Management of FUSARIUM HEAD BLIGHT IN WHEAT (North Dakota State University)

This material is based upon work supported by the U.S. Department of Agriculture, under Author Agreement Nos. 59-0206-4-012, 59-0206-5-007, 59-0206-6-012, 59-0206-4- 036, 59-0206-4-035, 59-0206-6-010 and 5-0206-5-005. This is a cooperative project with the U.S. Wheat & Barley Scab Initiative. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

The most prevalent and problematic disease in small grain farming (wheat and barley) in the U.S. and Canada is Fusarium head blight (head scab). Fusarium head blight (FHB) has been responsible for billions of dollars in yield and quality losses in the small grain industry. The pathogen causing the disease is well equipped to survive a variety of environmental conditions, putting wheat growers at a significant disadvantage. However, with a well-rounded approach including the proper biological, chemical, and cultural controls (integrated pest management), FHB can be mitigated to tolerable levels while offering a positive return on investment.

Management:
Biological Controls: The primary strategy for managing FHB is to plant a variety that has resistant traits to FHB.
Chemical Controls: Not all fungicides are created equal, and can provide mixed results depending on the primary chemical compound, and time of application. The best class to use against FHB is demeththylation, or succinate dehydrogenase inhibitors. The best time to make a fungicide application in wheat is when the crop is approximately 50 - 80 percent early flowering, or seven days after. For barley, the best time to make an application is 80 percent at full head, or seven days after. The pathogen's development is favored by warm, wet conditions. For a positive return on investment, it is best to track environmental conditions leading up to the time of spraying, to ensure there is a damage risk.
Cultural: In addition to selecting a resistant variety, crop rotation is another primary way to mitigate FHB damage. Other practices include tillage, to encourage decomposition of previously infected residue, as well as adjusting planting dates in one field in order to ensure not all fields can be infected at once.