News & Resources

EPA Pressed on Enlist Duo

23 Dec 2015

By Todd Neeley
DTN Staff Reporter

OMAHA (DTN) -- Agriculture interest groups Tuesday pleaded with the U.S. Environmental Protection Agency to reverse its decision to review the herbicide Enlist Duo's registration.

In a letter to EPA Administrator Gina McCarthy, the American Farm Bureau Federation, American Soybean Association, National Corn Growers Association, National Cotton Council and the National Farmers Union said the agency didn't follow the Federal Insecticide, Fungicide, and Rodenticide Act, or FIFRA.

The groups said EPA should have followed a FIFRA process that "recognizes due process by requiring EPA to comply with a number of procedural safeguards before a pesticide registration can be cancelled."

Back in November, EPA said in a motion filed in the U.S. Ninth Circuit Court of Appeals that the agency wants to pull the plug on Dow AgroScience's Enlist Duo herbicide. The agency cited "new information" it received about the potential environmental effects of the herbicide designed to work with genetically engineered corn and soybean.

EPA said because it had "new information regarding potential synergistic effects between the two ingredients on non-target plants, EPA seeks a voluntary remand in order to reconsider the Enlist Duo registration in light of the new information." In court documents, the agency said it "cannot be sure, without a full analysis of the new information, that the current registration does not cause unreasonable effects to the environment, which is a requirement of the registration standard under FIFRA."

In the letter to McCarthy this week, the ag groups said farmers are scrambling to fight weed resistance and ask EPA to reverse its decision.

"U.S. growers have an urgent need for a new mode of action as these regulatory delays have exacerbated the proliferation of hard-to-control weed populations," the letter states. "These delays are necessitating more intense weed control practices that complicate environmental management.

"Herbicide-tolerant cropping systems allow growers to more efficiently use active ingredients for weed control while providing environmental benefits like reduced tillage that improves soil heath and limits nutrient run-off. Additional herbicide modes of action will help proactively manage weed herbicide resistance."

The groups said EPA's decision essentially pushes aside what already was an extensive review of Enlist Duo.

"Among the many new requirements for registration of Enlist Duo at EPA was an unprecedented review of the potential effects of the product on threatened and endangered species," the ag group said in the letter. "After an exhaustive state-by-state review, EPA concluded that use of Enlist Duo in accordance with the product label, which imposed a 30-foot wind directional buffer zone, would have no effect on threatened and endangered species. This review took place on a product that simply combines two herbicides that have each been on the market for decades."

The ag groups said as is the case with any chemical, new information always will come to light.

"Congress has recognized this, and included in FIFRA several vehicles for reviewing products," the groups stated in the letter. "But none of these vehicles authorize the agency to withdraw a previously approved product in the absence of an 'imminent hazard.'"

Enlist Duo contains a mix of glyphosate and a new formulation of 2,4-D. The product received EPA registration in a select number of corn states in fall 2014. The genetically engineered trait package that gives crops resistance to those two herbicides was approved for corn and soybeans September 2014 and for cotton, July 2015.

In October 2014, EPA approved Enlist Duo for corn and soybeans in six states. In April 2015, EPA granted final approval of Enlist Duo for use in nine additional states, bringing the total to 15 states.

Dow had not yet fully launched the seed and herbicide package. It had been conducting research, seed production and "stewarded" trials for corn and soybean seed in 2015. Dow had said it was holding full commercial release pending Chinese approval of the genetically engineered traits in grain. Dow had said it did not want producers to run into grain sales issues; China has a recent history of being slow to approve a number of U.S.-approved traits and has refused U.S. corn that contained unapproved traits.

According to the motion filed by EPA last month, the agency originally registered the herbicide because it saw "no indication of synergism" with the combination of glyphosate and 2,4-D. So, in approving the new combination product, it reviewed the toxicology and other environmental effects of each herbicide individually. It did not ask for research trial data on the two active ingredients together because, at the time, EPA said "it is reasonable to assume that there are no synergistic interactions for the taxonomic groups that were not tested, including plants."

Enlist Duo had been labeled for use in Arkansas, Kansas, Louisiana, Minnesota, Missouri, Mississippi, Nebraska, Oklahoma, Illinois, Indiana, Iowa, Ohio, South Dakota, Wisconsin and North Dakota. EPA had considered approving the product for use in Tennessee, but decided against it because of concerns it would harm some the endangered plant species Spring Creek bladderpod.

To read the ag groups' full letter to EPA, visit: https://soygrowers.com/…

Todd Neeley can be reached at todd.neeley@dtn.com

Follow him on Twitter @ToddNeeleyDTN

(PS/AG)