Eyespot and Anthracnose have been showing up in our fields. It’s time to spray fungicide. Add some insecticide if you growing non-gmo corn varieties. Use only water as a carrier as some adjuvants and crop oils can inhibit the flow of pollen from the tassel to the silk.
Here is a good guide to help you choose a fungicide. I have had good luck with Fortix, Quilt Xcel, and Trivapro.
https://cropprotectionnetwork.org/2018/03/21/fungicide-efficacy-for-control-of-corn-diseases/