In-vitro Antifungal Activity of Medicinal Plant Extracts against Fusarium oxysporum Causing Wilt in Okra

Fusarium wilt, caused by Fusarium oxysporum f. sp. vasinfectum, is a devastating disease of okra (Abelmoschus esculentus) that can significantly reduce yield and quality. Chemical fungicides have been the primary means of control but pose environmental and health risks. This study evaluated the in-vitro antifungal activity of crude ethanolic extracts from Withania coagulans leaves, Zataria multiflora leaves, and Cuminum cyminum seeds against F. oxysporum f. sp. vasinfectum. Extracts at concentrations of 2%, 4%, and 8% were incorporated into potato dextrose agar (PDA) and compared to the fungicide Antracol (propineb, 0.5%) and control. Mycelial growth was measured daily for 7 days, and the percentage of growth inhibition was calculated. Z. multiflora exhibited the greatest inhibitory activity, reducing mycelial growth by 70%, 75%, and 82% at 2%, 4%, and 8% concentrations, respectively. C. cyminum showed significant antifungal activity, with inhibitions of 63%, 74%, and 77% at the same concentrations. W. coagulans was the least effective, producing 34%, 44%, and 59% reductions. Antracol outperformed all plant extracts, reducing growth by 94%. The results indicate the potential of Z. multiflora and C. cyminum extracts as environmentally friendly alternatives for managing Fusarium wilt in okra. However, higher concentrations and optimization of extraction methods are needed to compete with conventional fungicides. Future studies should focus on in vivo and field evaluations, identification of active compounds, and integration with other disease management strategies for sustainable okra production.