Kenneth Deahl

Research Plant Pathologist

Late blight, caused by Phytophthora infestans, is a fungal disease that has a devastating effect on potatoes and tomatoes. An outbreak of late blight in Europe in 1845 led to the great famine in Ireland that cost the lives of a half million people. In response to the detection of a new, more virulent population of this disease agent, Dr. Deahl studies the biology of Phytophthora infestans, occurrence and inheritance of fungicide resistance in potato late blight populations, classical and molecular genetics of Phytophthora infestans, pathosystems of tomato and potato late blight, glycoalkaloids and other naturally occurring toxins as resistance factors in plant pathogen and insect interactions.

Learn more about potatoes here.

Learn more about late blight here.

Above: Infected potato leaf, photo by Dr. Deahl. Right: Dr. Deahl inspecting a diseased potato tuber, image courtesy ARS Image Gallery.

Research Projects

Project Number: 1275-21000-142-00

Genetic Enhancement Of Quality Constituents And Disease Resistance In Solanaceous Vegetables

Project Number: 1275-21000-142-06

Evaluation Of Lycopersicon pimpinellifolium Accessions For Early Blight Resistance

E-mail
deahlk@ba.ars.usda.gov

Other information

Education

Post-Graduate Employment

Professional Societies

Advisory Appointments

Education

A.B., in Biology and General Science, Fairmont State College
M.S., in Plant Pathology, Agri. Microbiology, West Virginia University
Ph.D., in Plant Pathology and Plant Physiology, West Virginia University

Post-graduate Employment

1971- present .Research Plant Pathology, USDA:ARS : Potato Investigations/Vegetable Laboratory, Beltsville, Maryland

Professional Societies

Member, American Mushroom Institute
Member, American Society for Microbiology
American Phytopathological Society: Member, including Potomac Division; President, Potomac Division, 1993-1994.
Member, Mycological Society of America
Member, Potato Association of America
Member, Society of Industrial Microbiology
Fellow, Washington Academy of Sciences

Advisory Appointments

U.S. representative and member of Executive Board, PICTIPAPA -International Late Blight Cooperative Project .
U.S. representative for potato disease research on AID-funded, IPM initiative with scientist from central and eastern Europe.
Member of Board of Managers, Washington Academy of Science.
ADODR on eight potato projects with investigators in the United States. 1993-present.

Honors and Awards

Biographical report on Dr. Deahl's research "Blight Fighter" appeared as a Featured Article in The Furrow, April 2003.
Hot Potatoes, a new documentary featuring Dr. Deahl's research was shown on PBS and affiliated TV stations in Washington, Virginia and Maryland areas and nationally. July-August 2002. On July 22, 2002, the National Press Club awarded one of its 2002 prizes to Hot Potatoes, making it one of only six broadcast entries so honored.
Outstanding Paper of the Year Award, from the Potato association of America, 2000.
Recipient of the Syngenta trust fund award to study pink rot disease of potato.
Recipient of the 1999 Distinguished Service Award from The Potomac Division of the American Phytopathological Society.
Beltsville Area Fellowship Award winner, April, 1999.
Awarded a CIBA-Geigy Trust Fund for developing tests and monitoring fungicide insensitivity.
Co-recipient of a research grant ($25,000/year for three years) from the Irish government to study late blight in Mexico with Dr. Antonio Rivera Pená of the Metapec Research Center.
Awarded ARS Administrator’s Postdoctoral associateship 1995.
USDA Certificates of Merit, 1994(1), 1995(3).

Publications

1999-present

More information on these journal articles can be found using AGRICOLA at the National Agriculture Library web site. Many abstracts of the articles are online.

Dorrance, A. E., Inglis, D. A., Derie, M. L., Brown, C. R., Goodwin, S. B., Fry, W. E., and Deahl, K. L. Characterization of Phytophthora infestans in western Washington. Plant Dis. 83:423 428. 1999.

Kowalski, S. P., Domek, J. M., Deahl, K. L., and Sanford, L. L. Performance of Colorado potato beetle larvae, Leptinotarsa decemlineata

Deahl, K. L. and Jones, R. The Occurrence of Late Blight in North America, Global Initiative on Late Blight. Late Blight: A Threat to Global Food Security. 1:15 18. 1999.

