Global plant disease outbreaks dramatically decrease the yields as well as quality of the world's basic foodstuffs and other crops that are ideal for health and nutrition. The growing food needs of humanity and the mounting challenges in controlling plant diseases are making this problem more critical. The Greek roots of the word "epidemiology" are epi, which means "upon, among," demos, which means "people, region" and logos, which means "study, word, discourse." Since the time of the Bible, people have conjectured about the causes, treatments, and prevention of plant illnesses. However, plant pathology did not become an applied scientific field until the latter part of the eighteenth century, and this brief overview is limited to the last 250 years. Large (1940) used a series of common diseases like potato blight, vine mildew, wheat bunt, club root of crucifers, and coffee rust to depict the evolution of plant pathology in his most approachable work, Advance of the Fungi. The nineteenth century is known as the "era of the pathogen", when studies of the growth and life cycles of pathogens were conducted for a specific purpose. Pathogenicity was first detected in fungi, then in bacteria, and then in viruses at the turn of the century. Research on plant pathology spread globally following the two World Wars, especially after the Second.