Western Australia
January 21, 2010
Weeds have evolved a new form of resistance to the world’s most important herbicide, glyphosate, according to research led by Colorado State University.
Dr Todd Gaines, now of the WA Herbicide Resistance Initiative (WAHRI) in The University of Western Australia’s School of Plant Biology, warns that the glyphosate resistant weed populations could impact the use of glyphosate for the cultivation of the global food and fibre crops: rice, wheat, soybeans, maize and cotton.
In a paper published recently in the US journal Proceedings of the National Academy of Sciences (PNAS) lead author Dr Gaines documents his research on a new resistance mechanism in weeds, discovered in the particularly damaging weed species, Amaranthus palmeri.
This weed infests large areas of US crop land and can devastate yield, Dr Gaines said. In some regions of the US southern states, glyphosate resistant weeds are becoming so rife in cotton crops that mechanical harvesters are damaged and weed control sometimes must be done by hand. “Many locations are back to full tillage, and even manual, weed control,” he said.
In a commentary in the same issue of PNAS, UWA Winthrop Professor and WAHRI Director Stephen Powles, writes that in a world of more than six billion people, threats to food production have major repercussions, including famine, war and civil unrest.
“Glyphosate resistance evolution is a major adverse development because glyphosate is a one in a 100-year discovery that is as important for reliable global food production as penicillin is for battling disease,” Professor Powles said.
“In soybean, maize, cotton and canola crops engineered to be glyphosate resistant, this herbicide removes infesting weeds without damage to the crop. The massive adoption of these crops has meant excessive reliance on glyphosate for weed control over vast areas. Globally, no weed control tools are as good as glyphosate and its potential loss because of resistance is a looming threat to global cropping and food production.”
For more information:
- http://www.pnas.org/cgi/doi/10.1073/pnas.0913433107
- http://www.pnas.org/content/early/2009/12/10/0906649107
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