Crop Report
I focused this week’s crop report on the double-crop soybeans during my travels to southern Illinois, where my parents live. Due to a wet June and early July, the soybeans planted after wheat went in under less-than-ideal conditions. Most of the fields I walked or drove by are around 80–85% emerged. This made weed control tougher, and yields will likely be below average due to only 80–85% of the plants emerging in these fields. Waterhemp is a main issue in all soybeans. Early rainfall did not allow pre-emerge herbicides to do their job, and some fields unfortunately were not sprayed and relied solely on a post-emergence application. Even with these weed issues, overall the soybeans and corn crop look really good for southwest Illinois this time of year.
Both corn and soybean crops look great right now, with plentiful moisture from rains throughout most of July. This is keeping the crop green and mostly healthy, with the exception of corn leaf diseases coming in and an array of soybean feeders as well. I believe that growers who decided to spray fungicides this season will be happy with that choice. I worry about fields that were not sprayed. Unfortunately, I also see enough disease coming back in now that a second application may become necessary due to increasing tar spot and other diseases. Our saving grace will be that the corn crop is maturing at a rapid pace.
And just like that, conversations on drought have ended (for now) in northeast Illinois. Cumulative precipitation exceeded four inches in some areas last week. While the rain is welcome, earlier-planted corn that pollinated during the dry stretch has experienced kernel abortion. More favorable growing conditions should enhance grain fill and benefit later-planted and longer-maturity corn.
Dr. Boris Camiletti posted a “Red Crown Rot Progressing in Illinois” Bulletin article on July 28. The disease has been confirmed as far north as Livingston and Kankakee Counties. Growers in northeast Illinois are encouraged to watch for SDS‑like foliar symptoms in soybean and to submit samples to the plant clinic for confirmation.
Illinois Extension and the Kendall‑Grundy Farm Bureau are hosting a 2025 Crop Development Update meeting on August 12 at 11250 N. Church Road, Minooka. The meeting begins at 1:30 p.m. Dr. Giovani Preza‑Fontes, University of Illinois Agronomy Extension Specialist, will share expectations for a growing season filled with temperature and precipitation extremes. In addition, Steve Brand, Northern Illinois Extension Specialist, will provide insights into plant diseases observed across northern Illinois. This meeting is open to the public.
Frequent rains over the past week have maintained adequate soil moisture levels in northern Vermilion County. As I conducted my survey on the morning of 7/31, light rain was falling once again. Despite the relatively wet conditions for this time of year, disease pressure remained low in the corn and soybean fields visited. In corn, the most common sight was the tell‑tale “inverted V” chlorosis/necrosis pattern showing up in the lower canopy, in areas where nitrogen is limited and the plant is remobilizing nitrogen toward grain fill. Most corn fields surveyed were in the R3 “milk” stage, with some still in late R2 “blister” stage. Soybeans were generally in the R3 “beginning pod” to R4 “full pod” stages, although a couple of fields surveyed were nearing R5 “beginning seed.”
Subsoil moisture is still not adequate. Overall, we are one rain away from a fantastic finish on our beans. Most bean fields have some waterhemp or ragweed popping through in some capacity.
The heat and humidity have finally broken today after what feels like a very miserable few weeks. Over the past week, rainfall in LaSalle, Bureau, Marshall, and Putnam Counties has been sporadic, with some areas receiving nearly six inches and others less than an inch. Crops in areas with lower rainfall are still showing some heat stress. Overall, most crops look healthy, but the increased rainfall has finally brought disease to my four-county unit.
Tar spot has now been officially reported in all but Putnam County, though I suspect the disease is present there as well. Most growers have finished applying fungicide, and crops are now at stages where application is no longer recommended. Corn has reached R3 (milk), soybeans are at R5 (beginning seed), and double-crop soybeans are at V2–V3.
Pest pressure is low overall. Rootworm, bean leaf beetle, and Japanese beetle have been observed in soybean fields, but no significant damage has been reported.