Rosmarinus officinalis L. and Myrtus communis L. Essential Oils Treatments by Vapor Contact to Control Penicillium digitatum

Background: The antimicrobial activity of Essential Oils (EOs) has been used for centuries and nowadays the efforts to develop natural preservatives in postharvest management have augmented interest in their possible applications. Materials and Methods: Rosmarinus officinalis L. and Myrtus communis L. EOs, and two of their components, α- and β-pinene, have been tested in vitro against Penicillium digitatum, with the aim to assess their antifungal effects when applied as fumigation. The pathogen, inoculated on PDA dishes, was treated by EO-vapors contact and the fungal growth inhibition was recorded in order to evaluate the EOs antifungal activity. Results:The exposure to the EOs vapors shows different ability in the control of fungal growth related to the EO concentration used and the elapsed time between the fungal inoculum and EO vapor contact. The greatest antifungal activity was observed for rosemary EO, while a less control was found for the myrtle one. Treatment performed with α-pinene showed a control of the pathogen that was similar to the myrtle, whereas control with β-pinene was very poor. Highlight: Our finding revealed that plant EOs could be successful in controlling fungal postharvest disease in a dose and compound dependent manner, but deeper researches are needed about treatment parameters because the effectiveness seems to be affected by treatment modalities.