Disease and Pest Management Practices for Field Crops in Low-Rainfall Regions

Eyespot (strawbreaker footrot) causing extreme lodging

Eyespot (strawbreaker footrot) can cause extreme lodging

stripes on wheat leaves caused by Cephalosporium stripe

Cephalosporium stripe in wheat

root rot disease complex in chickpea

Root rot complex in chickpea

take-all can severely stunt wheat plants

Plants stunted by take-all (on left)

On left, untreated seed suffered severely reduced spring wheat emergence

Pythium damping-off suppressed

by seed treatment on right

hessian fly

Hessian fly adult

Rhizoctonia root rot in wheat

Rhizoctonia patches in wheat

Symptoms of physiologic leaf spot are very similar to those caused by Septoria diseases and tan spot

Physiologic leaf spot on winter wheat

Strong interest exists for improving farm profitability by reducing input costs and increasing cropping intensity. This often takes the form of annual cereal production without primary tillage. Root diseases are common in these production systems. Emphasis is on management practices that minimize economic risk from root diseases. Such practices include seed treatment, fertilizer placement, timing of planting, resistant varieties, weed management during non-crop periods, selection of the style of seed drill, and others. Pests such as Hessian fly occasionally infest wheat in experiments designed to examine disease management practices; in such cases our team also quantifies damage by the insect pests. Collaborators include multi-disciplinary teams of scientists in Washington, Idaho and Oregon. Representative papers include the following. Also see separate sections on Rhizoctonia root rot, seed treatment, root-lesion nematode, cereal cyst nematode, physiologic leaf spot, and agricultural sustainability


  • Smiley, R.W., S. Machado, J.A. Gourlie, L.C. Pritchett, G.P. Yan, and E.E. Jacobsen. 2013. Influence of semi-arid cropping systems on root diseases and inoculum density of soilborne pathogens. Plant Disease 97:(in press). (abstract) (extension version)
  • Smiley, R.W., S. Machado, J.A. Gourlie, L.C. Pritchett, G.P. Yan, and E.E. Jacobsen. 2013. Effects of crop rotation and tillage on Pratylenchus species in the semi-arid Pacific Northwest. Plant Disease 97:(in press). (abstract)  (extension version)
  • Sullivan, L.S., F.L. Young, R.W. Smiley, and J.R. Alldredge. 2013. Pest management in no-till facultative wheat in the Pacific Northwest, USA. Crop Protection 44:(in press).
  • Smiley, R.W., D. Backhouse, P. Lucas, and T.C. Paulitz. 2009. Diseases which challenge global wheat production - root, crown, and culm rots. . p. 125-153 in Wheat Science and Trade. B.F. Carver (ed.). Wiley-Blackwell, Ames, IA. (personal draft version) 
  • Smiley, R.W., R.G. Whittaker, J.A. Gourlie, and S.A. Easley. 2006. Geocenamus brevidens reduces yield of no-till annual spring wheat in Oregon. Plant Disease 90:885-890. (abstract)
  • Patterson, L-M., R.W. Smiley, and S.A. Alderman. 1998. Effect of seed treatment fungicides and starter fertilizer on root diseases and yield of spring wheat. Fungicide and Nematicide Tests 53:425.
  • Smiley, R.W., L. Patterson, K. Rhinhart, and E. Jacobsen. 1999. Disease management for annual crops in low-rainfall regions. Oregon Agricultural Experiment Station Special Report 999:59-67.
  • Smiley, R., R.J. Cook, and T. Paulitz. 2002. Controlling Root and Crown Diseases of Small Grain Cereals. OSU Ext. Publ. EM 8798. 6 p.
  • Smiley, R.W., J.A. Gourlie, R.G. Whittaker, S.A. Easley, and K.K. Kidwell. 2004. Economic impact of Hessian fly (Diptera: Cecidomyiidae) on spring wheat in Oregon and additive yield losses with Fusarium crown rot and lesion nematode. Journal of Economic Entomology 97:397-408. (abstract)
  • Paulitz, T., R. Smiley, and R.J. Cook. 2002. Insights into the prevalence and management of soilborne cereal pathogens under direct seeding in the Pacific Northwest U.S.A. Canadian Journal of Plant Pathology 24:416-428. (abstract)
  • Smiley, R.W. 1996. Diseases of wheat and barley in conservation cropping systems of the semi-arid Pacific Northwest . American Journal of Alternative Agriculture 11:95-103. (abstract)
  • Smiley, R.W., A.G. Ogg, Jr., and R.J. Cook. 1992. Influence of glyphosate on severity of Rhizoctonia root rot, growth, and yield of barley. Plant Disease 76:937-942. (abstract)
  • Smiley, R.W., L-M. Gillespie-Sasse, W. Uddin, H.P. Collins, and M.A. Stoltz. 1993. Physiologic leaf spot of winter wheat. Plant Disease 77:521-527. (abstract)
  • Smiley, R.W., W. Uddin, P.K. Zwer, D.J. Wysocki, D.A. Ball, T.G. Chastain, and P.E. Rasmussen. 1993. Influence of crop management practices on physiologic leaf spot of winter wheat. Plant Disease 77:803-810. (abstract)
  • Smiley, R.W., H.P. Collins, and P.E. Rasmussen. 1996. Diseases of wheat in long-term agronomic experiments at Pendleton, Oregon . Plant Disease 80:813-820. (abstract)
  • Smiley, R.W. 1997. Risk assessment for Karnal bunt occurrence in the Pacific Northwest. Plant Disease 81:689-692. (abstract)


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