Fusarium head blight in small grain research review
G. J. Endres, B. G. Schatz, and S. F. Zwinger
Fusarium head blight (scab) continues to be a critical small grain disease problem in south-central North Dakota. Research to address scab management has been conducted at the Carrington Center since 1993 in cooperation with other NDSU scientists and Extension specialists. Research emphasis at the Center has been identification of HRS and durum variety tolerance to scab and fungicide efficacy.
Current success with work on identifying small grain variety tolerance to scab has resulted in published ratings to assist growers with variety selection to reduce impact from disease. Experimental varieties are being tested at the Center that potentially will have improved levels of scab tolerance.
Trials are being conducted to evaluate existing and potential fungicides that are useful for scab management. At the Carrington Center in 1997, eight trials included fungicide work for scab suppression. Currently-labeled fungicides provide about a 50 percent reduction in field severity of scab. Grain yield and quality improvement, when data is averaged across fungicide trials, is generally positive. For example in 1997, average wheat yield improved 17 percent with Benlate + mancozeb or Folicur compared to the untreated check in six ND trials. At the Carrington Center in 1995-97, wheat yield and test weight improved 6.5 bu/ac and 1.2 lb/bu, respectively, with Benlate +mancozeb or Folicur compared to untreated checks. Unfortunately, yield and quality data is quite variable among locations.
Ultimately, growers cannot consistently achieve positive economic results with fungicides. Research is being conducted to improve fungicide application techniques and retention in order to increase fungicide efficacy of scab.
The long-term solution to scab management likely will be genetic resistance, which is several years away from commercial adaptation. On the short-term, a recommended scab management strategy would include the combination of tolerant varieties, crop rotation, sanitation, variable planting dates, and fungicides.