Abstract

In the present study, 35 extracts from 15 different medicinal plants traditionally used in the Venda region for the treatment of fungal related ailments were tested for antifungal activities against five Fusarium spp. including Fusarium oxysporum, Fusarium verticillioides,Fusarium graminearum, Fusarium nygamai and Fusarium proliferatum using the hole plate diffusion method. The microdilution method was used to determine the minimum inhibitory concentration and the minimum fungicidal concentration. Growth inhibition assay was conducted using an agar diffusion method. Out of the 35 extracts tested, 31 (88%) were active against at least one of the five Fusarium spp. However extracts of Warburgia salutaris, Rhoicissus tridentata, Syzygium cordatum, Ximenia caffra and Terminalia sericea gave zone of inhibition ranging from 10 to 20 mm with minimum inhibitory concentration (MIC) ranging from 3.75 to 0.06 mg/ml. Extracts from W. salutaris bark in hexane and Terminalia sericea bark in acetone were fungicidal to at least one of theFusarium spp. tested at concentrations between 0.06 and 7.5 mg/ml. The present study has revealed the importance of these medicinal plants in the possible control of fungal diseases caused by the tested Fusarium spp. and further justifies the use of these medicinal plants by the local populations. Further studies are needed to identify the active components of these plants that could be used as lead compounds in the development of new antifungal agents.

Key words: Fusarium, medicinal plants, South Africa, Venda, antifungal.