The control of Botrytis fruit rot in strawberry using combined treatments of Chitosan with Zataria multiflora or Cinnamomum zeylanicum essential oil

This study evaluated the efficacy of the combined application of chitosan (CS) and Zataria multiflora (ZEO) or Cinnamomum zeylanicum essential oils (CEO) on the inhibition of Botrytis cinerea, the causal agent of strawberry gray mold on laboratory media and fruits during storage (7 days at 4 °C followed by 3 days at 20 °C). The application of different CS, CEO and ZEO concentrations inhibited the mycelial growth of the assayed fungus. The mixtures of CS and CEO (CC) or ZEO (CZ) inhibited the mycelia growth in potato dextrose agar, as well as the growth of B. cinerea in artificially infected strawberries stored at both room and cold temperature. Moreover, combined treatments showed more significant mycelial inhibition results and reduction of the IC50, MIC and MFC values compared to pure EOs or CS (p < 0.05). In fruit decay assays, combined treatments (CC or CZ) were able to reduce fungal decay in the range of 60–85 % at 9th day of storage. These results demonstrate the potential of the combined application of CS and CEO or ZEO at sub-inhibitory concentrations to control post-harvest pathogenic fungi in fruits, in particular, B. cinerea in strawberries.