Selection and use of Metschnikowia pulcherrima as a biological control agent for postharvest rots of peaches and table grapes

In this study epiphytic yeasts were isolated from non-decayed fruit wounds and the possibility to use them as potential biological control agents for postharvest rot diseases was investigated. Of the 121 isolates, eight showed, in preliminary challenge experiments, inhibition of Monilinia laxa and Botryotinia fuckeliana. Six strains were classified as Metschnikowia pulcherrima, which has not been employed previously as a biocontrol agent on peach and table grape fruits, while the other two strains were included in the Kloeckera apiculata and Hanseniaspora guilliermondii species. M. pulcherrima strains were effective in reducing the incidence of brown rot in peaches and gray mold in table grapes (from 49 to 89% depending on the strain and fruit), but their biocontrol activities were not enhanced by the addition of calcium chloride. The colonization and persistance of M. pulcherrima strains on berry wounds were also observed during low storage temperature. The results indicate that a potential exists for the practical utilization of selected epiphytic M. pulcherrima antagonists in fruit postharvest diseases control.