Welcome to Principles of Plant Pathology. This course provides an introduction to the diseases that affect plants and the organisms that cause them. In this course, ou will be introduced to the amazing, microscopic world of plant pathogens and learn how this large and diverse group of microbes impacts our lives every day. You will see numerous examples of the battle that is waged between plant producers and plant pathogens for the plant products that we use for food, fiber, recreation, and aesthetic purposes. Throughout the lecture and laboratory sections of this course, examples of important plant diseases that affect the production of ornamentals, turfgrasses, field crops and vegetables are covered in detail. If you are interested in plant production, you need to be aware of the potential damage caused by pathogens and how to approach the development of a sound disease management system.