COLUMBUS, Ohio -- Those in the turfgrass industry with little time during the summer to establish turf from seed may get a boost from fungicides, according to an Ohio State University Extension study.
OSU Extension turfgrass specialists found that applying a granular fungicide at the time of seeding perennial ryegrass in late spring or early summer boosted seed germination, improved turf quality and increased speed of establishment by two weeks. The results may be beneficial for high school athletic fields, practice fields and parks and recreation where there is only a short period of time in the summer to establish ground cover for fall activities.
"Natural grass athletic fields in Ohio are excessively overused and it's always a challenge to get grass to grow when they are being used so much," said Pam Sherratt, an OSU Extension sports turf specialist. "The biggest thing is to keep the kids safe and the best way to do that is to maintain grass cover."
Sherratt said she and her colleagues stumbled across the findings while conducting another study on using plant growth regulators to reduce mowing time in fields during the spring and summer.
"Plant growth regulators reduce grass growth, and we wondered if the reduced growth might be more susceptible to turf disease, so we applied fungicides to see if we could control any diseases that cropped up," said Sherratt. "We found that the fungicide had a tremendous effect on the speed of establishment and the quality of the grass. We normally tell industry to expect turf to be ready for use in six weeks, but with the fungicide application we had play-ready turf in four weeks."
Additionally, researchers found that fungicide application increased biomass -- 7 grams of dry tissue compared to 0.15 grams from untreated turf; increased nitrogen content -- 3.76 percent compared to 3.16 percent from untreated turf; and produced better turf quality in color, density and uniformity.
Researchers speculate that the fungicide is suppressing pathogens in the soil that normally would impact grass performance. They also suspect that those pathogens are only present during the summer; a repeated study in October produced no results.
"We are not sure if there is something in the fungicide that is boosting turf performance or if the fungicide is suppressing soil pathogens. We speculate it's the latter, and it's most likely controlling pythium, a seedling disease present during warm, humid summers," said Sherratt.
Researchers plan to repeat the study next year to identify what soil pathogens are present, the minimum fungicide application that is required and application timing. The study is being supported by Syngenta.
"With fertilizer and seed costs increasing and a small staff to establish these fields quickly, anything we can do to aid high school athletics, parks and recreation and others in the turfgrass industry is always exciting," said Sherratt.
In addition to the fungicide study, the researchers found that the plant growth regulators slashed mowing times by 50 percent. As a result, it's possible for industry specialists to apply a plant growth regulator and a fungicide at the time of seeding in the spring, not only establishing a field more quickly, but allowing staff to spend less time mowing during the summer.