Pub of the Month: Conversion of Toxic tall fescue to novel endophyte tall fescue

Successful conversion from toxic KY-31 to novel endophyte tall fescue begins much earlier than most people anticipate. Seedheads need to be clipped before maturation, the existing stand needs to be sprayed out in July/August and reseeding needs to be in early September. Check out this simple checklist below for how to make the transition this summer and fall.

Conversion of Toxic Tall Fescue to Novel Endophyte Tall fescue

S. Ray Smith and Krista Lea – University of Kentucky

Replacement Protocol:


Soil sample; adhere to lime and fertilizer recommendations

  1. Take soil sample in May.
  2. Follow recommendations in soil test.

Remove/prevent all tall fescue seed heads in the spring via mowing or early hay cutting

  1. Clip/mow the pasture in early May as low as possible. 
  2. Clip/mow the pasture a second time in late May to remove tall fescue seed heads (Note: Fescue seed can be viable 15-20 days after pollination and then germinate in the fall).

Mid-Late Summer

Herbicide spray to kill out existing stand before planting novel endophyte tall fescue or other forages

  1. Graze tall fescue heavily during periods of growth.
  2. Stop grazing and allow tall fescue to regrow to five to six inches in height.
  3. Spray with glyphosate 4-6 weeks before planting – mid to late-July.
  4. Allow weeds and toxic tall fescue to germinate or re-grow from escapes.
  5. Re-spray glyphosate before planting – early September


Plant novel endophyte tall fescue seed

  1. In early to mid-September, just after last weed spray, plant a novel tall fescue variety using a no-till seed drill.
  2. No-till drill at 20 lbs/ac, and ¼ inch deep. To achieve better ground cover, set drill at 10 lbs/ac and go over field twice, the second pass perpendicular to the first pass.

Late Fall or early next Spring

Tall fescue seedling management

  1. Low rates of N can be used to enhance stand establishment (~40 lbs/N/ac)
  2. After planting, wait until tall fescue seedlings reach the 4-leaf stage (4 to 5 inches tall) before weed control.
  3. If needed, apply Weedmaster (2,4-D and dicamba) or similar herbicide to control broadleaf weeds. 
  4. Allow good sod development before grazing next spring. Ideally, wait until plants are 8 inches tall and flash graze (a large number of animals for half a day) or mow at 4 inches residual height or simply cut for hay in the spring (4 inch stubble height).

Forage Timely Tips: June

  • Make plans to attend the KFGC’s Summer Forage Tours.
  • Continue hay harvests. Minimize storage losses by storing hay under cover. 
  • Clip pastures for weeds and seedheads as needed.
  • Use slower grazing rotations allowing for a longer recovery periods. 
  • Use portable fencing to decrease paddock size and increase paddock number.
  • Do NOT graze below the minimum desired residual height (4 in for most forages).
  • When present, johnsongrass can provide high quality summer forage when managed.  
  • Crabgrass, a warm-season annual grass, can provide high quality summer grazing. It is a annual grass highly preferred by livestock. If desired, remember crabgrass needs some annual soil disturbance to keep coming back.
  • Begin grazing native warm-season grasses.  Start at 20-24” and stop at 8-10 inches.

Buttercup in hay and baleage

Kentucky pastures have exploded with the signature yellow flower of buttercup. Buttercup is the common name for a group of species from the genus Ranunculus. Buttercups are sometimes classified as short-lived perennials, but often grow as winter annuals. Four species of buttercups that may be found in Kentucky: bulbous buttercup (Ranunculus bulbosus), creeping buttercup (Ranunculus repens), tall buttercup (Ranunculus acris), and small flower buttercup (Ranunculus arbortivus). Each of these species have somewhat similar flower heads but differ in their leaf characteristics. New seed are produced during the time petals are showy. Waiting until after flowers appear can be too late to implement control tactics. This is one reason buttercups can survive year to year.

