EFFECTS OF ESSENTIAL OILS ON PHYTOPATHOGENIC FUNGI IN-VITRO

The essential oils of Thymus vulgaris L., of Lavandula R.C. hybrid and Mentha piperita L. were tested in vitro against the pathogenic fungi Rhizoctonia solani Kuhn, Pythium ultimum Trow var. ultimum, Fusarium s olani (Mart.) Sacc., Colletotrichum lindemuthianum (Sacc. & Magn.) Bri osi & Cav. All the oils tested inhibited fungal growth. The most effec tive oil was that of thyme, with a fungicidal activity attributable to thymol, found in a concentration of 50.06% in the oil tested. SEM obs ervations revealed that these oils cause degeneration of the fungal hy phae which appeared emptied of their cytoplasmic content.