Assessment of different control means to protect grape berries from biotic injuries in postharvest

To find alternatives similar in effectiveness to conventional fungicides, two commercial disease resistance inducers, EP5-Protect (Phenom Biotech, Milan Italy; EP) and BioDea Flavor (BioDea, Arezzo, Italy; WD), and bioactive extracts (BCEs) from a strain of Streptomyces albidoj avus (CARA17), were compared to the fungicide fludioxonil in in vitro and in vivo trials to control postharvest decay on table grapes by Botrytis cinerea and Monilinia laxa. Disease severity and incidence were recorded by Mckinney index values of 0.0-5.0. On culture media, EP, BCEs, and fludioxonil significantly inhibited the growth of both pathogens by 100% for B. cinerea, and 79-100% for M. laxa, while WD inhibited both pathogens by 15-25%. Similar results were obtained from experimental trials with inoculated grape berries treated with these compounds after harvest. Fludioxonil was the most effective treatment to control both pathogens applied to uninoculated or inoculated grapes. EP was significantly but moderately effective to control both pathogens and the other saprophytic microorganisms, whereas the effectiveness of BCEs from S. albidoj avus was significantly less, and WD was the least effective treatment. Our results indicate EP and BCEs may be promising to control postharvest decay on grapes and other fresh products. They could conceivably be used to replace sulfur dioxide fumigation currently used to protect grapes after harvest, in particular when storage is not prolonged.