Related Resources

• Disease Management in Wheat (CropWatch section)
• Wheat (CropWatch section)

As of May 20, field observations in Clay, Gage, Lancaster, Nuckolls, Perkins, Saline, Saunders, and Webster counties in Nebraska indicated very low levels of foliar fungal diseases in some wheat fields and no diseases in many fields. This is because it was relatively dry early in the growing season, creating unfavorable conditions for disease development and causing wheat in some fields to look stressed.

Fungal diseases observed at trace levels are Septoria tritici blotch and tan spot.  Virus diseases observed, also at low levels, are wheat streak mosaic and wheat soilborne mosaic.  During the last several weeks low to moderate levels of wheat soilborne mosaic virus were reported in isolated fields ranging from the southwest to the southeast parts of the state. No rust diseases have so far been observed in the state.

Wheat is mostly at the flag leaf to the boot growth stages, with a few plants starting to head.

With the rainfall that started on Thursday morning and is forecast to continue through the Memorial Day weekend, conditions will become conducive to development of fungal diseases, especially Septoria tritici blotch, tan spot, and powdery mildew.  Although the risk for rust diseases remains low, be on the lookout for leaf rust and stripe rust.

Continue to scout fields and be prepared to apply a fungicide if diseases start to develop due to wet conditions.  Given that disease levels have been low up to now, the best strategy is to wait until full heading and then make one fungicide application that will target both foliar diseases and Fusarium head blight (scab).  The best fungicides for this purpose are Prosaro, Caramba, or Proline.  The risk of Fusarium head blight is currently low, but it is likely to increase if rain continues into the heading growth stage.

Stephen Wegulo, Extension Plant Pathologist
Jennifer Rees, Extension Educator, Clay County
Dewey Lienemann, Extension Educator, Webster County
Randy Pryor, Extension Educator, Saline County
Paul Hay, Extension Educator, Gage County