Buttercup is a troublesome weed of hay and pasture fields and can be toxic if grazed. Harvesting for hay or baleage serves to detoxify this weed such that feeding risks are low. Buttercup can easily be controlled chemically. Management options include not overgrazing and thickening up the existing forage stand. Buttercup is a persistent problem in overgrazed pastures or hay feeding areas.

Buttercups are more than an unsightly weed. They can also be toxic. Grazing or mowing will release a powerful vesicant which causes blistering of the skin, mouth, and digestive system on contact. Fortunately, the blistering agent is detoxified rapidly by drying, such that it is not generally a problem in hay. Limited research in Europe indicates that it is detoxified in baleage as well.

Death of livestock due to buttercup is rare – A review of University of Kentucky Veterinary Diagnostic Laboratory records over the last 13 years found no cases of livestock deaths attributable to buttercup ingestion. If other forage is available, grazing livestock will usually avoid buttercup because the leaves, flowers, and stems have a sharp, acrid taste.

Most buttercup plants emerge from seed during the fall or late winter months. Therefore, pasture management that maintain thick stands and promote growth of more desirable plants during these months is one of the best methods to help compete against the emergence and growth of this plant. Mowing fields or clipping plants close to the ground in the early spring before buttercup plants can produce flowers may help reduce the amount of new seed produced, but mowing alone will not totally eliminate seed production.

Herbicides registered for use on grass pastures that contain 2,4-D will effectively control buttercup. For optimum results apply herbicide in the early spring (February – March) before flowers are observed and when buttercup plants are still small and actively growing. For best herbicide activity wait until daytime air temperatures are greater than 50 degrees for two or three consecutive days. Consult the herbicide label for further information on grazing restrictions, precautions, or other possible limitations.

Applying broadleaf herbicides like 2,4-D will damage clover. However, buttercup is able to germinate and grow because of insufficient ground cover of desirable forage species. In these cases, clover stands are likely not that thick or need rejuvenating.

Management Options

To prevent or inhibit buttercup germination in the fall, manage grass pastures to retain residual heights of three or four inches. Realistically speaking, pastures used for overwintering, hay feeding or calving will always be overgrazed and therefore will be prime spots for buttercup and other winter weeds encroachment. Overseeding these pastures in early spring with forages that establish aggressively (like red clover or ryegrasses) will add some desirable forage species to the spring flush of growth even though they will not eliminate buttercup emerging at the same time. Follow up with an early spring mowing to clip the buttercup and release the desirable species.

Cover up bare ground. Fall applications of nitrogen will produce taller grass (shading the ground) and will stimulate existing grasses to thicken up or tiller out the following spring. Timely mowing in the spring followed by nitrogen application can reduce buttercup seed production and will stimulate spring forage growth that helps shade the lower growing buttercup.

No matter how go about it, controlling buttercup is not a ‘once and done’ project. Nor will one method work alone – chemical control alone with leave bare ground unless there is a strategy to replant or fill in that area. However, we can manage pastures to reduce buttercup incidence and improve your pasture productivity at the same time. Happy foraging. ~ Jimmy Henning for Farmers Pride

Hay could be in short supply next winter

Have you started thinking about next winter’s hay supply? The question seems ludicrous given that we are in the beginning of the hay making season. But is it?

Kenny Burdine doesn’t think so. The extension agricultural economist with the University of Kentucky says it’s never too early to plan for winter hay needs, especially this year. He comes to this conclusion based on experience.

In 2007, a spring freeze in Kentucky damaged the spring forage growth, and summer drought impacted production for the remainder of the growing season. By late fall, it became clear that hay was in much shorter supply than expected. Average-quality grass hay prices more than doubled. Burdine recalls that a lot of cow-calf producers ended up feeding commodity feeds that winter instead of hay. “At that time, alternative feeds were relatively inexpensive, but that is not going to be the case this year.”

Burdine cites several reasons why he thinks it will be prudent to ensure adequate hay stocks going into winter.

