WINTER HARDINESS AND SURVIVAL OF FORAGE CROPS IN CANADA

Winter survival ratings of the chief forage crops grown in Canada were obtained by means of a national survey carried out at 42 stations for 21 species and 75 cultivars. By an appropriate grouping of these data, winter hardiness indices ranging from 100 to 45 and regional survival indices ranging from 100 to 20 were obtained. On the average, legumes were less hardy than grasses; only 12 cultivar hardiness indices out of 33 were above 80 for legumes, as compared to 33 out of 42 for grasses. Mean survival indices were 97 for humid coastal British Columbia, 94 for dry south British Columbia, 62 for the Prairie Provinces, 72 for Ontario, 69 for Quebec, and 70 for the Atlantic Provinces. Hardiness indices agreed with published hardiness data. Survival of cultivars depended chiefly on their inherent winter hardiness as well as on environmental factors and their general adaptation to individual regions.