Univ of Stuttgart, Hohenheim 1997
Justus Liebig Univ Giessen 1993
Plant Disease Diagnostics and Management Summer Course
Dr. Guido Schnabel is a plant pathologist at Clemson University with over 20 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 basic research program focuses on molecular mechanisms of fungicide resistance in various plant pathogens and his applied research program involves the development of cultural control strategies for soil-borne diseases. His extension efforts include resistance monitoring services for strawberry and peach growers in over 10 states on the East coast, the implementation of decision support systems to minimize the number of spray applications, and the evaluation of fungicide efficacy and smart sprayer technology. He is the creator of MyIPM, a smartphone app for fruit growers that provides critical disease diagnostics and management information. He authored or co-authored over 80 peer-reviewed articles in premier scientific journals and multiple book chapters. Because of his efforts and documented impact on disease management in fruit production, he received the APS Lee Hutchins Award for Excellence in Tree Fruit Research in 2011, The APS Excellence in Extension Award in 2015, and the Clemson University Godley Snell Award for Excellence in Research.
Integrated management of diseases affecting peach and strawberry, including brown rot, Armillaria root rot, peach scab, Alternaria fruit rot, gray mold, Anthracnose, and other summer diseases. Current projects are: (i) Characterization, identification, and molecular basis of resistance to multiple fungicides in Monilinia fructicola, Alternaria alternata, Colletotrichum species, and Botrytis cinerea.
Extension and Outreach
Clemson University Extension Specialist, Diseases of Fruit Crops. Extension programs are focused on (i) educating commercial growers and county agents on the biology, epidemiology, and management of diseases of fruit crops via extension presentations, publications (newsletters, proceedings, bulletins, etc), on-farm visits, and my website (www.peachdoc.com) (ii) provide tools for effective disease management: Spray guides, Peach Growers Handbook; MyIPM Smartphone App for Peach and Strawberry Disease Management, Resistance Management, and Disease Diagnostics; (iii) precision brown rot management: generate location-specific fungicide resistance profiles using the ProfileRT monitoring kit to prevent crop loss due to fungicide resistance; educate producers region wide about emerging and existing fungicide resistance issues and how to deal with them (iv) provide up-to-date information 24/7 via www.peachdoc.com that is relevant for grower education, aids in disease identification and management, and supports our fungicide resistance monitoring program.
Hu, M. J., A. Grabke, and G. Schnabel 2015. Investigation of the Colletotichum species complex causing peach anthracnose in South Carolina. Plant Dis. 99:797-805.
Hu, M. J., A. Grabke, M. E. Dowling, H. Holstein, and G. Schnabel 2015. Resistance in Colletotrichum siamense from peach and blueberry to thiophanate-methyl and azoxystrobin. Plant Dis. 99:806-814.
Fernández-Ortuño, D., A. Grabke, X. Li and G. Schnabel 2014. Independent emergence of resistance to seven chemical classes of fungicides in Botrytis cinerea. Phytopathology 105:424-432.
Yang, J., P. Brannen, and G. Schnabel 2015. Resistance in Alternaria alternata to SDHI fungicides causes rare disease outbreak in peach orchards. Plant Dis. 99:65-70.
Chen, S. N., Y. Shang, Y. Wang, G. Schnabel, Y. Lin, L. F. Yin, and C. X. Luo 2014. Sensitivity of Monilinia fructicola from Peach Farms in China to Four Fungicides and Characterization of Isolates Resistant to Carbendazim and Azoxystrobin.
Plant Dis. 98:1555-1560.-80
Grabke, A., D. Fernández-Ortuño, A. Amiri, X. Li, N. Peres, P. Smith and G. Schnabel 2014. Characterization of iprodione resistance in Botrytis cinerea from strawberry and blackberry. Phytopathology. 104:396-402.
Li, X.P., Fernández-Ortuño, D., S. Chen, A. Grabke, C. X. Luo, W. C. Bridges, and G. Schnabel 2014. Location-specific fungicide resistance profiles and evidence for stepwise accumulation of resistance in Botrytis cinerea. Plant Dis. 98:1066-1074. EDITORS PICK, APS, September, 2014
Fernández-Ortuño, D., P. K. Bryson, G. Schnabel 2014. First report of Pilidium concavum causing tan-brown rot on strawberry nursery stock in South Carolina. Plant Dis. 98:1010.
