By Todd Neeley
DTN Staff Reporter
OMAHA (DTN) -- EPA has approved the use of Enlist Duo herbicide in six states, the agency announced Wednesday. In addition, EPA also has opened a public comment period until Nov. 14 to consider the herbicide's registration in 10 more states.
The registration includes a number of restrictions designed to limit how and when the product can be used that are a first for such an herbicide release. EPA 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, such as those that have plagued glyphosate-resistant crops.
Enlist Duo is a new formulation of 2,4-D plus 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. A Dow spokesman told DTN that details of those sales intentions will be announced in coming weeks.
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.
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.
The six approved states are key corn and soybean areas and a important market area for 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.
Environmental groups were quick to criticize the decision. The Environmental Working Group, which has been active in efforts to stop Enlist's registration, said in a press release it was "deeply disappointed” that the agency decided to approve the "known harmful" herbicide.
Earthjustice attorney Paul Achitoff said in a statement "EPA hasn't bothered to consult the expert agencies about the herbicide's effects on endangered plants and animals, instead it made the absurd assumption it will have no effect at all. We are examining all legal options."
A main issue these groups have raised is that while both 2,4-D and glyphosate are already approved and widely used herbicides, this new Enlist system could vastly increase the amount of those herbicides applied in the environment during a crop season.
EPA said during the announcement to reporters that it determined 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.
He said the risk assessment for Enlist Duo 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. EPA reviewed 2,4-D in 2005, and once more in 2012 and now in 2014.
"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."
He said completing endangered species determinations,, not health or other concerns, is the main hurdle in approving use in the 10 additional states.
HERBICIDE USE RESTRICTED
The approval includes first-time label restrictions and requirements designed to manage what has become a nationwide problem with weed resistance due to overuse of a single herbicide. EPA also included restrictions to deal with the potential for drift and other off-target movement of 2,4-D that can damage sensitive crops.
Damon Palmer, US Enlist Commercial Leader for Dow AgroSciences, said the use restrictions are "similar and consistent with what EPA has done in the case of Bt hybrids and the mandatory refuge requirements."
The difference, Palmer said, is in the complexity of controlling weed resistance compared to insect resistance.
"With the insect situation, there was one approach -- a nonBt refuge -- that worked across the country. With weeds, there isn't that one approach."
"In north-central Iowa, the best answer to keeping weeds from becoming resistant to 2,4-D might be tillage. That's not going to work for a farmer with a lot of highly erodible soils."
The herbicide's label will include a wide range of "best management practices" farmers can pick from to control weed resistance. Palmer said the company is required to conduct farmer surveys about use, and report the first sign of resistance issues to EPA.
The Enlist Duo registration also has a sundown clause: the registration lasts for six years. Near the end of that, EPA will examine the product's use and could make additional restrictions or requirements, or pull the registration, if it feels the company isn't doing enough to curb resistance.
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.
In the Wednesday press briefing, 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 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 2,4-D and glyphosate 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.
Registering the product in southern states, which farmers there are anxious to see due to widespread issues of glyphosate-resistant weeds, 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.
Dow's Palmer said the Enlist Duo label will include expanded spray nozzle recommendations and other drift-control requirements. There are specific wind requirements for sensitive crops such as cotton, grapes and tomatoes. Farmers are forbidden, for example, in applying the herbicide any time winds are blowing in the direction of neighboring fields with those sensitive crops. So growers will have to work with neighbors, and consider prevailing winds, when making planting plans.
POTENTIAL EXPORT ISSUES
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).
Dow AgroSciences has not yet commented on how it will handle stewardship of the Enlist-trait grains if China or other potential importers don't approve the trait in time for 2015 harvest.
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 firstname.lastname@example.org
Follow Todd on Twitter @toddneeleyDTN
Pam Smith and Greg Horstmeier contributed to this story
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