The next argument over genetically engineered crops has arrived with Dow AgroScience’s bid to gain federal approval for soybean and corn varieties that resist the herbicide 2,4-D and for Enlist Duo, a 2,4-D-glyphosate mix that can be used on the new varieties.
The double-headed proposal has angered opponents of biotech crops, who say it’s the second coming of “Roundup Ready.” Introduction of crops that could resist glyphosate, the key ingredient in Monsanto Co.’s Roundup herbicide, resulted in heavy use of the chemical and, at first, excellent weed control.
But since Roundup Ready crops were introduced in 1996, at least 22 weed types have developed resistance to glyphosate, according to a 2012 report by Purdue University. The 2,4-D mix is intended to zap the “superweeds.”
U.S. Rep. Peter DeFazio, D-Ore., convened a congressional briefing on the topic May 21 and, in a prepared statement, said food manufacturers and chemical companies are “running a dangerous experiment with the food we eat.”
He said chemical companies got farmers “hooked” on their earlier products and now want to do the same with 2,4-D.
“This herbicide will only take farmers further down the road of no return,” DeFazio said in a statement released by his office.
David Mortensen, a Pennsylvania State University weed scientist who took part in DeFazio’s briefing, said the applications could result in a huge increase in 2,4-D use across a broad swath of America’s cropland.
“This is not a minor tweak in our agriculture system,” Mortensen said. “There are downsides when you use pesticides like this.”
Iowa farmer George Naylor, who also took part in the briefing, said 2,4-D use should not become a routine practice. Naylor, who grows non-GMO corn and soybeans, said he’s used 2,4-D twice in 38 years of farming. The herbicide should be used only as a last resort, “rescue” application against weeds, he said.
“Drift can be a huge problem and it will be a problem,” Naylor said.
The approval process is a big issue in the Midwest, where corn and soybeans are the predominant crops, but Northwest growers have a dog in the fight as well. Oregon wine grape growers say 2,4-D drift is already a problem, and this spring launched a campaign to establish voluntary 350-foot buffers from neighbors who use it. They favor a ban on 2,4-D use from April to October, and the Oregon Department of Agriculture has convened a committee to study the problem.
The Purdue University report noted that some weed scientists and growers believe 2,4-D-resistant crops will make farmers more dependent on seed and chemicals controlled by large corporations, will damage other crops and will accelerate the evolution of herbicide-resistant weeds.
Others argue that 2,4-D has been used since the 1960s without widespread damage. The Purdue report said there is no unified opinion among weed scientists and growers.
Approval is pending with the USDA’s Animal and Plant Health Inspection Service and U.S. Environmental Protection Agency. APHIS has issued a preliminary recommendation to approve all three 2,4-D-resistant varieties. Meanwhile, the EPA is assessing the risk of Enlist Duo pesticide to other plants.