Efficacy of native fluorescent Pseudomonads against soil-borne phytopathogenic fungi

Abstract

The present investigation was carried out to evaluate the antagonistic potential of fluorescent Pseudomonads isolated from different crop rhizospheres of zone III A and Zone II of Bihar against three soil-borne fungal phytopathogens viz., Rhizoctonia solani, Sclerotium rolfsii and Fusarium oxysporum using dual culture technique. Sixteen fluorescent Pseudomonads were isolated from different crop rhizospheric soils collected from different locations of Bhagalpur and kishanganj district. In vitro evaluation results indicated the significant differences among the fluorescent Pseudomonads in their efficacy against the test fungi. Among the sixteen fluorescent Pseudomonads tested, isolate BMGh shown maximum antagonism against Rhizoctonia solani with 55.66 per cent inhibition of pathogen over control followed by isolate whkh (47.16 per cent) and Msksn (46.22 per cent). Isolate CHGH was found least effective (15.09 per cent inhibition). Against Sclerotium rolfsii, isolate LnsB had maximum antagonism potential with 88.81 per cent inhibition of radial growth of the fungus followed by whkh (79.72 per cent inhibition) and isolate BRKH was found least effective (23.78 per cent) followed by CKSB (32.87 per cent). Isolates MZksn and BRGh were found to have maximum antagonistic potential against Fusarium oxysporum (58.74 per cent) followed by WHSB (56.65 per cent). The isolate MRKH was found least effective (15.39 per cent) followed by MSKSN (20.29 per cent). The effective fluorescent Pseudomonad isolates screened under in vitro may further used for effective management of soil-borne fungal plant diseases in integrated disease management strategies and in organic farming system.