I have received a question or two about Tan Spot (formerly Helminthosporium) in local wheat. Tan spot has been noticed in a few area wheat fields and these fields range from boot to early heading stage of development (Week of April 4, 2020). The pictures below are examples of Tan Spot that I have been seeing in the area.
What do I need to do about this? Here’s some advice from UGA Plant pathologist, Dr. Martinez-Espinosa. “Monitor the fields so that the infection is not high and it does not progress above flag leaf minus 1 or 2; if it does go to flag leaf minus 1, then a protective fungicide should be considered. Especially if rainy, misty foggy weather continues.
If the infection is low and it is only located on lower leaves and (hopefully) drier sunny weather; might not need a fungicide. Growers need to evaluate the weather forecast, yield potential, and disease pressure in their field to determine if a fungicide applications is needed. Currently, growers are considering applying fungicides to manage Fusarium head blight if their crop is approaching Feekes stage 10.5.1. If you have any questions please contact your local county Extension agent.