Horsfall was granted a Ph.D. degree from Cornell University in 1929. He accepted a position at the Agricultural Experiment Station in Geneva, NY, in 1929. In 1939, he moved to the Connecticut Agricultural Experiment Station in New Haven. Horsfall referred to himself as a “squirt gun” plant pathologist. He was involved in testing numerous fungicides and aided in developing the ethylenebisdithiocarbamate fungicides, which revolutionized chemical disease control. Horsfall’s work with fungicides also led him to develop several concepts in epidemiology and to develop the Horsfall-Barratt scale for disease evaluation. He published two series of treatises on plant pathology and led the first editorial committee of the Annual Review of Phytopathology. He was elected a fellow of the society in 1965 and received the APS Award of Distinction in 1972.
(Submitted for publication in July 2008.)