Currently, producers in drought-stricken areas have continued to feed hay during a time that is normally reserved for grazing. This will eat into hay reserves that might normally be available later in the year.

Burdine also points out that continuing dry conditions out west will impact hay supplies throughout the upcoming growing season. “I think it would be naïve to think that there isn’t potential for lower hay yields and increased demand for hay if the (drought) situation continues,” the economist notes.

Although hay markets are largely regional, Burdine writes that the potential for hay availability concerns are not just confined to areas dealing with drought.

“Hay is expensive to transport, but the wider hay value differences across regions become, the more incentive there is to move hay into greater deficit areas,” he explains. “We have seen this in the past, and this is one of the ways markets allocate resources when they become scarce.”

The potential implications of drastically higher fertilizer prices also need to be taken into consideration. Even where adequate soil moisture is available, Burdine thinks it is likely that producers will apply less fertilizer on their hay acres than what is normally done. If this occurs, lower hay production will occur in otherwise responsive fields and cut into future hay inventories.

Burdine is not necessarily predicting a repeat of 2007, but he does think it is valuable context and underscores the importance of planning for winter hay needs early. ~ Mike Rankin, Hay and Forage Grower. Read the full article here.

12th Eastern Native Grasslands Symposium

Join us in Kentucky at Louisville’s renowned Galt House Hotel, October 3-6, for the 12th Eastern Native Grasslands Symposium! This year’s Symposium will feature two days of speakers and poster presentations, as well as a full day of field trips. Continuing Education Units (CEUs) will be offered for professionals. Find out more information at

Corn that acquires its own nitrogen identified, reducing need for fertilizer

A public-private collaboration of researchers at the University of Wisconsin–Madison, the University of California, Davis, and Mars Inc., have identified varieties of tropical corn from Oaxaca, Mexico, that can acquire a significant amount of the nitrogen they need from the air by cooperating with bacteria.

To do so, the corn secretes copious globs of mucus-like gel out of arrays of aerial roots along its stalk. This gel harbors bacteria that convert atmospheric nitrogen into a form usable by the plant, a process called nitrogen fixation. The corn can acquire 30 to 80 percent of its nitrogen in this way, but the effectiveness depends on environmental factors like humidity and rain.

The dripping gel from this corn plant harbors bacteria that convert atmospheric nitrogen into a form usable by the plant. Photo: Howard-Yana Shapiro

Scientists have long sought corn that could fix nitrogen, with the goal of reducing the crop’s high demand for artificial fertilizers, which are energy intensive, expensive and polluting. Further research is required to determine if the trait can be bred into commercial cultivars of corn, the world’s most productive cereal crop.

The findings are reported Aug. 7 in the journal PLOS Biology. “It has been a long-term dream to transfer the ability to associate with nitrogen-fixing bacteria from legumes to cereals,” says Jean-Michel Ané, a professor of bacteriology and agronomy at UW–Madison and a co-author of the new study.

Legumes, such as beans, are the only group of crop plants previously known to acquire a significant amount of nitrogen through fixation, which they perform in specialized tissues called root nodules.

Howard-Yana Shapiro, the chief agricultural officer at Mars, a senior fellow in the Department of Plant Sciences at UC Davis and a co-author of the report, identified the indigenous varieties of corn in a search for cultivars that might be able to host nitrogen-fixing bacteria.

The corn is grown in the Sierra Mixe region of Oaxaca in southern Mexico, part of the region where corn was first domesticated by Native Americans thousands of years ago. Farmers in the area grow the corn in nitrogen-depleted soils using traditional practices with little or no fertilizer, conditions that have selected for a novel ability to acquire nitrogen. The biological materials for this investigation were accessed and utilized under an Access and Benefit Sharing Agreement with the Sierra Mixe community and with the permission of the Mexican government.

The corn is striking. Most corn varieties grow to about 12 feet and have just one or two groups of aerial roots that support the plant near its base. But the nitrogen-fixing varieties stand over 16 feet tall and develop up to eight or 10 sets of thick aerial roots that never reach the ground. Under the right conditions, these roots secrete large amounts of sugar-rich gel, providing the energy and oxygen-free conditions needed for nitrogen-fixing bacteria to thrive.

