Pathogenicity of Colletotrichum acutatum to different strawberry cultivars and anthracnose control with essential oils

Colletotrichum spp. is a significant strawberry (Fragaria × ananassa Duch.) pathogen causing yield losses of up to 80%.Due to the changing agrometeorological conditions, pathogens are able to spread in cooler climate countries.Essential oils (EO), as one of the environmentally friendly plant protection products, can be used to control plant pathogens.They possess antibacterial and antifungal properties.Because of the low toxicity and biodegradability, EO can be used in plant protection against pathogens instead of chemical products.This study aimed to determine the pathogenicity of strawberry C. acutatum and evaluate five essential oils at different concentrations as potential bio-fungicides against strawberry anthracnose (Colletotrichum acutatum).The C. acutatum pathogenicity was evaluated on detached strawberry leaves.The inhibitory effect of five EO at 200, 400, 600, 800 and 1000 µl L -1 was evaluated in vitro, and at 800 and 1000 µl L -1 -on detached strawberry leaves.The cultivar 'Deluxe' was found to be the most susceptible to strawberry anthracnose, while 'Rumba' and 'Elegance' exhibited resistance.The results of Mentha piperita EO revealed its antifungal activity against C. acutatum.Meanwhile, Salvia officinalis EO had no influence.The Coriandrum sativum and Hyssopus officinalis EO slightly inhibited C. acutatum growth.The results of Thymus vulgaris EO assay in vitro demonstrated that it could be an effective biocontrol agent against strawberry anthracnose.EO inhibited the mycelial growth of C. acutatum in vitro; however, the results of the assay on detached strawberry leaves showed that the efficacy of EO was not sufficient and needed further research.