Apple pathogens: organic essential oils as an alternative solution

Fusarium avenaceum, Botrytis cinerea, Penicillium expansum, and Neofabraea vagabunda, represent postharvest diseases which cause significant apple losses. The aim of this study was therefore to evaluate the effects of organic essential oils (EOs) (Thymus vulgaris, Lavandula angustifolia, Rosmarinus officinalis) against apple pathogens both in vitro and in vivo, as an integrated management tool. By GC–MS analysis a total of 101 compounds principally belonging to the groups of terpenes and terpenoids were detected in the extracted EOs. In vitro results showed T. vulgaris as the most active EO, both as agar infusion or biofumigant. Through agar infusion, starting from the lowest concentration (0.2 mL L-1), T. vulgaris reduced by 74.9%, 86.1%, 66.9%, and 45.7% F. avenaceum, B. cinerea, P. expansum, and N. vagabunda mycelial growth, respectively; as biofumigant, it completely inhibited the growth of all the tested mycelial pathogens. Application of EOs on apples through dipping treatment displayed some potential to inhibit the above-mentioned pathogens, especially by T. vulgaris and L. angustifolia. The efficacy of these organic EOs is probably strictly correlated to the chemical composition.