PLANT EXTRACTS AS BIOFUNGICIDES AGAINST SOIL-BORNE PATHOGEN ALTERNARIA SPP.

Abstract

In the presence of a warmer climate, increase the comparative abundance of fungal plant pathogens. Many of the most aggressive plant pathogens are soil-borne fungi. Alternaria species threaten food security as the chemical fungicides currently used against them are mostly ineffective because of the acquired resistance to active compounds. Broadleaf plantain (Plantago major L.) and rosemary (Rosmarinus officinalis L.) extracts, obtained by subcritical CO₂ extraction, were tested for their antifungal activity to investigate the possibility of their use for sustainable plant protection. The ability of the two plant extracts to inhibit mycelial growth was studied by in vitro assay on agar medium containing different concentrations of the tested extracts (200-1000 μL L^-1). Alternaria spp. isolate was transferred on the modified medium to test the extracts antifungal activity by calculating the average colony growth after 5 and 7 days. Results showed that rosemary extract had an apparent reducing effect on fungal growth that was dose-dependent. Because of this, it can be considered a potential alternative natural fungicide to the synthetic chemicals currently used to prevent and control soil-borne diseases.