University of California Seal


Walter Reuther

Professor Emeritus of Horticulture

UC Riverside

1911 –2010


One of the major contributors to UC Riverside’s international reputation in agriculture has passed away. Walter Reuther, 99, died on November 2, 2010, in San Diego, where he had made his home for a number of years.


Dr. Reuther was one of the commanding figures in the development of modern citriculture. In 1956, already well known worldwide, he joined the UCR faculty in what is now the Department of Botany and Plant Sciences. He retired as professor emeritus in 1979.


Walter Reuther was born on September 21, 1911, on a farm in Manganoui County, North Island, New Zealand, the fifth of seven children born to Arthur and Martha Reuther. His parents were German born, and during World War I the family was subjected to persecution. They immigrated to the United States in 1919, settling in Florida. Walter graduated from the University of Florida in 1933 with a B.S. in chemistry, and then went to work for the Florida Citrus Experiment Station as an assistant horticulturalist. In 1937 he entered the doctoral program in plant physiology at Cornell, receiving his Ph.D. in 1940. In 1941 he accepted a position as head of the USDA Date and Citrus Station in Indio. During his five years in Indio, Dr. Reuther was instrumental in introducing the Minneola tangelo, now the fruit’s most popular variety.


After the war Dr. Reuther returned to Florida, to the USDA Citrus Station in Orlando. There he began one of his most important research studies, elucidating the role of various minerals in citrus nutrition and describing the use of leaf analysis to pinpoint deficiencies. He and co-worker Paul Smith established the nutritional standards for citrus that are still in use today throughout the world.

In 1956 Dr. Reuther accepted a position with UCR as a full professor of horticulture, which at the time was very rare for a new hire, and chair of the Department of Horticulture. When he stepped down as chair 10 years later, Dean A. M. Boyce wrote that his “contributions to Agricultural Sciences on this campus and University-wide have been . . . outstanding and of inestimable value.” Among his contributions was his leadership of the group that in 1957 started the program now known as the California Citrus Clonal Protection Program, which provides the industry with true-to-type propagating material free of all known graft-transmissible diseases. This program has served as a model for all other citrus-growing countries.


Beginning in 1962, Dr. Reuther began a series of consulting projects that took him all over the world and led to his significant research work showing the effects of climate on citrus maturation rate, pH of juice, and flowering behavior. Lasting from two months to two years in length, these projects included assignments in 25 separate countries over three continents. He later wrote, “I was able to see much of the world’s citrus growing problems.” He pinpointed lack of expert technological knowledge as a major handicap for many countries, and was able to persuade governments to send their brightest students for graduate education in the US, many coming to Riverside.


Dr. Reuther is perhaps best known as the editor of The Citrus Industry, the multivolume work first published by the University of California Press starting in 1943. The first edition was edited by H. J. Webber and L. D. Batchelor, the first and second directors, respectively, of the UC Citrus Experiment Station. After a quarter century, much of the research cited was out of date, and Dr. Reuther undertook the massive task of editing or co-editing the second edition, the five volumes of which appeared between 1967 and 1989. The work remains a staple for citrus growers and researchers throughout the world.


During the course of his life, Dr. Reuther received many awards and honors. He was named a Fellow of the American Society of Horticultural Science and a Fellow of the International Society of Citriculture, an organization that he was instrumental in founding. He received the Albert G. Salter Award from the California Citrus Quality Council, was named as one of the 2,000 Outstanding Scientists of the 20th Century by the International Biographical Centre in the UK, and appeared in Who’s Who in America in 1992-93.


In a biographical memoir written when he was 91, Dr. Reuther referred to his “lucky life,” and expressed his debt to his mentors, J. R. Magness, George Potter, and A. M. Boyce, and especially his mother, Martha; and his beloved wife, Flora, who died in 2000. They were “the most profound influences in my life,” he wrote.


Dr. Reuther is survived by his sons, David and Charles, and four grandchildren.


Michael Roose (Chair)

Charles W. Coggins