This laboratory manual has been developed for students to facilitate comprehension of fundamental plant pathological laboratory techniques related to the isolation of pathogens. The manual covers the preservation of disease samples, the demonstration of Koch's postulates, the examination of various classes of fungicides and antibiotics, as well as methods for preparing and applying these agents. The manual also includes bioassays and biocontrol methods for plant pathogens, as well as the identification of important fungal pathogens. The manual is a fully-colored book that features digitized images to aid in the identification of diseases and pathogens. It also includes explanations of new terminologies to enhance students' understanding of the subject. This book will be valuable to novices, students, instructors, scientists, and researchers working in the fields of Plant Pathology and Agricultural Microbiology.