Grabke, A., M. Williamson, G. W. Henderson, and G. Schnabel 2014. First report of anthracnose on peach fruit caused by Colletotrichum truncatum in South Carolina. Plant Dis. 98:1154.
Li, X.P., Fernández-Ortuño, D., Grabke, and G. Schnabel 2014. Resistance to fludioxonil in Botrytis cinerea isolates from blackberry and strawberry. Phytopathology. 104:724-732.
Fernández-Ortuño, D., A. Grabke, P. K. Bryson, E. D. Beasley, L. A. Fall, P. M. Brannen and G. Schnabel 2014. First report of fludioxonil resistance in Botrytis cinerea from a blackberry field in Georgia. Plant Dis. 98:848.
Fernández-Ortuño, D., A. Grabke, P. K. Bryson, A. Amiri, X. Li, N. Peres, and G. Schnabel 2014. Fungicide resistance profiles in Botrytis cinerea from strawberry fields of seven southern U.S. States. Plant Dis. 98:825-833.
Fernández-Ortuño, D., A. Grabke, P. K. Bryson, R. J. Rouse, P. Rollins and G. Schnabel 2014. First report of fludioxonil resistance in Botrytis cinerea, the causal organism of gray mold, from strawberry fields in Maryland and South Carolina. Plant Dis. 98:692.
Yin, L.F., Wang, F., Zhang, Y., Kuang, H., Schnabel, G., Li, G.Q., and Luo, C.X. 2014. Evolutionary analysis revealed the horizontal transfer of the Cyt b gene from fungi to chromista. Molecular Phylogenetics and Evolution. 76:155-161.
Yuan, N.N., S. N. Chen, L.X. Zhai, G. Schnabel, L.F. Yin, and C.X. Luo, 2013. Baseline sensitivity of Monilia yunnanensis to the DMI fungicides tebuconazole and triadimefon. Eur. J. Plant Pathol. 136:651-655. -70
Chen, F. P. X. L. Liu, and G. Schnabel 2013. Field strains of Monilinia fructicola resistant to both methyl benzimidazole carbamate and demethylase inhibitor fungicides isolates from stone fruit orchards in the eastern United States. Plant Dis. 97:1063-1068.
Fernández-Ortuño, D., P. K. Bryson, A. Grabke, and Schnabel, G. 2013. First report of fludioxonil resistance in Botrytis cinerea from a strawberry field in Virginia. Plant Dis. 97:846.
Chen, F. , X. Liu, S. Chen, E. Schnabel and G. Schnabel 2013. Characterization of Monilinia fructicola strains resistant to both propiconazole and boscalid. Plant Dis. 97:645-651.
Grabke, A., D. Fernández-Ortuño, and G. Schnabel 2013. Fenhexamid resistance in Botrytis cinerea from strawberry fields in the Carolinas is associated with four target gene mutations. Plant Dis. 97:271-276.
Fernández-Ortuño, D., Chen, F., and Schnabel, G. 2013. Resistance to cyprodinil and lack of fludioxonil resistance in Botrytis cinerea isolates from strawberry in North and South Carolina. Plant Dis. 97:81-85.
Chen, F. P., X. L. Liu, and G. Schnabel 2013. First report of brown rot caused by Monilinia fructicola of sweet cherry in Maryland. Plant Dis. 97:145.
Yin L-F., Hu M-J., Wang F., Kuang H., Zhang Y., Schnabel, G., Li, G.Q. 2012. Frequent Gain and Loss of Introns in Fungal Cytochrome b Genes. PLoS ONE 7: e49096. doi:10.1371/journal.pone.0049096.
Li, X.P., Fernández-Ortuño, D., W. Chai, F. Wang, and G. Schnabel 2012. Identification and Prevalence of Botrytis spp. from Blackberry and Strawberry fields of the Carolinas. Plant Dis. 96:1634-1637.
Fernández-Ortuño, D. and G. Schnabel 2012. First report of thiophanate-methyl resistance in Botrytis cinerea on strawberry from South Carolina. Plant Dis. 96:1700.
