Black rot (Diplodia seriata) in organic apple production -infection biology and disease control strategies

摘要

During a three-year trial (2011 -2013) at an organic fruit farm in the Lower Elbe region (Northern Germany), the manual removal of fruit mummies and preventive applications of crop protection compounds (Myco-Sin and lime sulphur) were tested for theirinfluence on reducing black rot (Diplodia seriata; and fungal storage rots. Aspects'of the infection biology ofD. seriata were examined by monitoring the spore release (conidia) in response to rainfall and by scoring overwintered fruit mummies for colonisation by D. seriata. The removal of fruit mummies, either as a stand-alone treatment or in combination with Myco-Sin or lime sulphur applications, was able significantly to reduce pre-harvest fruit infections caused by D. seriata. A correlation betweenspore potential, the amount and intensity of rainfall and high temperatures was observed during the monitoring of primary infections. Storage rots, chiefly caused by Neofabraea spp., were controlled by a combination of fruit mummy removal and spray applications, the highest efficacies being observed with Myco-Sin.