Articles: Horse Tips
Fescue Suppression More Viable Than Eradication
By Donald Stotts
STILLWATER - Endophyte-infected fescue can cause serious health problems in
broodmares, but replacing fescue with a more advantageous type of pasture
can be a time- and labor-intensive process. "That's why a lot of horse
owners settle for removing broodmares from fescue pastures six weeks to
three months before the expected foaling date," said Phil Pratt, Oklahoma
State University Extension area plant pathologist headquartered at Muskogee.
But while removal may help promote a healthy mare and foal, it also signals
a waste of available pasture resources and a potential negative effect on
the amount of funds tied up in operational feed costs. "In eastern Oklahoma,
fescue is the most persistent, best adapted, cool season perennial forage;
unfortunately, most of Oklahoma's fescue is endophyte infected," said Bob
Woods, OSU Extension area agronomist. Eradication of existing fescue is
difficult, slow and expensive. Thus, suppression of fescue for bermudagrass
release may be a more practical option.
Much of the fescue in Oklahoma has invaded existing bermudagrass pastures.
Woods said this is partly caused by fescue being well adapted to wet,
cool, springtime soil conditions and the typically low pH found in
eastern Oklahoma. "Fescue growth is further encouraged by Oklahoma
pasture operators' tendency to fertilize before weather conditions are
favorable for bermudagrass growth," he said. Woods said herbicides,
fertilizer, fire or a combination of these strategies can be used to
suppress fescue and recover a stand of bermudagrass.
Recent work in Mayes County successfully changed the dominant grass from
fescue to bermudagrass. "Herbicide applications that have demonstrated
satisfactory control of tall fescue include Gramoxone applied at 1.5 pints
per acre or Roundup applied at two quarts per acre in late March or early
April," Woods said. Also, prescribed burning after brownout from an early
April herbicide treatment was found to increase the efficacy of the
"Fertilizer, especially nitrogen, that is applied before May will tend to
favor fescue production at the expense of bermudagrass," Woods said.
"Waiting until after May 15 to apply fertilizer will favor bermudagrass
production." According to Pratt, laboratory testing has indicated that more
than 85 percent of Oklahoma's fescue is infected with the endophytic fungus
Acremonium coenophialum (also called Neotyphodium), which is commonly
referred to as the fescue endophyte.
"Tests can be conducted to determine infestation rates," Pratt said.
"Contact your local Oklahoma Cooperative Extension Service office for test
This article has been graciously provided by OSU Animal Science