Azospirillum brasilense, a nitrogen-fixing bacterium found in the rhizosphere of various grass species, and increased the plant growth by growth substances produced by the bacteria like indole acetic acid and indole lactic acid which produced by A. brasilense from tryptophan (Tien et al., 1979; Okon and Vanderleyden, 1997; Bashan et al., 2004). Evaluation of 20 years of data indicated that 60 7...