Podosphaera cerasi - an old foe of US sweet cherry with a new name –its biology, epidemiology, and beyond

Sweet cherry is a high-value fresh market crop whose commercial value is directly related to fruit quality. Morphological studies and phylogenetic analyses have shown that a distinct powdery mildew species, Podosphaera cerasi, infects sweet cherry in orchards, nurseries, and greenhouses for stock production. The fungal species P. clandestina , which was thought to cause powdery mildew infection in sweet cherry, is now confined to the powdery mildew that infects Crataegus spp. The intricate nomenclatural-taxonomic history of sweet cherry powdery mildew is briefly outlined. This review has been written to serve production managers as well as applied and basic research regarding control of this pathogen. The economic impact of this powdery mildew, environmental aspects contributing to its epidemiology, management options including both conventional chemical and biopesticide products, as well as mycoviruses associated with P. cerasi are discussed. Additionally, an overview of host–pathogen resistance based on cultivar, fungicide resistance, the role of chasmothecia in epidemic initiation, and susceptible stages of fruit to infection are discussed.