Recent rainfall and cool temperatures have favored development of stripe rust to severe levels on flag leaves in fields that have not been sprayed as shown in Figure 1, a photo taken Wednesday, May 24, in a grower’s field in Webster County in south-central Nebraska.
A survey of wheat fields in the Nebraska Panhandle found only trace levels of stripe rust and low levels of tan spot, but widespread areas of wheat streak mosaic virus with severity ranging from mild to severe.
Research plots at UNL’s Agricultural Research and Development Center (ARDC) were surveyed for diseases on May 12. These plots are not sprayed with fungicide and therefore the diseases and disease levels in them can be representative of those in growers’ fields under similar conditions. Here's what we found.
Because of the presence of stripe rust and leaf rust in the state, as well as increasing incidence and severity of Septoria leaf blotch and tan spot, growers are encouraged to be vigilant in scouting their fields.
Wheat fields are still looking green (Figure 1). However, development of several diseases is increasing. On April 26, stripe rust was confirmed in Nuckolls County in south central Nebraska and on April 27, it was found at low to moderate levels in research plots at the University of Nebraska-Lincoln’s Havelock Research Farm near Lincoln in Lancaster County (Figure 2).
Winter wheat growth in Nebraska is progressing at a steady pace, with most fields now green with little or on disease; however, growers are urged to continue scouting their wheat for early signs of disease as current and forecasted wet weather this spring is likely to lead to severe disease outbreaks.