Biocontrol Potentials of Trichoderma harzianum and Pseudomonas fluorescens against Fusarium Wilt (Fusarium oxysporum) of Eggplant

African Journal of Agriculture | Vol. 13, No. 8, August 2026 | pp. 050–057

DOI: 10.46882/2026/AJA/000740

Article Type: Original Research Article

Title: Biocontrol Potentials of Trichoderma harzianum and Pseudomonas fluorescens against Fusarium Wilt (Fusarium oxysporum) of Eggplant

Names of Authors: Mariam K. Coulibaly¹, Yao A. Koffi¹

Authors’ Affiliations: ¹UFR Agroforesterie, Université Jean Lorougnon Guédé, Daloa, Côte d'Ivoire

Abstract: Fusarium wilt, caused by the soil-borne fungus Fusarium oxysporum f. sp. melongenae, causes substantial yield collapses in eggplant crops across West Africa. Chemical fungicides are expensive and raise concerns regarding environmental toxicity and pathogen resistance. This study evaluated the in vitro and in vivo biocontrol potential of Trichoderma harzianum and Pseudomonas fluorescens, applied individually and in combination, against Fusarium oxysporum. In dual-culture laboratory assays, T. harzianum and P. fluorescens restricted radial mycelial growth of the pathogen by 68.4% and 58.2% respectively. For the greenhouse trial, eggplant seedlings were grown in soil artificially inoculated with a virulent pathogen spore suspension (1.0 x 10⁶ spores/mL). The greenhouse results demonstrated that the combined application of T. harzianum and P. fluorescens as a seed treatment and root drench lowered disease incidence by 76.5% compared to the untreated infected control. This dual-inoculant treatment also reduced the plant wilt severity index to 1.2 on a 1-to-5 scale. Additionally, plants receiving the combined bio-agents showed significantly greater seedling vigor, root length, and shoot biomass than those in the single-agent and control treatments (p < 0.05). This growth enhancement is attributed to synergistic mechanisms, including mycoparasitism and induced systemic resistance, proving that dual biological treatments are a highly effective alternative to synthetic chemicals for managing fusarium wilt.

Keywords: Biological control, Fusarium oxysporum, Trichoderma harzianum, Pseudomonas fluorescens, Solanum melongena, Disease incidence

Manuscript Timeline: Received: April 11, 2026; Revised: May 20, 2026; Accepted: June 15, 2026; Published: August 09, 2026

Citation: Coulibaly, M. K., & Koffi, Y. A. (2026). Biocontrol Potentials of Trichoderma harzianum and Pseudomonas fluorescens against Fusarium Wilt (Fusarium oxysporum) of Eggplant. African Journal of Agriculture, 13(8), 050–057. DOI: 10.46882/2026/AJA/000740

Subscribe to read the full article: https://www.internationalscholarsjournals.org/subscribe-to-read