Illinois Crop Update | September 18, 2026
Russ Higgins – Commercial Agriculture Educator
Grundy County
Soil Conditions: Mildly Dry (soil is drier than normal, plant growth may have slowed)
Rain is expected for Northeast Illinois this week, if it materializes it will provide needed moisture. Its benefit to most crops at this stage is uncertain, but we will decrease the fire risk associated with starting harvest when crops are tinder dry. It’s becoming a challenge to share information on the 2026 crop; we are so close to harvest most are in a wait and see attitude. Several late season observations include a very rapid dry down for the corn crop. Moisture levels for hand shelled samples for 105-day (2550 GDU’s) and 108-day (2580 GDU’s) hybrids were 24.8% and 18.8% respectively. As mentioned in previous reports, the loss of color and drydown of the corn crops in this region has been dramatic. When hand shelling corn kernels that did not fill (aborted) on the ear were noticeable. Kernel abortion is when a kernel is successfully pollinated, starts to form but stops developing and shrivels because the plant cannot supply needed photosynthate during early grain fill. This is often due to environmental stress. Of note, in some soy fields is the variation of plants reaching maturity. This too can likely be attributed to environmental stress during the growing season. An example is areas that were temporarily ponded or saturated are lagging behind other parts of the field.
Talon Becker – Commercial Agriculture Specialist
Douglas County
Soil Conditions: Mildly Dry (soil is drier than normal, plant growth may have slowed)
Harvest is underway in Douglas County. During my survey Tuesday (9/15) morning, I saw both corn and soybean fields being harvested as well as a handful of others that had recently been harvested, or at least “opened up”. Most corn fields visited were at black layer (R6) or close to it, with the exception of a couple of fields that were presumably planted late due to early season wet conditions. Soybean growth stage across the county showed a bit more of a range, with the majority of fields at beginning maturity (R7) or beyond, but a fair number still mostly green across the canopy. Those soybeans that are still holding on to some green leaves are turning quickly as soil moisture continues to decrease in the area with warm temps and minimal rainfall. As I write this on Wednesday (9/16), we did catch some rain in the area from the south edge of a storm system that moved through this morning. Available reports from Douglas County show a range of ~0.1-0.8″ in accumulation from that storm, so probably not enough to keep people out of the fields too long, depending on how the scattered storms in the forecast for the rest of the week play out.
