Combining yeasts or a bacterial biocontrol agent and heat treatment to reduce postharvest decay of 'Gala' apples

'Gala' apples were treated after harvest with heat (38 degreesC for 4 days), and then wound-inoculated with the pathogen Penicillium expansum and the antagonist Pseudomanas syringae, or one of two yeast antagonists, to reduce postharvest decay. After storage for 7 days at 20 degreesC or 3 months at 1 degreesC, the least decay was found on fruit where wounds had been allowed to cure by heat treatment (38 degreesC) or cold storage (1 degreesC) for 4 days before inoculation with the pathogen. Addition of any of the antagonists before or after heat treatment further reduced the number and size of the lesions. The highest lesion incidence occurred on apples wounded after heat treatment followed by inoculation with the pathogen. Addition of the yeast antagonists to these fresh wounds reduced the fruit decay as well. While the heat treatment is phytosanitary in that it significantly reduces the pathogen population on the apple surface, it provides little residual protection. The residual protection from the antagonists adds to the control provided by the heat treatment. Published by Elsevier Science B.V.