Antimicrobial Potential of Microalgae Chlorella vulgaris water Extract in Controlling Grey Mould of Strawberry with a Devastating Disease Caused by the Ubiquitous Necrotrophic Fungal Pathogen Botrytis cinerea in Field Conditions

Strawberry (Fragaria ananassa Duch.) cultivation faces significant challenges due to Botrytis cinerea, a fungal pathogen responsible for grey mould. This study investigates the potential of microalgae Chlorella vulgaris water extract as a biocontrol agent against ubiquitous necrotrophic fungal pathogen B. cinerea, aiming to offer an eco-friendly alternative to chemical fungicides. A 10% water extract of microalgae C. vulgaris was prepared and tested in the field experiments. We initially tested different algae for inhibition of the fungal pathogen B. cinerea under laboratory conditions using a disk diffusion method. In the laboratory, the disc diffusion method revealed varying antifungal activities of different algal species, with C. vulgaris showing significant inhibition of B. cinerea. The field experiment was conducted on strawberries, assessing infection rates following treatment with B. cinerea and C. vulgaris. The results demonstrated that the treatment with C. vulgaris reduced the incidence of B. cinerea infection compared to the control, highlighting the potential of this algae as an effective biocontrol agent. This study contributes to the growing body of research supporting the use of natural products in sustainable agricultural practices, providing a promising alternative to chemical pesticides in strawberry production.