John Charles Walker (July 6, 1893 – November 25, 1994) was an American agricultural scientist noted for his research of plant disease resistance.[1] [2] [3] The New York Times said that Walker's "pioneering research in disease resistance in plants had a strong impact on world agriculture" and that Walker "was the first scientist to demonstrate the chemical nature of disease resistance in plants".[1] Walker is most known for developing disease-resistant varieties of onions, cabbages, beans, peas, beets and cucumbers.[1] [2] The National Academy of Sciences said that he was considered "one of the world's greatest plant pathologists" and that "his fundamental discoveries of plant disease resistance made a lasting impact on world agriculture".[2] Walker was professor emeritus at the University of Wisconsin–Madison.[1] He was also president and a fellow of The American Phytopathological Society and received the APS Award of Distinction.[3]