Vol. 9, Special Issue 12, Part A (2025)

In the present study, the in vitro antagonistic potential of Pseudomonas fluorescens seven isolates was evaluated against major soil-borne pathogens including Fusarium oxysporum f. sp. ciceri, Rhizoctonia bataticola, Rhizoctonia solani, and Sclerotium rolfsii. Bioefficacy was evaluated by dual culture assay were conducted on three media King’s B (KB), Potato Dextrose Agar (PDA), and a 1:1 combination of KB and PDA. The mixed KB+PDA medium consistently showed greater pathogen suppression compared to either KB or PDA alone. Among the isolates, Pf 2 exhibited the strongest antagonistic activity. Against F. oxysporum f. sp. ciceri, Pf 2 achieved inhibition levels of 79.84% on KB+PDA, 76.21% on KB, and 59.46% on PDA, while Pf 7 was the least effective across all media. For R. bataticola, Pf 2 recorded 73.78% inhibition on KB+PDA, whereas Pf 1 showed 63.88% inhibition on KB and Pf 2 achieved 47.03% on PDA. In the case of R. solani, Pf 2 suppressed growth by 77.52% on KB+PDA, 73.92% on KB, and 40.74% on PDA. Against S. rolfsii, Pf 2 demonstrated 81.60% inhibition on KB+PDA, 65.38% on KB, and 52.22% on PDA. Overall, isolates Pf 1 through Pf 5 displayed promising biocontrol potential, while Pf 6 and Pf 7 were comparatively less effective.