By Stephen Wegulo
Wheat disease surveys were conducted in Saline and Jefferson Counties in southeastern Nebraska on May 22. Growth stage ranged from flowering to soft dough. All fields visited looked healthy with a luxuriant green canopy (Figure 1), but they had trace to low levels of disease. The most commonly observed disease was the wheat streak mosaic virus (WSMV) disease complex (Figure 2). Other diseases observed were Fusarium head blight (FHB, Figure 3), Septoria tritici blotch (Figure 4) and stripe rust (Figure 5).
Management
Once symptoms of the WSMV complex appear, it is too late to control it. For next year’s wheat crop, the most effective management strategy is to control volunteer wheat, especially volunteer that emerges in wheat fields following pre-harvest hailstorms.
Volunteer wheat in summer crops such as sunflower and millet should also be controlled, as well as grassy weeds in wheat fields and summer crops. Volunteer and grassy weeds should be completely dead at least 14 days before planting winter wheat in the fall.
Additional management strategies for the WSMV disease complex include avoiding planting winter wheat too early, planting resistant or tolerant varieties, and avoiding planting winter wheat next to late maturing crops such as corn and millet that are hosts to the viruses or their wheat curl mite vector.
Source : unl.edu