Wheat Disease Update Central and Eastern Nebraska - UNL CropWatch, June 20, 2013
Figure 3. Fusarium head blight in a grower’s field in Saunders County on June 19.
June 20, 2013
Figure 1: Leaf rust on the flag leaf of a wheat line in a breeding nursery at the Havelock Research Farm in Lincoln on June 19.
Figure 2: Close-up of a wheat head affected by Fusarium head blight at the UNL Agricultural Research and Development Center near Mead on June 19.
A survey of wheat fields in Lancaster and Saunders counties on June 19 revealed severe levels of leaf rust (Figure 1) and low to moderate levels of Fusarium head blight (scab) (Figures 2 and 3). Other diseases observed were Septoria tritici blotch, black chaff, and low levels of stripe rust. Warm temperatures have slowed stripe rust development, but have favored leaf rust development. Leaf rust and stripe rust have also been observed in south central Nebraska wheat fields. It is too late to treat wheat fields with fungicides to control fungal diseases. Black chaff, a bacterial disease, cannot be controlled once it occurs.
Scab was observed at low to moderate levels in a grower’s field (Figure 3). Another grower’s field located about 15 miles from the affected field had hardly any scab. Therefore, the occurrence of scab in wheat fields appears to be sporadic and incidence and severity in general are low to moderate in affected fields. Growers in the eastern part of the state where rain preceded and coincided with wheat flowering are encouraged to check their fields for scab. For management information see Strategies for Handling Scabby Wheat Grain (6/21/13 CW).
Extension Plant Pathologist
Extension Educator, Clay County