"Peak Herbicide" – What Happens When Weeds Acquire Weed-killer Resistant GM Traits?


New Scientist is reporting that oil-seed rape (aka canola) has escaped cultivated land and become a tenacious weed. The battle against weeds is an age-old story, but this new problem comes with a twist. These "feral" canola plants have acquired a resistance to two of the most common herbicides – glysophosphate (Roundup) and glufosinate (Liberty Link). 

Several scenarios could explain how this happened, says Schafer, who conducted the project with her superviser, Cynthia Sagers. "It could have happened if one farmer planted glyphosate-resistant canola, and his neighbour planted glufosinate-resistant canola, for example." Canola plants escaped as weeds from one field could have been fertilised by pollen from the other, leading to a doubly resistant weed.

In case you're not familiar with how modern GM crops work let me explain. Modern crops have been genetically designed to resist the effects of certain herbicides so farmers can blanket their crops with herbicides that kill the weeds but not the crop. Seeds and herbicides are sold in tandem which is more expensive for the farmer, but the ability to kill off all the weeds leads to higher yields.

The scientists say this is not cause to freak out yet, but:

…there's a risk that genes for weedkiller resistance will spread to wild relatives. In 2002, two separate teams showed in controlled studies that wild sunflower and sugar beet could swap genes with genetically modified relatives and become fitter in the process. The latest findings in canola confirm that this is happening. 

The emerging resistance of weeds to herbicides is a ticking time bomb in American agriculture asreported earlier in July by St. Louis Today:

The problem, farmers and weed scientists say, is getting worse: Weeds are becoming increasingly resistant to Monsanto's Roundup, sold generically as glyphosate, forcing farmers to use other herbicides or "multiple modes of action." But during this season especially farmers are finding that these other modes of action aren't working either — and there appears to be little relief on the horizon. In Missouri, herbicide dealers have sold out of Cobra, one of the herbicides most widely used in tandem with glyphosate.

"Are they running out of options?" asked Aaron Hager, a weed scientist with the University of Illinois at Urbana-Champaign. "The simple answer is yes."

One way to describe the cycle is that we've reached "peak herbicide." If we soak our land in these chemicals over an extended period of time, weeds will eventually find a way around our toxic firewall and there will be diminishing returns. The answer right now is to add more chemicals, and to resurrect older more toxic varieties to use in combination with their modern replacements. This also means that farmer costs are going through the roof and food and other commodities are going to continue to get more expensive. 

Some voices are decrying the "fear mongers" who are questioning GM crops developments. A recent article reflects this:

"Fear mongering is easy to do," said Dr. Frank Shotkoski, Director of the Agricultural Biotechnology Support Project II (ABSPII) based in Cornell University, describing a sustained campaign against crops that have been genetically altered to bring resistance to insects and environmental stress.

"We are reaching a phase when the campaign against agricultural biotechnology is at a high peak," he said.

The key line in the article for me is this one:

"Not a single food safety issue has been verified, there is no evidence of a safety issue in the 15 years and so many million hectares of Bt crops planted," said Dr. Randy A. Hautea, Global Coordinator for ISAAA.

If a consequence of GM crops is a huge spike in the use of more toxic chemicals, isn't that a safety issue? It's take us 15 years to get to that point, but isn't it likely that this will endanger ag workers and degrade land? And isn't it possible that we won't be able to "verify" these consequences until it's too late? Before we hand over the fate of our entire food system GM crops and their chemical antecedents, I'd like to see a lot more research into the consequences to the health of people, land, and economies. I'm not anti-science but for now count me among the fear mongers.

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