Weed Resistance Costs Farmers Millions

, senior analyst, Food and Environment | September 27, 2011, 12:32 pm EDT
Bookmark and Share

Reuters’ Carey Gillam’s recent excellent analysis of the Roundup-resistant weed problem makes points that my colleagues at UCS have been arguing for a long time.

Overuse of any herbicide—such as we have seen with the widespread adoption of Monsanto’s genetically engineered Roundup-resistant crops—leads inevitably to the development of resistance.

This poses an environmental dilemma. Twenty-one species of agricultural weeds now continue merrily growing and choking out crops after being sprayed with Roundup. This in turn leads farmers to spray more—and more toxic—weed killers in desperate efforts at control.

Weed Resistance is Expensive

But as Gillam notes, this also creates economic woes for farmers:

In Ohio, the nightmare weed for farmer John Davis is “marestail,” an annual weed that grows well in key crop-growing areas of the U.S. Midwest and which is resistant to glyphosate and other herbicides.

Marestail in an Ohio soybean field, 2009. Credit: Andy Kleinschmidt

“I see marestail in my sleep,” said Davis, president of the Ohio Corn Growers organization. “I have spent a significant amount of dollars trying to control marestail until I realized I was not going to control marestail.”

Just how much of a blow?

Farmers and crop experts say that when superweeds take root in farm fields, yield reductions of 1-2 bushels an acre are common, even with extra pesticide doses.

With soybeans at more than $14 a bushel, a 1,000-acre farm might lose more than $20,000 to weeds on top of the costs of the added pesticides.

With farmers (along with everyone else) already feeling the pinch of a bad economy, a $20,000 loss of income is nothing to sneeze at. Extrapolate that out across the nation’s farm belt, and pretty soon you’re talking real money. Gillam quotes Penn State weed ecologist Dave Mortensen:

…Mortensen said farmer efforts to control resistant weeds are estimated to cost nearly $1 billion a year and result in a 70 percent increase in pesticide use by 2015.


What the Reuters story doesn’t say—but should—is that there is a common-sense solution to this problem. It’s called organic agriculture.

Organic is Better for the Environment…and the Bottom Line

Weeds aren’t a big problem on organic farms because complex crop rotations and the use of cover crops keep them from gaining a foothold. The money other growers spend on herbicides stays in the pockets of organic growers.

And a new report from the Organic Farming Research Foundation found that organic farms, on average, outperform all U.S. farms in terms of sales and operating profit. [NOTE: As of posting, the OFRF site appears to be down, but the report can be accessed here.]

Yes, production costs are also higher, because organic methods are more labor intensive.

But of course, that just means that organic farms create more jobs. And doesn’t that sound good right about now?

Posted in: Food and Agriculture Tags: , , ,

Support from UCS members make work like this possible. Will you join us? Help UCS advance independent science for a healthy environment and a safer world.

Show Comments

Comment Policy

UCS welcomes comments that foster civil conversation and debate. To help maintain a healthy, respectful discussion, please focus comments on the issues, topics, and facts at hand, and refrain from personal attacks. Posts that are commercial, self-promotional, obscene, rude, or disruptive will be removed.

Please note that comments are open for two weeks following each blog post. UCS respects your privacy and will not display, lend, or sell your email address for any reason.