Earlier this year, Matt Poore, cattle farmer, Professor and Extension Ruminant Nutrition Specialist made a New Year’s resolution to convert acres of toxic tall fescue to novel endophyte fescue on his farm. I jumped on the bandwagon and made the same resolution. Even though the non-toxic seed that completes these fescue conversions won’t go in the ground until September, we need to commit to our resolution now so that we can successfully establish high-quality forages this fall and kick the toxic fescue habit.
There are two critical things we must address immediately to prepare for novel fescue planting in autumn. First, soil test and construct a timeline and plan to correct any pH or nutrient deficiencies. Soil testing is straightforward and can be done in consultation with county extension personnel in your state soil testing lab. It’s easy, inexpensive, and will insure that you have adequate nutrients present for successful establishment. Second, prevent toxic fescue from producing seed that could contaminate the field in the fall. Seed production is slightly more complicated than soil testing, and timing is important to eliminate viable seed from forming. Keep in mind that just because you can see that stems have elongated and a seedhead is present that doesn’t mean you are too late! Panicles must open, plants must crosspollinate and seed need to fill and begin to mature before they can germinate and establish in the fall and cause problems.
Seed prevention can be accomplished in several ways depending on if you are using the Spray-Smother-Spray conversion method or the Spray-Wait-Spray method.
Spray-Smother-Spray (summer smother crop): If you plan to plant a summer smother crop like pearl millet or sorghum x sudan then spray the existing toxic tall fescue with 1-1.5 quarts of glyphosate (i.e. Roundup or Ranger) in mid-late April. Make sure that you’ve secured seed for a summer smother crop and, if needed, reserve a rental no-till drill for summer annual planting. Take delight in watching the herbicide eliminate those toxic plants from your forage system and prepare to no-till your selected summer annual or cover crop blend into the killed sod.
Spray-Wait-Spray: With this method, viable seed production is prevented in the spring without killing the existing fescue plant. Control of seed production is accomplished either mechanically (mowing) or chemically (Chaparral herbicide).
Mechanical Control: If you elect to mow, service the mower and make sure it is ready well ahead of pulling into the pasture. While timeliness is important, be patient and wait until many seedheads have emerged and opened and small orange colored anthers have emerged from seedheads. You can delay mowing 7-10 days past the beginning of pollination. Mow at a moderate height (6-8”) and pay close attention to not leave ‘skips’ behind. It often is necessary to mow a second time as additional seedheads can emerge after mowing. Close grazing in early-mid-spring decreases the amount of seedheads produced and delaying mowing after pollination decreases (but likely will not eliminate) a second flush of seedheads in the Spring.
Chemical Control: Seedheads can also be controlled with a timely application of Chapparal herbicide when plants are in the boot stage. Tall fescue growth will be suppressed by the metsulfuron in this application; however, plants will not be killed and fescue seedheads will be prevented from emerging. Other cool season forage species like bluegrass and orchardgrass are not impacted by the metsulfuron and will still produce seedheads. Picloram is also present in Chaparral. This chemical will kill many actively growing broadleaf species like thistle, buttercup or white clover but will not impact the germination and establishment of novel fescue planted later this fall. Follow the label recommendations closely as timing and rate of application are important for effective control.
After seedheads are prevented mechanically or chemically using the Spray-Wait-Spray method, continue grazing the Kentucky 31 tall fescue pasture until early August when we will kill it with two glyphosate applications spaced 4-6 weeks apart and plant novel tall fescue seed.
Georgia planting recommendations for tall fescue are here: https://georgiaforages.caes.uga.edu/species-and-varieties/cool-season/tall-fescue.html
Even though it’s March, don’t be afraid to make a late resolution and jump on the tall fescue replacement bandwagon with us. If we each commit to renovating a few acres every year, before you know it we’ll have whipped our toxic fescue habit. I’ll post occasional updates of how my conversion is going on this site if you’ll commit to joining us in the renovation process.
More detailed information about tall fescue is available for the University of Georgia in the Extension Bulletin entitled “Tall Fescue Production and Utilization” and the more recent Extension Bulletin, “Novel Endophyte-Infected Tall Fescue.” https://extension.uga.edu/publications/detail.html?pk_id=7045
Additional information and subsequent articles can be found at: The Alliance for Grassland Renewal