Efficacies of freshly isolated phosphate solubilising bacteria (PSB) on growth promotion in groundnut (Arachis hypogaea L.) upon commonly used PSB biofertilizers in eastern India

Present study was designed to assess the prospect of fresh phosphate solubilizing bacterial isolates (PSB), to ones, used as PSB bio fertilizer in growth promotion of groundnut (Arachis hypogaea L.). Phosphate-solublizing index (PSI) of 17 isolates varied from 1.692 to 3.033, after seven days incubation. Tricalcium phosphate solubilization by PSB ranged from 309.72 to 615.28 μg/ml and highest value was recorded for isolate JCA-5. Three most efficient fresh isolates were clustered under the genera Burkholderia, Bacillus and Brevibacillus. The supplementation of elite PSB isolates augmented growth and P-uptake irrespective of edaphic conditions for groundnut. Steady increments in root (22.6% and 25.5%) and shoot length (27.6% and 33.7%), root dry-weight (20.3% and 16.2%), shoot dry-weight (11.3% and 23.3%) and P-uptake (30% and 67%) of groundnut was evident in red-laterite soil and new alluvial soils respectively in comparison to the previously acknowledged PSB biofertilizers.