NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
July 13, 2000
The Environmental Protection Agency has granted a Section 18 crisis exemption for the use of the Plateau, a fall-applied herbicide, to control leafy spurge in North Dakota pastures, rangeland, hay fields and land enrolled in the Conservation Reserve Program.
Because of the herbicide's chemical makeup and its application time frame, North Dakota's cattle producers and owners or operators of CRP land now have another option for controlling leafy spurge, a noxious weed that infests more than 1 million acres, says an invasive weed specialist at North Dakota State University.
"The active ingredient in Plateau is imazapic, an ALS inhibitor that gives Plateau very good leafy spurge control," says Rodney Lym, an NDSU plant scientist. "A key advantage of this herbicide is that it's labeled for use under certain species of trees, and its fall-only application gives it a different window of control."Under the label in effect for the Section 18 exemption, there is no grazing restriction after a Plateau application, Lym says. The haying restriction is seven days. The label allows a single application of Plateau at a rate of from 8 to 12 fluid ounces of product per acre, and a methylated seed oil must be added to the herbicide.
Lym recommends applying Plateau at the 8-ounce rate, based on NDSU research. He explains, "Plateau does cause grass suppression of some species, especially cool-season grasses, but our data indicate that these grasses will recover."
The cost of applying Plateau is about $20 per acre, which is similar to treatments of Tordon 22K (picloram) plus 2,4-D. Unlike Tordon 22K, Plateau is not a restricted-use herbicide.
Lym adds, "Plateau doesn=t have the groundwater concerns that some of the other herbicides do."
The exemption for Plateau expires at the end of the year. According to the North Dakota Department of Agriculture, a maximum of 95,000 acres may be treated with Plateau.
"Our research has shown that a mid-September application is ideal," Lym concludes.###
Source: Rodney Lym (701) 231-8996
Editor: Dean Hulse (701) 231-6136