Australia
January 19, 2011

New Western Australian research could help reduce the risks of wild radish developing resistance to the important knockdown herbicide glyphosate.

Western Australian No-Tillage Farmers Association (WANTFA) researcher Mike Ashworth has been awarded a Grains Research and Development Corporation (GRDC) scholarship to conduct the research as part of a PhD.

The research will be conducted at the Australian Herbicide Resistance Initiative (AHRI), based at The University of Western Australia (UWA), in collaboration with WANTFA.
Mr Ashworth will explore the risks of wild radish developing resistance to glyphosate associated with changing use patterns of this herbicide, and examine strategies aimed at reducing the risks.

He said wild radish was WA’s worst dicot weed, and in many areas where it had developed resistance to Group B, C, F and I herbicides, it was a more significant weed than annual ryegrass.

“With these modes of action no longer effective against wild radish, growers are looking to herbicides like glyphosate to control it,” Mr Ashworth said.

“Given the past use of glyphosate to control wild radish, and the new use patterns, selection pressures are likely to increase, therefore increasing the risk of glyphosate resistance developing.”

Mr Ashworth said the introduction of glyphosate tolerant canola to WA offered many benefits including improved weed control, early seeding and the maintenance of no-till systems.
However, as with other weeds, careful management of glyphosate was needed to reduce the chance of wild radish becoming resistant to this important herbicide.

Other factors which might increase the risks included the increased use of glyphosate in late season crop applications and to maintain winter fallows.

“My research will include widespread surveying of wild radish in glyphosate tolerant canola, and strategies – such as crop competition, glyphosate application timing and application rates – which could help prevent resistance in wild radish,” Mr Ashworth said.

Mr Ashworth’s research will be supervised by AHRI director Professor Stephen Powles, Associate Professor Michael Walsh, of AHRI, and UWA lecturer in agronomy Dr Ken Flower.

The GRDC supports Grains Industry Research Scholarships to encourage post graduate training contributing to research priorities of the Australian grains industry.

Website: http://www.grdc.com.au

Published: January 19, 2011