Antifungal activity of essential oils against Macrophominaphaseolina

Macrophomina phaseolinais a soil-borne phytopathogen with has a wide geographical distribution, being responsible for causing serious economic losses inciting stem and root rot symptoms of infected plants. There is a growing worldwide demand for new treatments that promote food and nutritional security, with substances that are more effective and less harmful to the balance of ecosystems. Thus, this research aimed to evaluate the in vitro antifungal effect of essential oils (EOs) on the mycelial growth of M. phaseolina. The EOs used were tested at doses 0.8; 1.6; 3.2; 6.4 and 12.8 mu L per surface of the PDA (potato-dextrose-agar) culture medium. Mycelial growth inhibition and mycelial growth rate were analyzed. The evaluations consisted of measurements of the growth diameters with 3 and 6 days of incubation. The cinnamon EO, from the initial tested concentration; oregano and cloves EOs, at a concentration of 3.2 mu L demonstrated antifungal activity against M. phaseolina. The EOs of basil, tea tree, citronella, mint and thyme showed a fungistatic activity. Ginger and sweet Orange EOs inhibited less than 40 degrees/o of mycelial growth. The complete inhibition of mycelial growth was achieved with cinnamon, oregano and clove EOs, therefore, they presented potential for use as a biofungicide agent.