The scientific study of diseases in plants that are caused due to pathogens and environmental factors is under the scope of plant pathology. Some common pathogens are fungi, bacteria, viruses, protozoa, etc. Pathogens typically infect the plant through the release of toxins, cell wall degrading enzymes and effector proteins. Some abiotic factors such as frost, drought, poor drainage, deposition of mineral salts, etc. also have a significant effect on the incidence of physiological plant disorders. This field encompasses the study of disease etiology, pathogen identification, economic impact, plant disease resistance, genetics and management of pathosystem genetics, etc. This book is a compilation of chapters that discuss the most vital concepts in the field of plant pathology. Different approaches, evaluations and methodologies have been included herein. For someone with an interest and eye for detail, this textbook covers the most significant topics in this field.