Susceptibility of Almond Cultivars and Stone Fruit Species to Pruning Wound Cankers Caused by Phytophthora syringae. M. A. Doster, Graduate Research Assistant, Department of Plant Pathology, University of California, Davis 95616. R. M. Bostock, Associate Professor, Department of Plant Pathology, University of California, Davis 95616. Plant Dis. 72:490-492. Accepted for publication 8 January 1988. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0490.

For all almond cultivars commonly grown in California, inoculation of fresh pruning wounds with Phytophthora syringae resulted in canker development. Canker expansion rates were similar except in Ripon, which consistently had smaller cankers. Only Nonpareil developed cankers from inoculation of 3-wk-old wounds, which suggests that the length of cultivar susceptibility to infection may be important in determining disease severity in the orchard. Fresh wounds in almond, apricot, and peach trees were susceptible to infection and canker development caused by P. syringae, but only small cankers formed in plum and French prune trees.