Mycelial inhibitory effects of five essential oils and two antagonistic Trichoderma species against some plant pathogenic Fusarium species

In this study, inhibitory effects of five plant essential oils (EOs), including Zataria multiflora, Nepeta sp., Lavandula stoechas, L. officinalis and Artemisia dracunculus, on Fusarium graminearum UM29, F. graminearum UM89, F. verticillioides, F. brasilicum, F. oxysporum f. sp. lentis, and F. oxysporum f. sp. lycopersici and two antagonistic fungi Trichoderma harzianum and T. viride at five concentrations (75, 150, 300, 600 and 1000 μl/l) by mixing with PDA medium was studied. The chemical composition of EOs was explored by GC-MS. Also, the inhibitory effect of Trichoderma (T. harzianum T447 and T. viride T125) was investigated by dual culture assay and the effect of volatile compounds methods. Based on GC-MS results, thymol and carvacrol were identified as main constituents of Z. multiflora EO, and Nepetalactone and 1,8-cineole were the major components of Nepeta sp. EO. Zataria multiflora EO at concentration of 300 μl/l completely inhibited mycelial growth of the majority of Fusarium species evaluated in this study. The results of dual culture assay revaled the highest percentage of inhibition in the interaction between T. viride and F. brasilicum with a mean of 64.78% and the lowest in the interaction between T. harzianum and F. oxysporum f. sp. lycopersici with a mean of 36.52%. According to our results, Z. multiflora EO and T. harzianum T447 and T. viride T125had high mycelial growth inhibitory potential against Fusarium spp. Greenhouse and field assays are necessary to further evualte their efficacy in control of these plant pathogens.