This book provides a review of biocontrol agents. Chapter One discusses the biological control of bacterial pathogens in horticultural systems. Chapter Two focuses on the modes of action and applicability of the most used biological fungicides in vegetables and field crops. Chapter Three studies the biological control of fungal diseases of edible mushrooms. Chapter Four identifies different classes of biopesticides and more particularly, examines plant-based products/chemicals, discussing their integration in pest/vectors management programs. Chapter Five reviews the potential of phytoinsecticides, their action mechanisms, and their relative importance to integrated management strategies.