Guido Schnabel

Professor of Plant Pathology - Fruit Crops
Graduate Student Coordinator
Plant and Environmental Sciences Department, Public Service Activities

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


 Educational Background

Univ Stuttgart, Ger 1997

JLU Giessen, Ger 1993

JLU Giessen, Ger 1990

 Courses Taught

Plant Disease Diagnostics 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. His lab publishes in highly ranked, peer-reviewed journals. Since 2019 he has been Associate Editor of 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.

 Research Interests

-integrated management of diseases affecting peach and strawberry
-fungicide resistance identification and management
-molecular mechanisms of fungicide resistance in fungal plant pathogens
-efficacy of fungicides in vitro and in field trials
-prevalence and causes of peach skin disorders

 Extension and Outreach

-provide timely and useful information to commercial growers via production guides, presentations, website, newsletters, smartphone apps, etc
-generate applicable data for sustainable fruit production
-generate new outreach tools such as the MyIPM smartphone app.


Recent Publications
Ishii, H., P. K. Bryson, M. Kayamori, T. Miyamoto, Y. Yamaoka, and G. Schnabel 2020. Cross-resistance to the new fungicide mefentrifluconazole in DMI-resistant fungal pathogens. Pestic. Biochem. Physiol. In press.

Adelberg, J., J. Naylor-Adelberg, S. Miller, K. Gasic, G. Schnabel, P. K. Bryson, C. Saski, S. Parris, and G. Reighard. 2020. In vitro Co-culture System for Prunus spp. and A. mellea in Oasis® IVE Phenolic Foam. In press.

Wu, Y., C. Saski, G. Schnabel, S. Xiao, and M.J. Hu 2020. A high-quality genome resource of Botrytis fragariae, a new and rapidly spreading fungal pathogen causing strawberry gray mold in the U.S.A." Phytopathology in press.

Reighard, G., J. C. Melgar, and G. Schnabel. What we know and do not know about a peach skin bronzing disorder. Acta Horticulturae, in press.

Boatwright, H. and Schnabel 2020. Evaluation of the intelligent sprayer system in peach production. Plant Dis. In press.

Dowling, M., J. Gelain, L. L. May de Mio, and G. Schnabel 2020. Characterization of high fludioxonil resistance in Botrytis cinerea isolates from calibrachoa flowers. Phytopathology, in press.

Dowling, M. E. and G. Schnabel 2020. Understanding plant diseases with art and technology. Int. J. Hort. Sci. 20:959-966.

Dowling, M., N. Peres, S. Villani, and G. Schnabel 2020. Managing Colletotrichum on fruit crops; a ‘complex’ challenge. Plant Dis. 104:2301-2316.

Chen, F., G. Schnabel and others 2020. Histone H3 gene is not a suitable marker to distinguish Alternaria tenuissima from A. alternata affecting potato. PlosOne.

Miller, S. B., K. Gasic, G. R. Reighard, W. G. Henderson, P. A. Rollins, M. Vassalos, and G. Schnabel 2020. Preventative root collar excavation reduces peach tree mortality caused by Armillaria root rot on replant sites. Plant Dis. 104:1274-1279.

Munoz, M. G. Schnabel, W. Bridges, and J. E. Faust 2020. Expression of pink pigmentation in rose petals and its relationship with Botrytis cinerea. PHP. 21:152-156.

Chechi, A., Melanie L. Lewis Ivey Rachel R. Kaufman, Karen P. Bryson, and Guido Schnabel 2020. Quinone outside inhibitor-resistant Colletotrichum nymphaeae isolates from strawberry lack mutations in cytb gene. J. Plant Pathol. Doi 10.1007/s42161-020-00565-8.

Bennett, K., Vargo, M., Schnabel, G. (2020). Calcium application method impacts Botrytis blight severity on petunia flowers. HortScience, 55, 192-195.

Bennett, K., Jent, J., Samarakoon, U. C., Schnabel, G., Faust, J. E. (2020). Reduction of Botrytis cinerea infection on petunia flowers following calcium spray applications. HortScience, 55, 188-191.

Lawrence, B., G. Schnabel and J. C. Melgar 2020. Field performance and susceptibility to fungal pathogens of eleven blackberry cultivars. Int J Fruit Sci.

Chen, S., M. Hu, and G. Schnabel 2020. Paralogous CYP51s of Colletotrichum spp. Mediate Differential Sensitivity to Sterol Demethylation Inhibitors. Phytopathology 110:615-625.

Li, Y., S. S. Tsuji, M. Hu, M. P. S. Camara, S. J. Michereff, G. Schnabel, and F. Chen 2019. Characterization of difenoconazole resistance in Lasiodiplodia theobromae from papaya in Brazil. Pest Manag. Sci. 76:1344-1352.

Chen, F., S. S. Tsuji, Y. Li, M. Hu, M. A. Bandeira, M. P. S Camara, S. J. Michereff, G. Schnabel 2020. Reduced sensitivity of azoxystrobin and thiophanate-methyl resistance in Lasiodiplodia theobromae from papaya. Pestic. Biochem. Physiol. 162:60-68.

Cosseboom, S. D., G. Schnabel, and M.J.Hu. 2020. Competitive ability of multifungicide-resistant Botrytis cinerea in a blackberry planting over three years. Pestic. Biochem. Physiol. 163:1-7.

Munoz, M., J. E. Faust, and G. Schnabel 2019. Characterization of Botrytis cinerea from commercial cut flower roses. Plant Dis. 103:1577-1583.

Chechi, A., Stahlecker, J., Dowling, M. E. and G. Schnabel 2019. Diversity in species composition and fungicide resistance profiles in Colletotrichum isolates from apple. Pestic. Biochem Physiol. 158:18-24.

Chechi, A., J. Stahlecker, M. Zhang, C. X. Luo, and G. Schnabel 2019. First Report of Colletotrichum fioriniae and C. nymphaeae Causing Anthracnose on Cherry Tomatoes in South Carolina. Plant Disease 103:511.

Schmitz, L. T. and G. Schnabel, 2019. Infrequent occurrence of peach skin streaking and the role of rainwater attributes on symptom development. Plant Dis. 103:2606-2611.

Hu, M-J., S. D. Cosseboom, and G. Schnabel 2019. AtrB-Associated Fludioxonil Resistance in Botrytis fragariae Not Linked to Mutations in Transcription Factor Mrr1. Phytopathology 109:839-846.

Froelich, M. and G. Schnabel. 2019. Investigation of fungi causing twig blight diseases on peach trees in South Carolina. Plant Dis. 103:705-710.

Dowling, ME, Bridges, WC, Cox, BM, Sroka, T, Wilson, JR, and Schnabel, G. 2019. Preservation of Monilinia fructicola genotype diversity within fungal cankers. Plant Dis. 103:526-530.

Allran, J., G. Schnabel, and J. C. Melgar 2019. Peach bagging in the southeastern U.S., J. AM. POMOL. SOC. 73:38-46.

Cheng, S., G. Schnabel, H. Yuan, C. Luo 2019. LAMP detection of the genetic element ‘Mona’ associated with DMI resistance in Monilinia fructicola. Pest Manag. Sci., 75: 779-786.

Cosseboom, S. D., K. L. Ivors, G. Schnabel, P. K. Bryson, and G. J. Holmes 2019. Within-season shift in fungicide resistance profiles of Botrytis cinerea in California strawberry fields. Plant Dis. 103:59-64.


Professional Website
Schnabel lab program video
Schnabel lab smartphone app MyIPM