EPA approves new weed killer for engineered crops

Farm Forum

WASHINGTON (AP) — The Environmental Protection Agency has approved a new version of a popular weed killer to be used on genetically modified corn and soybeans.

The EPA said on Oct. 15 that it will allow the use of a 2,4-D weed killer called Enlist Duo, a new version of the popular herbicide used since the 1940s. It is designed to be used with genetically modified corn and soybeans approved by the Agriculture Department last month.

The seeds are engineered to resist the herbicide, so farmers can spray the fields after the plants emerge and kill the weeds while leaving crops unharmed.

The agriculture industry has anxiously awaited the approvals, as many weeds have become resistant to glyphosate, an herbicide commonly used on genetically modified corn and soybeans now. Enlist includes a combination of both the new version of 2,4-D and glyphosate.

Critics say they’re concerned the increased use of 2,4-D could endanger public health and more study on the chemical is needed. The USDA has predicted that the use of 2,4-D could increase by an estimated 200 percent to 600 percent by the year 2020.

The EPA said in a release that the agency’s decision reflects a large body of science and that officials used “highly conservative and protective assumptions to evaluate human health and ecological risks.” The EPA said the herbicide meets safety standards for the public, agricultural workers and endangered species. This is the third time EPA has reviewed the safety of the herbicide in recent years.

2,4-D is now used on other crops, including wheat, and on pastures and home lawns. It is the world’s most popular herbicide and the third most popular in the United States, behind atrazine and glyphosate.

Groups lobbying the agency to prevent its expanded use say they are concerned about 2,4-D’s toxic effects and the potential for it to drift. Corn and soybeans are the nation’s largest crops, and the potential for expanded use is huge.

Dow AgroSciences, which manufactures Enlist, says the new version has been engineered to solve potential problems, like drift before and after the herbicide hits the plant.

To further address concerns, the EPA is requiring a 30-foot buffer zone where the herbicide can’t be sprayed. The agency is also requiring farmers to stop spraying if wind speed is over 15 miles an hour. And the approval announced on Oct. 15 only allows the use of the weed killer in six states: Illinois, Indiana, Iowa, Ohio, South Dakota and Wisconsin.

The agency said it is taking comments on whether to register the herbicide in 10 additional states: Arkansas, Kansas, Louisiana, Minnesota, Missouri, Mississippi, Nebraska, Oklahoma, Tennessee and North Dakota.

Critics have expressed additional concern that weeds will eventually become resistant to the herbicide, as they have glyphosate. EPA says it is requiring better surveying and reporting of weeds to try and get ahead of that problem, and the approval will expire in six years, allowing EPA to revisit the issue of resistance.

Opponents were unmoved. The advocacy groups Center for Food Safety and Earthjustice each indicated they were considering lawsuits.

“EPA has turned its back on those it purports to protect — the American people and our environment,” said Andrew Kimbrell, executive director for Center for Food Safety.

Farmers said the tools are needed to combat growing weed problems across the country. Weeds resistant to the glyphosate can invade fields and spread quickly, sucking up needed resources and causing lower yields.

Pushing for the new herbicide’s approval has taken “determination and patience,” said John Linder, an Ohio farmer who is a member of the National Corn Growers Association.

Dow AgroSciences said it would announce in the coming weeks when it will start marketing Enlist.