Research

Research conducted in my lab is focused on the ecology and epidemiology of soilborne fungal pathogens. Our goal is to enhance short- and long-term disease management strategies based on improved understanding of the biology and ecology of soilborne pathogens. Specific investigations have emphasized: i) the effects of soil physical and chemical properties on fungal population dynamics and suppression of disease; ii) characterization of host resistance mechanisms to root pathogens and quantification of their effects on pathogen population dynamics and disease development; and iii) characterization of pathogen populations, including comparisons of populations from natural- and agro-ecosystems. We have worked in multiple host-pathogen systems to accomplish our goals, and outlines of current research projects can be viewed from the links below.

Teaching

I currently teach one of our Department’s undergraduate classes, PP 315, Principles of Plant Pathology. The course is offered each fall semester on campus and as a Distance Ed course in both fall and spring via the internet. The course provides students with an overview of plant pathogens, disease development, and disease management, while providing an opportunity for hands-on experience in working with organisms that cause plant diseases. It also offers undergraduates the opportunity to complete honors work outside of normal class requirements. Typical students in the class range from sophomores to graduate students with a very diverse set of backgrounds and interests.

Selected Publications

• McCorkle, K. Lewis, R., and Shew, D. 2013. Resistance to Phytophthora nicotianae in tobacco breeding lines derived from Beinhart 1000. Plant Dis. 97:252-258.
• Cheng, Lei, Booker, F. L., Tu, C., Burkey, K. O., Zhou, L., Shew, H. D., Rufty, T. W., and Hu, S. 2012. Arbuscular Mycorrhizal Fungi Increase Organic Carbon Decomposition Under Elevated CO_2. Science 337: 1084-1087.
 http://news.ncsu.edu/releases/mkhusoil/
• Taylor, R. J., Pasche, J. S., Shew, H. D., Lannon, K. R., and Gudmestad, N. C. 2012. Tuber rot of potato caused by Phytophthora nicotianae: Isolate aggressiveness and cultivar susceptibility. Plant Dis. 96:693-704.
• Abad, Z.G., Ivors, K.L., Gallup, C.A., Abad, J.A., and Shew, H.D. 2011. Morphological and molecular characterization of Phytophthora glovera sp. nov. from tobacco in Brazil. Mycologia 103:341-350.
• Cheng L, Booker FL, Burkey KO, Tu C, Shew HD, Rufty, T., Fiscus, EL, Deforest, JL, Hu, S. 2011. Soil Microbial Responses to Elevated CO2 and O3 in a Nitrogen-Aggrading Agroecosystem. PLoS ONE 6(6): e21377. doi:10.1371/journal.pone.0021377
• Nifong, J. M., Nicholson, J. S., Shew, H. D., and Lewis, R. S. 2011. Variability for resistance to Phytophthora nicotianae within a collection of Nicotiana rustica accessions. Plant Dis. 95:1443-1447.
• Sullivan, M. J., Parks, E. J., Cubeta, M. A., Gallup, C. A., Melton, T. A., Moyer, J.W., and Shew, H.D. 2010. An assessment of the genetic diversity in a field population of Phytophthora nicotianae with a changing race structure. Plant Dis. 94:(455-460).
• Gallup, C. A. and Shew, H. D. 2010. Occurrence of race 3 of Phytophthora nicotianae in  North Carolina, the causal agent of black shank of tobacco. Plant Dis. 94:(557-562).
• Gregg, J.P., Peacock, C.H., Shew, H.D., Tredway, L.P., and Miller, G.L.. 2010. Herbicide and nutrient effects on the development of gray leaf spot caused by Pyricularia grisea on tall fescue (Festuca arundinacea). Proc. 2nd European Turfgrass Soc. p. 83-84.
• Kerns, J.P., Shew, H.D., Benson, D.M., and Tredway, L.P. 2009. Impact of irrigation frequency, organic matter content and creeping bentgrass cultivar on the development of Pythium root dysfunction. Intern. Turfgrass Soc. Res. Jour. 11:227-239.
• Taylor, R. J., Pasche, J. S., Gallup, C. A., Shew, H. D., Gudmestad, N. C. 2008. A foliar blight and tuber rot of potato caused by Phytophthora nicotianae: New occurrences and characterization of isolates. Plant Dis. 92: 492-503.
• Elliott, P.E., Lewis, R.S., Shew, H.D, Gutierrez, W.A. and Nicholson, J.S. 2008. Evaluation of tobacco germplasm for seedling resistance to stem rot and target spot caused by Thanatephorus cucumeris. Plant Dis. 92:425-430.
