Growing season’s successes, challenges

DEKALB, Ill. — The 2025 corn and soybean growing season ended as it started — ideal conditions — along with the usual and unusual challenges sandwiched in between.

Crystal Williams, Pioneer agronomist in DeKalb, Lee, Ogle and Whiteside counties, recapped the northern Illinois growing season.

Planting began ahead of schedule.

“A lot people utilized opportunities to plant mid-April, depending on conditions and eagerness to get started or how willing they were to get started early,” Williams said.

“If they hadn’t gotten started then, a lot of people did start planting the last few days of April. Those dates seemed like they were the problem child days. Every spring has some days that, ‘Oh, I wish I didn’t plant’ or it might have caused some headaches. Those last few days of April were certainly that.”

Soil conditions were ideal until the end of April.

“Our soils worked up really beautifully this year, then we ended up getting a cool, heavy-like driving rain. We truly had garden soil for planting conditions and that rain caused a lot of crusting in some of that area,” Williams said.

The heavy rains forced some replants in the later planted crop and the need for rotary hoeing due to soil crusting.

Temperatures cooled toward the end of May, slowing heat accumulation and crop development.

“It was dry and hot in June, which it seems like has been kind of the norm the last couple of years. That being said, once we did get our shots of rain finally in July and heat that crop had a lot of energy to drive through and just shot up quite a bit. Things turned around quite a bit,” Williams said.

“We had good post-application windows, but from a fungicide timing standpoint between corn and soybeans it all kind of ran together a little bit. So, it was a little chaotic for much of that area.”

Pests

Corn rootworm continues to be a significant pest in many northern Illinois counties.

“Looking at the weather conditions and how that affected the corn rootworm populations, really any time we have a dry fall, followed by a dry spring, dry May and June, we’re going to have pretty favorable survival rates of corn rootworms,” Williams said.

“There was pretty heavy pest pressure this year. We’ve been kind of building that population. It’s very cyclical.

“We’ve had to have some conversations this year in terms of what are we going to do to change and control this corn rootworm population. Maybe a field popped up that didn’t seem like it had a problem or we didn’t realize there was an issue and this year we did find one.

“Rotating to soybeans is the easiest way in managing weeds in that field, as well, and is really the best way we can suppress a significant amount of corn rootworm.”

Diseases

Southern rust, tar spot, sudden death syndrome and other diseases also popped up during the growing season.

“Southern rust seemed to have stayed a little bit farther west. You can find southern rust and tar spot in northern Illinois. I heard of southern rust down in the Macomb area and the next thing it was up by the Quad Cities and kind of followed the Mississippi River up and then blew east a little bit,” Williams said.

“I feel like there was a little bit more pressure in Lee and Ogle counties than it was in DeKalb, in my opinion, but not that you couldn’t find it.”

Sudden death syndrome in soybeans was significant this year.

“A great treatment for that would be IleVO with your seed treatment. Some people cut that out this year because of input costs and different things. Anytime that we extend the time that soybeans are protected while they are below ground and not emerged, that’s really where we can inoculate a little bit earlier in that season,” Williams said.

“There was also a little bit of white mold, which is typically what we deal with, but it seemed like there was not as much white mold pressure this year.”

Corn Acres

Northern Illinois continued to lean toward corn in 2025.

“We do have quite a bit of continuous corn and I’d say we tended to run a little bit more corn even this last year because of markets. On average, I would say there’s a minimum of two to three years of corn-on-corn. Some stick to a two-year corn, one-year soybean rotation. Then there’s obviously more years of continuous corn than that, too,” Williams said.

Harvest

The crops dried down quickly in the fall, helped by the hot, dry weather. There was a lot of sub-20% corn in early October, which is typically not common in northern Illinois.

“I harvested a plot on Oct. 1 that was 100-day to 116-day, and everything was right around between 13% and 16%. It was planted mid-May. It was pretty surprising to see that,” Williams said.

“I think I said earlier this year I wouldn’t expect to be harvesting 15% corn again this year, and here I made myself out to be a liar.”