Globally herbicide resistance to Group A herbicides has been confirmed and documented in more than 40 grass weed species across more than 40 countries. Group A resistance is extensive and prolific with tens of millions of hectares affected, in fact it is the second most likely herbicide mode of action to develop resistance with only the Group B mode of action more likely.
Group A resistance commonly exists across wide areas of Australia in the grass weed species including more than 20,000 populations ofannual ryegrass, annual veld grass, more than 5,000 populations ofwild oats, phalaris, more than 200 populations of brome grass, crabgrass, crowsfoot grass and more than 200 populations of barley grass. Resistance has developed in broadacre and vegetable situations.
Research has shown that as few as 6 applications to the same population of annual ryegrass can result in the selection of resistant individuals. A population can go from a small area of resistant individuals to a whole paddock failure in one season.
|CHEMICAL FAMILY||ACTIVE CONSTITUENT (FIRST REGISTERED TRADE NAME)|
|GROUP A||Inhibitors of acetyl co-enzyme A carboxylase (Inhibitors of fat synthesis/ACC’ase inhibitors)|
|clodinafop (Topik®), cyhalofop (Barnstorm®), diclofop (Cheetah® Gold*, Decision®*, Hoegrass®), fenoxaprop (Cheetah® Gold* , Wildcat®), fluazifop (Fusilade®, Fusion®*), haloxyfop (Verdict®), propaquizafop (Shogun®), quizalofop (Targa®)|
|butroxydim (Falcon®, Fusion®*), clethodim (Select®), profoxydim (Aura®), sethoxydim (Cheetah® Gold*, Decision®*), tralkoxydim (Achieve®)|
* This product contains more than one active constituent
List of chemical families, approved active constituents and, in parenthesis, the trade name of the first registered product or successor. Refer to the APVMA website (www.apvma.gov.au) to obtain a complete list of registered products from the PUBCRIS database.
Content last updated: June 22, 2018