Pro Farmer Crop Tour reports mixed corn yields and disease pressure in Illinois and Iowa

Scouts surveying corn and soybean fields in Illinois and western Iowa reported yields that generally lagged behind recent averages. In Illinois, corn yields ranged from 132 to 213 bushels per acre with an average of 173.9 bushels, while soybean pod counts averaged 1,154 per 3-by-3-foot square. Observers noted nitrogen deficiency, disease symptoms such as rust, northern leaf blight and bacterial leaf blight, and occasional stalk damage.

In Iowa, corn yields measured between 162.5 and 264 bushels per acre, averaging about 190 bushels, and soybean pod counts varied widely, with averages around 1,034 to 1,564 per 3-by-3-foot square depending on the region. Reports highlighted continued disease pressure, including gray leaf spot, white mold and brown stem rot, as well as the wettest conditions recorded for a Crop Tour since its inception in 1993. Some fields showed wind-related stalk damage, but overall weed and insect pressure was described as minimal.

Tour consultants said corn yields were roughly 5% below the previous year and slightly under the three-year average, attributing lower ear lengths and kernel counts to dryness and high nighttime temperatures. Soybean crops were generally healthy, with pod counts exceeding both last year’s and three-year averages in several locations.

The Crop Tour’s large sample size—over 700 corn and soybean samples collected so far this season—was cited as enhancing the statistical reliability of its estimates compared with the USDA’s smaller objective yield survey, which typically gathers fewer samples per state.