Nearly Half of All US Farms Now Have Superweeds

| Wed Feb. 6, 2013 7:06 AM EST

Last year's drought took a big bite out of the two most prodigious US crops, corn and soy. But it apparently didn't slow down the spread of weeds that have developed resistance to Monsanto's herbicide Roundup (glyphosate), used on crops engineered by Monsanto to resist it. More than 70 percent of all the the corn, soy, and cotton grown in the US is now genetically modified to withstand glyphosate.

Back in 2011, such weeds were already spreading fast. "Monsanto's 'Superweeds' Gallop Through Midwest," declared the headline of a post I wrote then. What's the word you use when an already-galloping horse speeds up? Because that's what's happening. Let's try this: "Monsanto's 'Superweeds' Stampede Through Midwest."

That pretty much describes the situation last year, according to a new report from the agribusiness research consultancy Stratus. Since the 2010 growing season, the group has been polling "thousands of US farmers" across 31 states about herbicide resistance. Here's what they found in the 2012 season:

Superweeds: First they gallop, then they roar. Graph: Stratus

• Nearly half (49 percent) of all US farmers surveyed said they have glyphosate-resistant weeds on their farm in 2012, up from 34 percent of farmers in 2011.
• Resistance is still worst in the South. For example, 92 percent of growers in Georgia said they have glyphosate-resistant weeds.
• But the mid-South and Midwest states are catching up. From 2011 to 2012 the acres with resistance almost doubled in Nebraska, Iowa, and Indiana.
• It's spreading at a faster pace each year: Total resistant acres increased by 25 percent in 2011 and 51 percent in 2012.
• And the problem is getting more complicated. More and more farms have at least two resistant species on their farm. In 2010 that was just 12 percent of farms, but two short years later 27 percent had more than one.

So where do farmers go from here? Well, Monsanto and its peers would like them to try out "next generation" herbicide-resistant seeds—that is, crops engineered to resist not just Roundup, but also other, more toxic herbicides, like 2,4-D and Dicamba. Trouble is, such an escalation in the chemical war on weeds will likely only lead to more prolific, and more super, superweeds, along with a sharp increase in herbicide use. That's the message of a peer-reviewed 2011 paper by a team of Penn State University researchers led by David A. Mortensen. (I discussed their paper in a post last year.)

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