Enlist Duo Approved

OMAHA (DTN) -- EPA has approved the use of Enlist Duo herbicide and currently will limit its release to six states, the agency announced Wednesday. An agency official said the herbicide likely would become more widely available in the coming years. In addition, EPA also has opened a public comment period until Nov. 14 to consider the registration of the herbicide in 10 more states.

The herbicide registration includes a number of use requirements and restrictions that are unusual for an EPA registration. The agency is particularly interested in curbing weed resistance to herbicides, and said all new herbicide-tolerant crops will likely carry restrictions to guard against the overuse, and subsequent weed-resistance problems, that have plagued glyphosate-resistant crops.

Enlist Duo is a new formulation of 2,4-D and glyphosate created specifically to be used with crops that carry Enlist herbicide-resistance traits. Both the plant trait and the herbicide were created by Dow AgroSciences. The trait, in corn and soybeans, was earlier approved by federal agencies for planting in the U.S. Dow was awaiting the herbicide approval before announcing its intentions on selling the system for the 2015 crop season.

EPA approved the registration of the herbicide in Illinois, Indiana, Iowa, Ohio, South Dakota and Wisconsin. In addition, the new public comment period is to consider registration in 10 other states where the agency recently completed additional Endangered Species Act determinations -- in Arkansas, Kansas, Louisiana, Minnesota, Missouri, Mississippi, Nebraska, Oklahoma, Tennessee and North Dakota.

The six approved states are areas with strong penetration by Dow's Mycogen Seeds and other seed partners. The 10 additional states, particularly southern states of Arkansas, Louisiana, Tennessee and Missouri, are key battleground areas for tough glyphosate-resistant weeds such as Palmer amaranth.

Registering in southern states also raises a conflict between grain production and cotton. The fiber crop is especially sensitive to even minor amounts of 2,4-D drift and a tolerant trait is not yet available in cotton.

Jim Jones, assistant administrator for EPA's office of chemical safety and pollution prevention said during a conference call with reporters Wednesday that the agency has found the body of science in support of its decision to be comprehensive, and that the product likely will be made available where it is needed across the country at some point.

Such broader registration will depend on where the crop/herbicide system is needed to fight weed resistance, and where additional analysis finds no conflicts or concerns with potential harm to endangered species in other states.

"We're very confident in the science," Jones said, saying the decision would withstand a legal challenge. "When we announced a proposed decision back in the spring we had completed endangered species determinations on six states."

Allowing the product to be sold in multiple states, he said, "really is just an endangered species aspect of this. The decision protects everyone as well as the environment."

EPA determined that the body of science proves that Enlist Duo's risk to health and the environment to be low. "The resulting estimates are below levels of concern for human health as well as to endangered species," Jones said.

HERBICIDE USE RESTRICTED

The approval includes first-time restrictions to manage what has become a nationwide problem with weed resistance. Enlist Duo will be used to control weeds in corn and soybeans genetically engineered to tolerate 2,4-D and glyphosate.

Jones said EPA used "highly conservative and protective assumptions" in evaluating the risks Enlist Duo may or may not pose to human health and the environment.

The registration also requires 30-foot, in-field, no-spray buffer zones to minimize drift, does not allow spraying when winds are greater than 15 miles per hour and it can only be applied to the ground. In addition, EPA will require scouting and reporting for potential weed resistance to Enlist Duo, as part of the six-year registration. "This is designed for early protection of resistance," Jones said.

The agency noted dozens of other countries have approved these pesticides for use on numerous crops and residential lawns. Last year, Canada approved the use of Enlist Duo for the same uses that EPA is authorizing. Others include Argentina, Australia, Canada, Colombia, Japan, Korea, Mexico, New Zealand, South Africa and Taiwan. In addition, it is approved for use in 26 European Union nations.

When the registration expires in six years, it will allow EPA to revisit the resistance issue, Jones said. The agency intends to apply the same approach to weed-resistance management for all existing and new herbicides used on herbicide-tolerant crops.

This most recent assessment is the third time EPA has evaluated the safety of 2,4-D and the safety finding is consistent with past assessments that EPA has performed for 2,4-D. EPA reviewed 2,4-D in 2005, and once more in 2012 and now in 2014.

The Enlist hybrids and varieties, which already have U.S. approval for planting, contain traits that are not yet approved in China or the European Union. The issue of unapproved traits, specifically Syngenta's Viptera (MIR 162) and Duracade traits, have been implicated in issues selling corn and corn products in China. Grain companies and farmers recently sued Syngenta for loss of sales due to China not accepting grains and grain products such as dried distillers grains with solubles (DDGS).

EPA's final regulatory decision document on Enlist Duo herbicide is available in EPA docket EPA-HQ-OPP-2014-0195 at www.regulations.gov

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

Follow Todd on Twitter @toddneeleyDTN

Pam Smith and Greg Horstmeier contributed to this story

(GH/SK)

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