Evaluation of Pseudomonas fluorescens Isolates for their Bio-control Potential against Soil Borne Disease of Tomato

Stanzin Dorjey, Vishal Gupta*, V.K. Razdan and Richa Sharma

Division of Plant Pathology, Faculty of Agriculture, Sher-e-Kashmir University of Agricultural Sciences and Technology of Jammu, Chatha – 180 009, India.

ABSTRACT

Two major fungal pathogens, Fusarium oxysporum f. sp. lycopersici and Rhizoctonia solani were isolated from infected root, collar and stem regions of tomato plants.  A total of 25 rhizobacterial isolates showing Gram –ve reaction were isolated from the rhizosphere of tomato fields. Six selected isolates, based on their biocontrol activity against the test pathogens showed growth at 40C but there was no growth at 410C. The maximum growth of these isolates was at pH 7.0 and they isolates showed positive reactions for levan formation, phosphate solubilization, gelatin liquefaction, oxidase test and catalase test, that confirmed the identity of the isolates as Pseudomonas fluorescens. Under in vitroconditions, carbendazim showed 100 per cent inhibition of mycelial growth of F. oxysporumf. sp. lycopersici and R. solani at all the tested concentrations. Carbendazim also showed maximum plant vigour (1501.54 %), followed by isolate I-23 (1453.77 %). 

Keywords:  Soil borne disease, tomato, bio-control, management.