Control of Ralstonia solanacearum Infection in Tomato, Brinjal and Capsicum by antibiotic sensitivity test

Ralstonia solanacearum is one of the important dreaded soil's borne bacterial phytopathogen which causes enormous losses in the crop plants in tropical, subtropical and temperate region of the world. In India, the disease is highly prevalent and active throughout the year where the soil is acidic in the Eastern Plateau and Hill Region. Once the disease is established in the field, it cannot be controlled by chemical means. Keeping these in view, screening of potential antibiotics for the management of R. solanacearum was done. In the present study, three strains of R. solanacearum were isolated from Brinjal, Tomato and Capsicum. Against these three strains of R. solanacearum, four antibiotics were screened through food poison techniques viz. Kasugamycin, Streptomycin, Ceftriaxone and Gentamicin. The different strains of R. solanacearum and antibiotic sensitivity showed varied response. Among the screened antibiotics, Gentamicin showed strong antibacterial efficacy which inhibited 100% Colony-forming Unit (cfu) at very low concentration (1 ppm) followed by Ceftriaxone which inhibited >50% cfu at 1 ppm against all three strains. However, Streptomycin also showed antibacterial efficacy and inhibited >50% cfu at 3 ppm, but Kasugamycin was found less antibacterial as compared to other tested antibiotics and inhibited >50% cfu at 4 ppm.