• Dong, S., Shew, H. D., Tredway, L. P., Lu, J., Sivamani, E., Miller, E. S., and Qu, R. 2008. Expression of the bacteriophage T4 lysozyme gene in tall fescue confers resistance to gray leaf spot and brown patch diseases. Trangenic Res. 17:47-57.
• Shew, H. D., Fichtner, E. J., and Benson, D. M. 2007. Aluminum and plant disease. Pages 247-264, in: Mineral Nutrition and Plant Disease. L. E. Datnoff, W. H. Elmer, and D. M. Huber, eds. APS Press, The American Phytopathological Society, St.Paul. 278 pp.
• Dong, S., Tredway, L. P., Shew, H. D., Wang, G-L., Sivamani, E., and Qu, R. 2007. Resistance of transgenic tall fescue to two major fungal diseases. Plant Sci. 173:501-509.
• Ceresini, P. C., Shew, H. D., James, T. Y., Vilgalys, R. J., and Cubeta, M. C. 2007. Phylogeography of the Solanaceae-infecting Basidiomycota fungus Rhizoctonia solani AG-3 based on sequence analysis of two nuclear DNA loci. BMC Evolutionary Biology 7:163. doi:10.1186/1471-2148-7-163.
• Fichtner, E. J., Hesterberg, D. L., Smyth, T. J., and Shew, H. D. 2006. Differential sensitivity of Phytophthora parasitica var. nicotianae and Thielaviopsis basicola to monomeric aluminum species. Phytopathology 96:212-220.
• Gallup, C.A., M. J. Sullivan, and H. D. Shew. 2006. Black Shank of Tobacco. The Plant Health Instructor. DOI: 10.1094/PHI-I-2006-0717-01. APS web site: http://www.apsnet.org/education/LessonsPlantPath/blackShank/default.htm.
• Sullivan, M. J., Melton, T. A., and Shew, H. D. 2005. Fitness of races 0 and 1 of Phytophthora parasitica var. nicotianae. Plant Dis. 89:1220-1228.
• Sullivan, M. J., Melton, T. A., and Shew, H. D. 2005. Managing the race structure of Phytophthora parasitica var. nicotianae with cultivar rotation. Plant Dis. 89:1285-1294.
• Fichtner, E.J., Benson, D.M., Diab, H.G., and Shew. H.D. 2004. Abiotic and biological suppression of Phytopththora parasitica in a horticultural medium containing composted swine waste. Phytopathology 94:780-788.
• Uriarte, R.F., Shew, H.D., and Bowman, D.C. 2004. Effect of soluble silica on brown patch and dollar spot of creeping bentgrass. J. Plant Nutr. 27:325-339.
• Ceresini, P.C., Shew, H.D. Vilgalys, R., Rosewich-Gale, U. L., and Cubeta, M.A. 2003. Detecting migrants in populations of Rhizoctonia solani anastomosis group 3 from potato in North Carolina using multilocus genotype probabilities. Phytopathology 93:610-615.
• Johnson, E. S., Wolff, M. F., Wernsman, E. A., Atchley, W. R., and Shew, H. D. 2002. Origin of the black shank resistance gene, Ph, in tobacco cultivar Coker 371-Gold. Plant Dis. 86:1080-1084.
• Ceresini, P. C., Shew, H. D., Vilgalys, R. J. and Cubeta, M. A. 2002. Genetic diversity of Rhizoctonia solani AG-3 from potato and tobacco in North Carolina. Mycologia 94:437-449.
• Ceresini, P. C., Shew, H. D., Vilgalys, R. J., Rosewich, U. L., and Cubeta, M. A. 2002. Genetic structure of populations of Rhizoctonia solani AG-3 on potato in eastern North Carolina. Mycologia 94:450-460.
• Fichtner, E. J., Hesterberg, D. L., and Shew, H. D. 2001. Nonphytotoxic aluminum-peat complexes suppress Phytophthora parasitica. Phytopathology 91:1092-1097.
• Shew, H. D. 2001. Direct penetration. Pages 311-312. in: Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley and Sons, Inc. New York. Vol. 1. 598 pp.
• Shew, H. D. 2001. Indirect penetration. Page 571. in: Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley and Sons, Inc. New York. Vol. 1. 598 pp.
• Shew, H. D. 2001. Infection. Pages 572-574. in: Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley and Sons, Inc. New York. Vol. 1. 598 pp.
• Shew, H. D. 2001. Infection courts. Pages 574-575. in: Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley and Sons, Inc. New York. Vol. 1. 598 pp.
• Shew, H. D. 2001. Penetration. Pages 747-748. in: Encyclopedia of Plant Pathology. O. C. Maloy and T. D. Murray, eds. John Wiley and Sons, Inc. New York. Vol. 2. 769 pp.
• Harrison, U. J., and Shew, H. D. 2001. Effects of soil pH and nitrogen fertility on the population dynamics of Thielaviopsis basicola. Plant Soil 228(2):147-155.
• Hudyncia,J., Shew, H. D., Cody, B. R., and Cubeta, M. A. 2000. Evaluation of wounds as predisposing factors to infection of cabbage by Sclerotinia sclerotiorum. Plant Dis. 84:316-320.
