Essential oils to control postharvest diseases of apples and peaches: elucidation of the mechanism of action
Essential oils represent a powerful resource to control postharvest pathogens of pome and stone fruit. The efficacy of these natural products was investigated in vitro but only few of them were applied in vivo to assess the applicability in real conditions. Essential oils can be applied in several ways, by dipping or spraying the fruit surface or biofumigation, exploiting the volatility of the compounds. The last mode of application is preferable because there is no direct contact of the oil with the fruit. Thyme and savoury essential oils were successfully used as biofumigant against brown rot caused by Monilinia fructicola in nectarines and peaches. Moreover, the essential oils showed a positive role in slowing senescence processes and reducing weight loss. The antimicrobial activity of essential oils, useful to control fungal pathogens, is mainly due to a synergy of different chemical components. Apples treated with thyme essential oil at 1% concentration showed lower disease incidence of gray mold caused by Botrytis cinerea. In addition to direct inhibition of pathogen growth, essential oils participate also in resistance induction in the fruit host. The expression of pathogenesis related gene PR-8 was slightly higher in response to thyme essential oils. In the present article, several mechanisms of action of essential oils against postharvest rots development and the possibility to improve efficacy of natural products combining different control strategies were reported.
Spadaro, D., Banani, H., Santoro, K., Garibaldi, A. and Gullino, M.L. (2021). Essential oils to control postharvest diseases of apples and peaches: elucidation of the mechanism of action. Acta Hortic. 1323, 35-42
biofumigation, Botrytis cinerea, induction of resistance, Monilinia fructicola, savoury, thyme