Crop & Pest Report

Accessibility


| Share

Fusarium Head Blight (Scab) Risk in Winter Wheat (06/02/16)

Fusarium head blight (scab) risk season has begun in North Dakota as some of the winter wheat fields in the state have headed.

Fusarium Head Blight (Scab) Risk in Winter Wheat

Fusarium head blight (scab) risk season has begun in North Dakota as some of the winter wheat fields in the state have headed. Scab risk is highest when warm weather, high humidity and prolonged periods of moisture occur prior to and throughout the flowering stages of wheat. The best way to manage scab is to use less susceptible varieties and a well-timed triazole fungicide (ie: Prosaro, Caramba, Tebuconazole generics) application when 50% of the field is at early-flowering. However, recent research in wheat and barley have indicated post-flowering fungicide applications (up to 7 days after early-flowering) still offer scab and DON (mycotoxin) suppression.

Currently, the two scab forecasting models (NDSU Small Grains Disease Model and National Fusarium Head Blight Model) have different estimations of scab risk for flowering wheat in the state. For susceptible varieties, the NDSU model indicates most of the state is at moderate to high scab risk (Figure 1) and the National FHB model indicates low scab risk for the entire state (Figure 2). For moderately susceptible varieties, the NDSU model indicates moderate risk in the northwest and northeast portions of the state. Areas indicated to have the greatest scab risk in ND have received significant precipitation over the past seven days.

As a final note, scab models are a good guideline when making the decision to apply a fungicide. However, remember that other factors such as field location, yield potential and future weather conditions will influence the decision to apply a fungicide.

ppth.friskop.1png

ppth.friskop.2. 

Andrew Friskop

Extension Plant Pathology, Cereal Crops

Creative Commons License
Feel free to use and share this content, but please do so under the conditions of our Creative Commons license and our Rules for Use. Thanks.