Antagonistic Potential of Biocontrol Agents under in vitro Conditions for Management of Taro Bacterial Blight

Taro production is affected severely by bacterial blight, a devastating biotic stress induced by the quarantine pathogen Xanthomonas axonopodis pv. dieffenbachiae. Recognising the pathogen’s impact, several bio-agents were evaluated in vitro for potential management of bacterial blight in taro. Isolation of the causal agent and pathogenicity assays were performed on Colocasia cv. Piyaji kochu. The study involved the assessment of five bio-agents (Bacillus thuringiensis (Bt), Pseudomonas fluorescens (Pf), Trichoderma viride (Tv), Metarhizium anisopliae (Ma) and Beauveria bassiana (Bb), singly and in combination through dual culture plate assay, and one synergistic chemical (streptocycline@ 100 ppm as control) through Kirby-Bauer disk diffusion method. The integrated treatment of five bioagents exhibited the maximum inhibition zone (56 mm) and the greatest percentage suppression over control (62.22 mm).