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 Photo: Mary Ann Hansen, Virginia Polytechnic Institute and State University, Bugwood.orgIt may look like ordinary grass fading with the high temperatures, but the distinctive circle of wilting turf is a sign of summer patch. It strikes when the plant is weak, heat-stressed by the summer sun, and destroys annual bluegrasses from the roots up. During cooler years, light fungicide programs seem to work abundantly well, but when the heat turns up like it did in 2010, superintendents are sometimes caught off guard by the pathogen showing up in what was once a well-controlled part of the course.
A planned, coordinated fungicide program and cultural practices will combat summer patch, as well as keeping turf as unstressed as possible during the tough weather through cultural practices. Though applications can be costly, blocking the pathogen is easier than curing it; and to stop summer patch, timing is everything.
Idle Hour Country Club, Lexington, Ky.
Though the course dates back to 1924, Idle Hour Country Club saw a renovation in 2005 of its 18-hole course. The rebuild brought the course design back to its roots and plenty of L-93 creeping bentgrass greens and tees.
“We tried to match them up like the old greens,” says Ben Barnes, superintendent, “We didn’t have a problem with summer patch before, but we got summer patch in a lot of those. The pH on the calcite sand they built these things out of is very high.”
When he measured, Barnes found the level around 9.0, much higher than the recommended 6.0, not very welcoming to the turf.
“When they tried to seed them, they just got eaten up,” he says. “They had a big problem with summer patch right after they were put in. With the extreme heat in the summer, all those sand expansions had blackout and they had to reseed those greens.”
The next year, Barnes went on the attack, starting a fungicide program for summer patch and take-all patch, with a much more controlled result during the season.
“With the soil sprays we put down prior to the heat coming in, we’ve not really seen summer patch like that again,” he says.
While Barnes doesn’t treat before the cold weather breaks, he says the fungicide program is an important part of his setup for the season.
“Just about all of these diseases are controlled in the spring,” he says. “As soon as you get these programs in place, you should be in good shape. If you want to wait until the weather is right for the pathogen, it’s like anthracnose. Once it’s there, you can’t get rid of it.”
Barnes uses three applications for summer patch to protect his turf, once in early spring, late spring and early summer. A program that runs more often than that is too cost-prohibitive for his budget.
“We could just resod the grass for cheaper than that,” he says.
With the program in place, summer patch hasn’t been a common problem on the course. When there are outbreaks between the fungicide applications, his members sometimes mention them to him.
“The members see it sometimes, but they don’t want to pay for it,” he says. “They’ll ask, ‘What’s that? Can’t we get rid of it?’ and I tell them yeah, and what it would cost to do more application. Then they say, ‘Well, the grass’ll come back, won’t it?’”
Westover Golf Club, Granby, Mass.
For a municipal course like Westover Golf Club in Granby, Mass., taking on repeated applications of fungicide on a tight budget is tough already. Then enter the summer of 2010, when temperatures soared and the bluegrass-bentgrass mix of the fairways suffered under the stress, giving summer patch easy access to the 18-hole course. Without the means to keep the strained turf regularly damp, superintendent Marc Gauvin had to make some tough decisions for the good of the course.
“It was all over our fairways,” he says. “We got hit pretty hard there. I just don’t have the ability to irrigate every hole every night. We can water them every other night, but between stress from the temperatures and water schedule and budget limitations we just lost a hold of it.”
Gauvin had applied his regular schedule of fungicides in 2010: two applications during the summer, included with the Poa control program applications every 3-4 weeks. Even if he had been able to predict how quickly the turf would fall to the stress, he didn’t have the resources to combat the pathogen.
“It just came in so fast, it was really over before it started,” he says.
As summer patch swept through the course, he had to weigh his options for effectively taking it on within his municipal budget.
“My committee asked me how we could fix it, and I told them, ‘Well, we can do more apps at about $17,000, or I can spend about $2,500 on seed and we can just try to make a stronger stand,’” he says.
Though he was concerned he would just run into the same problem the following year, they went with the more immediately cost-efficient option, beginning an overseeding program with a bluegrass-bentgrass mix. He also changed culture practices to help the fairways boost resilience, raising his cutting height a little and verticutting the turf.
“Our budget was a consideration,” he says. “It was just late in the fiscal year when it happened. We had to try for a short-term loss over a long-term gain.”
Gauvin’s budget this year pulls back on his greens to be able to bring more focus to the fairways.
“We’re going to go out as early as we can and do a clean-up on fairways,” he says. “We’re just going to monitor things, probably do more daytime watering; we’re going to try to do some topdressing. We’ll just be a little more proactive. By altering the budget, I will be able to devote a little more of my budget to fairways.”
Even with these changes, Gauvin will continue to keep the same fungicide schedule, with two applications during the hot months.
“Every year, we’re doing better in getting what we need,” he says. “I’ve gotten myself into early-order programs and every program I can feasibly get myself into to help out. I’m optimistic we’re going to keep our turf this year.”
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