Biocontrol of postharvest brown rot of sweet cherries by Saccharomyces cerevisiae Disva 599, Metschnikowia pulcherrima Disva 267 and Wickerhamomyces anomalus Disva 2 strains

In this work, Metschnikowia pulcherrima Disva 267, Wickerhamomyces anomalus Disva 2, and Saccharomyces cerevisiae Disva 599 yeast strains were evaluated for their biocontrol activity on postharvest decay brown rot, mainly caused by Monilinia laxa on sweet cherries, using three increasing concentrations (10⁶, 10⁷ and 10⁸ CFU/mL). M. pulcherrima significantly reduced brown rot incidence, severity and McKinney index at all three concentrations, W. anomalus was effective at the concentration of 10⁷ CFU/mL, and S. cerevisiae reduced brown rot only at 10⁸ CFU/mL. M. pulcherrima and W. anomalus survived on the surface of sweet cherries during 2 weeks cold storage. When the three yeasts were sprayed on the canopy of sweet cherry trees at 10⁷ CFU/mL, M. pulcherrima and W. anomalus showed good survival and colonization. In contrast, under the same conditions, S. cerevisiae strain did not survive. None of the yeasts produced phytotoxic substances, both on intact and on wound-inoculated fruit. Therefore, M. pulcherrima Disva 267 and W. anomalus Disva 2 could be promising biocontrol agents, able to survive in field and storage environments, providing a clear decrease in postharvest decay. However, further investigations with large scale trials are needed to lead to a possible formulation and commercial use.