Microbial inoculants also known as soil inoculants are agricultural amendments that use beneficial endophytes (microbes) to promote plant health. Many of the microbes involved form symbiotic relationships with the target crops where both parties benefit (mutualism). While microbial inoculants are applied to improve plant nutrition, they can also be used to promote plant growth by stimulating plant hormone production (Bashan & Holguin, 1997; Sullivan, 2001).