Antifungal Activity of Plant Essential Oils Against Botrytis cinerea, Penicillium italicum and Penicillium digitatum

Plant essential oils have the potential to replace the synthetic fungicides in the management of postharvest diseases of fruit and vegetables.The aim of this study was to access the in vitro and in vivo activity of essential oil obtained from oregano (Origanum vulgare L. ssp. hirtum), thyme (Thymus vulgaris L.) and lemon (Citrus limon L.) plants, against some important postharvest pathogens (Botrytis cinerea, Penicillium italicum and P. digitatum). In vitro experiments indicated that P. italicum did not show any mycelium growth in presence of thyme essential oils at concentration of 0.13 μl/ml. Moreover, B. cinerea did not show any mycelium growth in presence of lemon and oregano essential oils at concentration of 17 μl/ml and 0.02 μl/ml, respectively. Moreover, the essential oils from three species were effective in reducing the spore germination. The in vivo experiments confirmed the strong efficacy shown in vitro by essential oils. These oregano and lemon oils were very effective in controlling disease severity of infected fruit by B. cinera in tomatoes, strawberries and cucumbers. In tomatoes, grey mould due to B. cinerea was completed inhibited by oregano essential oils at 0.30 μl/ml. Moreover, lemon essential oils induced a significant reduction of grey mould disease severity. In strawberries, grey mould was completed inhibited by lemon essential oils at 0.05 μl/ml. In addition, lemon essential oils at 0.05 μl/ml showed 39% reduction of infected cucumber fruits by B. cinerea. These results indicate that essential oils after suitable formulation could be used for the control of postharvest diseases caused by Botrytis and Penicillium pathogens.