This article was written by Dr. Bob Hunger, Extension Wheat Pathologist
Department of Entomology & Plant Pathology
Oklahoma State University – 127 Noble Research Center
Foliar wheat diseases remain relatively quiet in Oklahoma. On scouting done around Stillwater and from trips taken Thursday and Friday to west and a bit northwest of Oklahoma City and northwest up to Enid, the only foliar diseases of any consequence observed were leaf spot diseases (e.g. tan spot) in no-till fields (Figure 1A). Most of the wheat I saw was between 2 nodes readily apparent (GS 7) but ranged up to GS 8-9 (flag leaf just emerging to fully emerged). In some fields, powdery mildew was moderately severe on lower leaves in “hot spots,” but again, not at a high frequency. I saw no stripe and only sparse leaf rust, but Dr. David Marburger had a photo of stripe rust (Figure 1B) sent to him from a grower (Anderson Farms) that indicated the photo was taken from experimental plots at the Noble Foundation near Ardmore (Carter County). Apparently there was not much stripe rust, but there were low to moderate levels of leaf rust (Figure 1C).
Figure 1. (A) Tan spot symptoms as seen on wheat foliage in no-till fields; (B) stripe rust as seen in south central OK (Carter County); (C) a photo of leaf rust to compare with stripe rust.