Background and Objective: Groundnut seeds are susceptible to pathogenic fungal attacks due to their high nutrition content. Synthetic chemical fungicide treatment is the common strategy for controlling the seed-borne fungi. These fungicides are not eco-friendly, and their fungi resistance is of great concern. There is a need to find new substances with efficient antifungal potential. This study aimed to determine the phytochemical composition and antifungal activity of Allium sativum (garlic) extract on fungi associated with groundnut seeds.
Materials and Methods: Groundnut seeds were purchased from the Wurukum, Wadata, High level, and Modern markets. The garlic used in this study was purchased from the Wurukum market in Makurdi Local Government Area, Benue State, Nigeria. Three fungi of Aspergillus niger, Aspergillus flavus, and Rhizopus stolonifer were identified on groundnut seeds. Fungal isolation was done according to the Standard Blotter Method. Saburoud Dextrose Agar (SDA) medium was used to culture the fungal isolates. Aqueous garlic extracts were prepared using the maceration technique. The antifungal activity of the extract was tested using the pour-plating method. Phytochemical constituents were determined according to standard laboratory methods.
Results and Conclusion: The occurrence of Aspergillus niger ranged from 0.33-2.67, Aspergillus flavus 1.33-2.67, and Rhizopus stolonifer 0.67-1.33 across all the markets samples. The study identified Aspergillus flavus as the most dominant fungi on groundnut seeds. The aqueous extract of Allium sativum inhibited the mycelia radial growth of the tested fungi. The higher extract concentration (100% w/v) showed the higher inhibition than the lower concentration (50% w/v). This study revealed that garlic extract contains several bioactive compounds with antifungal potency (i.e., alkaloids, tannins, anthraquinones, saponins, terpenoids, cardiac glycosides, flavonoids, phenolic compounds, and steroids), which can be used to control the fungi associated with groundnut seeds.