Establishing that plants are incorporating nitrogen from the air is technically challenging.

“It took us eight years of work to convince ourselves that this was not an artifact,” says Ané, whose lab specializes in studying and quantifying nitrogen fixation. “Technique after technique, they’re all giving the same result showing high levels of nitrogen fixation in this corn.”

The group used five different techniques across experiments in Mexico and Madison to confirm that the Sierra Mixe corn’s gel was indeed fixing nitrogen from the air and that the plant could incorporate this nitrogen into its tissues.

“What I think is cool about this project is it completely turns upside down the way we think about engineering nitrogen fixation,” says Ané.

The gel secreted by the corn’s aerial roots appears to work primarily by excluding oxygen and providing sugars to the right bacteria, sidestepping complex biological interactions. The research team was even able to simulate the natural gel’s effects with a similar gel created in the lab and seeded with bacteria. The simplicity of the system provides inspiration to researchers looking to identify or create more crop plants with this trait.

“This corn showed us that nature can find solutions to some problems far beyond what scientists could ever imagine.”

Breeding the trait into commercial cultivars of corn could reduce the need for artificial nitrogen fertilizers, which have a host of disadvantages. More than 1 percent of the world’s total energy production goes toward producing nitrogen fertilizer. Developed countries contend with waterways polluted by leaching nitrogen, while adequate fertilizer is often inaccessible or too expensive for farmers in developing countries. Corn that fixes some of its own nitrogen could mitigate these issues, but more research will be required.

“Engineering corn to fix nitrogen and form root nodules like legumes has been a dream and struggle of scientists for decades,” says Ané. “It turns out that this corn developed a totally different way to solve this nitrogen fixation problem. The scientific community probably underestimated nitrogen fixation in other crops because of its obsession with root nodules.”

“This corn showed us that nature can find solutions to some problems far beyond what scientists could ever imagine,” Ané says. ~ Eric Hamilton, University of Wisconsin-Madison. Read the full article here.

Upcoming Events

June 16 – Equine Farm and Facilities Expo, Lexington |

August 11 – Eastern KY KFGC Field day, Quicksand |

September 13-14 – KY Grazing School, Versailles, KY |

October 3-6 – Eastern Native Grass Symposium, Louisville |

October 26-27 – KY Grazing conferences, Leitchfield and Winchester, KY |

November 14-17 World Alfalfa conference, San Diego, CA |

May 14-19, 2023 – International Grassland Congress, Covington , KY |

Looking for a Monthly Magazine FULL of Grazing Articles?

The Stockman Grass Farmer is an excellent print and digital monthly publication that provides great pasture and grazing articles written by graziers, who make their living from grassland based agriculture with every possible species that can be raised on pasture. 

Articles cover the ART & SCIENCE of making a profit from grassland agriculture while prioritizing regenerative soil health. If you aren’t familiar with The Stockman Grass Farmer, you can request a free sample issue here or call 800-748-9808.

 Coping with Fertilizer Prices

Most of you know the many advantages that we have as graziers and forage producers in Kentucky. But with the sky high price of fertilizer (which row crop producers require annually), now is an ideal time to appreciate that management intensive rotational grazing makes us not nearly as vulnerable to high fertilizer prices.  Rotationally grazed livestock harvest their own feed and spread their own manure and urine. The urine alone contains high levels of nitrogen and over 80% of the potassium that the animal consumes from the forage. The livestock, the soil and the enterprise all benefit. That’s a great message and one that we should all be promoting!

~ Bill Payne, retired dairy producer, grazing consultant, and KFGC board member.

