The EPA plans to release a report in the coming months, and the two agencies are expected to make final decisions simultaneously on use of the chemical and seeds. It was not clear when that would happen.
Dow AgroSciences has asked the USDA to deregulate one corn and two soybean varieties, all resistant to both 2,4-D and glyphosate, the generic form of Roundup.
The USDA said farmers could help curb resistance to 2,4-D by using a variety of means to fight weeds and not relying solely on the one herbicide.
Eighty-six percent of corn, soybean and cotton farmers in the South and 74 percent of those in the Midwest have had problems with hard-to-control weeds, Hamlin said, citing private data from agricultural services.
“These growers need new tools,” he said.
Moore said he currently uses both glyphosate and another herbicide in an effort to discourage resistance. He was not certain whether he would use the Enlist seeds and 2,4-D if that became an option because he has not had problems with Roundup resistance.
But he said he knows famers who have had trouble, and some have gone back to tilling. Weeds cannot be left in fields because they suck up the nutrients, water and sunlight meant for crops.
“Those are the three things that plants all need to grow,” Moore said. “I don’t want anything competing with my soybeans.”
Freese said he would rather see farmers use organic means to control weeds, perhaps by using cover crops that go into the ground after the harvest to hold soil in place and deter weeds until the next growing season.
Among its critics, 2,4-D is best known as a component of the Vietnam War-era herbicide Agent Orange, which has not been produced since the 1970s.
Agent Orange has been tied to health problems in Vietnam veterans, but scientists do not believe 2,4-D was the culprit. Instead, their research focused on dioxin, a cancer-causing substance found in another ingredient known as 2,4,5-T, which was banned by the EPA in 1985.