Incidence and etiology of postharvest fungal diseases of persimmon (Diospyros kaki thunb. cv. rojo brillante) in Spain

Abstract

‘Rojo Brillante’ is currently the most important persimmon cultivar in Spain. The incidence and etiology of postharvest diseases affecting this cultivar were determined under local conditions. Latent and wound pathogens were assessed for two consecutive seasons on commercially grown persimmons from two orchards. Healthy persimmons were either surface-disinfested or artificially wounded on the rind and placed in humid chambers at 20 or 25°C for up to 9 weeks. Additionally, decay was assessed on commercially handled persimmons stored at 1°C for up to 20 weeks. In all cases, the most frequent disease was alternaria black spot (ABS) caused by Alternaria alternata and an ABS severity index specific for ‘Rojo Brillante’ persimmons was established. Other minor pathogens causing latent infections, mostly stem-end rots, included Botrytis cinerea, Lasiodiplodia theobromae, Neofusicoccum spp., Pestalotiopsis clavispora, and Colletotrichum gloeosporioides. Penicillium expansum and, to much a lesser extent, Cladosporium cladosporioides were other pathogens causing wound infections. These two fungi and A. alternata and B. cinerea were also isolated from cold-stored fruit. Common isolates were identified by macroscopic and microscopic morphology and/or DNA amplification and sequencing. Pathogenicity of selected isolates was demonstrated by fulfilling Koch’s postulates. Disease development at 20 and 5°C was characterized on artificially inoculated persimmons.