Book excerpt: Rhizosphere biology is approaching a century of investigations wherein growth-promoting rhizomicroorganisms (PGPR) have attracted special attention for their ability to enhance productivity, profitability and sustainability at a time when food security and rural livelihood are a key priority. Bio-inputs - either directly in the form of microbes or their by-products - are gaining tremendous momentum and harnessing the potential of agriculturally important microorganisms could help in providing low-cost and environmentally safe technologies to farmers. One approach to such biologically-based strategies is the use of naturally occurring products such as PGPR. Written by an international team of experts, this book considers new concepts and global issues in biopesticide research and evaluates the implications for sustainable productivity. It is an invaluable resource for researchers in applied agricultural biotechnology, microbiology and soil science, and also for industry personnel in these areas.