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Mary Ann Hansen

Mary Ann Hansen
114C Price Hall
Blacksburg, Va. 24061


I have a Teaching/Extension (20%/80%) appointment in the School of Plant and Environmental Sciences. Both my teaching and Extension work focus on diagnostics of plant disease and abiotic problems. I co-manage the VT Plant Disease Clinic, which serves as the central diagnostics service lab for VCE county agents throughout the state.


  • Plant Disease Diagnostics


  • M.S. Plant Pathology, University of Wisconsin-Madison
  • B.S. Plant Pathology, The Ohio State University

Although my position does not have a formal research component, I occasionally participate in research projects with other faculty that involve plant disease diagnostics. I also supervise undergraduate research projects on newly detected plant pathogens.

Accurate plant diagnosis is the foundation for healthy lawns and landscapes, profitable crop production, and for development of an integrated pest management program that results in minimal impacts to the environment. The Virginia Tech Plant Disease Clinic (PDC) provides diagnostic services for plant problems caused by pathogens and abiotic factors to VCE agents across the Commonwealth, thereby improving agricultural profitability and promoting environmental sustainability. The bulk of my Extension efforts involve accurately diagnosing problems on plant samples received by the PDC each year from VCE offices across the state, and providing disease management recommendations to both commercial and home growers. I also support local VCE programs by giving presentations and hands-on workshops on common and emerging plant problems to grower groups, landscapers and Master Gardeners.

Currently Teaching

  • PPWS 4154: Plant Problem Diagnosis
  • PPWS 5154: Plant Problem Diagnosis

Previously Taught

  • PPWS 2104: Plants, Genes and People
  • PPWS 5034: Plant Clinic Experience
  • PPWS 4524: Pest and Stress Management of Trees
  • BIOL 1006: General Biology

Instructor and Plant Clinic Manager or Co-Manager | 1993-present
Virginia Polytechnic Institute and State University, Blacksburg, Va.

Diagnostician and Plant Clinic Manager | 1984-1993
Virginia Polytechnic Institute and State University, Blacksburg, Va.

  • Andy Swiger Land Grant Award. Virginia Tech College of Agriculture and Life Sciences, 2017.
  • American Phytopathological Society - Potomac Division Distinguished Service Award, 2015.
  1. Common Plant Diseases in the Landscape and Garden. Virginia Master Gardener YouTube Channel. Series of short videos on common diseases in Virginia. 2017-present.
  2. Reeves E; Hansen MA; Bush E. (2017). First report of bacterial leaf spot of a hardy pink (Dianthus gratianopolitanus hybrid) caused by Burkholderia andropogonis in Virginia. Plant Disease, 101(8), 1540. doi:10.1094/PDIS-02-17-0226-PDN
  3. Hansen MA; Demers J; Sutphin M; Yoder K; Bush E; Castlebury L. (2016). First report of European pear rust (Pear trellis rust) caused by Gymnosporangium sabinae on ornamental pear (Pyrus calleryana) in Virginia. Plant Disease, 100(10), 2166. doi:10.1094/PDIS-03-16-0396-PDN
  4. Liu H; Tolin S; Bush E; Creswell T; Hansen MA; Wang X. (2016). First Report of Tomato spotted wilt virus on Pittosporum tobira in the United States. Plant Disease, 100(2), 538. doi:10.1094/pdis-06-15-0681-pdn

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