11. May 2010 19:03
When Monsanto began selling genetically modified 'Roundup Ready' soybeans in the 1990s, it sounded too good to be true: farmers could spray a single chemical over their entire field that would kill all weeds in its path but leave crops unharmed. The chemical was glyphosate, originally marketed by Monsanto as Roundup but now sold by other companies as well. Roundup killed a wide range of weeds and was safer and less harmful to the environment than most other chemical herbicides, and with the development of crops genetically modified for glyphosate resistance, farmers were able to kill weeds by spraying entire fields indiscriminately.
Roundup Ready technology was a huge labor saver for farmers, and arguably provided environmental benefits by reducing the number of passes farmers needed to make when spraying fields and by replacing more toxic herbicides such as atrazine. But when a product sounds too good to be true, it usually is. Now, less than 20 years after the rise of Roundup, the extremely widespread use of the chemical has accelerated the evolution of glyphosate-resistant weeds.
The problem did not come out of left field. Warnings about future 'super-weeds' came early and often, but Monsanto held the position that resistance would never be a serious problem. When farmers began raising the issue, the company's response was simply: Spray more!
Predictably, that didn't work for long. Now there are at least 10 seriously glyphosate-resistant weeds in the U.S., and farmers are looking for new solutions – whether it be switching to more toxic herbicides, changing tillage methods, or trying integrated pest management strategies. Currently about 90% of soybeans and 70% of corn and cotton in the U.S. is grown from Roundup Ready seeds, and in the face of glyphosate resistance, it is not difficult to imagine these numbers to drop.
"It's a serious issue, but it's manageable," Monsanto representative Rick Cole told the New York Times when asked about the glyphosate resistance problem. One has to wonder: is he referring to farmers'
ability to manage herbicide-resistant weeds – or Monsanto's ability to maintain its monopoly of the seed and pesticide industries?
Map of glyphosate resistance in the U.S.