Duggar received an A.M. degree from Harvard University, working under W. G. Farlow and R. Thaxter, in 1895 and a Ph.D. degree from Cornell University in 1898. He was a charter member of APS and served on the first council. He wrote the first plant pathology textbook in this country, Fungous Diseases of Plants, published in 1909, and in 1924 completed a second textbook, Plant Physiology, With Special Reference to Plant Production. After becoming an emeritus professor in 1943, Duggar continued to work as a consultant for Lederle Laboratories, where he discovered new antibiotics in soil. Duggar made advances in the understanding of cotton root rot and discovered the conidial state of the pathogen, which resulted in the transfer of the species from Ozonium to Phymatotrichum. He also worked with crown gall and TMV and was the first to estimate the size of the virus particle.
(Submitted for publication in July 2008.)