ASSESSMENT OF WINTERHARDINESS IN RED RASPBERRIES

Abstract

Winterhardiness of red raspberries was evaluated over a period of four years. The results showed that injury was severe on all cultivars under study. Growing bud counts taken during the spring and early summer showed that only the buds growing in July reflected the relative hardiness. In only one year out of four did the recovery method indicate relative hardiness and give a clear indication of the time of injury. The possible influence of dormancy on the failure of the recovery method in the other three years is discussed. Cane elongation and leaf drop were clearly associated with winterhardiness. Latitude appeared to influence the relative hardiness of some cultivars.