Baker was a pioneer in nursery and ornamental pathology, soilborne pathogens, and biological control. His 1957 publication The U.C. System for Producing Healthy Container-Grown Plants revolutionized the nursery industry. He coauthored the first major book on biological control of plant pathogens with R. J. Cook in 1974, entitled Biological Control of Plant Pathogens. In 1939, he began working at the University of California, Los Angeles, and transferred to the Berkeley campus in 1961. He retired to Oregon and became a collaborator with the USDA and emeritus professor at Oregon State University. Baker participated in launching the Annual Review of Phytopathology and served on the editorial board from 1962 to 1977. Baker was elected a fellow of APS in 1969.
(Submitted for publication in July 2008.)