Symptoms and Signs
Cherry stem pitting is caused by a graft-transmissible agent that has not been identified but is thought to be a soilborne virus. Symptoms usually spread from tree to tree in a circular pattern, which is characteristic of spread by soilborne vectors. Trees on susceptible rootstocks will develop symptoms if replanted where diseased trees have been removed.
Cherry stem pitting is characterized by pits and grooves that develop in the wood of the trunk just underneath the bark of Bing sweet cherry on Mazzard, Mahaleb, or Stockton Morello rootstocks. The stem pitting symptoms develop on Prunus avium wood; that is, on Bing scion and Mazzard rootstock but not on Mahaleb or Stockton Morello rootstock.
Aboveground symptoms resemble those of root diseases and some other viruses. Buds on infected trees open later than normal. Leaves are smaller than normal and trees have a more open canopy because leaves are smaller and fewer. Fruit may be small and pointed with short stems, similar in appearance to fruit affected by X-disease (cherry buckskin). In some cases, foliage and fruit symptoms develop on one or two branches of a tree.
Management
To minimize problems with stem pitting, use certified planting stock and virus-free material in nurseries. Remove diseased trees and replant with Colt rootstock, which has been found to be resistant to stem pitting when used as a replacement rootstock in affected orchards.