Kentucky 31 (K31) tall fescue is without question the dominant forage species and variety in Missouri and the eastern U.S. and it is for good reason. E.N. Fergus, forage specialist from the University of Kentucky in the 1930s and 1940s, did a great favor for the livestock industry, when he propagated K31 fescue.
Fescue in general is palatable with outstanding quality at early growth. It can tolerate abusive grazing better than most other forages and survives drought, diseases, insects and cold weather. Fescue provides a consistent amount of fall and winter grazing very cheaply and better than any other perennial forage we grow. The seed is readily available and it is easy to establish.
Despite all the positive benefits of K31 fescue, the obvious downside is the endophyte and the toxicity created by it for livestock that affects performance.
Forage specialists do not promote replacing K31 fescue completely. However, livestock producers who learn how to use it and/or supplement their forage systems with other forage options, are ahead of the curve on dealing with the drawbacks. Too many Missouri livestock producers depend solely on K31 fescue for pasture and hay.
Novel fescue has the potential to significantly impact animal performance and farm profitability and some outstanding novel fescue brands are now on the market. Research out of Arkansas has found significant results in cow reproduction rates by converting just 25 percent of a farm operation to novels coupled with careful management.
Another good reason for a renovation of a fescue pasture is when there are many grassy weeds that have dominated a pasture or paddock. There are many pasture and hayfield stands that once were strong fescue fields, but aren’t anywhere close to that anymore. In most cases, there are no selective herbicides to eliminate or reduce less desirable species in a field and a complete renovation may be the only solution if a purer stand is desired. These grasses may include foxtail, nimblewill, broomsedge, purpletop and panic grass.
If a producer is starting with an existing stand of K31 fescue and intends to convert it to novel endophyte fescue, special measures to insure complete K31 elimination are highly recommended. Fescue seed can stay viable in the ground for at least 12 months so it is imperative to prevent seed production from the old K31 crop during the year of establishment.
If a producer is spending the extra money for novel seed and incorporating recommended steps to convert out of K31, we want to do everything possible to make it successful. This includes following preliminary steps to fully eliminate K31 crowns from surviving and planting at the best time of year. In most cases, a late-summer or early fall seeding is the most ideal. Unless conditions are too dry, this is usually during the month of September. There are at least two recommended methods for the conversion process. The most common method is to do a spray-smother- spray approach that involves a kill of the old fescue in the spring with heavy rates of glyphosate, then planting a summer annual smother crop followed by a second spray of glyphosate in the late summer prior to novel fescue planting. Summer annual options may be sorghum sudangrass, millet, teff or corn for silage or grain.
The first method is clearly the most expensive and time-consuming approach. However, another method to consider would be to do a spray-wait-spray approach. This involves not allowing the spring growth of K31 to go to seed, then spraying it out with a high rate of glyphosate in late June/early July. Instead of planting a smother crop, the field is left fallow for the summer. Then a couple weeks or less before later summer/ fall planting, do a second glyphosate spray. Missouri research has found that this method is also effective in eliminating any K31 resurgence in the new stand. Many will see the price of seed and think it’s just not worth it. Work done by ag economists out of Missouri and North Carolina have studied this issue closely. There are farms that have weaning weight data on calves that show major improvements in gain after cattle started grazing novel fescues. In some cow-calf operations it may take up to five years to get a full pay-back from the process in improved animal performance. But if fields are already in need of renovation to start with and are unproductive, then the pay-back starts at three years. If the plan is to only convert up to 25 percent of the farm to novels, the payoff can occur in about two years.
There are many factors that come into play when deciding if this is something a producer should consider. There are decades of research data that have shown that the fescue endophyte is a significant reducer of on-farm profit in the cattle business. Unfortunately, many producers do not recognize the quiet siphoning off of profits that occurs in a cow herds as a result of the endophyte.
This tool of using novel fescue for addressing the problem, combined with other measures, can be a huge benefit for a farm operation. There are farms that have weaning weight data on calves that show major improvements in gain after cattle started grazing novel fescues. Contact your nearest extension field specialist in agronomy if you have specific questions on how to convert to a novel fescue.
~ Tim Schnakenberg, Field Specialist Missouri, see more info on novel fescue at https://grasslandrenewal.org/