Optimization of the antifungal activity of essential oil isolated from aerial parts of Thymus kotschyanus Boiss & Hohen (Lamiaceae)

Abstract

Although utilization of synthetic chemicals is inevitable for management of economically detrimental agents, numerous side-effects such as environmental contaminations and effects of non-target organisms associated with them. Plant essential oils with low/without toxicity on mammals and as bio-degradable natural materials have been considered for different pests and fungi management in the recent years. In the present study, the essential oil of Thymus kotschyanus isolated by a Clevenger apparatus and its mycelial growth inhibition was measured against two phytopathogenic fungi Botrytis cinerea and Fusarium graminearum. The best models for predicting of antifungal effects were quadratic models. The essential oil showed a prospective mycelial growth inhibition against both phytopathogenic fungi. Optimization of the antifungal effects indicated that 206.207 ppm of the essential oil caused 50% mycelial growth inhibition of B. cinerea after 89.651 h. This value was 85.600 ppm for F. graminearum within 117.194 h. Results of the present study designated a great potential of T. kotschyanus essential oil for management of pathogenic fungi B. cinerea and F. graminearum.

Keywords: Essential oil, mycelial growth inhibition, response surface, Thymus kotschyanus