The applications of plant growth promoting rhizobacteria (PGPRs) as biofertilizers for cold area rice variety JP-5

Abstract

The aim of present study was to evaluate the effect of bacterial inoculation on different growth parameters of rice variety JP 5. A total of 18 bacterial strains were isolated from roots and rhizosphere of rice. Three bacterial strains (Azospirillum brasilense strain R1,Azospirillum lipoferum strain RSWT1 and Pseudomonas strain Ky1) were used to inoculate rice variety JP 5 at two experimental sites in Swat (Agriculture Research Institute (N) Mingora and Udigram). Plant growth promotion was observed in all inoculated treatments, which was evident from increase in number of tillers, straw and grain yields and total weight of the plants. A. brasilense strain R1 was more effective in plant growth promotion than other strains. At ARIN Mingora, Swat, inoculation of rice variety JP 5 withA. brasilense strain R1 showed 19% increase in the straw weight and 39.5% increase in the grain weight. At this experimental site, inoculation with A. lipoferum strain RSWT1 andPseudomonas strain Ky1 increased grain weight by 18. and 13.8% respectively. At Udigram, Swat, any significant beneficial effect of inoculation with A. lipoferum strain RSWT1 and Pseudomonas strain Ky1 was not observed whereas inoculation with A. brasilense strain R1 showed positive results of 15.5 and 27.4% increase over control in straw weight and grain weight, respectively. The study reveals that beneficial strains of PGPR can be used as biofertilizer for rice. Key words: Azospirillum, Pseudomonas, inoculation of rice, effects of inoculation.