The antifungal activity of the essential oils of ajowan, fennel and caraway was evaluated in vitro and in vivo conditions against growth of Alternaria alternata (Fr.: Fr.) Keissler. and Penicillium digitatum Sacc., two postharvest pathogens of tomato fruits. In vitro tests showed that ajowan and fennel oils exhibited the highest antifungal activity against A. alternata and P. digitatum, respectively. But caraway exhibited poor antifungal activity against two fungal species tested. Ajowan oil possessed the highest antifungal activity among tested oils in in vivo condition. Gas chromatography–mass spectrometry analysis of essential oils revealed that thymol (63%), trans-anethole (64%) and 2-caren-10-al (34%) were the main components of essential oils of ajowan, fennel and caraway, respectively. Therefore, essential oils may be used as an alternative for the synthetic chemicals for control of postharvest phytopathogenic fungi and for increasing the shelf life of plant products.
