During green revolution, high yielding varieties were introduced
to feed increasing population of world. For enhancing the crop
production synthetic fertilizers and pesticides were used without
caring about environmental problems and soil health (Elkoca et al.,
2010). Consequently, it is great challenge to search for sustainable
strategies to alleviate detrimental effects of intensive farming
practices. Plant growth promoting rhizobacteria (PGPR) are soil
borne bacteria that have ability to aggressively colonize the rhizo
sphere or plant roots or both when applied to seed or crops that
enhance the growth and yield of plants (Ashrafuzzaman et al., 2009;
Kaymak, 2011). These rhizosphere bacteria enhance growth of plant
and yield either directly or indirectly. The direct growth promoting
mechanisms are as follows: (i) nitrogenfixation; (ii) solubilization of
phosphorus; (iii) production of phytohormones such as auxins
(indole acetic acid (IAA)), cytokinins and gibberellins (iv) sequester
ing of iron by production of siderophores; (v) lowering of ethylene