2,4-D-resistant field corn, soybeans pass safety tests in Canada
Dow only needs to clear one more hurdle; seeds could be on market by spring
By Ian MacLeod, The Ottawa Citizen October 22, 2012
OTTAWA — Dow Chemical is close to selling controversial corn seed genetically modified to withstand dousing with the herbicide 2,4-D to repel “superweeds” on Canadian farms.
Health Canada and the Canadian Food Inspection Agency (CFIA) have completed three out four mandatory safety assessments on Dow AgroSciences’ 2,4-D-tolerant field corn and soybeans and approved the crops for human and animal consumption and plant biosafety.
The “Enlist” crops are engineered with recombinant DNA to tolerate spraying with a reformulation of the 1940s-era 2,4-D and glyphosate, for decades the most popular broad-spectrum weed herbicide in North America but to which weeds are becoming increasingly immune.
The novel corn and soybean seeds are now considered “unconfined” and approved for release into the environment, the government said Monday.
Pending a fourth and final safety approval for its “Enlist Duo” 2,4-D-glyphosate herbicide, Dow hopes to have the corn seeds on the Canadian market in time for next spring’s planting season and the soybeans by 2015.
“GM crops have been safely grown in Canada for the past 20 years,” the CFIA said in a statement. “High level of acceptance of these crops by farmers indicates that farmers value enhanced options for the management of weeds and pests that such crops provide.”
Similar approvals for the new Enlist biotech crop system are being sought by the company in the United States, Brazil and Argentina.
Dow rival Monsanto and chemical giant BASF, meanwhile, are awaiting federal approvals for their partnered new line of soybean seeds genetically modified to tolerate spraying with another proven broad leaf weed herbicide, dicamba.
The crops are the industry’s response to an invasion of glyphosate-resistant farm weeds. The herbicide is best known under the Monsanto brand name Roundup, for spraying on Roundup Ready corn, soybean and cotton genetically modified to tolerate glyphosate. The weeds die while the plants survive.
But the enormous success of the “Roundup revolution” that began in the 1990s has led to widespread dependence and overuse of glyphosate, resulting in superweeds immune to its killing properties.
In southwestern Ontario, two glyphosate-resistant broadleaf weed species — Giant Ragweed and Canada Fleabane — were found in nine fields between 2008 and 2010, the first such glyphosate resistance documented in Canada.
By last fall, 125 fields were infested. A third glyphosate-resistant weed, Kochia, was confirmed this year in southern Alberta
Superweeds have infested an estimated five million hectares in the U.S.
Without efficient weed control, farmers face increased production costs, reduced crop yields and the prospect of returning to the laborious practice of tilling their fields, which they say promotes soil erosion and pesticide run-off into streams.
But critics believe Enlist’s genetically-modified resistance to the chemicals will lead to widespread spraying and overspraying. That, in turn, could lead to resistance to 2,4-D and dicamba and another step along what some in agriculture say is a worrisome “herbicide treadmill.”
As well, because traditional 2,4-D is prone to vaporizing into a gas and drifting when sprayed, many U.S. farmers fear potential contamination of unprotected neighbouring conventional and organic crops.
The chief uses for field corn are as livestock feed and for ethanol fuel. In Canada, an estimated 25 per cent of the food products on a typical grocery store’s shelves contain field corn-derived ingredients, in everything from breads to toothpaste, according to Agriculture Canada.
The U.S. Food and Drug Administration has received more than 450,000 comments opposing approval of the 2,4-D tolerant cropping system, according to the Center for Food Safety, which opposes approval.
A U.S. farmers’ group in September dropped its legal fight to stop the Enlist technology in exchange for some concessions by Dow.
The company has agreed to amend its labelling instructions for farmers to specify for applications near sensitive crops, to assist in investigating any damage claims on non-targeted crops, and in educating growers and applicators in proper application to reduce off target movement, especially in areas with sensitive crops.
Dow also said it commits to pricing both the seed and herbicide technology competitively to reduce the likelihood that farmers will use generic 2,4-D, which does not have the reduced drift and volatility when they spray their crops.
While other U.S. groups still oppose Dow’s crop system, the agreement with the farmers’ group Save Our Crops could speed regulatory approval sought by the unit of Dow Chemical.
Kendra Resler Friend, a U.S. spokeswoman for the company, said Monday the concessions will extend to Canada.
Meanwhile, several medical and public health professionals have expressed concerns that increased use of 2,4-D could be harmful to humans.
Critics have cited studies that report an association between exposure to 2,4-D and non-Hodgkin’s lymphoma, a cancer of the white blood cells that can be fatal. 2,4-D has also been linked to birth defects, neurological damage in offspring, and interference with reproductive function, according to critics.
Regulators in Canada, the U.S. and European Union have all declared it safe if used as directed.
With a file from Reuters
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