PSEUDOMONAS FLUORESCENS MEDIATED NUTRIENT FLUX IN THE BLACK PEPPER RHIZOSPHERE MICROCOSM AND ENHANCED PLANT GROWTH

Abstract

Pseudomonas fluorescens strains identified earlier were found effective in promoting growth in black pepper vines were evaluated for their nutrient mobilization capacity in the black pepper rhizosphere. P solubilization potency of the strains was proved in vitro. In in planta studies, the strains significantly increased the final dry matter production in the treated plants compared to the untreated control. The role of P.fluorescens mediated nutrient flux in the soil microcosm in plant growth promotion was confirmed with the higher uptake of nutrients by the bacterized plants after 90 days of treatment and planting. Significant uptake of nitrogen (N) and potassium (K) was noticed in IISR-13, IISR-ll and IISR-6 treated plants as it is related to the drymatter yield. The uptake of K although was higher in bacterized plants, compared to the untreated check, only IISR-13 showed significantly higher levels; The bacterial population associated with the roots maintained a minimum population of log 6 even up to 90 days after treatment. The study revealed the enhanced nutrient mobilization in the rhizosphere of black pepper with PGPR treatment, which resulted in enhanced plant vigor.