Specific guidelines for Group N herbicides

Moderate resistance risk

Glufosinate-ammonium (Basta®, Liberty®) is the only Group N herbicide registered in Australia.

Resistance to Group N herbicides is rare and currently there are no documented cases of resistant weeds in Australia. Group N resistance has been discovered in other countries for 2 weed species – crowsfoot grass (Eleusine indica) and Italian ryegrass (Lolium perenne spp. multiforum) – which demonstrates the potential for weeds to develop resistance to this mode of action.

The risk of resistance to glufosinate-ammonium will be highest in situations where there is a reliance on this herbicide alone for weed control. This includes situations where:

  • other herbicides in the farming system, especially glyphosate, have developed resistance
  • weed escapes following application of glufosinate-ammonium are allowed to set and shed viable seed
  • there is a lack of non-herbicide weed control methods used

Weed control from glufosinate-ammonium is affected by climatic conditions (refer to the product label).

Horticulture

  1. Rotate glufosinate-ammonium with other knockdown herbicides with a different mode of action, such as Group L (e.g. paraquat), Group Q (e.g. amitrole) or Group M (e.g. glyphosate).
  2. Where possible use residual herbicides (that are effective on the same weeds as glufosinate-ammonium) either alone or in mixture with glufosinate-ammonium.
  3. Where possible use alternative modes of action to selectively control grass and broadleaf weeds.

Fallow

In high summer rainfall areas, weed control in fallow is heavily reliant on herbicides. Multiple sprays are often required to maintain a clear fallow between winter crops.

  1. Rotate glufosinate-ammonium with other knockdown herbicides with a different mode of action, such as Group L (e.g. paraquat), Group Q (e.g. amitrole) or Group M (e.g. glyphosate).
  2. Where possible use residual herbicides (that are effective on the same weeds as glufosinate-ammonium) either alone or in mixture with glufosinate-ammonium.
  3. Where possible use alternative modes of action to selectively control grass and broadleaf weeds.

The above recommendations should be incorporated into an Integrated Weed Management (IWM) program. In all cases try to endure surviving weeds from any treatment do not 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 FAMILYACTIVE CONSTITUENT (FIRST REGISTERED TRADE NAME)
GROUP N Inhibitors of glutamine synthetase
Phosphinic acids:


glufosinate (Basta®, Liberty®)

* 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. 


URL: https://croplife.org.au/resources/programs/resistance-management/specific-guidelines-for-group-n-herbicides/
Content last updated: June 28, 2019

CropLife Australia’s Resistance Management Strategies provide a guide for crop protection product rotation through product groups. The strategies are a useful tool that supports farmers’ adoption of resistance management. All crop protection products must be handled and applied strictly as specified on the product label or APVMA permits.

These Resistance Management Strategies do not replace product labels. They are a guide only and do not endorse particular products, groups of products or cultural methods in terms of their performance. It is important to check with the Australian regulator’s (APVMA) product database for contemporary information on products and active constituents. The database can be sourced through www.apvma.gov.au

The information given in this strategy is provided in good faith and without any liability for loss or damage suffered as a result of its application and use. Advice given in this strategy is valid as at 27 June 2019. All previous versions of this strategy are now invalid.