Crops are growing well with soybeans in the R2 to R3 stages, and corn is in VT to R1 stages. So far, not seeing any leaf diseases in corn or soybeans. Japanese beetles are being seen feeding on tender vegetation, but are not yet evident in fields. I have not found any root feeding in corn, and root systems in fields planted under good conditions are looking healthy and strong.
The wheat harvest is quickly wrapping up in the wetter areas of the region, with double-crop planting following soon after.
Post-emergent soybean herbicide applications delayed by wet field conditions are wrapping up, with the target weed species larger than desired.

The heat wave is upon us this week bringing 90+ degree temperatures with very high humidity. After a few weeks of cooler weather and lots of precipitation, the corn and soybeans that were not waterlogged are thriving and have jumped multiple growth stages since last week. I scouted corn fields anywhere between V5/V6 up to V10 with rapid growth from all the heat units being added into the environment. Soybeans are a bit more spaced out depending on planting date, with some fields as far along as R2 upper node flowering.

Water damage from previous storms is becoming increasingly evident where it was sitting for multiple days, drowning out both corn and soybeans, with many fields showing bare ground from a low spot leading to islands of complete crop loss. Much of this was heavily dependent on who received heavy and damaging rain and winds.

I would advise being vigilant about your scouting for disease. I have not seen tar spot or Northern Corn Leaf Blight (NCLB) yet, but a colleague in Morris Illinois, has found large NCLB lesions in fields. After 2 weeks of ideal tar spot weather, despite not seeing any today, I have concerns we may see early outbreaks this season, especially compared to last season and the early drought we experienced in northern Illinois.

In a recent report, I stated that warmer weather would benefit the 2026 crop, perhaps in the future I should qualify my term of “warmer weather”. A week of 90 degree plus days in Northeastern Illinois has allowed farmers and agribusiness the opportunity to play catch-up applying post herbicides. Last week, you could not travel a rural road without meeting a sprayer. Most fields have weed populations that have easily exceeded weed size management recommendations and most have drowned out areas that will likely germinate later season weeds. Fields this year are unlikely to have “perfect” weed control. Growers are encouraged to evaluate post herbicide applications and start scouting for leaf diseases in corn. Tar spot symptoms have been reported in the state, and one tool that can be utilized to see if a crop disease has been reported in your area is visiting the Crop Lookout Website. Crop Lookout is a real-time, interactive map that highlights emerging field crop issues across the United States and Canada. Updated throughout the growing season by university Extension specialists and research partners, the tool visualizes reports of diseases, pests, and other agronomic challenges as they develop. Northern Corn Leaf Blight or Goss’s wilt have been found in Grundy County as the crop is near the Tassel stage.

The warm temperatures across the county this week appear not to have slowed down crop progress at all. At the Hartsburg Research Plot in northern Logan County, soybean growth is mixed throughout the field. In the parts where there was standing water, plants are in the V5 stage, while the rest of the field is at V10. In the parts of the field that had standing water, there are many empty spaces where plants have not developed or failed to emerge. Volunteer corn is the most-present weed at the Hartsburg Research Plot this year, given the late planting date. Other weeds such as Palmer amaranth, Redroot pigweed, and Common waterhemp are also starting to show themselves. While there are Japanese beetles in the field too, they do not appear to be causing significant damage to the leaves, with only a handful of plants and leaves showing major signs of damage.

The heat is on and it has sped up the growth stages of both corn and soybeans. The corn growth stages of VT – R1 can be the most sensitive to heat stress. Warm nights (72F – 75F) combined with hot days can increase stress on pollen, silks, and fertilization, potentially reducing kernel set. But the good news is that we don’t have moisture stress and cooler weather is in the forecast. It has finally dried up enough to harvest wheat, plant double-crop soybeans, apply post herbicide on late planted soybeans, and apply fungicide/insecticide on early planted corn.

Some hot summer weather this week and a break from the rain has helped dry many fields up enough for spraying and other field work to resume in southern Vermilion County. While there were still some low lying or poorly drained areas of fields with standing water as of my survey on Tuesday morning, most of the water had receded. Time will tell over the next few weeks how well the crop that remains will recover. Much of the corn in that part of the county is still in vegetative growth stages, generally ranging from V8-V14. I did find a couple fields that had started to show tassels, although no silk emergence quite yet. Most soybean fields visited had reached early flowering (R1), at least in parts of the field. The most advanced soybeans I found were beginning to form pods, entering early R3. Wheat harvest has started in that part of the county, but most wheat fields were still standing as of Tuesday morning.