Farms.com Home   Expert Commentary

Is A Fungicide Necessary To Manage Winter Wheat Diseases This Fall?

Nov 16, 2016
By Emmanuel Byamukama
Assistant Professor & SDSU Extension Plant Pathologist
 
 
A few cases of stripe rust (Figure 1), powdery mildew and tan spot in winter wheat have been reported this fall. Producers are wondering if it is worthwhile to apply a fungicide to control these fungal diseases. In order to decide if a fungicide is needed, we need to know a few facts.
 
Fungicide Management
 
A fungicide is applied mainly as a protectant to prevent new infections from taking place and also to limit further inoculum development. This ensures that the leaves maintain their capacity to carry out photosynthesis. However, for winter wheat in fall, leaves will soon die from freezing temperatures and therefore applying a fungicide may not be beneficial. In cases where winter wheat seedlings (two leaf stage) are found with stripe rust and other fungal diseases, and warm fall weather(at least two weeks) is still in the forecast, a fungicide application may be necessary to help wheat plants establish well before vernalization.
 
However in established winter wheat that has more leaves, fungicide applications may be more effective when applied in the spring at the same time as herbicides. Fields, where fungal diseases are being identified in the fall, should be scouted early in spring. If these diseases are found on lower leaves, an early fungicide application may be needed.
Click here to see more...