Antifungal Activity of Essential Oil of<i>Eucalyptus camaldulensis</i>Dehnh. against Selected<i>Fusarium</i>spp.

Abstract

The objective of this study was to evaluate the antifungal activity of essential oil (EO) of <i>Eucalyptus camaldulensis</i> Dehnh. against five <i>Fusarium</i> spp. commonly associated with maize. The essential oil had been extracted by steam distillation in a modified Clevenger-type apparatus from leaves of <i>E. camaldulensis</i> and their chemical composition characterized by gas chromatography mass spectrometry. Poisoned food technique was used to determine the percentage inhibition of mycelial growth, minimum inhibitory concentration, and minimum fungicidal concentration of the EO on the test pathogens. Antifungal activity of different concentrations of the EO was evaluated using disc diffusion method. The most abundant compounds identified in the EO were 1,8-cineole (16.2%), <i>α</i>-pinene (15.6%), <i>α</i>-phellandrene (10.0%), and p-cymene (8.1%). The EO produced complete mycelial growth inhibition in all the test pathogens at a concentration of 7-8 <i>μ</i>L/mL after five days of incubation. The minimum inhibitory concentration and minimum fungicidal concentration of the EO on the test fungi were in the range of 7-8 <i>μ</i>L/mL and 8-10 <i>μ</i>L/mL, respectively. These findings confirm the fungicidal properties of <i>E. camaldulensis</i> essential oils and their potential use in the management of economically important <i>Fusarium</i> spp. and as possible alternatives to synthetic fungicides.