Biological Effects of Various Essential Oils on Citrus Decay Pathogens

Fatemeh Hosseini Zahani, Nima Khaledi

Penicillium digitatum and P. italicum have been identified as important postharvest pathogens of citrus in world. In the present study, we evaluated the antifungal activity in the various essential oil against pathogens. Essential oils of Syzygium aromaticum and Ferula assa-foetida were found to possess strong antifungal activity against pathogens. The essential oils had inhibitory activities on the growth, conidia germination and germ tube elongation. The main components of clove oil were included Eugenol (82.8%), β-caryophyllene (4.9%), Eugenyl acetate (2.3%) that identified by GC-MS. The minimum inhibitory concentration (MIC) values of the clove oil ranged from 900 to 1000 ppm against the tested pathogens. Spore germination and germ tube elongation of the pathogens in PDA was strongly reduced in the presence of the clove oil. The clove oil at MIC concentration was a more effective approach to disease severity reduction on fruit than the application of other concentrations after incubation for 15 and 50 days at 20 ^°C and 4 ^°C, respectively. Activity of cellulose and pectinase decreased with increasing concentration of clove oil. However, this effect of clove oil reduced over time. The results of this evaluation of indicate that a compound found in clove oil was effective in reducing decay and enzymes activity.