Phytoplasma diseases are associated by bacteria-like pathogens living in plant sap and spread by sap-feeding insects. They are emerging diseases and are difficult to control, mostly because their epidemiology is not known. This book will focus on detection and prevention of phytoplasma diseases in field and horticultural crops grown in the tropical belt. The book will review current prevention methods used in small and large-scale farms, and present research results aiming at developing sustainable management of phytoplasma diseases in the tropics.