Antifungal Activity of Some Essential Oils and Their Major Constituents on 3 Plant Pathogenic Fungi

11 plant essential oils are screened in vitro for their antifungal activities against Botrytis cinerea, Fusarium oxysporum and Rhizoctonia solani, which are causative agents of serious plant diseases. The radial growth of the test fungi were reduced in response to the oils. Among them, the essential oil from the bark of Cinnamomum zeylanicum inhibited 3 tested fungi growth, strongly, followed by those of oregano and thyme. The major constituents of the three essential oils, cinnaldehyde, carvacrol and thymol were tested for their effects on the fungi. From the results obtained, cinnamaldehyde, the major constituents of C. zeylanicum bark esential oil, has potential to be developed as a biopesticide for controlling phytopathogenic fungi causing serious damages on the important crops cultivated in Korea.