Time to Kill Toxic Fescue, When Grass Grows Strong

Farm Journal logo

"Now is the time to kill toxic tall fescue," says Craig Roberts, forage specialist.

Pasture renovation to plant new novel-endophyte fescue is a long process. Mid-May is time to start spray-smother-spray controls.

In a weekly agronomy teleconference, Roberts alerted regional University of Missouri Extension agronomists across the state.

An old stand of infected fescue pasture should be sprayed to kill the toxic grass. About 10 days later a "smother crop" will be planted to continue the grass-killing recipe.

Kentucky 31 fescue is the most widely used grass on Missouri farms. However, it contains an endophyte fungus that secretes toxin. That toxin protects the plant, which makes the grass hardy. But the toxin cuts livestock gains and lowers reproduction. Those are just two of many problems.

Now there are varieties of fescue that contain new endophyte fungi that are not toxic. A new group, the Alliance for Grassland Renewal, leads efforts to replace bad grass with good grass.

The first spraying with glyphosate knocks back the pasture so that a summer cover crop can be planted. That crop will "smother" tillers that escape spraying. Also, toxic fescue seeds surviving in the soil will germinate under the cover crop.

Spraying is fairly straightforward, Roberts says. The grass must be growing vigorously to absorb the herbicide and transport it to the roots.

"Growing conditions will be ideal," Roberts says. "There's adequate moisture for grass growth. Temperatures will be high enough in the 70s for conditions that move glyphosate through the plant."

The smother phase is trickier, Roberts says. He prefers to no-till drill grain crops into the dying grass. He suggests pearl millet or sorghum-Sudan grass, which are grain-growing grasses, as cover crops. The grass canopy in drill rows allows sunlight to enter the shade canopy and start growth of seedling grass and missed tillers.

A true smother crop such as crabgrass or annual ryegrass forms a thick carpet of growth that weakens remaining fescue grass. However, a thick mat of grass doesn't allow missed tillers to grow well or let dormant toxic seed in the soil sprout and grow.

The missed fescue should be growing vigorously at the end of the summer growing season. It will then be killed by the second spraying of glyphosate.

Some producers spray twice initially to start the process. The pasture is sprayed once. A week later, missed patches or strips of toxic fescue are sprayed again. Then a cover crop is no-tilled into a clean pasture.

"The spray-smother-spray recipe works," Roberts says. "It takes attention to details for success."

Any toxic seedlings left alive when the new endophyte is planted will compete strongly with newly seeded novel-endophyte fescue.

The spray-smother-spray renovation was perfected at the MU Wurdack Farm, a part of the Missouri Agricultural Experiment Station, at Cook Station in the Ozarks.

Regional MU Extension agronomists can assist growers with advice on pasture replacement.

Source: University of Missouri Extension


Latest News

Cash Fed Cattle 5 Weeks Steady

The first week of March saw warm temperatures across most of the Central Plains, but cash cattle prices were frozen in neutral with feeders unable to wrangle additional market leverage.

Vaccine Available To Kansas Meatpacking Workers

Kansas Gov. Laura Kelly said Thursday that every meatpacking plant worker in Kansas who wants a COVID-19 vaccination can get one by the end of next week.

2021-2022 Henry C. Gardiner Scholarships Winners Announced

Five Kansas State University students were named recipients of the 2021-2022 Henry C. Gardiner scholarships, awarded to students meeting rigorous criteria and exhibiting a commitment improving the beef industry.

Norbrook® Launches Cefenil® RTU Generic Injectable

Norbrook, Inc. launches Cefenil® RTU – generic ceftiofur hydrochloride injectable for treating common diseases like swine bacterial respiratory disease and foot rot, bovine respiratory disease and metritis in cattle.

Star Ranch Angus Brand Refresh

Carrying branded programs such as Tyson's Star Ranch Angus beef has benefits for both retailers and consumers. Shoppers still associate branded programs with better quality, better value and more consistency.

Embracing the Positives in Sustainable Cattle Production

Cattlemen are the original climate heroes, preserving natural resources, while producing safe, affordable and abundant protein. Speakers at NCBA's Winter Reboot discussed how cattle production contributes to society.