The Department of Plant Pathology, one of the biological science departments of the University of the Philippines Los Baños, was formally established in 1917, eight years after the founding of the College of Agriculture through the efforts of Dean Edwin B. Copeland and Professor Charles F. Baker. It has been the training ground for most of the country's plant pathologists.
The Department offers both undergraduate and graduate programs in Plant Pathology. The objectives of these programs are to train and develop students to become professionally and technically competent plant pathologists.
The Department is actively engaged in phytopathological research and extension. It maintains a Plant Pest Clinic which caters to the needs of the farmers with problems regarding plant health.