Whether you believe mushrooms growing in a circle follow the path made by fairies dancing in a ring or, as a Dutch superstition claims, the circles show where the devil set his milk churn, superintendents can agree that fairy ring is not welcome on a golf course.
Pat O'Brien, grounds superintendent at Hyde Park Golf and Country Club in Cincinnati, Ohio, first noticed fairy ring on the putting greens and zoysia grass fairways when he began at the course nine years ago.
O’Brien said the disease has been problematic with extreme shifts in soil moisture conditions - saturated to dry and vice versa. It has been difficult to determine where to place the fungicide, considering fairy ring is a soil pathogen, he added. And he’s still working toward finding the right set of tactics in his ongoing battle against fairy ring.
“We’re not sure yet. We have tried several different strategies and I am sure 100-percent control will be next to impossible,” he said. “This winter I had some great discussions with Lee Milller from the University of Missouri and Barb Corwin from Turfgrass Diagnostics. Both helped me adjust my strategy for this upcoming season.”
O’Brien’s approach this season is two preventive treatments 21 days apart with a DMI fungicide in the spring, beginning when soil temperatures reach 50 degrees for a five-day period. All applications will be watered in with .25" of irrigation. He’ll use a wetting agent on a monthly basis.
“Summer patch is also an issue on the 90-year-old putting surfaces, so QoI chemistries are employed that may also help control fairy ring,” he said.
For superintendents facing fairy ring for the first time, O’Brien suggests finding where the pathogen is located in the profile and targeting that area with the fungicide. As root pathogens have been very difficult to figure out agronomically, O’Brien is fully behind the new strategy, but knows what he’s facing.
“Another challenging season with fairy ring and summer patch ... hoping the adjustments will help,” he said. “It seems nuances with chemistries (DMIs) that may work at one course, may not work as well at others. Time will tell.”