Evaluating the Antifungal Effectiveness of Three Plant Extracts in Controlling Panama Wilt in Banana Plants

Abstract

Aims: This study aimed to evaluate the antifungal potential of Mikania micrantha, Senna alata, and Datura metel extracts against Fusarium oxysporum, the causal agent of Panama wilt in banana and to determine the optimal concentration of the most effective extract for fungal suppression. Study Design: Laboratory-based experimental research using in-vitro assays to assess the antifungal activity of selected plant extracts. Place and Duration of Study: The study was conducted at the Laboratory of the Institute for Agro-technology and Rural Sciences, University of Colombo, Sri Lanka, from February to July 2024. Methodology: The fungal pathogen was isolated from infected banana plant roots and cultured on Potato Dextrose Agar (PDA). Aqueous extracts of the plants were prepared and incorporated into PDA media. In Experiment 1, fungal colonies were exposed to five treatments: control (no application), M. micrantha extract, D. metel extract, S. alata extract, and a commercial fungicide. In Experiment 2, different concentrations (25%, 50%, 75%, and 100%) of the most effective extract from Experiment 1 were tested against Fusarium oxysporum. Fungal growth was monitored for seven days, and colony diameter measurements were statistically analyzed using SAS software, with Duncan’s Multiple Range Test at a 5% significance level. Results: Significant differences (p < 0.05) in fungal growth inhibition were observed among treatments. D. metel extract demonstrated the highest antifungal activity with a F. oxysporum growth inhibition of 68.4%, second only to the commercial fungicide (82.6%). The inhibitory effect was dose-dependent, with 100% D. metel extract achieving the highest suppression of F. oxysporum growth (77.9%), closely approaching the efficacy of the commercial fungicide. Conclusion: D. metel extract demonstrated strong antifungal potential against F. oxysporum, making it a promising alternative to chemical fungicides for managing Panama disease in bananas. Further research is needed to explore its field efficacy, mode of action, and possible integration with other biocontrol strategies for enhanced disease management.