Fernández-Ortuño, D., and G. Schnabel 2012. Resistance to pyraclostrobin and boscalid in Botrytis cinerea isolates from strawberry fields in the Carolinas. Plant Dis. 96:1198-1203. -60
Li, X., J. Kerrigan, and G. Schnabel 2012. Botrytis caroliniana, a new species isolated from blackberry in South Carolina. Mycologia 104:650-658.
Schnabel, G., D. Fernández-Ortuño, W. C. Bridges, and S. B. Hudson 2012. Multiyear evaluation of an orange peel oil-based spray additive for managing insect pests and brown rot of nectarine. Plant Health Progress doi:10.1094/PHP-2012-0617-01-RS.
Fuxing, Z., P. K. Bryson, and G. Schnabel 2012. Influence of storage approaches on instability of propiconazole resistance in Monilinia fructicola. Pest Manag. Sci. 68:1003-1009.
Fernández-Ortuño, D., X. Li, F. Wang, and G. Schnabel 2012. First report of gray mold of strawberry caused by Botrytis caroliniana in North Carolina. Plant Dis. 96:914.
Williamson, M., D. Fernández-Ortuño, and G. Schnabel 2012. First report of Fusarium Wilt of strawberry caused by Fusarium oxysporum in South Carolina. Plant Dis. 96:911.
Amiri, A. and G. Schnabel 2012. Persistence of propiconazole in peach roots and efficacy of trunk infusions for Armillaria root rot control. Intern. J. Fruit Sci., 12:437-449.
Chen, F. P., J. R. Fan, T. Zhou, X. L. Liu, and G. Schnabel 2012. Baseline sensitivity of Monilinia fructicola from China to the DMI fungicide SYP-Z048 and analysis of DMI-resistant mutants. Plant Dis. 96:416-422.
Schnabel, G. P., Agudelo, G. W. Henderson, and P. A. Rollins. 2012. Above-ground root collar excavation of peach trees for Armillaria root rot management. Plant Dis. 96: 681-686.
Jaensch, M., J. E. Frey, M. Hilber-Bodmer, G. A. L. Broggini, J. Weger, G. Schnabel, and A. Patocchi 2012. SSR marker analysis of Monilinia fructicola from Swiss apricots suggests introduction of the pathogen from neighboring countries and the United States. Plant Pathology 61:247-254.
Amiri, A., W. Chai and G. Schnabel 2011. Effect of nutrient status, pH, temperature and water potential on germination and growth of Rhizopus stolonifer and Gilbertella persicaria J. Plant Pathol. 93:603-612.-50
Schnabel, G. P. A. Rollins, and G. W. Henderson. 2012. Field Evaluation of Trichoderma spp. for control of Armillaria root rot. Plant Health Progress. doi:10.1094/PHP-2011-1129-01-RS.
Fernández-Ortuño, D., X. Li, W. Chai, and G. Schnabel 2011. First report of gray mold of strawberry caused by Botrytis cinerea in South Carolina. Plant Dis. 95:1482.
Chen, F. P., X. L. Liu, X. P. Li, and G. Schnabel 2011. First report of iprodione resistance in Botrytis cinerea on blackberry from South Carolina. Plant Dis. 95:1481-1481.
Hu, M.J., K. D. Cox, G. Schnabel, and C. X. Luo 2011. Monilinia species causing brown rot of peach in China. PLOS ONE 6:e24990. doi:10.1371/journal.pone.0024990.
Hu, M. J., C. X. Luo, A. Grabke, and G. Schnabel 2011. Selection of a suitable medium to determine sensitivity of Monilinia fructicola mycelium to SDHI fungicides. J. Phytopathol. 159:616-620.
Kalariya, H. M., G. Schnabel, C. Petri, and R. Scorza 2011. Generation and characterization of transgenic plum lines expressing gafp-1 with the bul409 promoter. HortScience 46:975-980.
Grabke, A., M. J. Hu, C. X. Luo, P. K. Bryson, and G. Schnabel 2011. First Report of Brown Rot of Apple caused by Monilinia fructicola in Germany. Plant Dis. 95:772
Liu, X., Yu, F. Schnabel, G., Wu, J., Wang, Z. and Ma, Z. 2011. Paralogous cyp51 genes in Fusarium graminearum mediate differential sensitivity to sterol demethylation inhibitors. Fungal Genet. Biol., 48:113-123.
