You’ve heard this song and dance before: Toxic tall fescue can’t be grazed without health and performance consequences. Combined, the lengthy list of maladies attributed to Kentucky 31’s endophyte fungus are estimated to cause $1 billion in losses to the cattle industry each year.

Why, after 17 years, has the conversion process to novel-endophyte varieties been so slow? Unfortunately, the list of answers to that question is about as long as the list of problems that toxic tall fescue inflicts.

“We need to remember that it took 30 years for full adoption of hybrid corn,” noted Craig Roberts, who recently retired as the University of Missouri’s extension forage specialist. While speaking to a crowd of farmers at the Novel Endophyte Tall Fescue Renovation Workshop in Batesville, Ark., Roberts said the process of killing an existing sod to plant a new one is not a familiar process, and to some, sounds crazy.

“It’s hard to kill Kentucky 31. You don’t just spray and plant or plow and plant,” the long-time novel endophyte proponent asserted. “There are really only two things that will kill Kentucky 31: armyworms and a nuclear explosion,” Roberts added sarcastically.

Another reason for the lack of conversion is that many acres are rented, making it difficult in the minds of many to justify the cost of conversion on land not owned.

The impact on cash flow is another reason why the conversion from toxic to novel endophyte tall fescue is a nonstarter for some farmers, even though future returns will easily outpace the initial investment.

Finally, the psychology of tearing up a perfectly “good” pasture runs counter to what is perceived as commonsense thinking.

Go slow

The process of converting a farm or most of a farm to novel endophyte varieties is not a rapid process from both a whole farm or individual pasture perspective. Typically, experts and farm experience dictate to start with a small percentage of your total acreage, maybe 10% to 20%.

Begin by converting those fields that are the most toxic, which can be determined with a tiller endophyte test. Roberts said thin and/or weedy pastures are good candidates for conversion as long as the cause for such a condition can be identified and corrected. Finally, the forage specialist emphasized that the new pasture requires periods of rest after it is converted; this helps ensure a long life. “You don’t have to move cattle daily, but it is important that you allow a recovery period,” Roberts explained.

“There are effective mitigation strategies to help avoid converting pastures,” the forage specialist stated. “But here’s the thing — no mitigation practice eliminates the toxin; they only reduce the problem. Cattle are still consuming poison, and that’s why we think conversion, either partial or full, is the way to go.”

Out with the old

Various methods to kill existing tall fescue stands have been tested and proven effective through the years. Roberts outlined the four most popular approaches.

Spray–summer smother–spray: This system was developed many years ago in Missouri. “The approach entails first spraying the toxic tall fescue with the highest legal rate of glyphosate in the late spring, perhaps after an early hay harvest and some time for regrowth,” Roberts said. “In Missouri, this would probably occur around May 15. Next, a summer annual smother crop such as a sorghum species or millet is planted in 7- to 8-inch rows. This is done to allow growth from escaped fescue tillers and seeds in the soil. Further, the smother crop can be used for summer grazing or hay.”

In late August, a second application of glyphosate is made to kill any emerged new tall fescue tillers and plants. Around September 1, about a week following a complete kill of the vegetation, the novel tall fescue seed is no-till planted without any companion crop or legume. “We don’t want any competition with the new grass,” Roberts noted. “We can always frost seed legumes into the stand later.”

Spray–winter smother–spray: A second approach is to smother during the winter months using cereal grains such as winter rye or wheat. In this system, the toxic tall fescue is sprayed with glyphosate during early fall when it is actively growing. Then the smother crop is planted to grow through fall and during the next spring. If desired, the cereal crop can be grazed or harvested for stored feed. A second glyphosate application is made in late spring to kill the smother crop, tall fescue escapes, and any weeds that might be present.

The field is then fallowed over summer. “If weeds become a problem, a third spray application can be made in late summer, then plant the new seed about week later,” Roberts explained.

Spray–wait–spray: Another approach for novel tall fescue establishment is to clip the toxic tall fescue in the late spring before viable seeds are formed. In Missouri, for example, this might be late-May to early June. The first spray application is done once there is adequate regrowth, generally during late June. The field then sits fallow, and the second spray application is done at least six weeks or more after the first glyphosate application, typically during late August for Missouri. Once again, the new novel fescue is then seeded about a week after the second spray application.

“This system is cheaper than the smother systems, and it’s been shown to work throughout the Fescue Belt,” Roberts said.

Prepared seedbed: A final option is to just make the seeding into a prepared seedbed. This would only be applicable where no toxic tall fescue exists in the current field.

In summarizing his years of experience of novel tall fescue establishment research and helping farmers, Roberts said, “One of the biggest problems I’ve seen hasn’t been related to the spraying, the smother crop, or the no-till drill; it’s been that the farmer does everything right and then purchases an endophyte-free variety instead of a novel endophyte variety. An endophyte-free variety will not persist in the Fescue Belt. You have to be sure of what you’re buying because some retailers won’t know the difference. To ensure it’s a novel endophyte variety, look for the Alliance for Grassland Renewal logo on the label,” he added.