The book fully conforms to the syllabus of the ICAR Fifth Dean's Committee Report prescribed for the undergraduate degree programme [B.Sc. (Hons) Agriculture]. It covers symptoms, etiology, disease cycle and epidemiology, and management of major diseases of Field Crops, such as Wheat, Sugarcane, Sunflower, Mustard, Chickpea, Lentil, Cotton, Pea, and Horticultural Crops, such as Mango, Citrus, Grapevine, Apple, Peach, Strawberry, Potato, Cucurbits, Onion and Garlic, Chillies, Turmeric, Coriander, Marigold and Rose. The list of additional important diseases from the aforementioned crops has been given in the book. Convincing tables and high-quality photographs furnished at appropriate places make concepts easy for students to comprehend. The book also contains objective-type questions like Multiple Choice Questions (MCQs) and Match the Following type of questions to enhance the understanding of the subject which will further help students to practice for the ICAR-JRF exam. However, these questions will also be useful for other competitive examinations such as ICAR-SRF, ICAR-NET, IARI, UPSC and Entrance exam for PG course. Besides undergraduate students, this book will also serve as a ready-to-use teaching material for teachers and a basic guide for researchers, plant protection specialists, extension workers and agriculture or horticulture officers, and growers.