Fruit epiphyte and environmental fungal populations in Clemenules mandarin orchards in Tarragona (Spain)

摘要

Fruit epiphyte and environmental fungal populations were examined in Clemenules orchards in Baix Ebre and Montsia areas (Tarragona, Spain). For two consecutive seasons, sampling was conducted twice (from September to December and from January toMarch) in four representative commercial orchards and in an organic orchard. Cladosporium was the most frequent genus present (89.8 percent and 80.4 percent of colonies isolated from the fruit surface at the first and second sampling, respectively; and72.1 percent and 32.7 percent of colonies isolated from the environment at the first and second sampling, respectively). Pathogenic fungi like Penicillium, Alternaria, or Rhizopus were more frequently isolated in the second sampling (8.4 percent and 25.9percent of Penicillium colonies from the fruit surface and the environment, respectively) than in the first sampling (1.2 percent and 0.6 percent of Penicillium colonies from the fruit surface and the environment, respectively). Both total fungal population and Penicillium population were found to be highly variable, with significant interactions among years, samplings and orchards. Total fungal population was highly correlated with temperature (r > 0.9). Environmental population, but not fruit epiphyte population, was higher in the organic orchard than in the commercial ones. With the exception of Rhizopus and Mucor, which were isolated more often from fruits located in the lower area in the tree canopy, the fungal population levels were similar in fruits located at different heights in the tree canopy.