Scott Harper

Scott Harper

Associate Professor, VirologyDirector, CPCNW 509-786-9230 Hamilton Hall  24106 N Bunn Rd.

Research Specialty and Interests

My research program focuses on viruses and other systemic pathogens of perennial crops in the Pacific Northwest, particularly those infecting fruit trees (Malus and Prunus spp.), grapevine (Vitis sp.), and Hops (Humulus lupus). Aspects of my research include:

  • The interaction of viruses with one another, and how this affects basic biological processes such as virus movement, transmission, and the expression of disease; I have a particular interest to see whether we can use virus-virus interactions to control diseases in perennials.
  • The viral infection process, tissue tropism and how this relates to disease – and to our ability to detect and eradicate viruses.
  • The detection and identification of novel viruses, as well as the development of new assays and tools for virus diagnosis.


  • Ph.D. School of Biological Sciences, University of Auckland, New Zealand (2009)
  • MSc (Hons). School of Biological Sciences, University of Auckland, New Zealand (2005)
  • BSc. School of Biological Sciences, University of Auckland, New Zealand (2003)

Professional Experience and Activities


  • Research Assistant Scientist, Department of Plant Pathology, University of Florida (2015-2016)
  • Postdoctoral Associate, Citrus Research and Education Center, University of Florida (2010-2015)
  • Scientist Level 1, Plant Health and Environment Laboratory, Ministry of Agriculture and Forestry, New Zealand (2008-2010)

Employment and Graduate Student Opportunities

Students interested in conducting research into viruses in perennial crop systems, the interaction of viruses with each other, their invertebrate vectors, and their plant host, or who are interested in virus diagnostics, are encouraged to inquire about potential projects.

For more information on graduate studies in the Department of Plant Pathology at Washington State University go visit the Plant Pathology website.


Full list on ResearchGate

  • Peer-reviewed articles
    • Harper SJ, Killiny N, Tatineni S, Gowda S, Cowell SJ, Shilts T, & Dawson WO (2016) Sequence variation in two genes determines the efficacy of transmission of Citrus tristeza virus by the brown citrus aphid. Archives of Virology 161: 3555-3559.
    • Killiny N, Harper SJ, Alfaress S, El-Mohtar C, Dawson WO (2016) Minor coat and heat-shock proteins are involved in binding of Citrus tristeza virus to the foregut of its aphid vector, Toxoptera citricidaApplied and Environmental Microbiology 82: 6294-6302
    • Harper SJ, Cowell SJ, & Dawson WO (2015) Finding balance: virus populations reach equilibrium during the infection process. Virology 485: 205-212.
    • Harper SJ, Cowell SJ, & Dawson WO (2015) With a little help from my friends: Complementation as a survival strategy for viruses in a long-lived host system. Virology, 478: 123-128.
    • Harper SJ, Cowell SJ, Robertson CJ, Dawson WO (2014) Differential tropism in roots and shoots infected by Citrus tristeza virusVirology460-461: 91-99
    • Harper SJ (2013) Citrus tristeza virus: Evolution of complex and varied genotypic groups.  Frontiers in Microbiology 4:93. doi: 10.3389/fmicb.2013.00093
    • Ward LI, Harper SJ (2012) Loop-mediated isothermal amplification for the detection of plant pathogens. Methods in molecular biology862:161-170
    • Harper SJ, Delmiglio C, Ward LI, Clover GRG. (2010) Detection of Tomato black ring virus by one-step RT-PCR. Journal of Virological Methods171(1): 190-194
    • Harper SJ, Dawson TE, Pearson MN (2010) Isolates of Citrus tristeza virusthat overcome Poncirus trifoliata resistance comprise a novel strain.Archives of Virology: 155(4): 471-480
    • Harper SJ, Ward LI, Clover GRG. (2010) Development of LAMP and Real-Time PCR methods for the rapid detection of Xylella fastidiosa for Quarantine and Field Applications. Phytopathology 100: 1282-1288.
    • Tang J, Harper SJ, Wei T, Clover GRG (2010) Characterization of hydrangea chlorotic mottle virus, a new member of the genus CarlavirusArchives of Virology 155(1): 7-12
    • Harper SJ, Yokomi RK, Dawson WO (2016) Citrus tristeza virus-aphid interactions. In: J.K. Brown, editor. Vector-mediated transmission of plant pathogens. St. Paul (MN): APS Press.Reviewed book chapters
  • Industry publications and popular articles
    • Harper SJ, Cowell SJ, Dawson WO (2015) To fit in – the conforming behavior of viruses. Virology Research Highlight
    • Harper SJ, Cowell SJ, Halbert SE, Brlansky RH, Dawson WO (2015) CTV status in Florida.  Citrus Industry (Extension Publication), April 2015.