Botryosphaeriaceae species associated with blueberry stem blight and dieback in the Centre Region of Portugal

Blueberry (Vaccinium corymbosum) cultivation in Portugal has been growing considerably in the last decade, making it a highly profitable fruit crop. Species of Botryosphaeriaceae are relevant pathogens of blueberry causing stem blight and dieback. In this study a survey was carried out in blueberry orchards in the centre region of Portugal in order to assess which species of Botryosphaeriaceae are associated with stem blight and dieback symptoms. Their presence as endophytes was also evaluated in asymptomatic plants. Four species were identified, Botryosphaeria dothidea, Neofusicoccum parvum, N. australe and N. eucalyptorum. Of these, B. dothidea and N. parvum were the most commonly found. Pathogenicity trials showed that the four species tested were pathogenic to blueberry plants and revealed that N. parvum, was the most aggressive species, and most likely the main causal agent of blueberry stem blight and dieback in Portugal. Neofusicoccum eucalyptorum, a common Eucalyptus pathogen, is reported for the first time as a pathogen of blueberry. This represents a significant host jump whose potential future effects on blueberry plantations are not fully understood.