Illinois Crop Update – August 23, 2024

Russ Higgins – Commercial Agriculture Educator

Grundy County

Soil Conditions: Mildly Dry (soil is drier than normal, plant growth may have slowed)

Recent precipitation and current cool conditions are favorable for both corn and soy crop grain fill. The extended forecast is dry and warmer, which could expedite the grain fill window. For crops on some lighter soils in the Northeast, recent rains appear to have arrived late. Corn in sandy and soils with poor water holding capacity senesced quickly over the recent week. In field areas that flooded or have decreased plant populations due to environmental conditions, I’m finding grass weeds happily filling the void. One species in particular, fall panicum, seems to be having an exceptional year. This summer annual can reach seven feet in height and is recognized by appearing to be growing in a zig-zag pattern caused by growth bending at the nodes. The seedhead is easily identifiable, resulting in a wide spreading panicle when mature.

For those in Grundy County and surrounding areas, Illinois Extension and the Kendall-Grundy Farm Bureau are partnering to host University of Illinois plant pathologist Dr. Boris Camiletti on Wednesday, August 28th at 1:30 pm at the Kendall-Grundy Farm Bureau building. Dr. Camiletti will lead a discussion on his research projects and share experiences in his first Illinois growing season. Producers, landowners, and agronomists are encouraged to bring plant samples the afternoon of the meeting for discussion or identification purposes. Anyone is welcome to attend, the Kendall-Grundy Farm Bureau building is located at 4000 N. Division street in Morris, Illinois.

Figure 1: Senescing corn 20, Aug 2024 Grundy County

Figure 2: Fall panicum in soy

Reagan Tibbs  – Commercial Agriculture Educator

Logan County

Soil Conditions: Near Normal

Crop conditions continue to look good around Logan, Menard, and Sangamon counties. While there has not been much rain in the last week, cooler temperatures have ensured plants are not under heat stress as we approach maturity. There have not been any significant reports of any diseases across the area, though some isolated cases may be present. Many local producers have also completed their third hay cutting for the year. With the cooler temperatures and rain over the last couple of weeks, many fields are already starting to grow back nicely and could see a fourth cutting.

Nick Seiter – Extension Field Crops Entomologist

Champaign County

It’s a good time to scout for fall armyworms in grass hay, pasture, alfalfa, etc; a quick survey of my colleagues in the states to our south indicated it is a big year for this insect (though they were unanimous that it was not as bad as in 2021, the last time we saw widespread damage in Illinois).

Talon Becker – Commercial Agriculture Specialist

Vermillion County

Soil Conditions: Moderately Wet (soil is damp, standing water may be present in low areas, water bodies are full)

Following the storms that came through the areas late last week, soils have plenty of moisture in the northern Vermilion County area.  There was standing water visible in some small ponds in headlands, but these were few and far between.  Crop health looked good, overall, but corn fields are starting to show some areas with late-season nitrogen stress with variable ear size and tip fill.  Signs of what appears to be Physoderma stalk rot (visual identification only) were also present in a number of corn fields. In fields surveyed, corn was at late R4 (dough) to early R5 (dent). Soybeans generally ranged from R4 (full pod) to R5 (beginning seed), with a few fields edging closer to R6 (full seed).  Weed control was variable.  Most corn fields I walked into were relatively clean, but soybean fields showed a range of weed control efficacy.

Figure 3: Soybean fields on either side of a road with varying weed control efficacy; field with large population of maturing waterhemp visible on the right.

Figure 4: Corn ear at early R5 (dent) with unfertilized or aborted kernels at the tip; corn plant showing disease signs consistent with Physoderma stalk rot.