Bacterial canker in sweet cherries is caused by the bacterium Pseudomonas syringae pv. syringae (PSS) van Hall and is commonly associated with production areas characterized by wet and cold weather, such as western Washington, Oregon, and southern Chile, among others. Historically, until about 1970, bacterial canker was not considered a significant threat in the arid, sweet cherry producing region of eastern Washington. However, since then, this disease has been observed more frequently, especially in newer plantings where tree losses of up to 75% have been reported. The apparent increase in disease levels observed in Washington can be attributed to several factors, with the seemingly most evident being the high susceptibility of the cultivar �Coral Champagne�. Additional factors influencing bacterial canker infection include extreme weather conditions and irrigation practices. The presence of other diseases, such as Little Cherry Disease (LCD) or Verticillium wilt, can further predispose trees to infection by PSS. This publication provides additional information on bacterial canker caused by PSS and provides an overview of the disease management practices for Washington sweet cherry growers and guidelines to better diagnose the disease and prevent confusion with other threatening diseases affecting the Washington sweet cherry industry
