Temperature

With at least four weeks left in the growing season, Ferrie encourages farmers to stay ahead of heavy disease pressure in fields, particularly in what he calls D hybrids — those that punch their yield card late-season.

Corn yield estimates in seven counties surrounding the community of Bloomington indicate farmers there will harvest an average crop, at best. That’s counter to what USDA predicts for Illinois yield results statewide.

USDA reports 73% of the corn crop nationally is in good to excellent condition – a 5% increase over this same time in 2024. Industry analysts believe the Aug. 12 Crop Production report will boost its estimate for the 2025 crop because of the overall favorable growing season.

The Midwest has been inundated with rain, heat, oppressive humidity and “corn sweat”. In fact, meteorologist Ryan Maue says the heat index hit 115°F Sunday night in Iowa — and 20°F to 25°F of that was coming from surrounding corn fields.

More reports of ‘overly tight tassel wrap’ are coming in across the Corn Belt – including from the reigning world champion corn grower. Hula shares how he strategically uses his planter to minimize pollination risks.

Portions of the central Plains, the Upper Midwest and the Mid-Atlantic will be in a heat dome by Tuesday. But first, those regions will see thunderstorms and heavy rains this weekend, according to the National Weather Service.

Both diseases are showing up earlier this summer than last year, according to Daren Mueller, Iowa State University plant pathologist. He says a new interactive tool from the Crop Protection Network can help farmers locate these diseases, and others, faster.

So far, the problem has been confirmed in four states. Agronomists are encouraging farmers to scout crops, estimate yield impacts in affected fields and determine whether to make adjustments to marketing plans.

Unlike most leaf diseases, tar spot starts impacting the crop at the bottom of plants. That means fungicides you apply must penetrate and get deep into the crop canopy to provide effective treatment. If you opt to not treat the disease, consider making plans to harvest early and pre-booking some dryer gas.

That percentage doesn’t tell the complete story, however. While farmers in the West and southeast Texas have endured weeks of dry conditions that’s not been the case in the central Corn Belt where growing conditions have been excellent.