The present investigation aims to evaluate the antifungal effects of the plant essential oils against major postharvest pathogens (i.e. Botrytis cinerea and Pythium aphanidermatum) cause decay of Snap bean pods (cv. Xera and Valentino). Three essential oils obtained from Camphor, Cinnamon and Carnation were tested at concentrations 0.25, 0.5 and 1%(v/v). The results of in vitro experiment indicated complete inhibition of B. cinerea and P. aphanidermatum at all concentrations of Cinnamon and Carnation tested. Under field conditions, pre-sprayed Snap bean plants with Cinnamon and Camphor treatments at 1% gave the highest levels of controlling decay of bean pods (cv. Xera) by B. cinerea. The same effects were given on pods of Valentino cv. at concentration 0.5% and 1% against the tested pathogen B. cinerea. Vaporization of Snap bean pods during storage with Carnation at 100 µL was the best treatment as suppressed completely the disease caused by the two tested mold pathogens (B. cinerea and P. aphanidermatum), while the same potential effectiveness was obtained on Valentino cv. using Camphor oil at 100 µL with both tested pathogens. Peroxidase and polyphenoloxidase activities were increased at 3 days and 7 days in bean pods taken from plants sprayed with Carnation or Camphor oils comparing with the control. This work might highlights the potential for using essential oils as vaporization for postharvest disease control of Snap bean pods, which was the main objectives of this study.
Keywords: Bean, B. cinerea, P. aphanidermatum, polyphenoloxidase, peroxides, plant essential oils. |
