FIELD APPLICATION OF BACTERIAL ISOLATE BACILLUS POLYMYXA FROM RHIZOSPHERE OF BRINJAL (SOLANUM MELONGENA L.)

The present study was conducted with the main purpose to evaluate on field beneficial effect of Bacillus polymyxa isolated from rhizosphere of brinjal (Solanum melongena L.). Brinjal (Solanum melongena L.) cultivar Arka keshav and Arka shirish were used in this study. The isolated bacteria identified to be Bacillus polyrnyxa was used as the inoculant. Inorganic fertilizers such as urea, superphosphate, and muriate of potash were used in reduced doses. The seeds of brinjal were obtained from Division of Vegetable crops. IIHR, Hesaraghatta. Bangalore. The results of field trial revealed that Bacillus polyrnyxabacterial inoculation significantly increased growth parameters, plant mineral content and yields. The Brinjal (Solanum melongena L.) cultivar Arka keshav plants treated with Bacillus polymyxa which received full doze of nitrogen and phosphorus showed a 79% increase in root dry weight over uninoculated controls. Plants that received half dose of nitrogen and phosphorus treated wit h Bacilluspolymyxa showed a 65% increase in leaf surface area in the first leaf over the uninoculated controls, which received the same level of nitrogen and phosphorus. The plants, which received half dose of nitrogen and phosphorus and treated with Bacillus polymyxa, showed a 23% increase in plant nitrogen and 47% increase in plant phosphorus over the uninoculated controls. Plants treated with Bacillus polymyxa and received full doze of nitrogen and phosphorus showed a 17% increase in plant nitrogen and 55% increase in plant phosphorus over the uninoculated controls. Plants which received half dose of nitrogen and half dose of phosphorus and treated with Bacillus polymyxa showed a 56% increase in copper content over the uninoculated controls. Plants, which received full dose of nitrogen and half dose of phosphorus and treated with Bacillus polymyxa, showed 84% increase in plant phosphorus and 94% increase in plant potassium over the uninoculated control. The photosynthetic efficiency of treated plants in all plots was higher than the respective uninoculated controls. The soil phosphorus content during the period of the experiment showed variation. The rhizosphere soil of the treated plots in which brinjal cv. Arka keshav was cultivated showed significantly higher values of available phosphorus content than the control plots. The plots treated with full doze of nitrogen and phosphorus showed a 66% improvement over the uninoculated controls. The rhizosphere soil of the treated plots in which Arka shirish was cultivated had significantly higher available phosphorus and nitrogen content in the soil than the control plots. In conclusion, the bacterial isolate from brinjal (Solanum melongena L.) plantsidentified as Bacillus polymyxa when used as inoculum in field trials showed significant improvement in growth parameters of treated plants over the uninoculated controls at all levels of fertilizer application.