This week’s survey in the southern half of Iroquois County showed good crop conditions overall, but with some variability across the surveyed region. At the time of this survey (8/12), overnight rains in much of the area had replenished topsoil moisture in most fields surveyed. However, soil cracking and tip dieback in corn were found in several fields.

Corn fields surveyed tended to be in the R4 “dough” to early R5 “dent” stages. About a third of the fields showed an inch or more of tip dieback, presumably due to moisture stress, given the soil conditions in the field and the lack of evidence of N stress in the plant canopies. Signs of foliar disease were minimal in corn.

Soybean fields surveyed tended to be in the R4 “full pod” to R5 “beginning seed” stages. Plant health looked good overall, but some fields showed areas of stunted growth and a lighter canopy color. At this stage in the disease progression, observed symptoms did not provide a clear diagnosis. If you are seeing this in your field, submitting samples to the Plant Clinic (https://extension.illinois.edu/plant-clinic) can help with early diagnosis.

Both corn and soybeans are progressing well so far in Edgar County. Soils in most fields surveyed were starting to get dry, with cracks forming and minimal moisture in the top 3–4 inches. At the time of my survey in the afternoon of 8/5, small pop-up showers were in the area, but they provided minimal relief. Of the corn fields surveyed, most are in the late R4 (“dough”) to early R5 (“dent”) stage, with a couple of fields still in the late R3 (“milk”) to early R4 (“dough”) stages. Relatively minor tip dieback—presumably due to recent moisture stress—was prevalent in many, but not all, fields surveyed. Foliar and stalk diseases are starting to show up, but pressure still appears minimal at this time.

Soybean fields surveyed were primarily in the R4 (“full pod”) to R5 (“beginning seed”) stages, with some stragglers still in the R3 (“beginning pod”) stage. Again, no major signs of disease are showing up yet in the soybean fields surveyed. Japanese beetle feeding was easy to find, although it was still below recommended thresholds for control (https://farmdoc.illinois.edu/field-crop-production/insects/japanese-beetle-management-guidelines.html).

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.”

With frequent rains over the past couple of weeks, topsoil moisture remains adequate, and crop health is looking good across Coles County. Full-season soybean fields ranged from R3 (beginning pod) to R5 (beginning seed). I saw minimal disease in the soybean fields I surveyed. Minor Japanese beetle feeding was common in fields visited, although it was generally contained to the uppermost leaves and resulted in less than 5% defoliation overall. The couple of double-crop soybean fields I found were in the V3–V4 range, with growth just starting to poke through the wheat stubble. Corn fields were generally around the R2 (blister) stage, with some stragglers still in R1 (silk) and a few early-planted fields reaching R3 (milk). I saw minimal foliar disease in the corn fields I walked into, although some common diseases—such as northern corn leaf blight, Physoderma brown spot, and common rust—are starting to show up in the lower canopy.

With about 0.5–1.0″ of rain and some cooler temperatures, this past week, corn and soybean crops in Douglas County are looking healthy during this vital flowering period. Most soybean fields are somewhere between the full flowering (R2) and beginning pod (R3) stages, with a few fields moving into full pod (R4). At least 50% of the corn fields I saw during my survey had started to flower. Most of those fields were still in the early stages of silking and anthesis (R1), but a couple of fields I visited were entering the blister stage (R2).

Wheat fields I drove by had all been harvested. Many had been planted to double-crop soybeans sometime last week before the rain, and I saw a couple of farmers getting ready to roll again as soils dried enough to allow for field traffic. In the southwest part of the county, several alfalfa fields had their second cutting, with one or two still standing. Oat fields looked to be a week or so away from harvest.

The heat this week has certainly helped move the crop along in Champaign County. And despite a couple of pop-up showers, it has also helped dry out fields enough for post-emergence herbicide applications, which were needed—and probably a couple of weeks past due—in several soybean fields. Soybeans with good early-season weed control remain relatively clean. Many soybean fields are starting to flower (R1) or have reached full flower (R2), but there are still plenty of later-planted fields in earlier vegetative growth stages (V2–V3).

