Ed Twidwell, far right, LSU AgCenter forage specialist, tells cattle producers about the results of his testing of different herbicides to control Vaseygrass. He spoke at the Vermilion Parish Cattle Field Day at Henry. (Photo by Bruce Schultz) (Click on photo to download larger image.)

News Release Distributed 10/01/10

HENRY, La. – Cattle farmers got a look at test results of a new herbicide that shows some promise of controlling Vaseygrass in pastures.

At an LSU AgCenter field day on Sept. 30, Ed Twidwell, forage specialist, said Pastora, a DuPont product, can also be used on Johnson grass, but he warned it kills Bahia grass and clovers and can also cause some stunting of Bermuda grass.

“We’re still trying to determine the best rate for it,” Twidwell said. “We still have some lingering questions about how well it’s going to work.”

He said the chemical was quite effective on Vaseygrass last year. “This year it didn’t work as well. I am seeing some inconsistent results with it.”

This difference in effectiveness may be due to environmental conditions such as amount of rainfall and temperature variations.

Twidwell said the chemical is not a one-shot solution to Vaseygrass. “It’s going to be a two- to three-year endeavor to get rid of it.”

Having a vigorous stand of desirable forage grasses such as Bahia grass or Bermuda grass will also aid in keeping the Vaseygrass from becoming established.

He said the cost is approximately $15 an acre for an application at the 1-ounce rate. It works best when growing conditions are good, he said, so it tends to be less effective in hot, dry weather.

Andrew Granger, LSU AgCenter county agent in Vermilion Parish, said hay producers may want to use two applications of the chemical per year, but a cattle producer probably would prefer to use it once a year.

Twidwell also showed the results of different treatments for controlling fence-line vegetation. He said the chemicals were applied Aug. 10, so the full effects may not be evident yet.

He said a favorite chemical, Grazon P+D, works well on briars and broadleaf weeds because it stays in the soil. Grazon P+D is slowly being replaced by another Dow product called GrazonNext. He said he was surprised at how well GrazonNext performed on woody plants.

Granger said the test changed his opinion of GrazonNext.

Twidwell said Remedy herbicide always performs well on woody plants, but it is expensive.

Twidwell said Velpar herbicide provided mediocre fence-line control thus far. It is slow-acting, and hot, dry weather conditions reduce its effectiveness. However, Granger said the chemical did a good job of controlling the poisonous plant Lantana found in the Gueydan, La., area in trials conducted by Granger and Twidwell several years ago.