Subseries 90a consists of selected files from the Office of the Director of the Agricultural Experiment Station (now Dean for Agricultural Research). Most of the files were created in the 1950s during the tenures of Directors Willard Merwin Fifield and Joseph Reilly Beckenbach. However, earlier documents from previous directors also exist. These include discussion of potato experiments in 1905, speeches and papers delivered at annual Citrus Seminars and Livestock Roundups, and records of the State Plant Board of Florida (1924-1945). The Plant Board, later renamed the Division of Plant Industry and now part of the Florida Department of Agriculture and Consumer Services, was originally administered through the Station. More recent files include extensive documentation on state and federal regulation of pesticides, fungicides, and fertilizers, files on spreading decline in Florida citrus, cooperative research with the Servicio Interamericano de Cooperacion Agricola (STICA) in Costa Rica, records of the Advisory Committee to the Everglades Research Program, records related to a Mediterranean Fruit Fly infestation in 1956--including "daily infestation reports"--and records related to Florida's water resources.

Subseries 90b contains the correspondence and administrative records of William M. Fifield, 1951-1956, Joseph R. Beckenbach, 1956-1968, John W. Sites, 1968-1976, and Howard Wilkowske, 1977. Some of these records relate to the administration and research programs of the experiment stations around the state. One also finds the records of the Fertilizer and Pesticide Committee through the 1960s and other important advisory committees such as the Florida Citrus Research Advisory Council, the Florida Foundation Seed Producers, and the Water Resources Council. In addition, special problems of an emergency nature are represented such as the work pertaining to the lethal yellowing disease of palms, citrus canker, and the Caribbean Fruit Fly. Information can be found on the history of new cultivar releases and solar energy research.

Fairly extensive records pertaining to IFAS's Costa Rican Mission during the 1950s provide details of the various research activities in that Central American nation.