EFFECT OF PHOSPHATE SOLUBILIZING BACTERIA ON GROWTH CHARACTERISTICS OF MAIZE, BEANS AND GROUNDNUT SEEDLINGS IN POTTED SOIL

Growth effects of phosphate solubilizing bacterial strains on maize, beans and groundnut seedlings in potted soil samples were investigated. The bacterial strains were isolated from uncultivated agricultural farmland on nutrient agar medium. The isolates were tested for their phosphate solubilizing potential using National Botanical Research Institute Phosphate (NBRIP) agar containing tricalcium phosphate as the sole phosphate source. The isolates showed varying phosphate solubilization index (PSI) ranging from 1.8 to 3.1. Among the isolates tested for phosphate solubilization, Pseudomonas sp. PSBA2, Pseudomonas sp. PSBN1 and Bacillus sp. PBSC1 showed higher phosphate solubilization index (PSI) values of 2.8, 3.1 and 1.9 respectively. The best growth performances (31.2 cm, 38.4 cm2, and 2.93 cm for plant height, leave area and shoot length respectively) were observed in maize inoculated with Pseudomonas sp. PSBN1 while the least performances with values of 6.4 cm, 2.8 cm2, and 2.9 cm for plant height, leave area and shoot length respectively was observed in beans inoculated with Bacillus sp. PBSC1. Results of this study are suggestive of the potential for the use of phosphate solubilizing bacteria as a biofertilizer.