In vitro evaluation of eight plant essential oils for controlling Colletotrichum, Botryosphaeria, Fusarium and Phytophthora fruit rots of avocado, mango and papaya

Abstract

In vitro efficacy of the essential oils extracted from eight plant species was tested at application rates of 100, 250, 500, 1000, or 2000 µl/l for controlling fruit rots. Results showed a 100% reduction of mycelium growth of Colletotrichum, Fusarium, Phytophthora, Botryosphaeria after applying thyme or savory oils at all concentrations tested. Mint and cinnamon oils inhibited mycelium growth of the five isolates at application rates of either 1000 or 2000 µl/l. Tea tree, lavender, myrtle, and eucalyptus oils were slightly effective at controlling mycelium growth of each fungus species tested. Savory oil with major constituent of carvacrol 71.2% and thyme oil with major constituent of thymol 73.3% showed the greatest potential of the essential oils tested for use as natural fungicides.