the partial or complete destruction of winter wheats and other winter crops (such as perennial grasses) from “starvation” as a result of a prolonged period under deep snow cover.
Damping-off is caused by insufficient light, the cessation of the flow of water and food from the soil, and the high humidity and temperature under the snow. In these conditions new nutritive elements do not form in the plants, and those accumulated earlier are depleted. As a result, carbohydrate starvation sets in, followed by protein breakdown, and, finally, by disease (fusiarial wilt, sclerotinia rot, and others).
Damping-off occurs primarily in mild winters, especially on overgrown and not very hardy fall crops that were covered with a thick layer of snow that did not melt early in spring (in hollows, on the edge of forests). Damping-off also occurs when a thick layer of snow (40-50 cm) covers winter crops not prepared for wintering or soil that has not frozen through. A hanging ice crust that lets in light and hence raises the temperature can also be a cause of damping-off. In all of these instances, the active life processes of the plants continue, and their respiration increases.
In order to prevent damping-off of plants, sowing too early and too thickly and excessive nitrogen fertilizing should be avoided; use of a phosphoropotash fertilizer, resistant strains, hill sowing, and rollers to pack down snow on in-completely frozen soil are recommended.
P. I. PODGORNYI