Tar Spot & Fungicide

Jul 10, 2023

As we drive across southern Iowa, we are starting to see many corn fields that are tasseled or tasseling. Now is the time to get the airplanes out to spray fungicide. If no diseases are present I generally wait until fields are 80% tasseled to have them sprayed. Based on industry and university testing the most consistent results come from tassel timeframe or just before tassel. If diseases are present you may want to apply earlier but so far this year there has only been light pressure of disease. Fields that are high yielding or fields that have a history of disease are my targets for fungicide application this year.

Tar spot has been talked about many times this year and the past couple of weeks have been optimum for tar spot inoculant. I still have not seen much of any this year so I do not see tar spot as a concern yet. I’d predict we’d see it on the eastern side of the trade territory because Eastern Iowa and Illinois have had the largest issue in the past years. Tar spot comes on very quickly so it is one to keep an eye on and apply fungicide as soon as possible if it’s seen. The Veltyma and Headline Amp we use have very good control of tar spot if it’s caught early. Remember that fungicide won’t fix the leaf tissue that’s damaged, it only stops the fungicide from spreading. This is why we have seen the trend to apply fungicides a little earlier, especially with the newer fungicides like Veltyma that provide long residual. Reach out to any of us at SFG about fungicide considerations this year and if there are certain fields to target.