501 © Springer Nature Singapore Pte Ltd. 2017 D.P. Singh et al. (eds.), Plant-Microbe Interactions in Agro-Ecological Perspectives, DOI 10.1007/978-981-10-5813-4_25 C. Kaur • G. Selvakumar (*) • A. Ganeshamurthy ICAR- Indian Institute of Horticultural Research, Hessaraghatta Lake Post, Bengaluru 560089, India e-mail: gselva74@rediffmail.com 25 Rhizocompetence of Applied Bioinoculants Chandandeep Kaur, G. Selvakumar, and A.N. Ganeshamurthy Abstract Concomitant with the demand for chemical free food, the demand for bioinocu- lants for plant growth promotion and protection against pests and disease causing organisms has also seen a phenomenal increase. This has led to the mushrooming of several products in the market that have met with varying degrees of success. Very often it has been observed that inoculant strains that perform exceedingly well under laboratory conditions fail under feld conditions. This can be primar- ily attributed to the utilization of non-rhizocompetent strains. Since the inocu- lated strain has to compete with a multitude of native microbes in the rhizospheric region, strains lacking rhizocompetence traits often fail to establish and perform in the rhizosphere. Rhizocompetence traits such as bioflm formation, sidero- phore production, antagonism, ability to utilize root exudates, motility, and pro- tease activity can prove to be game changers under feld conditions. This chapter attempts to highlight the importance of rhizocompetence traits in inoculant selection and development, in order to harness the beneft of applied inoculants. Keywords Bioinoculants • Rhizosphere • Rhizocompetence • Root colonization • Traits