Current conditions in Champaign County are mildly dry. Last week’s heat wave has broken slightly—just in time to pick back up for the Fourth of July weekend—with recent highs in the 90s and lows in the 70s giving way briefly to more moderate temperatures in the mid-80s and lows in the 60s. Rainfall has been limited, with the area consistently missing spotty showers, leading to visible stress in corn due to heat and lack of moisture. Soybeans are in the R1–R2 growth stages, and corn is progressing from V10 to R1 (silking). Most post-emergence herbicide applications are complete, though some fields are being evaluated for resprays due to waterhemp escapes, and fungicide planning is underway. Japanese beetles are present in both corn and soybeans; corn rootworm beetles and grape colaspis have also been noted in corn.

Crop is really progressing with the heat. Early-planted beans are starting to close rows, and post applications have been made. Constantly scouting beans for waterhemp escapes. Corn is 3–6 leaves from tasseling. Found tar spot in most of the corn across a three-county area. You really have to look to find it, but it’s definitely present. Of the 15 corn fields I’ve been in so far, I’ve found it in 13. It doesn’t seem to be hybrid-specific—same infestation level across multiple brands and hybrids.

Still very little subsoil moisture. Overall, compared to parts of Minnesota and Wisconsin I’ve recently seen, I’d say we’re a bit of a garden spot. We are truly blessed to be looking the way we do.

Some areas received between 1″ and 2″ of rain, while others nearby went without. Corn is lodged and forming brace roots after heavy winds. Earlier-planted corn in the area may have experienced greensnap. Recent spotty pop-up showers, along with the heat, were just what the crop needed to make up for previously hindered growth.

Wheat harvest is underway, with some double-crop soybeans hopefully getting planted ahead of forecasted rain. Post-emergence herbicide and sidedress/Y-drop applications are nearly wrapped up, with some beginning to mow roadside ditches.

Corn is at the V9–V12 growth stages, and soybeans are at R1 to R2. Japanese beetles have made their presence known at low levels in both corn and soybeans. Grape colaspis beetles have also been spotted in soybeans. Bacterial blight and Septoria brown spot are present in soybeans.

There are no signs of disease in corn at this time; however, leaf wetness and humidity could signal disease pressure in the future. Farmers are preparing and asking questions about fungicide applications. Many are also scouting for escaped weeds following post-emergence herbicide sprays.

The main story in southern Illinois this week has been wheat harvest. Despite many farms still having fields unplanted or in need of replanting, the hot weather has dried the wheat, and combines are rolling. Wheat yields are highly variable this year, largely due to the more than 20 inches of rain since March. Fields that are well-drained and typically good for wheat still yielded decently this year. However, fields with marginal drainage—those that are usually acceptable for wheat—had many flooded-out spots, which quickly brought down field averages.

On the bright side, test weights are still good where fungicide was applied. The downside is that, on average, yields are about 5–20% lower than last year. Some parts of fields are still hitting 100+ bushels per acre, but others are coming in at 40 bu/ac. Averages of 70–85 bu/ac seem common.

Hot weather is also drying out the ground, despite pockets of standing water and spotty convective storms. If the weather holds over the next week, double-crop soybeans and the remaining first-crop fields should get planted or replanted.

It’s a challenge to report on soil conditions in northeast Illinois due to isolated pop-up thunderstorms. Some fields received over an inch of rain, while many less fortunate areas are drying quickly under above-average temperatures. I’ve noted many soybean fields exhibiting significant leaf burn from post-herbicide applications—likely a result of tank mix chemistries, additives, and environmental conditions. As our day lengths shorten, we’re reminded that soybeans in our region have an indeterminate growth habit, meaning vegetative growth (additional leaves) continues even after reproductive growth (flowering) begins. Despite high temperatures and limited rainfall, most corn fields visited still have wet leaves early in the morning. Periods of leaf wetness and high relative humidity are key risk factors for several corn leaf diseases, including Tar spot and Gray leaf spot.