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.

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.

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.

Crops are off like a rocket in our territory. Favorable growing conditions—warm weather and timely rains—have set us up for success. With these conditions, concerns about crop diseases like the dreaded tar spot are becoming a reality. There have been several sightings of it in our territory. If the heat continues as it has this week, we believe it will help reduce the push of infection.

As for soybeans, many post applications have been applied. These treatments continue to show significant crop response on the leaves. We’re also seeing good success with these applications in controlling waterhemp and other tough-to-kill pests.

It’s that time of year when we encourage producers to take a two-week vacation—and come back to clean fields and beautiful crops! Corn is coming out of its ugly stage as it finds nitrogen, and soybeans are rebounding nicely after the initial setback from post applications. All in all, we’re excited about the potential our crops continue to show.

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.