Deborah R. Fravel was born in Morgantown, WV, received her B.A. degree in botany at Duke University in 1972, and her M.S. and Ph.D. degrees in plant pathology at North Carolina State University in Raleigh. Fravel joined the USDA Agricultural Research Service (ARS) at Beltsville, MD, in 1982 as a postdoctoral research associate and accepted a position as a research plant pathologist with the Soilborne Diseases Laboratory in 1984. She has served in several leadership positions within ARS, as acting national program leader for horticulture and sugar crops in 1999, as acting research leader of the Biological Control of Plant Diseases Laboratory from 1999 to 2000, and in her current position as research leader of the Genetic Improvement of Fruit and Vegetables Laboratory. Fravel is recognized internationally as a leader in research on the biological control of plant diseases and has made numerous landmark discoveries in this field.
Early in her career, Fravel discovered that the soilborne fungus Talaromyces flavus suppressed Verticillium wilt of several crops. Later, she led a research team that unraveled a novel mechanism of disease suppression by T. flavus. This team discovered that glucose oxidase produced by T. flavus generates hydrogen peroxide that kills microsclerotia of the soilborne pathogen Verticillium dahliae. This study was the first to identify the indirect action of an enzyme as a mechanism for biological control and laid the groundwork for others who then developed transgenic cotton plants expressing glucose oxidase, which are resistant to Verticillium wilt. Based on this work, Fravel was invited to write an article on antibiosis for the Annual Review of Phytopathology.
Fravel also participated in a research team that developed formulations that have been critical to the advancement of biological control. This team obtained two patents for the development of an alginate-clay matrix as an effective formulation for the biological control of fungi and bacteria. The alginate formulation was key to the development of GlioGard, the first fungus registered by the U.S. Environmental Protection Agency for control of plant diseases. The alginate prill is also widely used to produce consistent inoculum for experimental field trials of biological control agents. She also developed bacterial alginates for use in formulations, demonstrating that they were chemically more consistent and cheaper than marine alginates.
Throughout her career, Fravel has recognized that the success of biological control depends on effective biocontrol agents and, just as importantly, on knowledge of the factors that influence their efficacy. Therefore, she has taken a broad approach toward the development of management strategies that employ biological control agents as well as agricultural practices that promote the survival and activity of those agents. This approach has required the development of knowledge of pathogen biology, disease epidemiology, and the mechanisms of biological control. Her development of mathematical models to describe “epidemics” of Sporidesmium sclerotivorum controlling lettuce drop, caused by Sclerotinia minor, highlighted seasonal variation in performance of the biocontrol agent and allowed calculation of the minimum amount of biocontrol agent needed. By maximizing the value of expensive inoculum, Fravel demonstrated that the biocontrol agent could provide economic control of lettuce drop in production fields. Studying another system, Fravel showed that sublethal doses of fumigants or solarization resulted in weakened propagules of Verticillium dahliae that were extremely susceptible to the toxic effects of a biocontrol agent. Her work established that either sublethal heating (solarization) or fumigation with methyl bromide acted additively with T. flavus to suppress Verticillium wilt of eggplant. Later, a multipronged approach toward the management of Fusarium wilt led to the identification of a nonpathogenic isolate of Fusarium oxysporum that controls this disease on several crop plants, as well as an effective formulation, and to knowledge of the factors that influence the success of the biocontrol agent in many field environments. The nonpathogenic isolate of F. oxysporum has been used successfully in a commercial setting to reduce the number of dead plants by 50%. These projects demonstrate Fravel’s ability to translate her basic research into production systems.
Fravel is recognized worldwide as a leader in the field of biological control, particularly in the biological control of fungal wilt pathogens and in the formulation and commercialization of biocontrol agents. She has written numerous invited review articles on these topics, including a recent review of the commercialization of biological control for Annual Review of Phytopathology. She is widely sought out as a speaker at national and international conferences and has served on the scientific program committees for several international symposia on biological control or soilborne pathogens. She has conducted a great deal of collaborative research with scientists in industry and academia, hosting scientists from Russia, Greece, the Philippines, and Venezuela who have conducted research in her laboratory. She has received numerous invitations to visit laboratories in other countries (Russia, Brazil, Australia, New Zealand, Israel, France, Italy, and Greece) to consult on areas of common interest. Over the course of her career, she has served as a mentor to seven postdoctoral research associates.
In addition to a very productive research program, Fravel has an outstanding record of professional service, particularly to The American Phytopathological Society. She served as a senior editor of Phytopathology, responsible for biological control, from 2000 to 2002 and as an associate editor of Phytopathology from 1990 to 1992. She has been an active member of six committees and served as chair of the Biological Control and the Soil Microbiology and Root Diseases Committees. She established and maintained a valuable web site for the Biological Control Committee, listing commercially available products for the biocontrol of plant pathogens. In the early 1990s, she was one of three plant pathologists selected to participate in an APS program supporting the travel of women scientists to plant pathology departments that had no women on the faculty but several women graduate students. She has also served her profession as president of the International Verticillium Society, as a member of the Board of Directors of the Washington Academy of Sciences, and by contributions to numerous committees of the USDA ARS.
