nonselective (affecting plants generally). can be used to clear waste ground.

3.Foliage-applied:

A. Contact herbicides that kill only the plant organs with which they are in contact.

B. Translocated herbicides (systemic) are effective against roots or other organs to which they are transported from aboveground treated surfaces.

4. Soil herbicides:

A. Preemergence: prevents weed seedlings from emerging. Sprayed on bare soil.

Usually, activated by rain or irrigation.

B. Absorbed by the roots and translocated to the leaves.

Weed resistance to herbicides has become a major concern in crop production worldwide.

Resistance to herbicides is often attributed to lack of rotational programs of herbicides.

Active ingredient	Selective (kills)	Timing	Absorbed by
MCPA	Broadleaf weeds	post-emergence	leaves
D-acid-2,4	Broadleaf weeds	post-emergence	leaves
Triasulfuron	Broadleaf weeds	post-emergence	leaves, roots
Pyraflufen ethyl	Broadleaf weeds	post-emergence	leaves
Pinoxaden	grassy weeds	post-emergence	leaves
Bentazon	broadleaf weeds	postemergence	leaves
Trifloxysulfuron	broadleaf weeds	postemergence	leaves
pinoxaden	grassy weeds	post-emergence	leaves
Glufosinate Ammonium	broadleaf weeds and grasses (nonselective)	post-emergence	leaves
Fluazifop-P-butyl	grass weeds	post-emergence	leaves, systemic
metolachlor-s	annual grasses and broadleaf weeds	preemergence	soil
Pendimethalin	annual grasses and certain broadleaf weeds	preemergence	soil
Fomesafen	broadleaf weeds	preemergence	leaves and roots
Diquat	broadleaf weeds	post-emergence	leaves
Glyphosate (roundup)	broadleaf weeds and grasses (nonselective)	post-emergence	systemic
Chlorsulfuron	broadleaf weeds and grasses	post-emergence	Systemic
Oxadiazon	broadleaf weeds and grasses	preemergence	soil
Rimsulfuron Methyl	broadleaf weeds and grasses	post-emergence	leaves
Diuron	broadleaf weeds and grasses	preemergence	soil
Metribuzin	broadleaf weeds and grasses	post-emergence, preemergence	leaves
Linuron	broadleaf weeds and grasses	preemergence, post-emergence	soil, leaves
Alachlor	broadleaf weeds and grasses	preemergence	soil
Pyroxasulfone	broadleaf weeds and grasses	preemergence	soil, roots
Bromacil	broadleaf weeds and grasses	post-emergence	Systemic, roots
Atrazine	broadleaf weeds	preemergence, post-emergence	leaves
Cyprosulfamide+Izoxaflutole	broadleaf weeds and grasses	preemergence	Systemic, roots
Aclonifen	broadleaf weeds	preemergence	leaves
Terbacil	broadleaf weeds and grasses	preemergence	Systemic, roots
Pyrithiobac Sodium	broadleaf weeds	post-emergence	leaves
Propoxycarbazone sodium	grass weeds	post-emergence	leaves
Indaziflam	broadleaf weeds and grasses	preemergence	soil, leaves, systemic
Foramsulfuron + Isoxadifen ethyl	broadleaf weeds and grasses	post-emergence	leaves
Metamitron	broadleaf weeds	preemergence, post-emergence	soil, leaves
Isoxadifen ethyl+Tembotrione	broadleaf weeds	post-emergence	leaves
Clethodim	grass weeds	post-emergence	leaves
Carfentrazone-ethyl	broadleaf weeds	post-emergence	leaves
Saflufenacil	broadleaf weeds	post-emergence	leaves, roots, systemic
Triclopyr Butotyl	broadleaf weeds	post-emergence	leaves
Imazamox	broadleaf weeds	post-emergence	leaves, roots
Dimethenamid-p	broadleaf weeds and grasses	preemergence	soil
Oxyfluorfen	broadleaf weeds and grasses	preemergence, post-emergence	soil, leaves
Clodinafop-Propargyl	grass weeds	post-emergence	leaves
Florasulam	broadleaf weeds	post-emergence	leaves, systemic
Diflufenican	broadleaf weeds	post-emergence	leaves
Fluroxypyr	broadleaf weeds	post-emergence	leaves, systemic
Propyzamide	grass weeds	post-emergence	roots

You might also like these articles: