By John Lovett
University of Arkansas System Division of Agriculture
Arkansas Agricultural Experiment Station
FAYETTEVILLE, Ark. — Aside from a hook or slice, a lot can go wrong on a golf course, with pathogens that cause problems like “dollar spot” and water-repellent soil that can impact performance.
TURFGRASS — The 2023 Arkansas Turfgrass Field Day was held Aug. 1 in Fayetteville. (U of A System Division of Agriculture photo by Nick Kordsmeier)
Information to help golf course managers keep greens and fairways in prime shape represented a large part of Tuesday’s Turfgrass Field Day, hosted by the University of Arkansas System Division of Agriculture.
Research to support sports turf managers and lawn care experts was also presented during the first in-person turfgrass field day at the Milo J. Shult Agricultural Research and Extension Center in four years, said Mike Richardson, professor of turfgrass science for the Division of Agriculture. COVID-19 pandemic-era field days were held virtually.
Welcoming the field day participants, Deacue Fields, vice president of agriculture for the University of Arkansas System, said turfgrass experts must be able to interact with customers and have the technical knowledge to “do what’s right for the environment.”
Arkansas Agricultural Experiment Station Director Jean-François Meullenet noted Richardson has built the turfgrass program up over the past 25 years and, with two new faculty members, has “the strongest team we’ve ever had.” The new faculty members are Hannah Wright-Smith, assistant professor of turfgrass weed science, and Wendell Hutchens, assistant professor of turfgrass science and pathology.
“We look forward to having a great impact on your industry over the years,” Meullenet told the approximately 175 field day participants.
While golfers are more concerned about where their golf ball lands on the grass, scientists with the experiment station are pushing the limits of that turfgrass to survive with minimum resources. In addition to conducting trials of wetting agents, which work to improve the flow of water through water-repellent soils found on putting greens, researchers are also testing herbicides to control unwanted grasses and fungicides to control pathogens that cause diseases like “brown patch,” “yellow spot,” and “dollar spot.”
“Dollar spot is the most common, widespread problem on putting greens,” Hutchens said. “It’s fairly easy to manage, but it occurs everywhere.”
Dollar spot appears as white or tan spots of dead turf about the size of a silver dollar and is common on golf course putting greens that are mowed below one-eighth of an inch. Hutchens has compared many different experimental and market-available fungicides with an untreated control. Results indicate that all the fungicides performed “very well” in this trial, Hutchens said, but they worked best when applied on 14-day intervals compared to 21-day intervals.
“For dollar spot, there are a lot of good 21-day products, but I really like the idea of leaning on the side of caution with 14-day intervals,” Hutchens said. “In low disease pressure situations, I trust 21-day intervals, but in high disease pressure situations, 14-day intervals are the way to go.”
Based on his research, Hutchens said he was also in favor of using two active ingredients in fungicide applications to cover a wide variety of diseases and combat resistance, or the ability of a pathogen to withstand the fungicide treatment.
“Focusing on one mode of action, or one group of fungicides, that’s where you start to slowly develop resistance,” Hutchens said. “But a critical approach to reducing resistance is keeping inoculum levels down in such low populations that it’s hard to really build up resistance. That’s why we go with regular intervals.”
For lawn care professionals, Wright-Smith gave a presentation on her research to control difficult broadleaf weeds with two new herbicide active ingredients from Corteva Agriscience — Arylex™, available for commercial turf as GameOn and Relzar. She is also testing Rinskor™. Relzar and Rinskor™ are not yet commercially available. The study aimed to compare herbicides for broadleaf weed control and evaluate how new herbicides performed compared to currently used herbicides.
ARKANSAS TURF — Speakers and organizers of the 2023 Arkansas Turfgrass Field Day gather for a photo in front of the Arkansas Razorback logo. (U of A System Division of Agriculture photo by John Lovett)
Her report states that multiple applications made four to eight weeks apart are still recommended for complete control of broadleaf weeds in turf.
Wright-Smith has also been a partner with Richardson on a study to develop management tools for new putting greens using Zoysiagrass.
Some field day-goers also heard insights on turfgrass management from guest speakers John Reilly, director of agronomy at Longboat Key Club near Sarasota, Florida, and John Rowland, U.S. Golf Association’s Southeast region agronomist. They demonstrated the USGA’s GS3, a Bluetooth-enabled golf ball with sensors that measure turf firmness and rolling metrics. The device sells for about $3,000 and comes with a subscription to the USGA Deacon app for data analysis.
Use of product names does not imply endorsement by the University of Arkansas System Division of Agriculture.
To learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu. Follow on Twitter at @ArkAgResearch. To learn more about the Division of Agriculture, visit https://uada.edu/. Follow us on Twitter at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit www.uaex.uada.edu.