RAPID EVALUATION OF PLANT-EXTRACTS AND ESSENTIAL OILS FOR ANTIFUNGAL ACTIVITY AGAINST BOTRYTIS-CINEREA

A rapid assay to determine antifungal activity in plant extracts and e ssential oils is described. Wells in microtiter plates were loaded wit h Botrytis cinerea spores and plant extracts or essential oils. Subseq uent changes in optical density following spore germination in the wel ls was measured after 24 h using an automatic microtiter plate reader driven by a software program developed for this purpose. Extracts from 345 plants and 49 essential oils were evaluated for their antifungal activity against B. cinerea. Among 345 plant extracts analyzed, 13 sho wed high levels of antifungal activity, with species of Allium and Cap sicum predominating. Among the 49 essential oils tested, palmarosa (Cy mbopogon martini), red thyme (Thymus zygis), cinnamon leaf (Cinnamomum zeylanicum), and clove buds (Eugenia caryophyllata) demonstrated the most antifungal activity against B. cinerea. The most frequently occur ring constituents in essential oils showing high antifungal activity w ere: D-limonene, cineole; beta-myrcene; alpha-pinene, beta-pinene; and camphor.