2025/09/25 by Haruna, S. G., Mahmud, B. A., Mubarak, A. H.
#Biological control #Fusarium wilt #compost fungi #growth inhibition #tomato
paper · doi:10.82552/njhs.v29i3.76-83
An in vitro study evaluated the efficacy of three fungal isolates; Trichoderma sp., Aspergillus niger, and Aspergillus flavus recovered from bio-enriched cow dung compost in managing Fusarium oxysporum f. sp. lycopersici (Fol), the causal agent of tomato wilt. The experiment was set up in a randomized complete design with five treatments: Fol paired with each test fungus, Fol treated with Contap Plus® fungicide (Hexaconazole 5% SC), and a Fol-only control, each replicated five times. Radial growth measurements and percentage growth inhibition were recorded at 24-hour intervals for 7 days post-inoculation to assess temporal inhibition patterns. Statistical analysis using ANOVA (P ≤ 0.01) revealed significant treatment effects. Trichoderma sp. demonstrated superior antagonistic activity, restricting Fol growth to 1.22 cm, 2.28 cm, and 2.32 cm at 3, 5, and 7 days after inoculation (DAI), respectively, achieving 39.4% maximum inhibition by 7 DAI. Both Aspergillus species showed moderate suppression, with A. niger (30.8% inhibition) outperforming A. flavus (26.1% inhibition) at the final assessment. The chemical control achieved 85.2–88.7% inhibition across all time points, while the pathogen control exhibited unrestricted growth. Morphological characterization revealed that Trichoderma sp. produced distinctive concentric conidial rings with delayed sporulation (6 days), whereas Aspergillus isolates displayed characteristic conidial head structures. The significant suppression by Trichoderma sp. (LSD = 1.28 at 7 DAI) correlates with its known mycoparasitic and antibiosis mechanisms against soil-borne pathogens. These findings highlight Trichoderma sp. from bio-enriched cow dung compost as a promising biocontrol agent for integrated management of Fusarium wilt in tomatoes, particularly in organic production systems. Further research should investigate formulation stability, field efficacy, and potential synergistic combinations with reduced fungicide doses to develop sustainable disease management strategies.