Moderate resistance risk
Globally, herbicide resistance to the Group Z herbicide mode of action has been confirmed and documented in 5 weed species across 4 countries.
Group Z resistance exists in Australia in more than 200 populations of wild oats resistant to flamprop. Many of these flamprop resistant wild oats also show cross resistance to Group A herbicides. There is also endothal resistance confirmed in annual poa (winter grass).
To assist in delaying the onset of resistance, rotate with herbicides from other modes of action.
Consider using alternative methods of weed control to reduce weed numbers before applying herbicides. These may include summer crop rotations, delayed sowing to control wild oats with a knockdown herbicide, higher seeding rates, brown manuring to stop seed set, etc.
The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to ensure surviving weeds from any treatment do no set and shed viable seed. Keep to integrated strategies mentioned in this brochure including rotation of mode of action groups. Make sure you rotate between products from different mode of action groups. Always consult the product label prior to use.
CHEMICAL FAMILY ACTIVE CONSTITUENT (FIRST REGISTERED TRADE NAME)
GROUP Z Herbicides with unknown and probably diverse sites of action
Arylaminopropionic acids: flamprop (Mataven L®)
Dicarboxylic acids: endothal (Endothal®)
Organoarsenicals: DSMA (disodium methylarsonate; Methar®, Trinoc®*), MSMA (monosodium methylarsonate; Daconate®)
* 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 28, 2019