Crabgrass and a Living Legend

Crabgrass is a summer annual grass that can be a valuable part of a full season grazing and hay program in Kentucky. Crabgrass is highly palatable and is well adapted to Kentucky although it is often thought of as a weed. It has often been part of Kentucky pastures, especially those that have been overgrazed. The advent of improved varieties of crabgrass has changed the perception of crabgrass as an opportunistic weed to a valuable high quality forage. This article is an update on the varieties available, quick establishment tips and a bit about the family behind the improved varieties of crabgrass.

Figure 1. Crossbred steers grazing improved crabgrass as part of the grass-fed beef operation of Michael and Stacey Palmer of Marshall County Kentucky. Improved crabgrasses are the result of the visionary work of R.L Dalrymple and Dalrymple Family Farm in Thomas, Oklahoma.

Crabgrass can be established using a prepared seedbed, but it also has value as a renovation forage for tall fescue pastures, especially areas that have been disturbed by hay feeding or livestock trampling. Crabgrass will make good use of the soil nutrients left behind in hay feeding areas. These areas are ideal for the introduction of crabgrass because the soil is already disturbed. Crabgrass establishes best when it is worked into the soil between ¼ to ½ inch deep. No-till seedings are possible but depth control is critical.

For renovation, crabgrass should be broadcast at 3 to 6 lb/acre onto disturbed sod and rolled with a cultipacker. Chain harrowing after seeding can help cover the seed, which is essential for successful establishment. Seed may need to be mixed with a carrier such as pelletized lime to flow through spinner seeders. It is critical to check the spread of crabgrass seed as it typically only travels half as far as a carrier. Crabgrass can be seeded with red clover for additional yield and forage quality. For more information on using crabgrass for forage, see UK publication AGR-232 Crabgrass. To get to the online version quickly, type ‘crabgrass uky’ into your web browser.

The driving force behind improved crabgrass varieties is one man, R.L. Dalrymple. RL spent a career at the Noble Foundation doing applied research and extension on pasture and grazing systems. Growing up he observed how his parents had used crabgrass for forage on their west central Oklahoma farm. As part of his Noble Foundation efforts, R.L. selected and released ‘Red River’ as a public variety in 1988 and he has released other varieties as shown below. All of these improved crabgrasses are erect, high yielding, high quality annual forages.

Red River. The original improved variety, released by Noble Foundation as a public release. There are known problems with uncertified seedlots, so it is best to specify Certified seed.

Impact. Derived from Red River at the Noble Foundation, this variety was selected to grow longer into the fall. Barenbrug has the marketing rights. Impact is a component of the commercial blend ‘Mojo’.

Dal’s Big River®. A refinement and improvement over Red River only available as trademarked, certified Seed. Red River and Dal’s Big River have rough seed coats that can have variable amounts of ‘fuzz’ making the seed flow poorly through spinner spreaders and conventional seeding equipment. As noted above, carriers help seed flow.

Quick-N-Big®. Quick-N-Big was released in 2010 and was selected to germinate earlier and provide quicker earlier growth than Red River or Dal’s Big River. It is very upright in its growth habit.

Quick-N-Big Spreader®. Released in 2016, this variety is much like Quick-N-Big except it tends to root more around the crown, if there is space to spread. Quick-N-Big and Quick-N-Big Spreader have smooth seed coats and flow more readily than Red River and Dal’s Big River.

Mojo. Mojo is a commercial blend of Impact and Red River varieties, owned and distributed by Barenbrug. Mojo is only available as coated seed, and the coating comprises 50% of the bag. Coating greatly improves the ability of the crabgrass to flow through drills and spread from spinner seeders.

Crabgrass usage in Kentucky is growing, such as producing grass finished beef at Michael Palmer’s farm in Marshall County. Having a high quality summer grass alternative that can complement tall fescue is a valuable option.

I am sure R.L. would be work pretty hard to deflect any accolades for this work. Yet accolades are due. In my opinion he is one of the legends of forage agriculture, both for improved crabgrasses as well as a career of contributions to farmers and ranchers. And it is a privilege indeed to know a living legend. ~ Dr. Jimmy Henning, originally published in  Farmer’s Pride.