Comparison of the occurrence of fungi causing postharvest diseases of apples grown in organic and integrated production systems in orchards in the Czech Republic.

During the years 2013–2015, the occurrence of fungi causing postharvest diseases of apples was evaluated in three apple orchards with integrated and organic production systems in the Czech Republic. The postharvest disease fungi were more frequently recorded in fruits from organically cultivated apple trees (average 29.97%) than those from integrated production (17.67%). This difference is statistically significant. Neofabraea, Penicillium, Alternaria and a sterile grey mycelium were the most frequently recorded taxa in apples grown in organic and integrated production systems. There were also significant differences in the frequency of occurrence of the most frequent fungal taxa between years. In 2013 and 2014, Neofabraea was the most frequently isolated genus in both cultivation systems, whereas in 2015, Penicillium was the most frequently recorded genus also in both cultivation systems, which was likely caused by the low precipitation in the 2015 growing season.