This book covers all aspects of the diversity and core microbiome of the bio-control agents. Their bioprospecting and application at the field level is also discussed. The application of bio-control agents is unique in plant production due to various reasons, including its environment-friendly nature, management of plant resistance and incentivizing the rhizosphere to phyllosphere signaling. The chapters provide information on major plant-associated diversity of beneficial microorganisms, various pathogen management strategies, and improving plant immunity by the application of bio-control agents. Additionally, the exploitation, development, and quality control of bio-control agent-based formulations for farming systems and industrial-level production is discussed. This approach provides a novel framework for fostering sustainable development in crop production and protection. The book targets researchers, microbiology students, the biofertilizers industry, and those in agricultural and environmental fields.