All seven strains were used as fresh suspension and powdered formulations. Assays were conducted separately for each formulation tested. For fresh suspensions, seed of cv. IR-64 were surface sterilized with 2% sodium hypochlorite for 2 min. Bacterization of the seed was achieved by soaking rice seeds in 108 cfu ml−1 PGPR suspensions (100 g/500 ml), prepared as described earlier, and amended with 0.2% sterilized carboxymethyl cellulose (CMC) as a sticker. The suspensions were incubated at 26 °C in a rotary shaker at 150 rpm for 6 h to facilitate attachment of bacterial cells to the seed coat. Later, the seed were allowed to dry in an incubator at 30 °C. The seeds treated with sterile distilled water amended with CMC and seeds soaked in distilled water alone served as controls.