Susceptibility to peach leaf curl (Taphrina deformans Berk.) Tul. in a peach germ plasm collection

Summary

The susceptibility of 1103 peach genotypes (738 dessert peach, 168 clingstone, 197 nectarines) and 152 unselected seedlings to leaf curl (Taphrina deformans) was assessed. No cultivars rated zero, which is equivalent to immunity, only six rated 1, while 62% had the highest susceptibility rating 5. Presence or absence of leaf glands and fruit type were not correlated to resistance or susceptibility. The distribution of the different fruit type and the unselected seedlings over the various susceptibility categories indicates a loss of resistance to leaf curl during selection for improved agronomic characters.