Recent years' weather has challenged disease control
Those who pride themselves in finding the silver lining in even the worst situations must have loved the last couple of years. Mother Nature has presented some of her most difficult seasons in recent memory, challenging golf-course superintendents throughout the nation to keep their turf alive and their courses attractive and playable. On the positive side, these superintendents found that if their disease-control programs held up under these conditions, they could probably withstand anything Mother Nature could dish out.
One recent year in particular stands out for Stephen Rose, grounds superintendent for the B.P.O. No. 222 Flint Elks Lodge and Country Club in Flint, Mich. "[Nineteen ninety-five] was terrible right from the start," he says. "We went from a cold, wet spring to a hot, dry start of the summer, then it turned hot and humid. That's when the stress set in and, for a lot of people, the roof caved in. We were fortunate, though, because we made it through [that year] without losing any grass."
Lousy weather certainly hasn't been isolated to the Great Lakes region, as Tony Kirk can attest. His course has also faced some bad weather in recent years. He also cites 1995 as one of his most-recent nightmares. "The summer of 1995 was probably one of the worst we've ever had," notes Kirk, superintendent of The Pit Golf Links course in Pinehurst, N.C. "It rained the whole month of June. In a typical day, we would get rain, the sun would come out, and we would heat up quickly to about 95oF. When the heat and humidity go up high, that's when you have problems."
Although weather conditions play a key role in the development and appearance of turf diseases, other factors are significant as well. Chief among these are: the layout and design of the course; the types of soil from which the course is constructed; soil-fertility levels; and the volume of play a course receives and the related stress it causes. One thing The Pit and the Elks Club courses have in common is their volume of play: both record at least 40,000 rounds annually. Both courses also feature native-soil construction. The 18-hole Pit Golf Links was constructed out of an old sand quarry that provided sand for construction of the Blue Ridge Parkway. The native soils have a relatively high sand content, too, so compaction only poses a problem in spring when play is heaviest.
The 18-hole Flint Elks course is really two nine-hole courses in one. The front nine opened for play in 1958 and the back nine in 1971. The back nine has more sand construction while the front nine is made up of native heavy clay soils. Much of the soil, in fact, resembles white potter's clay.
Not surprisingly, Rose says, "Compaction can be a serious problem on the front nine, especially with the amount of traffic and cart play that we have." To combat this compaction and some of the problems that go with it, Rose implemented a program of deep aeration in recent years. On this schedule-May, July and October-the superintendent hires an outside contractor to deep-drill aerate (at a depth of 8 to 10 inches) his front-nine greens. Rose also uses a soil reliever in June and August on the front-nine greens and the practice green. The sandier soils on the back nine only need aeration once, in the fall.
Rose believes the two- or three-time-a-year schedule on the front nine will keep that area in good shape. He says, "We had much better root growth in '95 than we had in the past, and I'm sure that helped us keep disease in check and survive the summer."
While native clay soils provide Rose with some of his stiffest challenges in maintaining the health of his turf, Kirk is tested by some of his course's design features. Architect Dan Maples designed The Pit to preserve some of the historical identity of the quarry. For example, the original quarry workers excavated sand by removing the topsoil and mounding it. Many of these mounds remain and are prominent on several holes. The mounds create a bowl-shaped effect on the fourth and eighth greens, reducing air flow and slowing water drainage.
"Most of the time, if we're going to have some disease trouble, it will show up first on these two holes," Kirk says. The most troublesome diseases at The Pit, which Golf Digest ranks among the top 50 public courses in America, include brown patch, dollar spot, leaf spot, summer patch and Pythium.
The disease that gave Kirk the biggest headaches during recent years has been brown patch. "We had it pop up on about six greens [during one summer]," he says.
The appearance of the brown patch led him to try a new systemic fungicide, Eagle (from Rohm and Haas Co.). From the sterol-inhibitor family of chemistry, this fungicide provides both preventive and curative control of 15 turfgrass diseases, including brown patch, summer patch, dollar spot, melting out and necrotic ring spot.
Kirk applied the fungicide to some of the brown-patch trouble spots and got a dual benefit. It cured the infected areas, plus it provided lasting control. In fact, 18 days after the initial application, when Kirk was applying a preventive-control spray, he saw no disease in the treated areas.
Although Kirk also uses these types of products on a curative basis, he tries to run his disease-control and fungicide program on more of a preventive basis. He sprays every 14 to 21 days depending on the chemicals used. Some of the other fungicides he uses are Aliette (from Chipco/Rhone Poulenc), Fore (from Rohm and Haas), Chipco 26019 (from Chipco/Rhone Poulenc), Daconil (from ISK Biosciences Corp.) and Curalan (from BASF Corp.).
"We run a pretty small crew-10 or 11 compared to 15 to 20 for most crews in the area-so we need to get the most out of every hour of every day," Kirk says. "If we spray on a preventive basis, it keeps us from having to take care of emergencies all the time and that lets us make better use of our time.
"Besides, I think we just get better control," he adds. "It doesn't take long for a disease to come in and take over, if you're not paying attention. You want your grass to be as healthy as possible, and I think a preventive schedule is the best way to keep our grass healthy."
Rose finds the best-and most economical-way to keep his grass healthy is through a combination of cultural and chemical practices. In addition to his aeration program, some of the key cultural practices the Michigan superintendent employs include: spiking to relieve surface compaction without disrupting play; organic fertilizers; wetting agents to improve water absorption; and morning watering of greens. Rose sets his irrigation schedule to begin at 10 p.m. and finish at 4 a.m., watering the greens last.
"Watering early in the morning removes the dew that can carry fungus into the grass," says Rose, who has to use every trick available because of his tight operating budget. Rose's total annual maintenance expenditures are limited to $120,000. This sum includes everything except capital purchases such as new equipment.
About $15,000 of that annual budget is spent on fungicides, so Rose is particular about the products he uses. "Longevity and cost are pretty high priorities when I'm selecting a fungicide," he notes, "but I'm also concerned about phytotoxicity and any possible environmental problems. Another important issue is ease of application."
Rose, who spends most of his time on the course, also applies all fungicides, herbicides and pesticides. One of the things he likes best about this particular systemic, sterol-inhibitor fungicide is its water-soluble packets. "They're clean and easy and really limit your exposure to the chemicals," he says.
While Kirk tries to use a preventive-application schedule, Rose uses a hybrid of sorts. "With the exception of Pythium and summer patch, I'd say we follow a preventive/curative approach. We don't spray until we see the first signs of disease or until we know the conditions are right for disease."
The biggest disease problems Rose faces on a yearly basis are dollar spot, summer patch, anthracnose, leaf spot and Pythium. Brown patch normally is not a problem although it did show up a bit in recent years.
Rose added the new systemic to his arsenal of fungicides several years ago to see how it would perform as a preventive measure against summer patch. He applied the product in May and June and then made an early-fall application as a curative treatment for dollar spot. In all instances, Rose says, "The performance was excellent. It worked flawlessly, and the length of control far exceeded my expectations.
"[This chemical] fit very well into my total fungicide program," Rose adds. "It addressed my biggest needs-dollar spot and summer patch-and it was very cost-effective. It will definitely [continue to] be part of my program." Technical credit: Rohm and Haas Co. (Philadelphia).
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