Abstract

Following 2 experiments designed to enable the infection mechanisms of B. cinerea to be compared directly with those reported for D. applanata, the relative resistance of 7 cultivars to 3 isolates of each pathogen in the field was determined. Principal components analysis of data from 5 estimates of resistance to each pathogen showed that 40% of the variation described a common resistance. Chilcotin and Meeker had the strongest common resistance and Glen Prosen and Malling Jewel the weakest. The remaining variation described cultivar differences in relative bud length after petiole inoculation with either pathogen, and differences in the relative importance of spring and autumn symptoms. Only 7% of the variation indicated independent resistance to the 2 pathogens and this was not influenced by cultivar differences.