Many wheat producers were disappointed with their yields and test weights in the 2011 crop. Much of the problem involved scab, or Fusarium Head Blight, and had more to do with what kind of residue they planted into than when they planted, or what variety they planted.

The fungus, Fusarium graminearum, causes head blight in wheat, and also infects sorghum, millet, oats, barley and corn. The fruiting bodies of the fungus overwinter on the residue of these crops.

Prolonged periods of high humidity (2-3 days) coupled with temperatures ranging between 75° and 85°F (23.9-29.4°C) are favorable for disease development. A period of wet weather from mid-late June resulted in significant incidence of scab in fields planted into the residue of crops that host the fungus.

To minimize wheat scab, producers can utilize variety resistance, crop rotation, tillage and foliar fungicides applied at flowering. The potential benefit of variety resistance is best with some of the spring wheat cultivars, but limited with winter wheat. Consider the resistance to scab in the variety recommendations. If seed from a scab infected crop is planned to be planted, cleaning the seed aggressively to remove as many of the scabby kernels as possible is recommended, and fungicide seed treatments can improve germination and seedling vigor.

For more information on wheat scab, access SDSU Extension publications Wheat Scab and the spring and winter wheat variety recommendations.