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Hillary Mehl

Assistant Professor

Though the focus is applied plant pathology, my program integrates basic laboratory and applied field research to elucidate complex interactions between crop plants, their associated microbial communities, and environmental factors in order to better understand the epidemiology of plant diseases and develop novel strategies to manage these diseases and improve food safety and security. Specific research areas include 1) evaluation and optimization of different plant disease management strategies including chemical and biological control, crop host resistance, and cultural practices; 2) development of rapid, quantitative molecular detection methods for utilization in disease diagnostics, assessment of host resistance to specific pathogens, and study of plant pathogen population dynamics; and 3) elucidation of epidemiological factors driving plant disease development through studies of interactions between crops and their associated microbial communities at both individual field and agroecosystem scales.


Ph.D., Plant Pathology, University of California, Davis, 2007

B.S., Botany, Humboldt State University, 2001


  • August 2013 – present - Assistant Professor, Department of Plant Pathology, Physiology and Weed Science, Virginia Polytechnic Institute and State University, Blacksburg, VA
  • October 2011 – July 2013 - Assistant Research Scientist, School of Plant Sciences, University of Arizona, Tucson, AZ
  • October 2007 – September 2011 – Postdoctoral Research Plant Pathologist, USDA-ARS, University of Arizona, Tucson, AZ

Other Teaching and Advising

  • Advising students in the Department of Plant Pathology, Physiology and Weed Science at Virginia Tech

Program Focus

With a split research and extension appointment, I work with scientists, growers, and industry in Virginia and the surrounding region to solve persistent and emerging plant disease problems impacting field crops including cotton, peanut, soybean, corn, and small grains. My goal is to identify and implement novel, cost-effective, and environmentally sound strategies to prevent or control diseases in field crops and to deliver educational programs responsive to the needs of stakeholders in Virginia and beyond.

  • Sylvester, P. N., Land, F. D., Mehl, H. L., Collins, A. A., Paul, P. A., and Kleczewski, N. M. 2018. Evaluating the profitability of foliar fungicide programs in mid-Atlantic soft-red winter wheat production. Plant Disease: in press.
  • Allen, T. W., Bradley, C. A., Sisson, A. J., Byamukama, E., Chilvers, M. I., Coker, C. M., Collins, A. A., Damicone, J. P., Dorrance, A. E., Dufault, N. S., Esker, P. E., Faske, T. R., Giesler, L. J., Grybauskas, A. P., Hershman, D. E., Hollier, C. A., Isakeit, T., Jardine, D. J., Kelley, H. M., Kemerait, R. C., Kleczewski, N. M., Koenning, S. R., Kurle, J. E., Malvick, D. K., Markell, S. G., Mehl, H. L., Mueller, D. S., Mueller, J. D., Mulrooney, R. P., Nelson, B. D., Newman, M. A., Osborne, L., Overstreet, C., Padgett, G. B., Phipps, P. M., Price, P. P., Sikora, E.J., Smith, D.L., Spurlock, T.N., Tande, C.A., Tenuta, A.U., Wise, K.A., and Wrather, J. A. 2017. Soybean yield loss estimates due to diseases in the United States and Ontario, Canada, from 2010 to 2014. Plant Health Progress 18:19-27.
  • Mehl, H. L. 2017. Evaluation of new high oleic Virginia-type peanut cultivars for disease tolerance, yield, and quality. Peanut Science 44: 100-110.
  • Mehl, H. L., and Cotty, P. J. 2013. Intraspecific competition during infection by Aspergillus flavus is influenced by plant host species. Plant Pathology doi: 10.1111/ppa.12038.
  • Mehl, H. L., and Cotty, P. J. Nutrient environments influence competition among Aspergillus flavus genotypes. Applied and Environmental Microbiology 79: 1473-1480.
  • Mehl, H. L., Jaime, R., Callicott, K. A., Probst, C., Garber, N. P., Ortega-Beltran, A., Grubisha, L. C., and Cotty, P. J. 2012. Aspergillus flavus diversity on crops and in the environment can be exploited to reduce aflatoxin exposure and improve health. Annals of the New York Academy of Sciences 1273: 7-17.
  • Mehl, H. L., and Cotty, P. J. 2011. Sequence of host contact influences the outcome of competition among Aspergillus flavus isolates during host tissue invasion. Applied and Environmental Microbiology 77: 1691-1697.
  • Mehl, H. L., and Cotty, P. J. 2010. Variation in competitive ability among isolates of Aspergillus flavus from different vegetative compatibility groups during maize infection. Phytopathology 100: 150-159.
  • Mehl, H. L., and Epstein, L. 2008. Sewage and community shower drains are environmental reservoirs of Fusarium solani species complex group 1, a human and plant pathogen. Environmental Microbiology 10: 219-227.
  • Mehl, H. L., and Epstein, L. 2007. Fusarium solani species complex isolates conspecific with F. solani f. sp. cucurbitae race 2 from naturally infected human and plant tissue and environmental sources are equally virulent on plants, grow at 37º C, and are interfertile. Environmental Microbiology 9: 2189-2199.
  • Mehl, H. L., and Epstein, L. 2007. Identification of Fusarium solani f. sp. cucurbitae race 1 and race 2 with PCR and production of disease free pumpkin seeds. Plant Disease 91: 1288-1292.