Evaluation of the Efficacy of Propolis Extracts Based on Different Solvents Against Some Plant Pathogenic Fungi

Propolis is a bee product produced as a natural defense mechanism by bees to protect their hives. It consists of plant resins, secretions from bees, and other substances collected from plants, containing biologically active compounds with antimicrobial, antioxidant, and anti-inflammatory properties. Due to these characteristics, propolis finds applications in various fields. In this study, pure propolis extracts obtained by DMSO, ethanol, methanol, glycerol, acetone and supercritical CO2 extraction of propolis were tested for their antifungal activity against three phytopathogenic fungi, Fusarium oxysporum, Alternaria alternata and Verticillium spp. Antifungal activity tests were conducted in vitro using zone inhibition measurements on PDA medium. Our findings revealed that the antifungal efficacy of propolis and its impact on mycelial growth parameters varied depending on the type of propolis extract used, demonstrating a dose-dependent relationship. In the present study, the ethanol + propolis preparation was found to be more successful in inhibiting the growth of fungal hyphae at a dose of 200 µl for all fungi compared to other solvents. The other solvents showed different levels of inhibition depending on the fungal species. In general, the acetone, DMSO, and glycerol preparations of propolis were less effective in the inhibition of fungal growth. The results obtained indicate that ethanol-based propolis extracts have potential for the control of agriculturally important phytopathogenic fungi.