US to approve Dow's Enlist Duo herbicide

The US Environmental Protection Agency (EPA) is making available for a 30-day public comment period a proposed regulatory decision to register Dow AgroSciences' Enlist Duo herbicide containing glyphosate and the choline salt of 2,4-D for use in controlling weeds in corn and soybeans genetically engineered (GE) to tolerate 2,4-D.

“Weeds are becoming increasingly resistant to glyphosate-based herbicides and are posing a problem for farmers,” the announcement stated. “If finalized, EPA's action provides an additional tool to reduce the spread of glyphosate resistant weeds.”

Data from late last year showed that more than 86 percent of corn, soybean and cotton growers in the South and 61 percent in the Midwest reported “hard to control” weeds on their farms, according to Dow.

The proposal imposes requirements on Dow to include monitoring and reporting to EPA, and would allow EPA to add more restrictions on the use of the pesticide if resistance develops.

Dow AgroSciences sent applications to EPA requesting the use of the new, lower volatility formulation of the choline salt of 2,4-D and glyphosate on GE corn and soybeans.

The company also sought USDA approval to introduce 2, 4-D-tolerant corn and soybeans into the U.S. market. These GE corn and soybean plants are the first developed to be resistant to 2,4-D and are intended to provide farmers with new plants to help address the problem of weeds that have developed resistance to other herbicides.

EPA said it is making the decision to register Enlist Duo herbicide available for public comment because the choline salt of 2,4-D, which is less prone to drift and volatilization than its other forms, is not currently registered for these uses.

The agency noted that glyphosate is already registered for several varieties of GE soybeans and corn, so no further assessment is needed for glyphosate. 2,4-D is one of the most widely used herbicides to control weeds and  is registered in the United States and in dozens of other countries, EPA noted.

EPA is accepting comments until May 30, 2014, and is expected to issue a final decision by early fall.

“In its review, the EPA acknowledged the significant scientific advancements Dow AgroSciences has achieved with Enlist Duo herbicide” said Damon Palmer, U.S. commercial leader for Enlist, Dow AgroSciences. “Enlist Duo herbicide will help solve the weed control challenges growers are facing, and will be another option to further reduce the potential for development of herbicide-resistant weeds.”

The draft label for Enlist Duo includes proposed registration for Iowa, Illinois, Indiana, Ohio, South Dakota and Wisconsin, a Dow announcement said. The company is working with EPA to expand the list of states.