The last droplets of the calendar year come out of the spray nozzles. So what’s the next step?
It’s time to wait for winter. Snow mold can be a destructive nuisance that appears at the wrong time. What happens in the snow or rain during the winter months does not appear until the following spring. Impressing golfers at the start of a new season requires a calculated fall application schedule.
“As with so many diseases that we fight in the field, be sure to apply before you start to feel the pressure,” says Kyle Miller, BASF Senior Technical Specialist. “Make sure the timing in late fall is preventative and your application comes out just before you expect permanent snow cover. After that there is not much you can do.
An application of snow mold marks the end of the spray season for lawn crews in wet and cold parts of the country. Do you notice that a certain word is missing in the previous sentence? There is a prominent type of snow mold that does not require snow to become a problem on playing surfaces. Color can help a lawn manager identify pink snow mold, also often referred to as microdochium patch or plaque. Fusarium, which is caused by the pathogen Microdochium nivale. Symptoms are expressed as pink, white, or beige patches.
“Pink snow mold can occur in many different geographic areas, from north to south,” says Miller. “One of the characteristics of pink snow mold is that you don’t have to have a layer of snow to catch it. Symptoms of the disease may appear in the spring because you have this sporodochia on the infected limbo. When you get the sunlight on it, it appears really pink.
Miller adds that pink snow mold can occur as far south as Florida and can be a problem for both warm and cold season grasses. The disease is also of concern along stretches of the west coast from southern California to upper Washington. Cool, but not in Miller’s words “super cold wet weather,” can make turf susceptible to pink snow mold. The disease can develop under the feet of golfers enjoying winter rounds. “He likes wet conditions,” Miller says. “That’s why in the spring we can see it in many areas, even moving south, because we can have cool and wet weather. “
The other important type of snow mold is more associated with winter. Caused by the pathogen Typhula incarnata, gray snow mold needs at least 60 days of snow cover to thrive, according to Miller. Color can also help a lawn manager identify gray snow mold, as the symptoms are expressed as gray and white spots. “Ultimately,” says Miller, “if you have snow cover for more than two months, you will have conditions favorable to gray snow mold. It must be continuous. We can’t have a 30 day snow window and then another 40 days snowfall later in the winter. It wouldn’t be long enough to incubate this snow mold to express itself. A third more aggressive pathogen, Typhula ishikariensis, causes speckled snow mold, which requires 90 days of snow cover to develop, according to Miller.
Gray, speckled snow mold can become a problem in parts of the Upper Midwest, where prolonged snow cover creates ideal conditions for winter activities such as snowmobiling and cross-country skiing. The same conditions, however, might not be ideal for golf in early and even mid-spring if proper snow mold control tactics are not deployed.
Culture control practices are limited, Miller says, beyond developing a fertility program to ensure playing surfaces don’t get too lush in winter. The lush the grass, the more sensitive it becomes to snow mold pathogens.
Miller recommends that superintendents start thinking about snow mold applications and fungicide selection as early as mid-summer. Of course, it may seem early. But the transition from summer to winter can happen quickly, especially given the number of items on to-do lists in late summer and fall.
“Make sure your timing is such that you’re not caught in the falling snow before you have your application on the ground,” Miller says. “Don’t wait too long, because if you spray on snow covered grass, this fungicide will not hit the target.”
The purpose of a request in late fall is simple. “We’re trying to stop a very, very high amount of this inoculum so that we don’t see symptoms in the spring,” Miller said. In high pressure areas, Miller adds, two applications to high value surfaces such as greens can provide additional protection: a first application about 45 days before snow cover, followed by a second application 30 days later.
The options for reducing the severity of the disease are numerous, with multiple chemical classes and active ingredients providing control. Researchers, manufacturers and turf managers have spent decades perfecting snow mold control programs.
“We have been fighting snow mold for many years and companies like BASF have developed product recommendations, mostly applied in combinations or premixes, which have been proven successful through research across the snow mold belt. snows, ”Miller said. “There are many products that are very effective against snow mold and they can give you a really nice clean surface in the spring after the snow cover has melted. “
Miller calls Insignia® SC Intrinsic® brand fungicide (active ingredient: pyraclostrobin) and Trinity® fungicide (active ingredient: triticonazole) as “fundamental” for snow mold in the BASF portfolio. “These two products, when tank-mixed, are very effective against snow mold,” he says. “In severe areas we would like to add other products to help them, but it is the two BASF base products that have shown great results on snow mold.”
When it comes to the final spray of the calendar year, turf teams only have one chance to make a clear first impression on golfers at the start of the new season.
“It’s important to understand when snow mold will be more severe, when it will be a little less severe, and to understand some of the conditions that can arise during the winter months to predict what to expect the following spring. . Miller said. “When we have a winter where we have a lot of warm weather and a lot of precipitation, we probably won’t have as much pressure because it’s not under the snow. However, fungicides may not last that long in warmer conditions, so we have one thing that works for us and another that works against us.
“Most importantly, it’s all about timing and using products that have been proven to work in research trials. Often the answer is not one or two fungicides. It can be a combination of two, three, or maybe four fungicides depending on where you are and the pressure level you see in that particular area. ?
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