The production of phytohormones by PGPR is considered to be an important mechanism by which the bacteria promote plant growth, from germination to senescence (Vessey, 2003). The determination of endogenous concentrations of hormones is essential to elucidate the role of a particular hormone in any physiological process. The mechanisms by which PGPR enhance plant growth is through the production of phytohormones such as indole-3-acetic acid (IAA), auxins, ethylene, cytoxin and gibberellin within the root zone (Gnanamanickam, 2006). These are known to function as coordinators of plant growth and development (for example, regulating the density and length of root hairs, thereby increasing the root surface zone which improves absorption of water and nutrients from the soil) (Gray and Smith, 2005). Among them, the most and well-studied are auxins and IAA (Gnanamanickam, 2006).