• UD Search
Agriculture & Natural Resources

Nathan Kleczewski Ph.D. – Extension Plant Pathologist

Education and Professional Experience

  • 2013-Current.  Extension Plant Pathologist. University of Delaware, Department of Plant and Soil Science
  • 2012-2013: FMC-GIO Research Plant Pathologist
  • 2010-2012: Post Doctoral Researcher, Purdue University, Department of Botany and Plant Pathology
  • 2009-2010: Post Doctoral Researcher, Indiana University, Department of Biology
  • 2009: Ph.D. Plant Pathology, The Ohio State University.
  • 2004: B.S. Plant Ecology and Organismal Biology, The University of Wisconsin-Oshkosh (Summa Cum Laude)


Duties:  Statewide applied research and extension responsibilities for disease management of field crops

My duty as an extension plant pathologist is to identify and address disease management issues in agronomic crops through applied research and extension.  My applied research program evaluates management strategies as components of the integrated disease management of corn, soybeans, wheat, and barley.  In addition, my program strives to prevent outbreaks of new diseases by working closely with other extension specialists, extension agents, consultants, and growers to evaluate emerging disease issues throughout the region.

Results of my work are shared with regional stakeholders and are presented in peer-reviewed scientific journals, extension publications, conferences, and professional meetings.  Educational programs are aimed at increasing awareness, knowledge, and expertise in plant pathology of certified crop advisers, producers, and other stakeholders.  I also mentor and advise graduate students interested in advanced degrees in applied plant pathology.

Current and ongoing applied research in my lab:

  • Best management practices for Fusarium Head Blight of wheat and barley
  • Assessment of soybean cyst nematode resistance in regional soybean cultivars
  • Fungicide efficacy and economics in small grains, corn, and soybean
  • Seed and in furrow treatment for suppression of nematodes and soil borne-pathogens in field crops
  • Epidemiology of Soybean Vein Necrosis Disease

Selected Publications (Peer Reviewed)

Manamgoda, D.S., A. Minnis, N.M. Kleczewski, S.L. Flory, L.A. Castlebury, and K.D. Hyde. 2013. Bipolaris drechsleri sp. nov. Fungal Planet Description Sheets 213:26.

Minnis A., A.Y. Rossman, N.M. Kleczewski and S.L. Flory. 2012.  Bipolaris microstegii sp. nov. Fungal Planet Description Sheets 129: 151.

Bauer J. T., N. M. Kleczewski, J. D. Bever, K. Clay and H. L. Reynolds. 2012. Nitrogen-fixing bacteria, arbuscular mycorrhizal fungi and the productivity and structure of prairie grassland communities. Oecologia 170(4) 1089-1098.

Kleczewski N.M., S. L. Flory and K. Clay. 2012. Variation in pathogenicity and host range of Bipolaris sp. causing leaf blight disease on the invasive grass Microstegium vimineum. Weed Science 60(3):486-493.

Kleczewski N. M., J. T. Bauer, J. D. Bever, K. Clay and H. L. Reynolds. 2012. A survey of endophytic fungi of switchgrass (Panicum virgatum) in the Midwest, and their putative roles in plant growth. Fungal Ecology 5(5):521-529.

Kleczewski N.M., D.A.Herms and P. Bonello. 2012. Nutrient and water availability alter belowground patterns of biomass allocation, carbon partitioning, and ectomycorrhizal abundance in Betula nigra. Trees: Structure and Function 26(2) 525-533.

Kleczewski N. M. and D. S. Egel, 2011. A diagnostic guide for Fusarium wilt of watermelon. Online. Plant Health Progress. doi:10.1094/PHP-2011-1129-01-DG.

Flory, S.L., N.M. Kleczewski, and K. Clay. 2011. Ecological consequences of pathogen accumulation on an invasive grass. Ecosphere 2(10):12 pp.

Kleczewski N. M. and S. L. Flory. 2010. A new leaf blight disease on the invasive grass Microstegium vimineum caused by a Bipolaris sp. Plant Disease 94(7): 807-811.

Kleczewski N. M., D.A.Herms, and P. Bonello. 2010. Effects of soil type, fertilization and drought on carbon allocation to root growth and partitioning between secondary metabolism and ectomycorrhizae of Betula papyrifera. Tree Physiology 30(7):807-817.