Sign out. Newsletter signup: Tiny, dark brown bumps develop at the center of each lesion. Spores are produced throughout winter and are spread by splashing rain and wind. Note the gray lesions with purple borders on this 'Elberta' fruit.
The disease is most noticeable in spring, as new growth is most susceptible.
Shot hole disease
Gem SC at 2. Leaf infections first appear as small red spots which enlarge and become purple with a tan-white center. Disinfect your cutting tools. An enriched soil and plenty of space between plants helps reduce likelihood of disease. The fungal pathogen Wilsonomyces carpophilus affects members of the Prunus genera. Utah State University Extension.