Dennis R. Hoagland

Dennis Robert Hoagland (born April 2, 1884 in Golden , Colorado , † September 5, 1949 in Oakland , California ) was an American plant physiologist and soil chemist at the University of California, Berkeley .

Hoagland earned a bachelor's degree in chemistry from Stanford University in 1907 and became a lecturer in animal nutrition at the University of California, Berkeley in 1908 . In 1912/1913 he obtained a master's degree in agricultural chemistry from Elmer V. McCollum at the University of Wisconsin – Madison . In 1914 Hoagland received his first professorship (assistant professor) in this subject at UC Berkeley, in 1922 he became an associate professor , and in 1927 he was given a full professorship.

During the First World War , Hoagland tried to replace the lack of imports of fertilizers based on potash salt from the German Reich to the United States with plant extracts from brown algae . He investigated the ability of plants to take up salts against a concentration gradient . During his systematic investigations he developed the widely known Hoagland's solution (see hydroponic fertilizer #track element additive according to DR Hoagland ). He discovered the energy dependency of vegetable salt intake and was able to show that various plant diseases are caused by deficiencies in trace elements such as zinc . Further work dealt with the pH dependence of plant growth.

In 1916 Hoagland was elected as a Fellow in the American Association for the Advancement of Science (AAAS), in 1934 as a member of the National Academy of Sciences , and in 1945 of the American Academy of Arts and Sciences . In 1940 he and Daniel I. Arnon received the Newcomb Cleveland Prize of the AAAS for the work Availability of Nutrients with Special Reference to Physiological Aspects . Hoagland was president of the American Society of Plant Physiologists , which awarded him its Stephen Hales Prize in 1929 .

Dennis R. Hoagland was married to Jessie A. Smiley since 1920 († 1933); the couple had three sons. His students included William Zev Hassid , Daniel I. Arnon and Folke Karl Skoog .

literature

• Walter P. Kelley: Dennis Robert Hoagland 1884–1949 (PDF; 1.1 MB). In: Biographical Memoirs. National Academy of Sciences, 1956
• Dennis Robert Hoagland. In: Encyclopædia Britannica . Retrieved November 16, 2018 . 

Web links

• Life data, publications and academic family tree of Dennis R. Hoagland at academictree.org

Individual evidence

1. ^ Dennis Hoagland. In: nasonline.org. National Academy of Sciences, accessed November 16, 2018 . 
2. ↑ Book of Members 1780 – present, Chapter H. (PDF; 1.2 MB) In: American Academy of Arts and Sciences (amacad.org). Retrieved November 16, 2018 . 
3. ^ Newcomb Cleveland Prize Recipients. In: nasonline.org. American Association for the Advancement of Science, accessed November 16, 2018 .