Resistance is futile

Fungicides are important tools in a superintendent’s efforts against a wide variety of disease that plague turf, interfere with play, and test superintendent job security.

Golf Course Industry, in partnership with AMVAC Chemical Corp., recently surveyed golf course superintendents, via the online research survey portal SurveyMonkey, about their experiences with fungicide resistance issue. Most importantly, how they dealt with these issues and the steps they take to keep their programs effective. In addition, we further delved into this issue by closely examining how a trio of diverse superintendents manage resistance issues.

So what did we learn? In a nutshell, while the majority of superintendents (75 percent) indicated they haven’t dealt with resistance issues in the last three years, more than half (68%) subscribe to regular product rotation to avoid resistance issues. From these data points, it could be surmised that product rotation is, in fact, working for superintendents.

In addition, dollar spot is, by far, the most troublesome pathogen when experiencing resistance issue, followed by anthracnose.

The following superintendents shared their experiences with fungicide resistance.

Todd Voss

Double Eagle Club

Todd Voss is in charge of the turf at the Double Eagle Club in Galena, Ohio. The Jay Morrish/Tom Weiskopf design opened for play in 1992, and Voss notes resistance issues appeared even before the course was finished.

“Back during construction it seemed like a lot of new golf courses developed resistance to the Class DMI fungicides,” he says. “Whether it was use or varieties of disease blown in, I don’t know, but by 1996 we were diagnosed with resistance to the DMI class [fungicides].”

So Voss stopped using DMI class fungicides and worked with plant pathology experts at Ohio State and supplier product specialists to develop an alternate approach.

Around 2006 Voss was advised he could go back to using Class DMI fungicides. By that point, however, he had found an alternate approach he was comfortable with. And while protocols are always subject to adjustment because of changes in regulations, Voss, who today is also Double Eagle’s chief operating officer, has the tools he needs to combat his most pressing concern, dollar spot.

“Our backbone is chlorothalonil,” he says, “And we have chosen to go with lighter rates (but) more frequent. Because of label restrictions we also will add one or two applications of an iprodione product, and we’ve also started using some other chemistries, some of them being more of a blend that does have some DMI classes in the mix. I’m working very closely with the plant pathology department at Ohio State to make sure we do not make the same mistakes again when it comes to fungicides.”

By spraying weekly Voss actually uses less product over the course of a season. “Weekly, we use less than we would if we were doing bi-weekly or monthly applications,” he says. “Even though we’re spraying more, at the end of the day we’re spraying a lot less (active ingredient).”

Voss concedes he and his team have an advantage that superintendents at most other clubs do not because Double Eagle is an exclusive private club with limited play, it’s relatively simply for the crew to spray on a weekly basis without getting in the way.

Alan Fitzgerald

LedgeRock Golf Club

Alan Fitzgerald has been the superintendent at LedgeRock Golf Club in Mohnton, Pa., since it opened for play in 2006. In fact, Fitzgerald supervised the grow in.

At first, Fitzgerald relied primarily on generic-brand fungicide to make his budget work; his chief nemesis was dollar spot. But there came a point where the genetic brands began to lose their effectiveness.

To complicate matters, around 2013, the quality of the club’s irrigation water declined dramatically and the water became too alkaline. This rendered the fungicides Fitzgerald was using less effective. And as it turned out, those products weren’t saving him any money either.

“I started doing the math on the cost of generic vs. the control we were getting out of them,” Fitzgerald says. “And I started looking at the name-brand products and the cost of spraying them and I had noticed that the brand-name products during that period were providing way better control

“Basically how it worked out was the name-brand cost was about double the cost of the generic, but I was getting over double the control period. It’s not just spent money; you’re not spraying (as often), there is less wear and tear on the machines, you’re not paying your guys to go out and spray. It’s not just the cost of the material, it’s the cost of the other stuff too.”

At present, Fitzgerald’s fungicide toolkit contains an assortment of generics along with name-brand products such as Emerald, Curalan, Secure or Lexicon.

“With the new generics, we’re getting much better control than we were with them,” he says. “But we’re not using as much (product) as we used to. With some of the new chemistries from the big-name companies and the name-brand products, we’re getting 21-28 days out of things as oppose to maybe 10 out of a generic.”

Fitzgerald notes that the application rates on today’s fungicides are lower than their predecessors. When it comes to preventative spraying, his philosophy might be described as minimalist, unless circumstances like the weather dictate otherwise. If hot summer weather dictates he spray preventatively to prevent a pythium outbreak, he will. But that approach is the exception rather than the rule.

“We have a pretty good tolerance of disease,” he says. “I will do a preventative application one or two times to knock down the populations before they appear, but generally once the season starts we wait. We’re not on a tight schedule where we spray every two weeks or three weeks. We’ll wait until we see something.”

Fitzgerald doesn’t have to deal with a lot of play; perhaps 10,000 rounds per season.

Gregory Jack

TPC Treviso Bay

Gregory Jack has been the superintendent at TPC Treviso Bay in Naples, Fla., since November of 2014. The club is a private facility and gets the bulk of its play from November through late April, but allows non-member play during the off-season.

Jack, who has been in the turf industry for 12 years, has dealt with dollar spot, pythium root rot and an assortment of other diseases. He says he hasn’t had any significant resistance issues, but says on some occasions his fungicide of choice hasn’t worked as well as he would have preferred.

“We use the (approach) ‘change the mode of action,’” he says. “Changing chemistries.”

Keeping track of rotating fungicides can be a daunting task. So Jack has developed a system for doing just that. “I’ve actually broken down a spreadsheet with all my fungicides,” he says, “When I’m doing early ordering, it’s based on which category and the cost per application. I break it down from that standpoint so I can rotate chemistries.”

To further tilt the odds in his favor, Jack maintains what he calls his fungicide file, which contains a list of what fungicides fall into what particular category along with their individual characteristics. He also relies on the efforts of researchers at various academic institutions, notably Ohio State University and also the University of Kentucky, which published a study last year on the chemical control of turfgrass diseases.

“It (lists) which fungicide works for which actual disease,” Jack says, “the efficiency rating and then the base, how long it’s good for.

“You can look at it and say ‘Which disease am I wanting to go after, which products work well on it, and then, How can I rotate them?’” he adds.

It can be argued that a superintendent can never have too much information at hand. When dealing with a problem, time is of the essence.

“I keep that file in a separate-colored folder,” Jack says. “I know right where it is. Usually during our peak season it sits right on top of my desk.”

Offensive strategy

Sometimes the best defense against fungicide resistance issues is a good offense, i.e. an effective preventative program. Eric Johnson is the director of agronomy at Chambers Bay in University Place, Wash. He hosts about 35,000 rounds each year, but his disease concerns have been minimal.

“We really don’t have any major disease issues,” he says. “Our current programs are preventative for microdochium in the fall, winter and early spring and fairy ring. Our programs are monitored, reviewed and adjusted when necessary. We try to stay up to date with new chemistry and consider replacing fungicides (or other practices) if it benefits the health of the turfgrass.”

Johnson believes promoting overall plant health is the most effective way to ward off fungicide issues. “We attempt to minimize inputs while doing all we can to optimize plant health,” he says. “Gathering input from sales representatives, technical representatives, colleagues and online research is very helpful in setting up our program.”