Arthur W. Galston (1920-2008) was an American botanist and bioethicist who, as a graduate student at the University of Illinois, discovered the defoliant properties of a chemical that was subsequently studied and utilized by the United States Army. His research and 1943 Ph.D. dissertation were focused on finding a chemical means to make soybeans flower and fruit earlier. In the early 1950s, biological warfare scientists at Fort Detrick, Maryland, began investigating defoliants based upon Galston's discoveries eventually producing the controversial toxic defoliant Agent Orange which was used by the U. S. Air Force for defoliation in Southeast Asia during the Vietnam War.
Galston's research and 1943 Ph.D. dissertation focused on finding a chemical means to make soybeans flower and fruit earlier.  He discovered both that 2,3,5-triiodobenzoic acid (TIBA) would speed up the flowering of soybeans and that in higher concentrations it would defoliate the soybeans. He was drafted into the U.S. Navy as an enlisted man and ultimately served as Natural Resources officer in Naval Military Government on Okinawa until his discharge in 1946.
In 1951, biological warfare scientists at Fort Detrick, Maryland began investigating defoliants based upon Galston's discoveries with TIBA, eventually producing the toxic defoliant Agent Orange used by the U. S. Air Force for defoliation in Southeast Asia during the Vietnam War. During this time, Galston taught as an associate professor at the California Institute of Technology before moving to Yale University where he taught from 1955 onwards.
Beginning in 1965, Galston lobbied both his scientific colleagues and the government to stop using Agent Orange. Galston and U. S. geneticist Matthew S. Meselson appealed to the U. S. Department of Defense to investigate the human toxicology of Agent Orange. The research conducted by the Department of Defense led to the discovery that Agent Orange caused birth defects in laboratory rats. In 1971 this information led to U. S. President Richard M. Nixon banning the use of the substance. Galston made numerous trips to Vietnam and China, including, with Ethan Signer of MIT, as the first American scientists invited to visit the People's Republic of China. In 1971, he met Chou En-lai, then Prime Minister, as well as King Norodom Sihanouk of Cambodia, who then resided in Shanghai.
After his retirement as a biologist in 1990, he became affiliated with Yale's Institution for Social & Policy Studies, where he helped to found the Interdisciplinary Center for Bioethics. He also taught bioethics to Yale undergraduates. In 2003-2004 his introductory bioethics course attracted 460 students, making it one of the most popular courses in Yale College.
Galston authored more than 300 papers on plant physiology and co-edited two books on bioethics.
He also co-founded the Gray Is Green: The National Senior Conservation Corps, a non-profit organization dedicated to helping older Americans lead more sustainable lives.
Galston died on June 15 2008, in Hamden, Connecticut.
- Schneider, Brandon (Winter 2003). "Agent Orange: A deadly member of the rainbow". Retrieved 2008-07-12.
- Galston, Arthur (March 2002). "An Accidental Plant Biologist". Plant Physiology. American Society of Plant Physiologists. pp. Vol. 128, pp. 786–787. Retrieved 2009-02-10.
- "Arthur Galston". The Economist. June 28, 2008. p. 94. Retrieved 2009-02-10.
- Pearce, Jeremy (2008-06-23). "Arthur Galston, Agent Orange Researcher, Is Dead at 88". New York Times. Retrieved 2008-07-12.
- Galston, Arthur W. (1972), "Science and Social Responsibility: A Case History", Annals of the New York Academy of Sciences; 196:223.