Formulation of essential oils and yeast for controlling postharvest decay of tomato fruits.

The yeast, Saccharomyces cerevisiae, Candida tenuis and the commercial backing yeast of Saccharomyces cerevisiae mixture (CBY) and/or peppermint, melon and rose essential oi1s were evaluated for their in vitro activity against the fungal growth of Botrytis cinerea, Rhizopus stolonifer and Alternaria alternate the causal agents of tomato fruit decay. S. cerevisiae mixture (CBY) proved it self to have the highest inhibitory effect on the growth of the pathogenic tested fungi fol1owed by the two other yeast isolates S. cerevisiae and C. tennis. All the tested concentrations of peppermint oil had not negative effect against the viability of tested yeasts, while significant reduction in the populations of all yeast isolates was observed at melon and rose oils treatments even at the lowest concentration tested. Peppermint oil showed superior inhibitory effect against the growth of tested pathogenic fungifol1owed by rose and melon oils, respectively. Mixtures of peppermint oil with any of yeast isolate showed high inhibitor effect against the pathogenic fungal growth compared with rose and melon oils mixtures. Under storage conditions, application of carnauba wax formula containing either S. cerevisiae or S. cerevisiae (CBY) combined with peppermint oil (1%) had more superior effect for reducing gray mould, soft rot and black rot incidence as well as disease development of tomato fruit，reaching up to 100% under artificial inoculation of decay pathogenic fungi. On the light of the obtained results in the present study, it could be concluded that the application of carnauba wax containing 1% peppermint oi1 combined with S. cerevisiae or S. cerevisiae (CBY), could control several post-harvest diseases of tomato fruit without affecting tomato fruit quality under storage conditions.