As the leaves begin to change, the temperature drops and Halloween décor goes on clearance, it’s time to begin thinking about snow mold applications in the North.
Superintendents should plan to make snow mold fungicide applications between Oct. 15, but not later than Dec. 1, says Jim Kerns, assistant professor and extension specialist in the department of plant pathology at the University of Wisconsin-Madison.
Kerns, who completed snow mold research trials in 2008 and 2009, observed quite a bit of snow mold breakthrough last season, and said several misconceptions among superintendents may be to blame.
1. Bragging rights
“One thing we see, at least in the upper Midwest, is there appears to be bragging rights to see who gets the application down right before it snows,” Kerns says. “That’s not the most important thing. Essentially, superintendents just need to get it down before a snow is forecasted – there’s no need to try to time it to get it out the day before it snows.
“There’s a misconception that if they get it out an hour before it snows that it’ll be more effective,” Kerns says. “That’s far from the truth.”
In fact, if that’s the case there’s more room for error due to rushing, so there’s often more breakthrough that if they got the application down a week before the snow, he says.
2. Right rates
There are several varieties of snow mold that afflict golf courses, including gray snow mold and Microdochium patch (pink snow mold).
“It’s pretty imperative you know what disease you’re working with,” Kerns says. “Because the control isn’t always the same.”
Luckily for superintendents, there are many fungicides that work for snow mold, Kerns says. He recommends superintendents consult their states’ researchers or extension specialists to find the mixture that best suits their conditions and budgets.
Generally, Kerns recommends the high label rates for snow mold applications. For pink snow mold, he advises superintendents to mix a systemic fungicide with a contact fungicide; for gray snow mold, consider a three-way mixture, adding a DMI fungicide.
For more specific recommendations, results of the treatments used in Kerns’ snow mold trials are available here: http://www.plantpath.wisc.edu/tdl/pdf/uwsnowmoldreports2009.pdf
“We don’t like just one active ingredient out there,” he says.
3. Spreading it out
Kerns said he’s seen some superintendents making three to four applications and accumulating the rate.
“With Instrata, I’ve seen some putting down the 9- to 11-ounce rate, but breaking it up three times in the fall,” he says. The thinking is they’ll couple a September application for dollar spot and leaf spot into their snow mold coverage. “But they’re 3 ounces short because they’re starting in September. I only look at October and November applications as being effective for snow mold.”
4. Late-season fertilizer applications
“Late season nitrogen applications can make snow mold more severe,” Kerns says, referring to nitrogen research Doug Soldadt, assistant professor and soil science extension specialist at the University of Wisconsin-Madison, conducted. “We typically see a breakthrough if they’re applying fertilizer into November.”
Supers say…
Scott Miller, CGCS at Maroon Creek Club in Aspen, Colo., aims to get his snow mold applications down on greens and tees during the first two weeks of October. Fairways are treated in mid-October.
“It’s a good time for us weather-wise because we don’t want to get caught with an early snow around Oct. 15 and then you can’t spray,” he says, adding the course gets both pink and gray snow mold and is typically under snow cover from around Nov. 1 through April 1.
In the three years he’s been at Maroon Creek, he’s been applying an Instrata/Medallion mixture. This year he plans to add Chipco 26 GT to the mix, which he says, based on university research, appears to enhance snow mold protection.
Scot Gardiner, CGCS at Boulder Pointe Golf Club in Oxford, Mich., has dealt with snow mold there for 10 years. He typically expects 90 days of snow cover, beginning as early as November (usually around Thanksgiving) and lasting as late as mid-March.
Gardiner begins fairway treatments with PCNB around Nov. 10. Because Boulder Pointe has play until the first snowfall, he tries to predict several days before the first snowfall to make greens applications with Instrata.
In the Maryland mountains, where Mark Jewell is director of golf maintenance operations at Rocky Gap Lodge & Golf Resort in Flintstone, he treats for pink snow mold in anticipation of 10 to 60 days of snow cover.
“It’s just kind of a crap shoot up here in the mountains, says Jewell, who’s been there for three years. “It’s a weird place to grow grass. You never know what kind of storms you’re going to get.”
Rocky Gap allows golf through November, so Jewell typically waits until the first week of December to make one fungicide application at the rate of 15 ounces per 1,000 square feet. He applies snow mold protection only to the 3.2 acres of bentgrass greens. Snow mold’s not a problem in the areas with higher heights of cut, he says.
He waits until the facility closes to make the application because he says he’s found that mowing after applying a snow mold application decreases efficacy. This year he’ll use Tourney for the second time. Two years ago he used Instrata and had some breakthrough when snow melted in January.
“I had mowed after putting down the application at the end of November, so then I had to put a second app down in January,” he says. “I don’t know for a fact if the mowing was a contributing factor, but I think it was because some of the protection is on the leaf tissue.”
Jewell decided to try Tourney because he likes to try a variety of products. So far, he’s been happy with the snow mold control and its Poa-suppression attributes.
“When applied at the highest label rate for snow mold, last year, we were off on the right foot for spring when the snow melted,” he says. “It looked like it had two apps of Proxy on it already.”