In vitro Evaluation of Bioagents and Their Consortia against Fusarium oxysporum f. sp. ciceris Causing Wilt of Chickpea

Abstract

The microbial consortia (combinations of bioagents) are increasingly used for crop protection in preference to single bioinoculants to overcome the inconsistent performance of chemical pesticides. Wilt of chickpea caused by Fusarium oxysporum f. sp. ciceris is a serious soil-borne disease in chickpea-growing regions. The four biocontrol agents Trichoderma asperellum UASR strain, Bacillus subtilis SE76, Streptomyces nenu DS-11 and Pseudomonas fluorescens UASR strain were evaluated in vitro against F. oxysporum f. sp. ciceris. The antagonistic potential of bioagents against the pathogen was higher in consortia than in single bioagents. The four-member consortium T15 (T. asperellum +B. subtilis + Streptomyces nenu + P. fluorescens) was superior to all other treatments in inhibiting mycelial growth of F. oxysporum f. sp. ciceris (87.77 %). Among three-member consortia, the highest inhibition was recorded in T13 (T. asperellum + Streptomyces sp. + P. fluorescens) with 81.25 per cent, followed by T12 (T. asperellum + B. subtilis + P. fluorescens) (76.22 %). Among two-member consortia, T7 (T. asperellum + P. fluorescens) recorded the highest inhibition (79.13 %). Among individual antagonists, T. asperellum proved to be the most effective (62.14 %) followed by Streptomyces nenu (53.00 %) and B. subtilis (50.33 %), while P. fluorescens recorded the least inhibition (47.22 %). These findings demonstrate that rationally designed, compatible microbial consortia can provide substantially greater in vitro suppression of Fusarium than individual bioagents, supporting their further development as components of integrated wilt management in chickpea.