Incidence and etiology of postharvest diseases of fresh fruit of date palm (Phoenix dactylifera L.) in the grove of Elx (Spain)

Abstract

The incidence and etiology of postharvest diseases affecting fresh date fruit in the palm grove of Elx (Spain) were determined under local environmental conditions. Latent and wound pathogens were assessed for two consecutive seasons on fruit from two important commercial cultivars, ‘Boufeggous’ and ‘Medjool’, grown in different orchards. Healthy dates were either surface-disinfested or artificially wounded in the rind and placed in humid chambers at 20ºC for up to 7 weeks. Irrespective of cultivar, season, orchard, and type of infection, the most important causal agents of disease were Penicillium expansum, Alternaria alternata, Cladosporium cladosporioides, and a black aspergillus species belonging to the Aspergillus niger clade. These fungi were identified by macroscopic and microscopic morphology and/or DNA amplification and sequencing. Their pathogenicity was demonstrated by fulfilling Koch’s postulates. Disease development at 20 and 5ºC was characterized on artificially inoculated dates.