Abstract
Seeds from soybean collected from different commercial markets were surveyed for seed-borne fungi. Ninetyeight fungal colonies were isolated all over three monthly isolations constituting twenty-two fungal species. The isolated fungi were belonging to the genera: Alternaria, Aspergillus, Cephalosporium, Chaetomium, Cladosporium, Colletotrichum, Curvularia, Fusarium, Macrophomina, Mucor, Penicillium, Rhizoctonia, Rhizopus, Sclerotium, Stemphylium, and Verticillium. Assay of the antifungal activity of four ethanolic extracts of clove, cinnamon, garlic, and mint was carried out against the most common fungal species (Aspergillus flavus, A. niger, Fusarium solani, F. oxysporium, and F. moniliforme), which significantly reduced the growth of tested fungi. Clove extract recorded the highest antimicrobial potentiality against the seed-borne fungal species, followed by cinnamon, garlic, and mint. Clove and cinnamon achieved minimum inhibitory concentration (MIC) values less than that of the reference antifungal drug fluconazole. Simultaneously, garlic and mint recorded MIC values equal to or higher than that of control. A combination of clove and cinnamon, clove and garlic, cinnamon and garlic, cinnamon, and mint extracts increased the mean relative activity percentage. They decreased MIC values below their values when used individually; this indicated synergistic interaction between the two extracts. A combination of clove with mint and garlic with mint recorded a decrease in the percentage of mean relative activity and an increase in MIC values than their values when used individually, indicating antagonistic interaction between them.