Headhouse Unit 4 At Method 206, Box 7903NCSU CampusRaleigh, NC 27695Phone: 919.515.6984Fax: 919-513-1279
B.S., Colorado State University (1976)
M.S., (Plant Pathology), N. C. State University (1980)
Ph.D., (Plant Pathology), N. C. State University (1983)
Research and Extension
Dr. Shew conducts research and extension programs aimed at reducing damage caused by peanut diseases through the integrated use of host resistance, seed treatments, fungicides, disease advisories, and innovative cultural practices. She also is interested in developing disease control methods that are suitable for use in organic production of peanuts and in prevention of post-harvest diseases of sweetpotato.
Dr. Shew works closely with NCSU peanut breeder Dr. Tom Isleib to identify and characterize resistance to leaf spots, Sclerotinia blight, Cylindrocladium black rot, southern stem rot and other important diseases in advanced peanut breeding lines. We also work with Drs. Tom Stalker and Shyamlrau Tallury to identify useful sources of disease resistance in wild Arachis spp and in wild species-derived lines.
Disease advisories are widely used in North Carolina for timely application of fungicides for peanut disease control. In collaboration with the State Climate Office (SCO) of North Carolina, disease advisories are issued daily to peanut growers throughout the growing season. Dr. Shew also has been investigating methods for adjusting advisories to account for differences in host resistance, and collaborating with the SCO to develop methodologies to improve the quality and delivery of disease advisories.
Virtually all peanut seeds in conventional production are treated with seed treatment fungicides. Stand establishment and seedling diseases have emerged as major impediments to organic production of peanuts. Several biological agents and cultural methods are under investigation for use in organic production systems. Similarly, Rhizopus rot of sweetpotato is of particular concern for the organic and baby food markets, where fungicide use is not acceptable. We are investigating methods to optimize Rhizopus control by use of biological control agents.
Many annual weeds commonly found in peanut fields during winter fallow are hosts of Sclerotinia minor, causal agent of Sclerotinia blight. It is possible that fungal populations are maintained on these weeds in the absence of a cultivated host. In addition to harboring peanut pathogens, weed hosts may help to maintain diverse field populations of S. minor. We have conducted extensive studies to characterize weed hosts and population diversity of S. minor in peanut production areas.
Plant Disease and Insect Clinic
Dr. Shew serves as director of the Plant Disease and Insect Clinic (PDIC) at North Carolina State University. She supervises the diagnostic staff of two plant pathologists and one entomologist, administers the PDIC budget, and acts as the NC State lead PI in the Southern Plant Diagnostic Network.
Dr. Shew co-teaches PP 506, Epidemiology and Disease Control with Drs. Mike Benson (coordinator; cultural practices, biocontrol) and Turner Sutton (fungicides). Dr. Shew teaches the introductory epidemiology section and sections on host resistance and disease forecasting.