Henri Tibo Ambata Ambata¹, Moïse Ntah A Ayong¹, Benissa Mylaure Jiogue¹, Jeanne Fabiola Ndondoni Dikongue¹, Felecite Nyami Ndjen^{1, 2}, Francine Pamela Noumegna Kamsu¹, Olivier Youassi Youassi¹, Séverin Nguemezi Tchameni^1,, Modeste Lambert Sameza¹

This study aimed to evaluate the antagonistic effet and organic extract of T. harzianum and T. asperolloides against Fusarium oxysporum elaedis, agent responsible of fusariose of oil palm (Elaeis guineensis Jacq). In vitro, the antagonistic activities were carried out by direct confrontation and antibiosis. The ability of Trichoderma spp to produce hydrolytic enzymes was determined in specific solid media. After fermentation, organic extracts were obtained, phenolic and flavonoid compounds were evaluated and their antifungal activity was done in vitro against mycelial growth of the pathogen. The results obtained show that the both antagonists used have significantly reduced the mycelian growth of the pathogen. In direct cofrontation, the inhibition of myelian growth was 64.58% and 70.8% respectively, for T. harzianum and T.asperelloides. The non-volatile compounds produced the inhibition of mycelial growth of Fusarium oxysporum. The inhibition was 75.0% and 71.0%, respectively. The inhibition percentage of volatile compounds was 43.75% and 25.00% respectively. T. harzianum and T. asperelloides produced respectively, cellulases (62.3mm and 66.3mm), lipases (43mm and 66.7mm), amylases (44.6 mm and 68.3 mm) and proteases (54.6 mm and 52mm). The organic extract of these antagonists’ content phenolic and flavonoids compounds. At 400 µg/ml these organic extracts significantly inhibited the mycelial growth of F. oxysporum. The inhibition was 69.29% and 40.69% respectively for crude extract of T. harzianum and T. asperelloides. There were significant and positive correlation between polyphenol and flavonoid content and the inhibition of mycelial growth of the pathogen. These results showed that, T. harzianum could be used to develop a bioproduct to protect oil palm.

Antagonistic activity, hydrolytic enzymes, Trichoderma, Fusarium oxysporum elaedis, oil palm