Cooke, L. R. and Deahl, K. L. Potato Blight Global change and new problems ñ the appearance of new genotypes of Phytophthora infestans in Europe and North America is raising new problems for late blight control. Pesticide Outlook. 9:22 28. 1999.

Baker, C. J., Orlandi, E. W., and Deahl, K. L. Oxygen metabolism in plant/bacteria interactions: characterization of the oxygen uptake response of plant suspension cells. Physiological and Molecular Plant Pathology. 57:159 167. 2000.

Baker, C. J., Deahl, K. L., Domek, J., and Orlandi, E. W. Scavenging of H2O2 and production of oxygen by horseradish peroxidase. Arch Biochem. Biophys. 382:232 7. 2000.

Kowalski, S. P., Perez, F. G., Sanford, L. L., and Deahl, K. L. Partial preparative purification and leptine I from foliage of wild potato, Solanum chacoense (Bitt.) Prep. Biochem. Biotechnol. 30:133 144. 2000.

Kowalski, S. P., Domek, J. M., Sanford, L. L., and Deahl, K. L. Effect of ± -Tomatine and Tomatidine on the Growth and Development of the Colorado potato Beetle (Coleoptera: Chrysomelidae): Studies Using Synthetic Diets. J. Entomol. Sci. 35:290-300. 2000.

Hollister, B., Dickens, J. C., Perez, F. G., and Deahl, K. L. Differential Neurosensory Responses of Adult Colorado potato beetle, Leptinotarsa decemlineata, to glycoalkaloids. Journal of Chemical Ecology. 27:1105 1116. 2001.

Baker, C. J., Orlandi, E. W., and Deahl, K. L. Oxidative Metabolism in Plant/Bacterianteractions: Characterization of a Unique Oxygen Uptake Response of Potato Suspension Cells. Physiological and Molecular Plant Pathology. 59:25-32. 2001.

Baker, C. J., Mock, N. Deahl, K. L. Bailey, B., and Roberts, D. P. Oxidative Metabolism in Plant/Bacteria Interactions: Characterization of the Oxygen Uptake Response of Bacteria. Physiological and Molecular Plant Pathology. 59:17-23. 2001.

Cooke, L. R., Carlisle, D. J., Wilson, D. G., and Deahl, K. L. Natural occurrence of Phytophthora infestans on woody nightshade (Solanum dulcamara) in Ireland. New Disease Reports 85(4): 1 2. 2002. (on line) - Plant Pathology. 51:393-394. 2002.

Deahl, K. L., Cooke, L. R., Black, L. L., Wang, T. C., Perez, F. G., Moravec, B. C., Quinn, M., and Jones, R. W. Population changes in Phytophthora infestans in Taiwan associated with the appearance of resistance to metalaxyl. Pest Manag Sci. 58:1-8. 2002.

Deahl, K., Pagani, L., Vilaro, M.C., Perez, F.G., Moravec, B., Cooke, L.R. 2002. Characteristics of Phytophthora infestans isolates from Uraguay. European Journal of Plant Pathology. 109: 277-281.

Baker, C.J., O'Neill, N.R., Deahl, K., Lydon, J. 2002. Continuous production of extracellular antioxidants in suspension cells attenuates the oxidative burst detected in plant microbe interactions. Plant Physiology and Biochemistry. 40: 641-644.

Fisher, D.G., Deahl, K.L. and Rainforth, M.V. 2002. Horizontal resistance in Solanum tuberosum to Colorado potato beetle (Leptinotarsa decemlineata Say). Am. Journal of Potato Research. 79: 281-295.

Wattier, R.A.M., L.L. Gathercole, S.J. Assinder, C.J. Gliddon, K.L. Deahl, D.S. Shaw, and D.I. Mills. 2003. Sequence variation of intergenic mitochondrial DNA spacers (mtDNA-IGS) of Phytophthora infestans (Oomycetes) and related species. Molecular Ecology Notes. 3: 136-138.

