Speeding Snowmelt to Control Snow Mold Justin Clawson, Michael Pace, Eric Galloway, Matt Yost, and Earl Creech The high level of snowpack in the winter of 2022– 2023 created a renewed interest in speed-melting snow to prevent snow mold on winter wheat crops, golf courses, and homeowners’ lawns. Snow molds are diseases caused by fungi growing under snow cover or in cool, wet weather. Winter wheat can be infected by three types of snow molds, while turf grasses can be infected by two kinds of snow molds. Plants will have a bleached color for pink snow mold or a thin layer of white or gray mycelium leaving the plants gray or white after they dry out for gray snow mold. This fact sheet will discuss ongoing research in Utah aimed at using soil amendments to speed the melting of snow to reduce snow mold pressure for small grains.
Researchers applied the fly ash at a rate of 200 pounds/acre on approximately 12 inches of snow on March 26. The snow was again melted in 3 days; however, the snow mold had continued to grow under the snow and the winter wheat plots were a complete loss. It was estimated that they should have applied the product 3 to 4 weeks earlier since snow mold spreads quickly under ideal conditions. The conclusion was that a lower rate of 100 pounds/acre would be sufficient for snow removal compared to the 200 pounds/acre used (Dewey & Nielson, 1971).
Speed-Melting Research
Further research conducted from 1975–1985 at the Blue Creek Research Farm in Box Elder County, Utah, found that snow mold in Utah occurs when snow is deeper than 12 inches and remains covered for 70 days or longer. This research also
Early research at Utah State University to control snow mold under 12 inches of snow in winter wheat research plots in Logan, Utah, used a product called lampblack, which is a finely powdered black soot from incomplete combustion of carbonaceous materials. The product was applied using a knapsack duster to winter wheat at a rate of 7 to 9 pounds/acre. Within 3 days, the treated area was bare of snow and snow mold was immediately halted while the untreated area remained under snow for another 2 weeks. Another product they tried in the spring of 1969 was coal-burning furnace ash applied aerially with a crop duster airplane. This product was relatively easy to find at the time and very lightweight.
Figure 1. USU Snowcat Applying Petroleum Coke, Greenville Research Farm, Logan Utah, March 2008
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