The effects of Alcaligenes 637Ca, Agrobacterium A18, Staphylococcus MFDCa1, MFDCa2, Bacillus M3 and Pantoea FF1 were tested on peach cv. Elegant Lady' on GF677 and Nemaguard rootstocks. Average increases in citric, malic, oxalic, butyric and fumaric acid in the leaf were obtained from rhizobacterial root inoculations of 33.1, 17.5, 21.7, 26.5, and 44.7% in Elegant Lady/Nemaguard, respectively. FF1 showed the highest FC-R activity in the roots of Nemaguard (112.4nmolFWgr(-1)hr(-2)) and GF677 (162nmolFWgr(-1)hr(-2)). The highest FC-R activity in the leaf was with MFDCa2 in Elegant Lady/Nemaguard (57.1nmolFWgr(-1)hr(-2)) and 637Ca in Elegant Lady/GF677 (87.9nmolFWgr(-1)hr(-2)). PGPR strains used in this study expressed increased leaf organic acid content, FC-R activity in the roots and leaf, increased active Fe content in the leaf, and possessed a great potential for the improvement of iron availability to plants.