ANTIFUNGAL POTENTIAL OF Lippia multiflora MOLD. AND Melaleuca leucadendron L. ESSENTIAL OILS AGAINST SOME ROOT BORNE FUNGI OF IPOMEA BATATAS (L) LAM. IN CÔTE D’IVOIRE

Abstract

The objective of this study was to evaluate the antifungal activity of Lippia multiflor and Melaleuca leucadendron essential oils against three phytopathogenic fungi (Rhizopus sp., Fusarim sp., and Aspergillus sp.) associated with Ipomea batatas tuberous. Essential oils had been extracted by steam distillation method from leaves of selected plants and their chemical composition was characterized by gas chromatography-mass spectrometry (GC-MS). Essential oil composition characterization was followed by the estimation of percentage mycelial growth inhibition, minimum inhibitory concentration, and minimum fungicidal concentration of the isolated essential oils against the tested pathogens by the Sabouraud dilution medium method. Antifungal activity of different concentrations of isolated essential oils was evaluated by using the microdilution method. The most abundant compounds identified in the M. leucadendron essential oil are 1,8-cineole (38.2%), viridiflorol (13.4%), α-Pinene (12.5%), α-terpineol(9.2%), and geranial (22.8%) while L. multiflora essential oil have neral (18.7%), 1,8-Cineole (11.4%), α-Phellandrene (6.8%), sabinene (3.5%) as active ingredients. The concentration of essential oils which completely inhibited the mycelial growth and spore germination of all the tested pathogen varies and it was reported 0.33µL/mL and 0.66µL/mL for L. multiflora respectively while it was reported 24 µL/mL for M. leucadendron, for both effect, seven days of incubation. The minimum concentration of fungicidal essential oil against Aspergillus sp. was 0.33µL/mL for L. multiflora. The findings of the current study confirm the fungicidal properties of the tested essential oils and their potential use in the management of economically important fungal pathogens of Ipomea batatas. Further, these essential oils can be used as possible alternatives to synthetic fungicides.