Comparative Efficacy of Fungal Bio-Agents Against Fusarium udum

Evaluation of six bio-agents against Fusarium udum causing pigeonpea wilt revealed 29.3 and 8.5% increased growth of Trichoderma harzianum (Pantnagar) and Aspergillus niger (Delhi), respectively in the presence of F. udum while maximum colony growth inhibition of F. udum in dual culture was found with Gliocladium virens (Pantnagar) and T. viride (Coimbatore). Mycoparasitismsuch as coiling, entwining and lysis of F. udum was observed with T. harzianum, T. viride and G. virens isolates but not of A. niger and Penicillium citrinum (Lucknow). The culture filtrates of six bio-agents inhibited F. udum colony growth by 18.1–53.6% at different concentrations, highest being in A. niger which showed 36.4% mean growth inhibition. The culture filtrate of A. niger also reduced sporulation in F. udum. The production of viable conidia was 13.1–23.6% in culture filtrates of all bioagents against 30.1% in control. However, T. viride (Kanpur) isolate at 10,000 ppm could lower the viable conidia production up to 10.3% while A. niger at 5000 ppm could reduce the conidial viability up to 4.5%. All bio-agents reduced pigeonpea wilt and F. udum population in the soil in variable degrees up to 90 days of sowing.