James G. Horsfall

James Gordon Horsfall (January 9, 1905 – March 22, 1995) was an American biologist, a plant pathologist and an agriculturist.[1] [2] Horsfall was most noted for the discovery of several organic fungicides which changed the way crops' fungus diseases are treated worldwide.[1] Prior to his discovery these diseases were treated either with heavy metals which were poisonous to humans or somewhat ineffective sulfur based compounds.[1] The Horsfall-Barratt scale devised by him, and still in use, allows for the easy assessment of crop damage level based on the extent of leaf damaged by fungal or bacterial infections in the field on a 12-point scale. Horsfall was a member of the National Academy of Sciences.[1] The New York Times called Horsfall a "leading plant pathologist".[1]

Life and career

Horsfall was born in Mountain Grove, Montana and was raised in Monticello, Arkansas. The family came from ship owners in Liverpool. Horsfall's father was interested in horticulture and worked at an experimental fruit growing station. He went to study at the University of Arkansas with an interest in cars and engineering. He worked briefly with Dwight Isely, counting insects to determine the timing of insecticide application in cotton. He found himself sidelined, which he claimed was due to his nonconformity. After graduating with a BS in 1925 he went to study plant pathology at Cornell University. James' brother William R. Horsfall became an entomologist. He received his doctorate from Cornell University in 1929.[2] He experimented with tetrachloroquinone to treat diseases since it was a strong oxidant and it was believed that Bordeaux mixture worked through oxidation. Although his experiments made in 1938 showed successful action, it was not possible to publish since the chemical was made by US Rubber Company (Uniroyal) and they made the chemistry known only later.[3] It was however found to break down in sunlight and then they tried 2,3-dichrolo-1,4-naphthoquinone as a substitute. He later experimented, along with Dimond and Heuberger, with sulfur based organic compounds such as disodium ethylene-bis-dithiocarbamate. This turned out to be water soluble and they found that the zinc based analog worked better.[4] He later discovered that sugar concentrations in plant parts was correlated with resistance to fungal infection by Alternaria in potatoes. He became a founding editor of the journal Annual Review of Phytopathology.[5]

References
  1. New York Times: James G. Horsfall, Leading Plant Pathologist, 90; By Robert McG. Thomas Jr; Published: March 29, 1995
  2. Waggoner, Paul E. (1995). "James Gordon Horsfall, 1905 to 1995" (PDF). Phytopathology. 85: 836.
  3. Horsfall, James G.; Turner, Neely (1943). "Injuriousness of bordeaux mixture". American Potato Journal. 20 (12): 308–320. doi:10.1007/BF02889717.
  4. Dimond, A. E.; Heuberger, J. W.; Horsfall, J. G. (1943). "A water soluble protectant fungicide with tenacity". Phytopathology. 33: 1095–1097.
  5. Horsfall, James G. (1975). "Fungi and Fungicides the Story of a Nonconformist". Annual Review of Phytopathology. 13: 1–14. doi:10.1146/annurev.py.13.090175.000245. PMID 22594555.
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