WINTER SURVIVAL OF SNOW MOLD INOCULATED ALFALFA UNDER VARYING LEVELS OF SNOW COVER

Two snow mold pathogens, LTB (low temperature basidiomycete) and Pleno domus meliloti (PM), were applied to alfalfa overwintering under varyi ng levels of snow cover. Conditions during the two year experiment did not appear to be conducive for P. meliloti development as there were no differences in percent survival or forage yield between PM-inoculat ed and noninoculated plots. Deep snow appeared to be most conducive to LTB infection. However, optimal soil temperatures (-5 to +1 degrees C ) during March at 5 cm depth under intermediate and shallow snow cover also encouraged pathogenesis and resulted in 74% yield losses under i ntermediate and 46% under shallow snow cover.