The incidence of storage rots after postharvest apple washing

Abstract

The effect of four postharvest apple washing treatments and two unwashed treatments on fruit surface microflora and the development of storage rots in punctured and uninjured fruit were assessed. A significantly higher incidence of storage rot was observed in punctured apples (16-35%) than in uninjured apples (1-3%) after washing in water with high fungal populations (P<0.01 ). In contrast, no significant difference in rot incidence was observed between punctured (2%) and uninjured apples (1%) when the apples were washed in water containing few fungi. Most rots (90%) were apparently caused by Penicillium spp. Rots with Mucor spp., Botrytis spp. and Alternaria spp. were also present. Significant relationships were identified between (a) fungal concentrations in wash water and storage rot incidence in punctured apples, (b) post-washing fruit surface fungal populations and storage rot incidence in punctured apples and (c) fungal concentrations in wash water and fruit surface fungal concentrations. Yeast populations had no effect on rot incidence.