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Citrus Breeder Leaves a Grapefruit Legacy

Citrus Breeder Leaves a Grapefruit Legacy

Robert K. Soost is one of the breeders of the popular Melogold and Oroblanco grapefruit

(March 20, 2009)

Robert K. Soost, citrus breeder from UC RiversideEnlarge

Robert K. Soost, citrus breeder from UC Riverside

RIVERSIDE, Calif. ( – Professor Emeritus Robert K. Soost, one of the two botanists who developed the University of California, Riverside’s popular Oroblanco and Melogold grapefruit varieties, died March 8, 2009 at Petaluma Valley Hospital. He was 88.

Soost, a world authority on citrus genetics and breeding, spent 39 years as a professor of Botany and Plant sciences at UC Riverside. But his affiliation with the campus stretched over 60 years.

He and his colleague James Cameron developed Oroblanco and Melogold, which were patented by the university in 1981 and 1986 respectively and now commonly found in grocery stores. They also developed the Pixie and Gold Nugget mandarin varieties, which are small and easy to eat and have become favorites with people who are knowledgeable about citrus.

Born on November 13, 1920, in Sacramento, he attended Sacramento Junior College, and in 1942 graduated from UC Berkeley. He served in the Army Signal Corps during WWII. In 1949 he earned his Ph.D. in plant genetics from UC Davis. He was a member of Phi Beta Kappa and Sigma Xi, and a Fellow of the American Association for the Advancement of Science and the American Society for Horticultural Science.

Soost joined the staff of the University of California Citrus Experiment Station, located in Riverside, in 1949 as a junior geneticist. In 1961, seven years after the Riverside station had turned into a full-fledged university campus, he was named an asociate professor of genetics. Three years later he became a full professor. In 1968 he was appointed chairman of the Department of Botany and Plant Sciences, a post he held for the next seven years.

In 1986 he retired, but he continued his service to the campus as an emeritus professor. He and his wife, Jean, eventually relocated to the Bay Area community of Inverness, California.

He was an honored Fellow of the California Native Plant Society and a dedicated volunteer researcher with the Pt. Reyes National Seashore rare plant monitoring group.

In addition to his wife, he leaves three daughters, Anita Soost, Janet Clinton, and Elaine Soost and four grandchildren, Stacy Clinton, Brian Clinton, Soquel Schafer, and Simon Schafer.

A memorial service will be held at 2 p.m. Saturday April 4, 2009, at the Dance Palace Community Center in Point Reyes Station, California.

Donations in his memory may be made to the Marin chapter of the California Native Plant Society ["CNPS Marin" c/o Daniel Kushner, 201 Ross St., San Rafael, CA 94901], the Environmental Action Committee of West Marin [], or the UCR Foundation Citrus Variety Collection Endowed Fund [].

The University of California, Riverside ( is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment has exceeded 21,000 students. The campus opened a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual statewide economic impact of more than $1 billion.

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