Biocontrol of postharvest diseases on sweet cherries by four antagonistic yeasts in different storage conditions

Four antagonistic yeasts, Trichosporon pullulans, Cryptococcus laurentii, Rhodotorula glutinis, and Pichia membranefaciens were effective against several of the main postharvest pathogens (Alternaria alternata, Penicillium expansum, Botrytis cinerea, and Rhizopus stolonifer) on sweet cherries at 25 degreesC. T pullulans was the most effective for controlling all the diseases at 25 degreesC. Biocontrol efficacy of the four yeasts was further evaluated against A. alternata and P expansum at 0degreesC in air and undercontrolled atmospheres (CA) with 10% O-2 + 10% CO2. The results indicated that the activities of C. laurentii and R. glutinis against A. alternata and P expansum were markedly enhanced by combination with CA conditions. Fruit treated with the two yeasts and stored in 10% O-2 + 10% CO2 for 60 days had better control for both diseases than fruit stored at 0 degreesC for 30 days. T pullulans had a poor effect against either A. alternata or P expansum at 0degreesC in air or in CA conditions. All four yeasts grew rapidly in the wounds of sweet cherries at 25 degreesC. Low temperature and CA conditions did not significantly affect the populations of C. laurentii and R. glutinis, but suppressed the growth of T pullidans and P. membranefaciens. (C) 2003 Elsevier B.V. All rights reserved.