Horticultural crops are attacked by a large group of pathogens inflicting moderate to heavy crop losses. Due to the increased demand of fruits and vegetables and other horticultural products, more efforts are being put in horticulture sector for further boosting production to meet increased demand. Although availability of planting material and designer agro-techniques has increased in horticulture sector but biotic factors continue to be the bane of horticulture production. Crop health management during active growth phase and post harvest health management assumes significance to reduce the loss and increase the productivity. Production of quality planting materials is fast becoming an important input in disease management programmes especially in production of disease/virus free plants. Many accredited laboratories are being established to test the genetic fidelity and virus indexing of micro-propagated plants. In the present book the available information on the disease diagnostic methods developed for fruits, vegetables, plantation crops, spices and ornamentals are presented in a detailed form. These are comprehensively covered with respect to individual crops by experienced scientists.