The book is divided into two parts, namely, principles of plant pathology and important plant diseases in crops. Principles of plant pathology include history of plant pathology, symptoms of plant diseases, epidemiology and forecasting of plant diseases, host-parasite inter-relationships and their interactions, effect of climatic conditions on plant diseases, physiologic specialization, defence mechanism, methods of studying plant diseases, principles of plant disease control. Some diseases caused in different crop plants like cereals, pulses, vegetables, oilseeds, fibre crops, spices, condiments, fruits, sugarcane, tea, coffee and tobacco etc. Are discussed in detail.