Luo, C. X., M. J. Hua, X. Jin, L. F. Yin, P.K. Bryson, and G. Schnabel 2010. An intron in the cytochrome b gene of Monilinia fructicola mitigates the risk of resistance development to QoI fungicides. Pest Manag. Sci., 66:1308-1315.
Zhu, F. X., A. Amiri, P. K. Bryson and G. Schnabel 2010. First report of the beta tubulin E198A allele for fungicide resistance in Monilinia fructicola from South Carolina. Plant Dis. 94:1511.-40
Schnabel, G., A. Amiri, and P. Brannen 2010. Sustainable brown rot management of peaches in the southeastern United States. Outlooks of Pest Management, 21:208-211.
Blaedow, K., K. Baumgartner, K. D. Cox, and G. Schnabel 2010. Natural infection of an herbaceous host by Armillaria: a case study on Hemerocallis. Can. J. Plant Pathol. 32:351-360.
Amiri, A., P. Brannen and G. Schnabel 2010. Reduced sensitivity in Monilinia fructicola field isolates from South Carolina and Georgia to respiration inhibitor fungicides. Plant Dis. 94:737-743.
Nagel, A. K., H. Kalariya, and G. Schnabel 2010. The Gastrodia antifungal protein (GAFP-1) and its transcripts are absent from scions of chimeric-grafted plum. HortScience 45:188-192.
Amiri, A., P. Brannen and G. Schnabel 2009.Validation of the Lipbalm Tube Assay for Evaluation of Fungicide Sensitivity in Field Isolates of Monilinia fructicola. Online. Plant Health Progress, doi: 10.1094/PHP-2009-1118-01-RS.
Nyczepir, A. P., A. K. Nagel, and G. Schnabel 2009. Host status of three transgenic plum lines to Mesocriconema xenoplax. HortScience 44:1932-1935.
Amiri, A., I. J. Holb and G. Schnabel 2009. A new selective medium for the recovery and enumeration of Monilinia fructicola, M. fructigena and M. laxa from stone fruit. Phytopathology 99:1199-1208.
Schnabel, G. and C. Crisosto 2008. Seasonal applications of a pyraclostrobin and boscalid mixture do not impact same-year peach fruit quality attributes. HortTechnology 18:678-684.
Amiri, A., Bussey, K. E., Riley, M. B., Schnabel, G. 2008. Propiconazole inhibits Armillaria tabescens in vitro and translocates into peach roots following trunk infusion. Plant Dis. 92:1293-1298.
Nagel, A.K., Schnabel, G., Petri, C. and Scorza, R. 2008. Generation and characterization of transgenic plum lines expressing the Gastrodia antifungal protein. HortScience 43:1514-1521.-30
Luo, C. X, Cox, K. D., Amiri, A. and Schnabel, G. 2008. Occurrence and detection of the DMI resistance-associated, genetic element 'Mona' in Monilinia fructicola. Plant Dis. 92:1099-1103. ---Plant Disease Editor’s pick from APS Journals Online---
Holb, I. J. and Schnabel, G. 2008. A detached fruit study on the post-inoculation activity of lime sulphur against brown rot of peach (Monilinia fructicola). Australasian Plant Pathology 37:454-459.
Amiri, A., Scherm, H., Brannen, P. M., and Schnabel, G. 2008. Laboratory evaluation of three rapid, agar-based assays to assess fungicide sensitivity in Monilinia fructicola. Plant Dis. 92:415-420. ---One of the most-read articles from APS Journals Online---
Holb, I. J. and Schnabel, G. 2008. The benefits of combining elemental sulfur with a DMI fungicide to control Monilinia fructicola isolates resistant to propiconazole. Pest Manag. Sci. 64:156-164.
Luo, C. X. and G. Schnabel 2008. Adaptation to fungicides in Monilinia fructicola isolates with different fungicide resistance phenotypes. Phytopathology 98:230-238.
Luo, C.X. and G. Schnabel 2008. The cytochrome P450 lanosterol 14-demethylase gene is a demethylation inhibitor fungicide resistance determinant in Monilinia fructicola field isolates from Georgia. Appl. Environ. Microbiol. 74:359-366.