Stephen Wegulo
Extension Plant Pathologist
Figure 1. One of two adjacent wheat fields with a high incidence of wheat streak mosaic virus in Deuel County on June 18.
Figure 2 (above). Cephalosporium stripe on a wheat leaf in a state variety trial in Lincoln County on June 17.
Figure 3. A wheat head prematurely whitened by Cephalosporium stripe in a breeder nursery in Lincoln County on June 17.
A survey of wheat fields in western Nebraska (Furnas, Red Willow, Lincoln, Cheyenne, Deuel, and Box Butte Counties) June 17-19 revealed mostly trace to low levels of disease.
Exceptions were a high incidence (percentage of infected plants) of wheat streak mosaic virus in two adjacent commercial fields in Deuel County (Figure 1) and a moderate to high incidence of Cephalosporium stripe in a state variety trial and breeder nursery in Lincoln County.
Cephalosporium stripe is a soilborne fungal disease. The causal fungus invades the vascular system of the wheat plant, causing stripes to form on leaves (Figure 2), stunting, and premature whitening of heads (Figure 3).
Other diseases observed during the survey included bacterial streak, Septoria tritici blotch, tan spot, Fusarium head blight, and loose smut. No rust diseases were observed. Wheat in many fields appeared stressed from lack of moisture.
Statewide, the overall impact of disease on wheat yields this year will be minimal due to a combination of dry conditions and early season cool temperatures.
Source : unl.edu