Takuma Tanada

Takuma Akuma Tanada (, October 30, 1919 – January 4, 2018) was an American plant biologist who made several discoveries related to the effects of light radiation on plants, including his discovery of the Tanada effect. He conducted research at the United States Department of Agriculture and in 2011 was awarded a Congressional Gold Medal, the highest civilian award in the United States, for his assistance to the U.S. military in World War II.

Tanada was born in Hawaii in 1919 to Japanese immigrants. Tanada attended the University of Hawaii studying botany, and received a B.S. in 1942, and a M.S. in 1944. Tanada and his brother Shigeo volunteered for the Army. He translated top-secret Japanese communications for the Military Intelligence Service and was promoted to technical sergeant. He later discovered that the electric charge causing roots to stick to glass is generated by the trace element boron.

Tanada married Toshiyo Shimizu on February 21, 1947, in Yokohama, Japan.

Tanada retired to Napa with his wife in 1983 to be close to Juliet Tanada, their daughter, an optometry teacher at Berkeley. His wife died in 1986. In retirement Tanada was still growing a large fruit and vegetable garden in Browns Valley. He died in January 2018 at the age of 98.

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