Superintendents will soon decide if and when to apply snow mold fungicides.Colder temperatures at the end of Thanksgiving weekend triggered numerous calls to our offices regarding application timing for snow mold control. Effective snow mold control, like so many programs for turf management, is timing dependant. If applied too early and warm weather ensues, then it may force removing the fungicide by mowing. Waiting too long, however, runs the risk of a surprise snowstorm or freezing temperatures preventing fungicide applications from being made at all. Ideally, applications should be made after the last mowing and before the first snow fall. This is easier said than done given recent weather patterns. All told, keep the following few thoughts in mind:
· The long-range weather forecast, for what it is worth, suggests that this winter will be nothing like last winter in the Mid-Atlantic Region. Colder temperatures will be the rule. With recent cold weather, turfgrass growth has slowed dramatically. Some isolated warm weather may occur, but turf growth should be minimal. The need for mowing should soon cease which will pave the way for snow mold applications.
· If snow mold protection is applied to putting greens and you are forced to mow because weather results in turf growth, reapplication of fungicide may be necessary. This is especially important if using a contact fungicide as a component of your control strategy. Look closely at clipping yields when making this decision. If significant clippings aren’t being removed when mowing then you are not removing the fungicide.
· If covering greens, snow mold applications are a must. Covers provide a very good environment for snow mold development. Use fungicides that you know to be effective against both pink and gray snow mold, and use the higher label rates for control. Turf conditions beneath covers should be inspected periodically to be certain snow mold infection is not occurring!
· More and more golf facilities are choosing not to treat fairways for snow mold because of the costs involved with application to large acreages. This can be a risky proposition that may lead to some fairway scarring in late winter and early spring. Remember, lack of snow cover does not mean turf will not be infected. Pink snow mold (Michrodochium nivale) can occur without snow cover. The grass will generally recover in the spring once warmer temperatures persist, but playability can be affected until damaged turf fully heals. This potential damage is important to communicate to course officials when financial decisions are made on whether or not to treat fairways for snow mold.
Many fungicides are effective for snow mold control. The keys are proper application timing and some cooperation from the weather. To this end, closely monitoring weather forecasts is critical in determining proper timing.
The Mid-Atlantic Regional agronomists are part of your agronomic support team. If you have a question or concern, give us a call or send an e-mail. You can reach Darin Bevard (dbevard@usga.org) at 610/ 558-9066 or Keith Happ (khapp@usga.org) at 412/ 341-5922.