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2022 Fellow Dr. Bonnie Ownley​

The society grants this honor to a current APS member in recognition of distinguished contributions to plant pathology or to The American Phytopathological Society. Fellow recognition is based on significant contributions in one or more of the following areas: original research, teaching, administration, professional and public service, and/or extension and outreach.

Bonnie H. Ownley was born in Elizabeth City, NC. She received a B.S. degree in biology from the University of North Carolina, Chapel Hill, in 1979; an M.S. degree in microbiology from Auburn University in 1983; and a Ph.D. degree in plant pathology, with a minor in soil science, from North Carolina State University in 1987. After a postdoctoral fellowship with the USDA-ARS in Pullman, WA, Ownley joined the faculty of the Department of Entomology and Plant Pathology at the University of Tennessee in 1992; was promoted to professor in 2011; has served as the only graduate director of the new Ph.D. program in entomology, plant pathology, and nematology since 2015; and is the inaugural assistant head of the department.

Ownley elucidated the impact of edaphic factors in disease and biological control. She demonstrated that variations in soil physiochemical factors play a significant role in suppressing take-all of wheat by fluorescent pseudomonads. Her research explained some of the site-to-site variability of the disease and formulated recommendations for soil amendments that increased biological control activity and revealed practices to avoid. She applied similar approaches to the benefit of other biological control systems (e.g., Trichoderma koningii), mycorrhizal symbiosis, and understanding disease development.

Ownley overturned dogma concerning the importance of Beauveria bassiana in plant disease suppression through her discovery that B. bassiana as an endophyte suppresses soilborne plant pathogens. Ownley unequivocally demonstrated that the application of B. bassiana conidia to seed resulted in endophytic colonization and reduction in plant losses and disease symptoms caused by Rhizoctonia solani in cotton and tomato and, with collaborators, developed methodologies needed to carry out these novel experiments. Ownley and her team further demonstrated that endophytic B. bassiana in tomato leaves led to infection and pathogenicity of the corn earworm, indicating the dual pathogenicity of individual strains. Her group is now expanding these findings to impacts on nematodes. Recently, Ownley and a mentee used meta-analysis to dissect plant interactions with B. bassiana to understand the potential role of the fungus in endophytic activity and the mitigation of disease reactions and insect mortality across the plant kingdom. These pioneering studies provided the basis for the emerging field of dual-use biological control and resulted in a most cited article from the journal Fungal Ecology for the year.

Another example of the productivity of the holistic approach taken by Ownley is her investigation of neglected aspects of the switchgrass crop system. Working with colleagues, significant yield increases and patentable discoveries were achieved. Ownley’s work overturned the long-held belief that disease management in switchgrass was unnecessary and demonstrated that poor stand establishment, which can plague this crop, was due to soilborne and seedling pathogens. Dollar spot, spot blotch, common root rot, necrotic roots, rust, and leaf spots influencing stand establishment and yield were documented in a series of plant disease notes and translated to growers through Extension fact sheets, the popular press, presentations, and a guidebook.

Additionally, Ownley was a pivotal member of a transdisciplinary team whose discovery that phenolics, terpenoids, and other metabolites in the switchgrass waste stream were antimicrobial and effectively controlled human and plant pathogens, which led to a U.S. patent. Ownley continues to develop this and other natural products with significant implications for disease control, for example, terpenoids of flatsedge that have great promise as biopesticides. The team has also extended knowledge of the agroecology of biological control agents that control pathogens by demonstrating negative impacts of some essential oils on biological control agents. Along with conventional chemical products, growers now have a series of essential oils demonstrated to be practical for disease management.

Several other projects demonstrate Ownley’s use of transdisciplinary research to avoid reductionist approaches to understanding the complexity of soil systems controlling soilborne pathogens. For example, she explored ways to collaborate across the mathematical/biological divide to elucidate interactions in soil ecology, and the results will have implications for microbial manipulation and management. In addition to the mathematical modeling for different systems described in a 2019 paper, Ownley used meta-analysis to tease out the biological implications of identified biological functions. Her meta-analyses for this and other systems have helped to set appropriate expectations for management practices for biological control. This approach is leading to predictions of whether biostimulants or biological controls will work in particular systems or with particular plant pathosystems. Likewise, she has teamed with soil scientists to determine how best to incorporate biostimulants and biological controls in anaerobic soil disinfestation (ASD) treatments. Since 2011, Ownley has been responsible for the pathology portions of grants and papers that have demonstrated the impact of ASD against sclerotia-producing fungi and other soilborne plant pathogens. Volatiles and organic acids produced during ASD kill plant pathogens but also create an unfavorable anaerobic soil environment for plants. The team is focused on use of biostimulants to enhance growth and plant establishment following ASD. Lastly, working at times as the leader or a collaborator in a multistate project that lasted for over 30 years, Ownley collaborated with colleagues from 10different locations to evaluate regional differences in biological and chemical treatments for soilborne pathogens across the southern United States.

Ownley has served as a leader in APS since 1990 and recently served as a member of the APS Nominations Committee. She served as a senior editor for Phytopathology, as the president of the APS Southern Division, and on several subject matter committees, including the Soil Microbiology and Root Diseases Committee and many committees within the Southern Division. At the University of Tennessee, she is a former faculty senate president. She is the immediate past president of the Tennessee University Faculty Senates, a statewide organization of faculty senates. She has pressed diligently to change policies that disadvantaged women and underrepresented minorities. She has generously shared her knowledge from the University of Tennessee as a member and presenter for the Committee on Diversity and Equality.