Click here to download a printable PDF of Australian Glyphosate Resistance Register: Summary and Background (545KB)

Click here to download the full register of confirmed Glyphosate Resistant populations in Australia (93KB)

1. Glyphosate Resistant Weeds in Australia: summary
Glyphosate resistance was first documented for annual ryegrass (Lolium rigidum) in 1996 from a site in Victoria.  In 2007, glyphosate resistance occurred in populations of awnless barnyard grass (Echinochloa colona) in New South Wales.  In 2008, glyphosate resistance occurred in populations of liverseed grass (Urochloa panicoides) in New South Wales. Currently, there are 78 documented glyphosate-resistant populations of annual ryegrass, 3 documented glyphosate-resistant populations of awnless barnyard grass and 2 documented glyphosate-resistant populations of liverseed grass.

Glyphosate resistant annual ryegrass has occurred in the following situations:
Broadacre cropping
Chemical fallow - 24 sites - NSW
No-till winter grains - 10 sites - NSW, Vic, SA, WA
Horticulture
Tree crops - 3 sites - NSW
Vine crops - 14 sites - SA, WA
Other
Driveway - 1 site - NSW
Fenceline - 16 sites - NSW, SA, Vic
Firebreak - 2 site - SA
Irrigation channel - 6 sites - NSW
Railway - 1 site - WA
Airstrip - 1 site - SA

The glyphosate-resistant awnless barnyard grass and liverseed grass all occur in summer chemical fallow situations in NSW.

Glyphosate-resistant annual ryegrass populations by states:
NSW - 39 populations
SA - 27 populations
WA - 5 populations
Vic - 7 populations

The increase in confirmed cases of glyphosate resistance between 1996 and 2008 is:

All of the glyphosate resistant populations have occurred in situations where there has been intensive use of glyphosate, often over 15 years or more, few or no other effective herbicides used, and a few or no tillage operations.  This suggests the following are the main risk factors for the evolution of glyphosate resistance:

• Intensive use of glyphosate – every year or multiple times a year for 15 years or more
• Heavy reliance on glyphosate for weed control
• No tillage

2. Australian Glyphosate Resistance Register: background
Further details of glyphosate resistant populations in Australia are available from the National Glyphosate Sustainability Working Group website’s Australian Glyphosate Resistance Register

The Glyphosate Resistance Register contains information regarding all the known glyphosate resistant weed populations present in Australia. The register is managed by Dr Chris Preston at the University of Adelaide. Populations are added to the register when they are confirmed by one of the testing services or by researchers. Tests need to be conducted as a rate response with populations being sprayed with agriculturally-relevant rates of a commercial glyphosate formulation. Each test needs to include a known susceptible population. The minimum information needed to register a population is:
Location
Rate response
Researcher contact
Source of seed

The register is updated approximately every six months. Click here to download the full register of confirmed Glyphosate Resistant populations in Australia (93KB)

The register output lists weed species, location as ABS statistical regions, type of cropping system or other land use, the year resistance was confirmed, whether resistance to other herbicides exists in the population and the level of resistance as compared to a known susceptible population.

Acknowledgements: I would like to thank Dr. Rex Stanton and John Broster of Charles Sturt University, Prof Steve Powles of WAHRI, Dr. Peter Boutsalis of Plant Science Consulting and Dr. Abul Hashem of Department of Agriculture, Western Australia for sharing data from their testing.


How to cite this information: Preston, C. (2005) Australian Glyphosate Resistance Register. National Glyphosate Sustainability Working Group.Online. Available www.weeds.crc.org.au/glyphosate

For more information on the content of the Australian Glyphosate Resistance Register contact Dr. Chris Preston, phone: 08 8303 7237 email: christopher.preston@adelaide.edu.au

This register has been produced by the national Glyphosate Sustainability Working Group, a collaborative initiative aimed at promoting the sustainable use of glyphosate in Australian agriculture, involving the CRC for Australian Weed Management, Monsanto, Syngenta, Nufarm, WA Herbicide Resistance Initiative (University of WA), University of Adelaide, Charles Sturt University, Queensland DPI&F, Department of Agriculture WA, NSW Department of Primary Industries, CRT/Town & Country and the GRDC. 2006.

Contact
Rex Stanton (Chair)
Phone: 02 6938 1618
Fax: 02 6938 1861

The GSWG gratefully acknowledges the financial support of the CRC for Australian Weed Management, CropLife Australia and GRDC.