A field study was executed to understand the impact of phosphate solubilizing micro-organisms on the performance of castor crop. The pooled data results showed that application of 20 kg P2O5 ha-1+ seed treatment with phosphate solubilizing bacteria (PSB) (T5) and 20 kg P2O5 ha-1+bean treatment with bio-phos (T1) have produced 35.7 and 26.0% higher bean yield over control (T2). The application of PSB showed positive effect on improving the soil phosphatase enzyme activity and castor bean yield. Efficacy of PSB was found higher at lower P than at medium or high P fertilizer dose. The higher water use efficiency and P use indices like phosphorus use efficiency, agronomic efficiency and apparent recovery efficiency of applied P and net returns (Rs. 32,120 ha-1) and B:C ratio (2.13) were also associated with the application of 20 kg P2O5 ha-1+bean treatment with PSB (T5).