Antifungal activity of thyme, oregano and laurel essential oils against Aspergillus niger Tiegh

A range of pathogenic fungi are associated with postharvest fruit spoilage in storage that cause significant economic losses every year. To control postharvest mycoses, fungicide application is the usual practice. However, the use of essential oils as an alternative strategy to chemical fungicides has been considered for management of the postharvest fruit decay in order to ensure nonnegative impact on human health. Mycotoxigenic fungi Aspergillus niger Tiegh. is economically important pathogen which causes postharvest black rot on various fruits. The present study evaluated the vapor phase antifungal activity of three essential oils - thyme (Thymus vulgaris L.), oregano (Origanum vulgare L.) and laurel (Laurus nobilis L.) against postharvest pathogen A. niger. The antifungal activity of selected essential oils were evaluated by disc volatilization method on PDA medium. The vapor phase of all tested oils showed a significant (p < 0.05) fungistatic growth inhibition of pathogen A. niger, where thyme oil achieved the highest pathogen inhibition (99.8%), while laurel oil was less effective (36.3%). The obtained results suggest that the tested vapor phase (especially of thyme and oregano oils) could potentially be extremely useful fumigants to prevent and control the fruit rot in storage.