Pruning practices influence infection and dissemination of <em>Calosphaeria pulchella<em>, the cause of Calosphaeria canker of sweet cherry

Abstract

Calosphaeria canker of sweet cherry, caused by Calosphaeria pulchella, is a limiting factor for sweet cherry production, but the role of pruning practices on pathogen dissemination remains unknown. Three experimental treatments were compared during summer and winter seasons, to assess their effects on pathogen transmission. The treatments were: i) using disinfected pruning shears; ii) pruning shears used to cut through diseased branches before each subsequent cut (non-disinfected pruning shears); and iii) artificial inoculation of fresh pruning wounds with C. pulchella. Six months after pruning, branches were cut from trees for disease assessment and fungal isolation. Pruning with non-disinfected pruning shears increased disease incidence and severity, compared with the use of disinfected shears. Artificially inoculated branches gave the greatest disease incidence and severity. Results from the various treatments were consistent for both winter and summer pruning. These confirm that frequent disinfection of pruning tools is advised for the effective management of Calosphaeria canker of sweet cherry.