Pesticidi i Fitomedicina (Jan 2010)
Effects of Essential Oils from Thyme, Cinnamon and Clove on Mycelial Growth of Colletotrichum acutatum
Abstract
Effects of the volatile phase of thyme, cinnamon and clove essential oils onColletotrichum acutatum were investigated. Mycelial disc was placed in the center of thePetri dish (V=66 ml) containing PDA. Different volumes of either non- or ethanol-dilutedessential oils were placed on the inner side of the dish cover to obtain final concentrationsof 153, 107, 76, 46, 15, 14, 12, 11, 7.6, 3.82, 1.53, 0.153 and 0.0153 μl/L of air. The dishes were sealed with Parafilm and incubated in up-side-down position. After 7 days of incubation,mycelial growth was recorded by measuring the colony diameter. If no mycelial growthwas recorded, the disc was transferred to a new PDA plate in order to evaluate whetherthe activity was either fungistatic or fungicidal. Mean growth values were obtained andthen converted to inhibition percentage of mycelial growth compared with the controltreatment. All the tested essential oils inhibited mycelial growth of C. acutatum in the dosedependent manner. Mycelial growth was totally inhibited by thyme oil in the concentrationof 76 μl/L of air. The same results were obtained by cinnamon and clove oil in the concentrationof 107 μl/L of air. Thyme and cinnamon oil had fungicidal effect in concentrationsof 107 and 153 μl/L respectively. The results obtained provide evidence on the antifungalin vitro effect of the tested essential oils as potential means for the control of C. acutatum.
