Response of the susceptible cultivar Kanzler, the partially resistant cultivar Mikon and the resistant cultivar Asta (genes of resistance Pm2, Pm6) to powdery, were tested in two years small plot-experiments. Disease severity was influenced by weather conditions. There were highly significant differences in disease severity, infection type and number of diseased plants between the susceptible cultivar and the cultivars with partial resistance and specific resistance. Smaller differences were between the partially resistant cultivar and the resistant cultivar than between the cultivar with partial resistance and the susceptible cultivar. The most affected leaf was the third leaf from the top in all tested cultivars. Among these cultivars were differences in the highest development of disease in single growth stages.