Rhizospheric Pseudomonas fluorescens as rejuvenating and root proliferating agents in black pepper

Abstract

Six strains of Pseudomonas flureseens,which had been found efficient in root-rot suppression in black pepper (piper nigrum L.)caused by phytophthora capsici were tested for their ability in rejuvanating phytophthora infected black pepper cuttings.Among the treatments,which had only bacterial application .IISR-6 ensured survival of 67% of the infected cuttings where as only 22% of the untreated plants survived 3 months after treatment .the combined application of IISR-51,IISR-6+IISR-13 and IISR-51+IISR-11 with metalaxyl Mancozeb resulted in 100% survival of the infected plants ,showing an sdditive effect.Experiments conducted for root-proliferation activity of the p.flurescens showed that the bacterialks strains helped increase the root biomass of the plants (30-135%) .All the strain increased the root length and root area in the treated plants (12-127%,43-200%,respectively).Strains were also found to produce plant growth hormones viz.IAA & GA.