The frequent rainfall and extended periods of high relative humidity have also stimulated the development of a disease in wheat known as Fusarium head bight (head scab). The Fusarium fungus infects wheat during the flowering or during the early stages of grain fill.
Symptoms include large tan lesions that affect an entire spikelet or portion of the head. The fungus often produces an orange mass of spores at the base on areas of the head infected first. The symptoms of Fusarium head blight are most obvious at the late milk and early dough stages of kernel development.
To date, the disease has been reported at trace levels in many areas of central Kansas but incidence is highest in the southeast portion of the state. Unfortunately, there is nothing that can be done for the disease this late in the growing season, but it is important to check fields for signs of disease to help set harvest priorities.
Figure 1. Symptoms of Fusarium head blight in wheat. Photos by Erick DeWolf, K-State Research and Extension.
Figure 2. Close-up of symptoms of Fusarium head blight showing the orange reproductive structures of the fungus.
Erick De Wolf, Extension Plant Pathology
Doug Shoup, Southeast Area Crops and Soils Specialist