Chemical Burn Question Peanut Notes No. 166 2024

Question:

Is this leaf spot disease?

Jordan:

This is chemical burn and not the leaf spot we spray fungicides to control. Spots likely match up with when you sprayed herbicide last. Leaf spot disease will start in the bottom of the canopy in most cases. In our non-treated controls for fungicide trials, it is late August at the earliest when we begin to see lesions form that is caused by the pathogen.