SNOW MOLD INFECTION OF ALFALFA, GRASSES, AND WINTER WHEAT BY SEVERAL FUNGI UNDER ARTIFICIAL CONDITIONS

Abstract

Snow mold infection by an unidentified low-temperature basidiomycete and Typhula spp. developed best under artificial conditions when inoculated plants in pots were incubated for 2 months at 2 °C with 80 to 90% R.H. in the special cabinets described or with other covering. A saturated atmosphere was detrimental to mycelial growth and infection. Freezing temperatures and complete host dormancy were not required but greenhouse-grown plants benefited from prior conditioning for 2 weeks at 2° to 5 °C with light for 8 hours daily. The reactions of alfalfa varieties, creeping red fescue, Kentucky bluegrass, red top, timothy, and winter wheat to the low-temperature basidiomycete were similar to those previously observed in the field. T. idahoensis Remsb. caused moderate to severe damage and T. itoana Imai caused slight to moderate damage to the grasses and winter wheat. Typhula sp. from alfalfa was highly virulent to that host. The low-temperature basidiomycete was the only snow mold organism tested that synthesized HCN in culture or in the plant tissues.Sclerolinia borealis Bub. & Vleug. caused slight damage to winter wheat and grasses after 3 months at 2 °C but did not develop well under any of the conditions employed.