Guido Schnabel

Plant and Environmental Sciences Department, Public Service Activities

Office: 105 Collings St./220 BRC
Phone: 864-656-6705
Personal Website:


 Educational Background

Univ of Stuttgart, Hohenheim 1997

Justus Liebig Univ Giessen 1993

 Courses Taught

Plant Disease Diagnostics and Management Summer Course


Dr. Guido Schnabel is a plant pathologist at Clemson University with over 25 years of experience working with pathogens of fruit crops. He has an active research and extension program focused on management of diseases of small fruits and stone fruits. Together with his technician Karen, MS students, PhD students, and postdocs he publishes in highly ranked, peer-reviewed journals. He currently is Associate Editor of the international journal 'Pesticide Biochemistry and Physiology'. His research and extension activities were recognized with the APS Lee Hutchins Award for Excellence in Tree Fruit Research in 2011, The APS Excellence in Extension Award in 2015, the Clemson University Godley Snell Award for Excellence in Research and the Clemson University Centennial Professorship Award for years 2017/2018. His outreach efforts are best known for his regional fungicide resistance monitoring as well as the development of the MyIPM smartphone app.

 Research Interests

Integrated management of diseases affecting peach and strawberry. Dr. Schnabel studies molecular mechanisms of fungicide resistance in Colletotrichum, Monilinia, and Botrytis; monitors resistance in the field; and determines the efficacy of fungicides both in vitro and in field trials. He identifies and characterizes tree fruit pathogens and has also developed cultural management strategies of root diseases.

 Extension and Outreach

Extension programs include commercial grower education, county agent support, extension presentations, publications, on-farm visits, using technology for information transfer, identification of pathogen resistance, and farm-specific consultation to improve disease and resistance management.


Publications 2018/2017
Dowling, M. E., Hu, M-J., and G. Schnabel 2018. Fungicide resistance in Botrytis fragariae and species prevalence in the Mid-Atlantic United States. Plant Dis. 102:964-969.

Chen et al. 2018. Analysis of RPA190 revealed multiple positively selected mutations associated with metalaxyl resistance in Phytophthora infestans. Pest Manag. Sci. 74:1916-1924.

Cosseboom, S.D., K. Ivors, G. Schnabel, and G. Holmes 2017. First Report of Botrytis mali causing gray mold on strawberry in California. Plant Dis. 102:679.

Rupp, S., C. Plesken, S. Rumsey, M. Dowling, G. Schnabel, R. Weber and M. Hahn 2017. Botrytis fragariae, a new species causing gray mold on strawberries, shows high frequencies of specific and efflux-based fungicide resistance. Applied and Environmental Microbiology. 83: 83:e00269- 17.

Cordova, L. G., L. V. Madden, A. Amiri, G. Schnabel, and N.A. Peres 2017. Meta-analysis of a web-based disease forecast system for control of anthracnose and botrytis fruit rots of strawberry in southeastern United States. Plant Dis. 101:1910-1917.

Hu, M.-J., M. E. Dowling, and G. Schnabel 2017. Genotypic and phenotypic variations in Botrytis spp. isolates from single strawberry flowers. Plant Dis. 102:179-184.

Dowling, M.E., M.-J. Hu, and G. Schnabel 2017. Identification and characterization of Botrytis fragariae isolates on strawberry in the United States. Plant Dis. 101:1769-1773.

Samarakoon, S. C., G. Schnabel, J. E. Faust, K. Bennett, J. Jent, M. J. Hu, S. Basnagala, and M. Williamson 2017. First report of resistance to multiple chemical classes of fungicides in Botrytis cinerea, the causal agent of gray mold from greenhouse-grown petunia in Florida. Plant Dis. 101:1052.

Hu, M-J., C. Peng, J.C. Melgar and G. Schnabel 2017. Investigation of potential causes of peach skin streaking. Plant Dis. 101:1601-1605.

Dowling, M.E., Schnabel, G., Boatwright, H.G., and S. Everhart 2017. Novel gene-sequence markers for isolate tracking within Monilinia fructicola lesions. Pest Manag. Sci. 73:1822-1829.

Dowling, M. E. and G. Schnabel 2017. First report of Botrytis mali causing gray mold on strawberry in the United States. Plant Dis. 101:1034.

Hao, X.J., Hu, M.J., Chen, S.N., and G. Schnabel 2017. Challenges in assessing efficacy of polyoxin-D zinc salt against Colletotrichum species. J. Plant Pathol. 99:513-516.

Rennberger, G., M. Dowling, A.P. Keinath and G. Schnabel 2017. First Report of Root Rot Caused by Pythium ultimum on Acanthosicyos horridus (Cucurbitaceae). Plant Dis. 101:258.

Chen, S. N., N. Yuan, G. Schnabel and C. X. Luo 2017. Function of the genetic element ‘Mona’ associated with fungicide resistance in Monilinia fructicola. Mol. Plant Pathol. 18:90-97.


Professional Website