US corn, cotton and soybean farmers are facing an epidemic of glyphosate resistant weeds, resulting from “massive over-reliance” on the broadacre herbicide glyphosate since 1996, according to one of the world’s leading weed resistance experts.
Australian Herbicide Resistance Initiative director, Professor Stephen Powles, based at the University of Western Australia in Perth, is just back from a three-week tour of the US where he witnessed the growing “epidemic” of glyphosate-resistant weeds attacking the nation’s cotton, soybean and corn belts.
Prof Powles had observed emerging issues with the nation’s over-reliance on glyphosate on annual visits to the US for the past seven years – and has been sounding warnings to its agricultural industry for almost a decade about the inherent dangers of resistance, with farmers excessively reliant on Roundup Ready (RR) crops.
Unfortunately, he said the forecast epidemic is now underway.
Prof Powles wanted Australian farmers to be aware of the potential dangers and warned them to respect glyphosate and ensure this “one-in-100-year chemical” remained effective on Australian farms.
“Over-use glyphosate and lose it – that’s the message coming to us here in Australia from the US,” he said.
Prof Powles said the introduction of RR genetically modified (GM) crops in the US in 1996 by Monsanto had been “spectacularly successful”, exceeding industry expectations and sweeping the market to the point where the US’s huge corn, cotton and soybean areas planted them almost exclusively.
In the southern cotton growing regions, for example, he said farmers’ rotations include cotton, corn and soybean – which often meant RR cotton, followed by RR corn and RR soybeans.
Nearly all of the US’s massive soybean crop – 35 million hectares – all of its massive 40m ha of corn and 95 per cent of its 2.5m ha of cotton were RR varieties, he said.
“I don’t call it the corn, soybean and cotton belt – I call it the glyphosate belt,” Prof Powles said.