Universal Answers

Few turfgrass diseases disregard regional boundaries like fairy ring. Bermudagrass or bentgrass. Paspalum or Poa annua. Zoysiagrass or ryegrass. Consider this one case where the warm- and cool-season divide 

doesn’t exist. “We see them in all grasses,” says Clemson University turfgrass pathology professor emeritus Dr. Bruce Martin. “Grasses are really less important than soil conditions and environment. We 

see them everywhere.” Finally, a disease story for everybody who manages golf turf! Seriously, though, fairy ring presents universal challenges for superintendents and their teams. 

Martin annually co-presented a national seminar with fellow turfgrass research legend Dr. Bruce Clarke of Rutgers University. The pair always surveyed attendees about their top five disease challenges. Fairy ring always made the list. And fairy ring frustrations aren’t limited to one golf-abundant nation. “They can occur everywhere, and they are a big problem worldwide,” Martin says. “They would probably be in that top five anywhere you go around the world.” Now that we have established a far-reaching audience, let’s delve into specifics.

Think short-sleeve weather. “We usually see fairy ring pop up in spring and early summer, once soil temperatures are consistently above 55 degrees,” says BASF technical representative Dr. Emma Lookabaugh. “Further south into places like Florida, we can see it pop up almost year-round.” 

Basics such as regular aerification and topdressing are part of any solid disease management program. Regular wetting agent usage is also critical to fairy ring control.

“One, they help drive your fungicides a little deeper,” Lookabaugh says. “But then they also help re-wet hydrophobic soil conditions or localized dry spots associated with fairy ring fungi.” 

Environmental conditions and site-specific disease history are benchmarks for establishing effective spray programs. With fairy ring, the line between preventive and curative control can be blurry.

 “A lot of people tend to be more reactive when they have fairy ring and start treating when they see green rings and discolored turf,” Lookabaugh says. “If you wait to apply fungicides until after you see symptoms, it can take time and multiple fungicide applications to bring fairy ring back into check. This is especially true in situations with necrotic rings and dead turf, because at that point, you are in a recovery phase and are trying to stimulate turf to regrow.”

Staying ahead of fairy ring means closely monitoring soil temperatures. Spoiler: Get ready to see a familiar number. “We usually trigger preventive applications when soil  temperatures are consistently above 55 degrees. For some areas, like south Florida, timing preventive applications can be tricky because temperatures rarely get low enough,” Lookabaugh says. “Make repeat applications on a 28-day interval as long as conditions favor disease development. In some cases, two to three well-timed fungicide applications can provide season long control but in other cases, additional applications are needed. In south Florida, you need to build in fairy ring prevention almost year-round.”

DMI fungicides have proven success against fairy ring, but historically turf safety concerns have limited their utility for summer fairy ring applications. Maxtima® fungicide and Navicon® Intrinsic® brand fungicide provide two new, summer-safe DMI entries into fairy ring fungicide rotation programs, Lookabaugh says.
 

"Maxtima fungicide and Navicon Intrinsic brand fungicide bring advanced turf safety to the table,” she adds. “Superintendents can feel confident using these products in the heat of summer, 95 degrees and up even with PGRs in the tank, and not worry about injuring or thinning turf.”

Insignia® SC Intrinsic® brand fungicide, Honor® Intrinsic® brand fungicide, Xzemplar® fungicide, and Lexicon® Intrinsic® brand fungicide are other BASF fungicides that provide effective control of fairy ring when used properly, Martin says. 

“We demonstrated years ago  those were great fairy ring products when they are tank mixed with a soil wetting agent,” he adds. “That combination of the cultural practices and the characteristics with the fungicides has led to some pretty nice programs. The other thing to remember: the fungicides don’t control just fairy ring, even though we are watering those in thoroughly for fairy ring. We’re also going to get activity for other diseases like take-all root rot and even dollar spot, because some of those are translocated back through the turf to control foliar disease.”

Falling behind on fairy ring control leads to a lengthy recovery process.

“You’ll be looking at it for a long time,” Martin says. “Once they bust out on the greens, it’s a long road to get them under control. It usually takes a couple of months. Folks would put down an application of an effective fungicide and then call back after a week or two weeks and say, ‘Hey, nothing has changed.’ I’d say, ‘You’re not going to see anything change for a couple more weeks. Be patient.’ That’s why the preventive programs have been so popular, because they have by and large done a good job of putting fairy ring at least in a manageable light.”