St. John 108
3190 Maile Way
Honolulu, HI 96822

Phone: (808) 956-8351

Fax: (808) 956-3894


Scot C. Nelson

Emeritus Specialist, Plant Pathology 


Plant Disease Epidemiology and Management


State College Area High School, State College Pennsylvania (1974)
B.A. History, Pennsylvania State University (1979)
M.S. Plant Pathology, Texas A & M University (1988)
Ph.D. Plant Pathology, North Carolina State University (1992)

Research Interests:

plant pathology, plant disease management, plant disease epidemiology, plant disease diagnosis, app development

<p> <p> <strong>Courses taught:</strong></p> <p> PEPS 405 (Plant Pathogens and Diseases) (4 cr) Fall semesters, hybrid course</p> <p> PEPS 430 (Plant Disease Management) (3 cr) Spring semesters, online course</p></p>

Selected Publications:

  • Nelson, S. C., Corcoja, I., and Pethybridge, S. J. 2017. Cluster: a new application for spatial analysis of pixelated data for epidemiology. Phytopathology PHYTO-07-17-0223-R. (In press).
  • Pethybridge, S. J., and Nelson, S. C. 2017. Estimate, a new iPad application for assessment of plant disease severity using photographic standard area diagrams. Plant Dis. PDIS-07-17-1094-SR. (In press).
  • Vaghefi, N., Kikkert, J. R., Bolton, M. D., Hanson, L. E., Secor, G. A., Nelson, S. C., and Pethybridge, S. J. 2017. Global genotype flow in Cercospora beticola populations confirmed through genotyping-by-sequencing. PLoS ONE 12(10): e0186488.
  • Vaghefi, N., Nelson, S. C., Kikkert, J. R., and Pethybridge, S. 2017. Genetic structure of Cercospora beticola populations on Beta vulgaris in New York and Hawaii. Scientific Reports 7:1726 DOI:10.1038/s41598-017-01929-4 pp 1-16.
  • Vaghefi, N., Pethybridge, S. J., Shivas, R. G., and Nelson, S. C. 2016. Confirmation of Paracercospora egenula causing leaf spot of eggplant in Hawaii. Australasian Plant Dis. Notes (2016) 11: 35. doi:10.1007/s13314-016-0223-4.
  • Pethybridge, S., and Nelson, S. 2015. Leaf Doctor: A New Portable Application for Quantifying Plant Disease Severity. Plant Disease 99: 1310-1316.
  • Melzer, M. J.; Shimabukuro, J.; Long, M. H., and Nelson S. 2014. First Report of Capsicum chlorosis virus Infecting Waxflower (Hoya calycina Schlecter) in the United States. Plant Disease 98: 571-572
  • Miyasaka, S. C., McCulloch, C. E., and Nelson, S. C. 2012. Taro Germplasm Evaluated for Resistance to Taro Leaf Blight. HortTechnology 22:838-849.
  • Hollingsworth, Robert G., Collins, Topaz P., Smith, Virginia Easton, and Nelson, Scot C. 2011. Simple Statistics for Correlating Survey Responses. Journal of Extension, Article No. 5TOT7.
  • Nelson, S. C., and Abad, Z. G. 2010. Phytophthora morindae, a new species causing black flag disease of noni (Morinda citrifolia L.) in Hawaii. Mycologia 102:122-134.


  • Plant Pathology Laboratory - St. John 108 - Members