Oregon Clover Commission
An herbicide used on soybeans has proven tantalizingly effective against two troublesome weeds in Oregon clover fields, but remains out of reach for farmers.
Despite performing well in killing dock and tiny vetch during field trials, Python — the brand name for flumetsulam — did in some “outlier” cases cause damage to clover foliage.
Those instances of crop injury were enough to dissuade Dow AgroSciences, the herbicide’s manufacturer, from seeking to extend the chemical’s label registration to include clover in the U.S.
Because clover is grown on relatively few acres, the possibility for the company to earn a small profit is negated by the potential for lawsuits, said Bryan Ostlund, administrator of the Oregon Clover Commission.
“Any liability issue becomes magnified,” he said.
Dow AgroSciences did not respond to requests for comment as of press time.
While the Oregon Clover Commission has reached an impasse with Dow, the organization is still hoping to provide farmers with access to Python through another path.
At its Oct. 10 meeting in Salem, Ore., the commission unanimously voted to continue paying a consultant to explore the possibility of extending the herbicide’s federal registration to clover through an entity other than Dow.
One option would be for a smaller chemical company that specializes in niche crops to license the herbicide from Dow, taking on any liability as well as the responsibility of registering Python with the U.S. Environmental Protection Agency.
The other possibility is for a “third party registrant” — such as an agronomy company — to perform those functions at the commission’s behest, which isn’t seen as a desirable outcome.
“It gets expensive real fast,” said Ostlund.
Dock and tiny vetch are an expensive problem for clover farmers because no other currently registered herbicides can treat the weeds, said Nicole Anderson, an Oregon State University Extension field crops agent.
“They’re weed species we don’t have any other management tools for,” she said.
Seeds from dock and tiny vetch often don’t get blown out by the combine during harvest, which means they wind up at the seed cleaner, Anderson said.
Buyers have high expectations that clover seed be pure, so they have little tolerance for weed species, she said. “The growers lose a lot of good seed trying to get those levels met.”
Generally, Python achieves good weed control with limited crop injury risk in clover, Anderson said.
In field trials, though, OSU tested the herbicide’s efficacy even during periods that growers normally wouldn’t spray the chemical.
It was during these times that “outlier data points” of crop damage occurred, she said.
Though the label for Python wouldn’t allow the chemical to be sprayed during these periods, Dow nonetheless felt the risk was too great, Anderson said.