Hey, GM Crops Are Great -- If You Like Superweeds, That Is

Last Updated Apr 16, 2010 8:30 AM EDT

A new biotech report from the National Research Council, which concluded that genetically engineered crops offer "substantial net environmental and economic benefits compared to conventional crops," might look like a cause for celebration in the halls of companies like Monsanto (MON). Alas, it's not. In fact, it may be just the opposite.

The beefy 318-page report offers a few hopeful nuggets -- farmers who plant genetically modified crops (soybeans, corn, canola and cotton) don't need to till their soil as much, thus reducing the soil erosion and pollution runoff that often results from tilling. And in many instances GM crops produce higher yields for farmers and help them control pests better, thus saving money.

But -- and this is a big but -- the authors warn that the continued rampant use of GM crops that are engineered to be resistant to the chemical herbicide glyphosate (also known as Monsanto's herbicide Roundup) could cause the "evolution of glyphosate-resistant weeds." What they're talking about here is Mother Nature's blowback. It's the overuse of a particular chemical, in this case Roundup, that causes weeds to cleverly evolve to resist it.

In some areas of the country, the attack of the superweeds has already begun. In the south, farmers have responded by dousing their fields with even more glyphosate, which is the agricultural equivalent of treating your hangover with a couple bloody Marys. It's a blunt strategy that may work for a while, but will only breed even stronger weeds later down the road.

And news of GM farmers dumping more chemicals into the environment isn't exactly a selling point for a technology that already has a few image problems and a few critics who would love nothing more than to see it banned from fields all together. A report from The Organic Center last year found that over the past 13 years farmers in the US applied 318 million more pounds of pesticides as a result of planting GM seeds, largely due to glyphosate-resistant superweeds.

And the problem seems to be one that gets worse over time. In the first three years of GM crops, author Charles Benbrook writes, everything worked as it was supposed to and GM crops needed less pesticides than conventional ones. But in 2000, the trend reversed and it's been downhill ever since. Although a small amount of this huge increase in pesticide use was offset by reduced insecticide use on another so-called Bt variety of GM crops.

The rise of superweeds gives weight to what anti-GMers have been saying -- in some cases screaming -- for years: In the long-term, GM crops don't work and they wreak havoc on the environment.

Monsanto will no doubt cherry pick the various happy findings in the NRC report. The company issued a cheery statement saying the report "affirms what farmers know -- that agricultural biotechnology has delivered substantial environmental and economic benefits." But when you add superweeds to a Justice Department antitrust investigation and a court case that threatens the future of Roundup Ready sugar beets, it's a recipe for troubled times ahead.

Image by Flckr user Rétrofuturs (Hulk4598) / Stéphane Massa-Bidal