The EPA cleared the Dow weedkiller Enlist Duo, which contains the herbicides glyphosate and 2,4-D, for use on genetically engineered corn and soybean in six Farm Belt states. “This action provides an additional tool for the agricultural community to manage resistant weeds,” it said. EPA will decide later whether to register the weedkiller for use in the rest of the major corn and soybean states. On Sept 17, USDA approved the GE corn and soybean strains created by Dow to tolerate the herbicide.
The herbicide was developed as a way to combat so-called superweeds that resist treatment by glyphosate, which is used widely. Some environmental groups say the Dow weedkiller will be a short-lived stopgap against superweeds and will result in massive applications of herbicides in the end. “Giving a chemical company the green light to bring a known harmful weed killer to market for use on millions of acres of crops puts public health and the environment in danger,” said the Environmental Working Group.
For Dow, the “package of genetically altered corn and soybean seeds and complementary herbicides…could become the best-selling product line ever for the Indianapolis company,” said the Indianapolis Star. Dow said it will begin sale of the GE crops and herbicide for 2015 crops. It took five years to obtain federal approval of the seeds and weedkiller, said the Star. Bloomberg said Dow’s chief executive “is counting on the Enlist system to help double earnings at Dow AgroSciences in five to seven years.”
In its announcement, EPA said it set limits on how, when and where the herbicide can be applied and will require action to monitor and curtail new development of superweeds.
“The registration will expire in six years, allowing EPA to revisit the issue of resistance. In the future, the agency intends to apply this approach to weed resistance management for all existing and new herbicides used on herbicide tolerant crops,” said the announcement. EPA said its assessments showed the new herbicide met the legal threshold of “reasonable certainty of no harm” to human health.
The six states where Enlist Duo can be used are Illinois, Indiana, Iowa, Ohio, South Dakota and Wisconsin. To prevent pesticide “drift,” farmers will have to leave a 30-foot-wide no-spray buffer in fields where the herbicide is used, spray it only from ground equipment and to forgo spraying if winds are above 15 mph. Dow also will be required to carry out extensive surveys of weed reaction to the chemical and to educate growers about superweeds.
“This final step should place a necessary, new tool in the hands of corn and soybean farmers in immediate need of new systems to combat growing weed pressures throughout the Corn and Cotton belts,” said the National Corn Growers Association.
EPA is accepting comment until Nov 14 on whether to approve the herbicide for use in Arkansas, Kansas, Louisiana, Minnesota, Missouri, Mississippi, Nebraska, Oklahoma, Tennessee and North Dakota.
The EPA docket on the herbicide is available here. An EPA question-and-answer sheet is available here.
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