Title: The weeds eating US agriculture

[Stock & Land 19 Feb 2012 by Colin Bettles] -- 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. [Image: Glyphosate-resistant Johnson grass in a Roundup Ready soybean crop.]

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. “Given our knowledge in Australia of herbicide resistance, what would anyone with any basic knowledge of Australian cropping think of that? “If you know enough about weed resistance you would know that you can’t use one chemical across one continent, but that is exactly what’s occurring in the US.”

He said glyphosate resistance problems were severe in the southern cotton growing regions from Texas through to Mississippi. Similar issues were appearing, but less dramatically, in the northern corn and soybean belts – in States like Iowa, Illinois and Indiana, considered the grain basket of the world – and were expected to spread to the Mid West.

Prof Powles said “monster” glyphosate resistant weeds were now appearing on a large scale in the southern US, like Palmer pigweed which grew to more than two metres in height and destroyed crop yields. He said the southern US was riddled with glyphosate-resistant Palmer pigweed in key cotton growing areas.

Prof Powles said the US industry was well aware of the problems, but it had never faced a chronic herbicide resistance problem before like Australia had in the past – and learning to manage it would not come without some pain. “There’s going to be more expense for US farmers in battling this issue,” he said. “They are doing loads of hand weeding in cotton crops, something that has not been seen for 100 years.”

Original source



Article: WeedsNews2955 (permalink)
Categories: :WeedsNews:herbicide resistance, :WeedsNews:agricultural weed, :WeedsNews:weed control
Date: 23 February 2012; 1:54:08 pm Australian Eastern Daylight Time

Author Name: David Low
Author ID: adminDavid