Wheat Disease Update - UNL CropWatch, June 28, 2013
Figure 1. Figure 1. A grower’s wheat field at Hemingford in Box Butte County in the northern Panhandle on June 25. (Photos by Stephen Wegulo)
June 28, 2013
Figure 2. A stripe rust hot spot in a wheat field at the UNL High Plains Ag Lab in near Sidney on June 25.
Figure 3. Wheat tillers showing symptoms of wheat streak mosaic at the UNL High Plains Ag Lab in near Sidney on June 25.
Figure 4. Saline County state variety trial in a grower’s field southwest of Wilber on June 27.
Figure 5. Septoria tritici blotch on a flag leaf in the Saline County state variety trial on June 27.
A survey of wheat fields in the Nebraska Panhandle on June 25 showed that wheat was in the grain filling stage of development (Figure 1). Stripe rust was found at trace to low levels of incidence (percentage of plants infected) and appeared to occur in small hot spots (Figure 2) scattered within fields. Within hot spots, severity (percentage of leaf surface covered with pustules) ranged from low to moderate. The stripe rust is not expected to develop to epidemic levels due to hot summer temperatures and lack of adequate moisture in the Panhandle. Other diseases observed were wheat streak mosaic (Figure 3) and tan spot.
Back east in Saline County on June 27, wheat had turned color and appeared to be ready for harvest in a grower’s field where a UNL state variety trial was planted (Figure 4). In the variety trial, which appeared to be greener than the rest of the grower’s field, Septoria tritici blotch (Figure 5) was found at high incidence with moderate severity on flag leaves. Other diseases observed at the Saline County state variety trial were leaf rust and stripe rust.
Extension Plant Pathologist