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.

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.

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.

Overall, it’s been a very hot and humid week across northern IL as we begin to move out of the heat dome that has been sitting over us for the past five days. This week alone, we’ve added nearly 200 GDUs from the heat wave in DeKalb County, with seasonal totals reaching 959 GDUs. Isolated rainstorms have brought some relief to drought-stricken areas. Some fields are still showing signs of stress with “pineapple” corn, but overall, the corn crop has looked better this past week. With temperatures expected to remain high as we enter July, I expect early-season stunting or growth delays in both corn and soybeans to be largely overcome.

Corn has begun to shoot up across most fields I scouted. Lake County still has some shorter corn, but as you head further west along the I-88 corridor, the stands get taller—reflecting the pattern of rainfall and the impact of late-spring cool temps. Corn is between V6/V7 and V9/V10 depending on planting date and is nearly 5′ tall in some fields. Much of the drought stress from last week has been alleviated thanks to healthy weekend rains across northern IL, along with isolated storms this week. More storms are expected, and it would be great if some of the drier fields could catch them. I haven’t seen any tar spot or other fungal diseases so far this season, but with rising moisture and temperatures into the 80s, we may begin to see it in the lower canopy. Tar spot has been found in western IL, and you can track its spread at the Crop Protection Network:
https://cropprotectionnetwork.org/maps/tar-spot-of-corn

Soybeans are progressing well. On Wednesday, 6/25/25, I saw the first field beginning to flower as we enter the R1 stage. Fields range from third trifoliate to R1 flowering, depending on environmental conditions and planting dates. The further west you go, the taller the beans, with Lake County again showing some of the shorter growth. Overall, I haven’t seen any early-season diseases, and most visible damage is from herbicide burn following post applications.

Wheat had a strong week of ripening after a cool May and early June. Disease pressure remains low in the fields I scouted, with full heads present. The grain is still quite wet in the head, and plants need more time to mature and dry down. If warm temperatures continue in the upper 80s, I’d expect harvest to begin in some fields around or just after the Fourth of July.

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.

A light shower last weekend and nearly an inch of rain in the first couple of days this week took the edge off for the crop in most of my immediate area. The high temperatures and high humidity are pushing the corn along pretty fast now. Visible plant stress is minimal, especially after the shot of rain we got. Some spotty hail managed to poke a few holes in the beans in certain areas, but the corn is largely unscathed. Most soybean fields have now received their post-emergent herbicide passes—the fields that haven’t are pretty obvious from the road. Farmers and retailers are working diligently to get those taken care of, as we’ll be into corn pollination and fungicide season before we know it.

Currently, the corn and soybean crops are looking good. Soybeans range from V3 to R2 (full bloom), while corn varies from V7 to R1 (silking), with most of the crop at V10+ and some expected to reach VT before July 4. Weed control is generally looking good. Alfalfa fields are ready for the second cutting.

The high temperatures over the last week have caused many corn fields to grow at a rapid pace. There is hardly a corn field that isn’t knee-high—one week before the Fourth of July. At the University Research Plot in Hartsburg, IL, corn is at the V9–V10 stage, with other fields in the area at V7–V8. Soybeans have faced a tougher challenge with the high temps. While some fields are handling the heat well, many are showing signs of stress, including cupped leaves. There are no additional signs of insect or disease pressure yet, but continued high temperatures will likely lead to more issues.