Exploring the Potential of Bilberry Extracts as Natural Antifungal and Bioherbicidal Agents in Agriculture: Composition and Antioxidant Activity

Abstract

This study aims to investigate the composition of the leaf essential oil and the total phenolic and flavonoid contents as well as the antioxidant activity of the n-hexane, ethyl acetate, and methanol extracts of Vaccinium myrtillus leaves collected from two different locations (Muğla and Mersin, Turkey). In addition, the antifungal activity against Sclerotinia sclerotiorum (SS), Fusarium oxysporum f sp. melonis (FOM), Fusarium oxysporum f sp. cucumerinum (FOC), and Rhizoctonia solani (RS) and the bioherbicidal activity against Taraxacum officinale and Rumex crispus were evaluated for the first time. The methanolic extract inhibited mycelium growth of SS, FOM, FOC, and RS in a dose-dependent manner. No significant difference was observed in antifungal activity between the two different collection sites. In the bioherbicidal activity tests, the methanol extract of the fruits completely suppressed the root-shoot development of Taraxacum officinale, while also significantly inhibiting the root-shoot development during the seed germination of Rumex crispus compared to the control group at 3 mg/mL concentration for both locations. Based on the results of the GC/MS analysis, the major constituents identified in the leaf essential oils collected from the Muğla and Mersin locations were α-pinene (29.16%/15.75%), eucalyptol (22.19%/26.46%), linalool (12.66%/25.27%), and linalyl acetate (7.43%/2.71%). The total phenolic and flavonoid contents of the plant extracts for the Muğla and Mersin samples were determined as (42.80‒157.58 GAE/g extracts), (29.38‒151.44 GAE/g extracts) and (10.52‒37.88 QE/g extracts), (14.81‒44.18 QE/g extracts) respectively. In addition, the plant exhibited significant antioxidant activity. These findings indicate quantitative differences in the chemical composition of the essential oils between the two geographical locations. These findings are significant as they provide insights for the development of new natural antifungal agents with potential applications in agriculture.