The average crop productivity in India is considerably lower than the global average productivity for almost every crop including field crops. Diseases are one of the major causes for lowering of crop yields, destroy up to 20-30% of crop produce during pre-harvest and post-harvest stages. In this direction, a book presenting exclusively on “Diseases of Nationally Important Field Crops” is lacking in the market, as a result potential reader are deprived of being up-to-date relevant information. The present book is aimed to fulfil the gap of knowledge and embodies 33 chapters covering major diseases of nationally important field crops (cereals, pulses, oil yielding crops, cotton, tobacco etc.), highlighting the etiology, symptoms, disease cycle, economic importance, distribution, and management aspect with advanced approaches. The present book shall serve as an important reference source to UG/PG students, academics, professionals, scientists, researchers, extension personnel dealing with plant diseases in universities and institutes, bureaus, directorates, research stations, KVKs etc.