Early corn is about head high, around V14–V15. Brace roots are just starting to emerge in these fields, which will help in some cases where plants are still leaning from last week’s strong windstorm. Later corn is generally in the V6–V8 range and starting to grow more rapidly. I passed one wheat field already harvested during my survey and a few others that were fully mature (Feekes 11.4) and not far from harvest themselves.

Although the heat and break from the rain were needed for many farmers to wrap up early-season field operations, conditions could quickly tip toward the dry side with rapidly growing (and transpiring) crops. As always, timely rains will be critical to replenish soil moisture and minimize stress during these hot summer days.

After the strong storms that passed through the region yesterday (June 18), most fields in northern Vermilion County are saturated, with a little standing water in low-lying areas and compacted headlands. The storms also brought strong winds, but fortunately, the damage to crops seems to be minimal in that part of the county.

Most corn in the area was leaning, but there were only a couple of areas where the crop was nearly flat. The affected corn was on the more advanced end of the crop growth range in the region, which is around the V8 to V10 growth stages. However, I saw minimal greensnap, so much of that corn, which is currently horizontal, will likely recover — albeit with a goosenecked stalk. Later-planted corn, generally in the V3 to V4 range, was affected little by the winds.

Soybeans ranged in growth stage from V1/V2 to R1, with some earlier-maturity soybeans starting to open their first flowers. Weed control in both corn and soybeans was mixed, with the wet conditions likely contributing to an inability for farmers to get timely postemergence herbicide applications completed.

I found a couple of wheat fields during my survey, both of which were in the Feekes 11.2 growth stage, with kernel starches at a “soft dough” consistency.

I traveled north to Ford County for my crop survey on Monday (06/09) of this week, and there was a bit of variability across the county in both growth stage and stand health. That variability was driven by soil moisture status, with saturated soils and localized ponding in low areas and headlands of fields in some parts of the county. Subsequently, these fields currently have uneven crop growth and canopy color, and in some cases, areas that will require a replant. However, most fields I saw during my survey appeared healthy, overall. Corn ranged in maturity from V2/V3 up to V7/V8. Similarly, soybean fields ranged from VE (a couple fields) to V3/V4. The few wheat fields I came across were moving into the ripening stage (Feekes 11.1), with grain heads turning to a golden amber color and kernel starches turning to a milky substance.

At the time of my survey (6/3) in northern Champaign County, soil moisture conditions were near normal in the top several inches, although some wet corners and low areas of fields could still be found. But with about an inch of rain falling on Wednesday (6/4), soils are currently a little on the wet side. Overall, the corn and soybean crops are looking healthy in the area with some of the corn starting to take off. The average growth stage of corn fields encountered during my survey was around V3-V4 with some of the earlier planted fields reaching V6-V7. Side-dress ammonia was being applied in a few corn fields in the area, as well. Soybeans were largely in the VC-V1 range, with a few fields a bit further along. Weed control looked good, for the most part, and post-emergence herbicide applications had been made in many of the soybean fields visited. Wheat fields surveyed were finished flowering (Feekes 10.5.4) but developing kernels are still in the “watery ripe” stage.

All but maybe a handful of corn and soy fields have been planted in Douglas County. For both corn and soy, most fields are still in earlier stages of development (V1-V2), and I also saw several fields that were just now emerging (VE). However, there were a number of fields in certain pockets of the county reaching V3-V4 for soy and V4-V5 for corn. The few wheat fields I saw were on the tail end of flowering (Feekes 10.5.4).

Weed pressure appeared to still be low in most corn fields, but I found a few soybean fields that will be needing a post-emergence application before too long. With warmer weather and not too much rain in the forecast next week, soils should be dry enough to handle traffic in most fields. The warmer weather also means emerged weeds, particularly waterhemp, will grow quickly, thereby reducing the efficacy of chemical control options. Because of this and varying degrees of herbicide resistance in waterhemp populations, it is recommended to apply post-emergence herbicides when waterhemp is no more than 3-4 inches in height. For more information on waterhemp biology and control options, check out the resources on the Getting Rid Of Weeds (GROW) website.

https://growiwm.org/wp-content/uploads/2024/09/20200921-factsheet-waterhemp-ada-usdadraft.pdf