The Environmental Protection Agency is weighing an emergency request by Texas regulators to allow cotton farmers to deploy a controversial herbicide, marking a new front in the war on “super weeds” that has divided agricultural groups and environmentalists.
The Texas Department of Agriculture asked the EPA last month for an exemption to permit growers to douse fields this summer with propazine—a chemical little-used in U.S. agriculture—to control an invasive plant known as palmer amaranth, or pigweed.
Pigweed, which can grow 3 inches a day, is one of several nasty invaders that have developed resistance to the nation’s dominant weed killer, glyphosate, which is widely sold by Monsanto Co. as Roundup.
Texas, at the behest of the state’s cotton growers, is asking the EPA to let farmers spray propazine, the active ingredient in the herbicide Milo-Pro, on up to 3 million acres, or nearly half of the state’s estimated cotton acreage this season. The Lone Star state is the nation’s largest cotton producer, accounting for 33% of last year’s crop, which was valued at $5.2 billion, according to the U.S. Agriculture Department.
The Center for Food Safety, a nonprofit advocacy group, and other environmental watchdogs oppose the proposal on the grounds that propazine poses potential risks to human health. Propazine has been identified by the EPA as a possible human carcinogen and is a restricted-use pesticide requiring a license to purchase and apply, according to Milo-Pro’s manufacturer.
Propazine is closely related to atrazine, a herbicide used by many corn growers that is banned in the European Union. Critics of the sister herbicide cite studies indicating it can interrupt sexual reproduction in frogs, and result in potential human reproductive problems.
The EPA says that propazine’s similarity to atrazine suggests it may cause disruptions to hormonal systems in rats, and has the potential to leach into groundwater or reach surface waters by runoff.
Milo-Pro, produced by Iowa-based Albaugh Inc., is currently approved by the EPA only for use on grain sorghum crops in Texas, Oklahoma, New Mexico, Colorado and Kansas, according to Jim Musser, a sales manager for the company.
Originally registered in the 1950s, propazine’s EPA registration was cancelled in 1988 due to failure of chemical companies to provide data for a groundwater monitoring study, but a new registration was issued a decade later.
“We’ve been selling Milo-Pro for the past five seasons and we’ve had no issues with groundwater or surface water after conducting the required testing,” said Mr. Musser. “It’s further down the molecular chain than atrazine and is used on far less acres.”
The EPA began seeking public comment on the request Wednesday and typically rules on emergency exemptions within 50 days. The EPA declined to comment on the request.
“Pigweed is a really serious problem for farmers,” said Bill Freese, science policy analyst at the Center for Food Safety. “But propazine is not the solution. We need to have farm practices that don’t create resistant weeds in the first place, so we don’t have to resort to toxic herbicides to treat them.”
U.S. farmers have had some success in controlling pigweed using a growing arsenal of herbicides, but Texas’s proposal underscores the challenge farmers face in keeping the weed from strangling their crops.
“Weed resistance is of utmost concern for us,” said Ned Meister, director of regulatory activities for the Texas Farm Bureau. “The purpose of the request is to put another tool in the toolbox for farmers to address weeds that are resistant to other chemicals.”
Farmers for a decade have been fighting weeds that have developed resistance to glyphosate, especially in the South, where a longer growing season and warm climate have made it the battle’s front line.
St. Louis-based Monsanto revolutionized the pesticide business in the mid-1990s when it began selling genetically modified seeds, some of which were altered to withstand sprays of glyphosate, which kills plants by halting their internal protein production. Farmers embraced Monsanto’s Roundup, which could destroy many weeds while leaving crops unscathed. But they increasingly have used herbicides considered harsher than glyphosate in recent years, including the chemicals 2, 4-D and dicamba, to fight the super weeds.
Besides chemicals, farmers can try to stem pigweed’s growth by rotating crops each year, planting cover crops and hand weeding. But finding labor for weeding nowadays is tough, according to cotton farmers.
“One pigweed plant can produce thousands of seeds, so it doesn’t take many plants to get you in trouble in a hurry,” said Walt Hagood, a third-generation farmer who grows cotton, grain sorghum, wheat and other crops near Lubbock, Texas. “In some places, pigweed is starting to take whole fields.”
—By Jesse Newman and Tony C. Dreibus via. The Wall Street Journal
Posted by: Charlie Middleton