EPA considers regs to curb herbicide resistance in weeds
Environmental authorities are considering new regulations to prevent biotech crops from causing herbicide resistance in weeds.
The new restrictions would pertain to herbicides that are sprayed on crops genetically engineered to withstand the chemicals, according to an official with the U.S. Environmental Protection Agency.
“The goal is to implement a stewardship program,” said Alan Reynolds, biotechnology team leader for the agency.
Reynolds spoke about the possible restrictions during the July 10 meeting of a task force on genetic engineering convened by Oregon Gov. John Kitzhaber.
Many biotech crops can withstand glyphosate herbicides, which eases weed control for farmers.
Critics say the crops have encouraged more glyphosate usage, increasing the chances that weeds will develop resistance to the chemical.
In response, biotech developers are trying to commercialize new genetically engineered crops that can withstand additional herbicides, such as 2,4-D.
Dow AgroSciences has created corn and soybeans that can tolerate its Enlist Duo product, a combination of glyphosate and a new type of 2,4-D.
Weeds that can tolerate glyphosate would nonetheless be killed by the 2,4-D, slowing the spread of resistance.
USDA is still deciding whether to deregulate the crops and allow them to be grown freely.
Meanwhile, the EPA is examining additional restrictions for Enlist Duo to minimize the “selection pressure” that leads to herbicide resistance in weeds, Reynolds said.
The agency may implement new labeling restrictions for the herbicide and other new products, he said.
Manufacturers may also have to abide by “terms and conditions,” such as including restrictions in licensing contracts with growers who buy biotech seed, he said.
“Companies must work with their growers to try to make this work,” Reynolds said. “That contract then obligates the grower to implement” herbicide stewardship practices.
Reynolds did not speak about specific requirements, but weed scientists recommend using cover crops, tillage and other practices to discourage resistance.
Ivan Maluski, director of the Oregon-based anti-GMO group Friends of Family Farmers, said he was skeptical of the EPA’s proposal.
Weed resistance to herbicides is spreading quickly, but the EPA would only place new restrictions on existing herbicides when they’re reviewed every 15 years, he said.
“It’s not much consolation, from my perspective,” said Maluski.
Officials from the USDA and U.S. Food and Drug Administration also participated in the task force meeting, giving a primer on federal biotech regulations.
The USDA’s Animal and Plant Health Inspection Service only has the authority to regulate biotech crops that were developed with the help of plant pests, like agrobacterium, said Mike Firko, deputy administrator of Biotechnology Regulatory Services.
Crops that were genetically engineered without the use of such pathogens — like glyphosate-tolerant Kentucky bluegrass — cannot be regulated by the agency, he said.
Firko pointed out the agrobacterium can naturally reconfigure plant genes, but scientists are now able to direct how those changes occur.
“This is a process that has been happening for eons,” he said.
Even so, the agency must regulate crops that rely on agrobacterium for genetic engineering, even if the microbe has “disarmed” to be non-pathogenic, Firko said.
Several officials from the FDA also explained that biotech developers can submit their crops to the agency for a voluntary food safety consultation.
The agency has about 15 staff members who help companies determine whether biotech crops could be toxic or pose allergen risks.
While the process is voluntary, most biotech crop developers prefer to consult with the FDA to preempt later questions about safety, the officials said.
During consultation, the agency considers evidence submitted by the biotech developer and any other available research, but doesn’t conduct its own analysis, the officials said. “We typically do not generate data on our own.”