Infection of flowers and fruits of red raspberry by Botrytis cinerea

The frequency and site of symptomless infection of flower buds, flowers, and fruits of red raspberry by Botrytis cinerea was studied using surface-disinfestation and culture techniques. Flower buds were rarely infected but open flowers were rapidly colonized and necrotic stamens and styles were an important source of infection for the developing fruit. The receptacle tissue within the drupelet cluster cavity was mostly sterile. Dichlofluanid sprays reduced symptomless infection of fruits and were more effective when applied early. Post-harvest rot tests indicated that incidence of grey mould was not related to symptomless infection unless fruits were surface-disinfested before subjecting to the rotting test.