Fall is not far around the corner, and in more northern reaches, disease concerns will be shifting from dollar spot to snow mold. While none of the three types of snow mold cause permanent damage, a significant outbreak of any of the three is probably the most devastating disease a manager can face in terms of the visual impact. Avoiding this scenario makes preventive use of fungicides well worth the investment anywhere extended snow cover may occur.
Gray and Speckled Snow Molds:
Gray snow mold caused by Typhula incarnata and speckled snow mold caused by Typhula incarnata require extended periods of snow cover to develop. Gray snow mold grows faster and has larger sclerotia than speckled snow mold, and typically requires at least 60 days of cover to develop. Speckled snow mold, Typhula ishikariensis, is thought to require at least 90 days of cover to occur. With enough continuous coverage, it is possible to have a mix of Typhula in the same outbreak, and they may also have some pink snow mold mixed in. Fortunately, all three respond similarly to preventive fungicide applications.
Pink Snow Mold and Microdochium Patch:
Pink snow mold, Microdochium nivale, is the fastest growing snow mold and can even occur without continuous snow coverage if enough precipitation occurs during winter months, which is referred to as Microdochium patch. One or two preventive fungicide applications in the fall can prevent pink snow mold, but Microdochium patch can require more extended preventive programs to cover long periods of favorable conditions as is more commonly encountered in the Pacific northwest.
Fortunately, for snow mold prevention, one doesn’t have to predict which type(s) may occur to select an effective product. Application just prior to the first persistent snowfall is the most advantageous, but if that snow is delayed, a follow up application before the next snow forecast can help ensure there is still adequate prevention in place. Years of trials have shown that the use of multiple modes of action provide the best prevention.
Enclave, a Snow Mold Standard:
With four active ingredients in the formulation, Quali-Pro's Enclave fungicide is an excellent choice for snow mold protection. Year after year, Enclave has been a proven performer in snow markets from one side of the US to the other. In the 2021-2022 winter season, a single, 8 fl oz per 1000 ft2 application of Enclave prior to snow cover was consistently a top performer in trials from New York, New Hampshire, Wisconsin, Michigan, Minnesota, Idaho, Utah, and Oregon, including a good sampling of pressure from all three species of pathogens. So no matter where you might be, if snow cover is in the forecast, Enclave can cover all the snow mold bases.