Differential Tolerance of Some Arid-Range Wheatgrasses to Snow Mold

Abstract

Snow mold is most severe under a prolonged spring snow cover, where temperatures are favorable for growth of certain fungi. In the spring of 1971 a replicated plot containing 30 accessions of wheatgrasses provided an opportunity to study differential tolerance to snow mold. On the basis of the percent of 1-year-old plants killed, fairway wheatgrass A-12477X (mean of 4 accessions) was most susceptible with 29.4% mortality, fairway wheatgrass A-1770 (3 accessions) averaged 13.7%, and fairway wheatgrass NM-251 (5 accessions) averaged 2.7%. Crested wheatgrass Nordan (4 accessions) averaged 4.9% mortality. Crested wheatgrass A-1874 (1 accession) averaged 11.3% and crested wheatgrass PI 277354 (2 accessions) averaged 2.3%. Five other sources of crested wheatgrass had significantly less mortality than Nordan. Siberian wheatgrass (5 accessions) averaged 4.2% mortality. Intermediate wheatgrass (1 accession) had no mortality, and only 2 plants out of 300 showed moderate injury.