Spurred to action by a lawsuit brought by a coalition of conservation groups, the EPA has revoked approval of Dow AgroSciences’ Enlist Duo herbicide. In its decision Wednesday (Nov. 25) morning, the EPA cited concerns about the herbicide’s potential impact on endangered plants and animals covered under the Endangered Species Act.
The herbicide – to be used in conjunction with genetically engineered crops – was expected to be widely adopted in 2016 in efforts to combat herbicide-resistant weeds.
Before the Wednesday announcement, the EPA had already approved Enlist Duo for use in Arkansas, Louisiana, Mississippi, Missouri, Illinois, Indiana, Iowa, Ohio, South Dakota, Wisconsin, Kansas, Minnesota, Nebraska, Oklahoma and North Dakota.
In a statement following the decision, Dow AgroSciences says it “is confident in the extensive data supporting Enlist Duo herbicide. We are working with EPA to quickly provide further assurances that our product’s conditions of registered use will continue to protect the environment, including threatened and endangered plant species. Recognizing the pressing needs of U.S. farmers for access to Enlist Duo to counter the rapidly increasing spread of resistant weeds -- and in light of the comprehensive nature of the regulatory assessments already conducted to support the Enlist Duo registration -- we expect that these new evaluations will result in a prompt resolution of all outstanding issues.”
Bob Scott, University of Arkansas weed specialist, says the development “will do U.S. agriculture no favors. Everyone knows it’s increasingly difficult to deal with herbicide-resistant weeds – especially Palmer pigweed and waterhemp. There just aren’t enough control options and the short list of ones available is only getting shorter. Producers were hoping to use Dow’s Enlist Duo to help deal with these weeds in 2016 and to have that yanked away is difficult to understand.”
Jason Norsworthy, a colleague of Scott’s at the university, says his phone has been “blowing up for the last hour. I’ve got a lot of calls to return. People are clearly worried about this – and they’re right to be.”
What is Norsworthy’s initial response to the news?
“I’m completely taken aback and am somewhat speechless. The Enlist Duo formulation is something that Dow AgroSciences has had in place – and we’ve been working with them -- for close to five years. The company has been open and forthcoming with information.
“This is just unexpected in light of the fact that EPA had already granted registration in a handful of states, one being Arkansas. We were going into the next growing season with the intention of having this technology available in cotton. The approval of the technology by the Chinese was all that was holding up Enlist Duo in soybeans.”
The EPA move is “a major setback in our fight against herbicide-resistant weeds,” says Norsworthy. “We need every tool available to deal with resistance. This will place a lot more pressure on the one tool remaining: Liberty. Going into 2016, we expect a sizable amount of our acreage to be in LibertyLink crops.
“This isn’t a minor deal. With PPO resistance, we have a single post-emergence option available to kill resistant pigweeds. Enlist Duo was going to be our second.
“We know the only way producers will manage weeds effectively long-term is through the use of multiple modes of action. This ruling hampers that.”
And what about the anticipated EPA label approval for the dicamba technology? “That’s supposed to be out in the coming months. How is that potentially impacted by this? The mindset moving forward is hard to calculate. This really changes the perspective for 2016 and beyond, I think.”