Herbicide Resistant Weeds

HERBICIDE RESISTANT WEEDS SUMMARY TABLE Friday, January 16, 2009
Herbicide Group Click for details	Mode of Action	HRAC Group	Example Herbicide	Total
ALS inhibitors	Inhibition of acetolactate synthase ALS (acetohydroxyacid synthase AHAS)	B	Chlorsulfuron	97
Photosystem II inhibitors	Inhibition of photosynthesis at photosystem II	C1	Atrazine	67
ACCase inhibitors	Inhibition of acetyl CoA carboxylase (ACCase)	A	Diclofop-methyl	35
Synthetic Auxins	Synthetic auxins (action like indoleacetic acid)	O	2,4-D	27
Bipyridiliums	Photosystem-I-electron diversion	D	Paraquat	24
Ureas and amides	Inhibition of photosynthesis at photosystem II	C2	Chlorotoluron	21
Glycines	Inhibition of EPSP synthase	G	Glyphosate	15
Dinitroanilines and others	Microtubule assembly inhibition	K1	Trifluralin	10
Thiocarbamates and others	Inhibition of lipid synthesis - not ACCase inhibition	N	Triallate	8
Triazoles, ureas, isoxazolidiones	Bleaching: Inhibition of carotenoid biosynthesis (unknown target)	F3	Amitrole	4
PPO inhibitors	Inhibition of protoporphyrinogen oxidase (PPO)	E	Oxyfluorfen	3
Chloroacetamides and others	Inhibition of cell division (Inhibition of very long chain fatty acids)	K3	Butachlor	3
Carotenoid biosynthesis inhibitors	Bleaching: Inhibition of carotenoid biosynthesis at the phytoene desaturase step (PDS)	F1	Flurtamone	2
Arylaminopropionic acids	Unknown	Z	Flamprop-methyl	2
Nitriles and others	Inhibition of photosynthesis at photosystem II	C3	Bromoxynil	1
Mitosis inhibitors	Inhibition of mitosis / microtubule polymerization inhibitor	K2	Propham	1
Cellulose inhibitors	Inhibition of cell wall (cellulose) synthesis	L	Dichlobenil	1
Pyrazoliums	Unknown	Z	Difenzoquat	1
Organoarsenicals	Unknown	Z	MSMA	1
Total Number of Unique Herbicide Resistant Biotypes				323