Cherry (Prunus spp.)-Black Canker

Cause An uncharacterized graft-transmissible pathogen, probably a virus spread in nursery propagation. In 1959, the disease was described as fairly common in older 'Royal Ann' plantings throughout Oregon. The most severely affected cultivar is Royal Ann, but the disease has also been observed in Bing, Republican, and Deacon.

Symptoms Cankers develop on 1-year-old twigs, having slightly swollen areas with the bark split lengthwise. These grow into rough black cankers, the ultimate size of which is more or less determined by the size of the affected branch. Some infected trees are severely cankered in many parts of the tree. No fruit or leaf symptoms have been observed.

Cultural control Plant virus-indexed (and found to be free of all known viruses) trees.

Reference Hadidi, A., Barba, M., Candresse, T., and Jelkmann, W. 2011. Virus and Virus-like Diseases of Pome and Stone Fruits. St. Paul, MN: APS Press.