Presentations

Reviewed N.I. Vanilov Institute of Plant Industry, St. Petersburg, Russia. July 18-20, 1998.

Presented symposium paper "The occurrence of Late Blight in North America" at the Global Initiative on Late Blight (GILB). Quito, Ecuador. March 16-19, 1999.

Baker, C. J., N. O’Neill and K. Deahl. 2000. Production of extracellular phenolic antioxidants provides a buffer against low-level buildup of ROS in plants. 8^th Annual Oxygen Society Meeting. San Diego, CA.

Invited paper "Recent population of late blight in North America" at the Late Blight Mini-Symposium at the Potato Association of America Meeting in St. Augustine, Florida. April 2001. Sponsored by GILB.

Invited to visit Taiwan to work with pathologists and quarantine officials on efforts to control emerging late blight problems in tomato and potato. Pending.

Collaborators

Greg Forges, CIP, Quito, Ecuador; Late blight on non-Solanum hosts in South America

William Fry, Cornell University, Ithaca, NY; Biology of Phytophthora infestans

Richard Jones, USDA, ARS, VL, Beltsville, MD; Pathosystems of tomato and potato late blight

Juan Landeo, CIP, Lima Peru; Stable resistance in potato hosts

Hector Lozoya, PICTIPAPA, Metepec, Mexico; Testing for late blight resistance in wild potato hosts

Maria Cristina Pagani, INIA, Canelones, Uruguay; Novel late blight genotypes in Uruguay

Jean Ristaino, North Carolina State University, Raleigh, NC; Novel genotypes of P. infestans

David Shaw, University of Wales, Bangor, UK; Sexual cycle in Phytophthora infestans

C. Jacyn Baker, USDA, ARS, MPPL, Beltsville, MD; Oxygen metabolism in potato/bacteria

Robert Young, West Virginia University, Morgantown, WV; Expression of late blight resistance in transgenic potato clones

Mary Hooker, University of Massachusetts, Cambridge, MA; Acetylcholinesterase inhibition by potato glycoalkaloids

Frank Turano, George Washington University, Washington, DC; Characterization of oxygen uptake responses in potato suspension cultures

W. Belknaps, USDA, ARS, PW, Albany, NY; Transgenic potato with novel resistance genes

John Bamburg, USDA, ARS, MWA, Madison, WI; Potato glycoalkaloid in breeding and wild species

David Levy, The Volcani Center, Israel; Potato glucoalkaloids as resistance factors

Lowell Black, AVRDC, Shanhua, Taiwan; Occurrence of late blight in tomatoes in Taiwan

Ray Knake, Gustafson LLC, Urbandale, IA; Late blight control in tubers

Robert McMillan, University of Florida, IFAS, Homestead, FL; Field expression of late blight resistances

Paul Shoemaker, North Carolina State University, Fletcher, NC; Tomato late blight

Marc Cubeta, North Carolina State Unievrsity, Plymouth, NC; Occurrence of late blight in southern area

Dallice Mills, Oregon State University, Corvallis, OR PCR-based haplotyping of late blight populations

Antonio Rivera Pena, Edo. de Mexico, Mexico; Occurrence of late blight in wild species

H. W. (Bud) Platt, Agiculture and Agri-Food Canada Chalottetown, Canada; Occurrence and characterization of late blight in Canada

Gary Secor, North Dakota State University, Fargo, ND; Pink rot control in tubers

Ward Tingey, Cornell University, Ithaca, NY; Potato glycoalkaloids and insect resistance

David Weingartner, Hastings, Univeristy of Florida, Hastings, FL; Occurrence of the A2 mating strains of P. infestans

G. Craig Yencho, North Carolina State University, Plymouth, NC; Genetics of potato glycoalkaloids

Louise Cooke, Dept. Agriculture of Northern Ireland, Belfast, UK; Occurrence and inheritance of fungicide resistance

Jim Duncan, Scottish Crop Research Institute, Dundee, UK; Biology of Phytophthora

Francisco Flores, PRECODEPA, Toluca Mexica, Mexico; Breeding for late blight resistance using wild species

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