• Gutierrez, W. A., and Shew, H. D. 2000. Factors that affect development of Sclerotinia collar rot on tobacco seedlings grown in greenhouses. Plant Dis. 84:1076-1080.
• Shoemaker, P. B. and Shew, H. D. 1999. Major tobacco diseases: Fungal and bacterial diseases. Pages 183-197, in: Tobacco: Production, chemistry and technology. D. L. Davis and M. T. Nielsen, eds. Blackwell Science, Oxford.
• Gutierrez, W. A., and Shew, H. D. 1998. Identification and quantification of ascospores as the primary inoculum for the collar rot disease of greenhouse-produced tobacco seedlings. Plant Dis. 82:485-490.
• Hood, M. E., and Shew, H. D. 1997. Initial cellular interactions between Thielaviopsis basicola and tobacco root hairs. Phytopathology 87:228-235.
• Hood, M. E. and Shew, H. D. 1997. The role of parasitism in the ecology of Thielaviopsis basicola. Phytopathology 87:1214-1219.
• Hood, M. E., and Shew, H. D. 1997. The influence of nutrients on development, resting hyphae and aleuriospore induction of Thielaviopsis basicola. Mycologia 89:793-800.
• Gutierrez, W. A., and Shew, H. D. 1997. Sources of inoculum and management of diseases of greenhouse-produced tobacco seedlings. Plant Dis. 81:604-606.
• Carlson, S. R., Wolff, M. F., Shew, H. D., and Wernsman, E. A. 1997. Inheritance of resistance to race 0 of Phytophthora parasitica var. nicotianae from the flue-cured tobacco cultivar ‘Coker 371-Gold’. Plant Dis. 81:1269-1274.
• Hood, M. E., and Shew, H. D. 1996. Pathogenesis of Thielaviospsis basicola on a susceptible and a resistant cultivar of burley tobacco. Phytopathology 86:38-44.
• Hood, M. E., and Shew, H. D. 1996. Applications of KOH-aniline blue fluorescence in the study of plant-fungal interactions. Phytopathology 86:704-708.
• Abad, G., Shew, H. D., Grand, L. F., and Lucas, L. T. 1995. A new species of Pythium producing multiple oospores isolated from bentgrass in North Carolina. Mycologia 87:896-901.
• Jones, K. J. and Shew, H. D. 1995. Early season root production and zoospore infection of cultivars of flue-cured tobacco that differ in level of partial resistance to Phytophthora parasitica var. nicotianae. Plant and Soil 119:55-61.
• Shew, H. D. and Melton, T. A. 1995. Target spot of tobacco. Plant Dis. 79:6-11.
• Wilkinson, C. A., Shew, H. D., and Rufty, R. C. 1995. Evaluation of components of partial resistance to black root rot in burley tobacco. Plant Dis. 79:738-741.
• Abad, Z. G., Shew, H. D. and Lucas, L. T. 1994. Characterization and pathogenicity of Pythium species isolated from turfgrass with symptoms of root and crown rot in North Carolina. Phytopathology 84:913-921.
• Meyer, J. R., Shew, H. D., and Harrison, U. J. 1994. Inhibition of germination and growth of Thielaviopsis basicola by aluminum. Phytopathology 84:598-602.
• Shew, H. D., and Shew, B. B. 1994. Host Resistance. Pages 244-275 in: Epidemiology and management of root diseases. C. L. Campbell and D. M. Benson, eds. Springer-Verlag, Heidelberg, 344 pp.
• Shew, H. D. and Shoemaker, P. B. 1993. Effects of host resistance and soil fumigation on populations of Thielaviopsis basicola and development of black root rot on burley tobacco. Plant Dis. 77:1035-1039.
• Johnk, J. S., Jones, R. K., Shew, H. D., and Carling, D. E. 1993. Characterization of populations of Rhizoctonia solani AG-3 from potato and tobacco. Phytopathology 83:854-858.
• Shew, H. D., and Lucas, G. B. 1991. Compendium of Tobacco Diseases. APS Press, St. Paul. 90 pp.
• Meyer, J. R., and Shew, H. D. 1991. Soils suppressive to black root rot of burley tobacco, caused by Thielaviopsis basicola. Phytopathology 81:946-954.
• Meyer, J. R., and Shew, H. D. 1991. Development of black root rot on burley tobacco in relation to pathogen population, host resistance and soil chemistry. Plant Dis. 75:601-605.
• Shew, H. D., and Main, C. E. 1990. Infection and development of target spot of flue-cured tobacco caused by Thanatephorus cucumeris. Plant Dis. 74:1009-1013.
• Meyer, J. R., Shew, H. D., and Shoemaker, P. B. 1989. Populations of Thielaviopsis basicola and the occurrence of black root rot on burley tobacco in western North Carolina. Plant Dis. 73:239-242.
• Shew, H. D. 1987. Effect of host resistance on spread of Phytophthora parasitica var. nicotianae and the subsequent development of tobacco black shank under field conditions. Phytopathology 77:1090-1093.