With only about an inch of rain over the past 30 days from a single event, the crop is drying down quickly in Northern Champaign County. Corn fields surveyed were generally at R6, or “black layer,” but are still a little way from harvestable. Most fields are still showing green leaf tissue above the ear leaf, but senescence will likely progress quickly with warmer weather in the forecast and minimal chances for rain at this time. Harvest operations were taking place in a couple of seed corn fields I drove by, but I didn’t see any combines rolling in production fields quite yet. Some soybean fields are at R8, or “full maturity,” and will likely be ready for harvest any day now, while others are still in the late R6, or “full seed,” stage—still green throughout much of the canopy. The couple of double-crop soybean fields I visited were at R5, or “beginning seed,” but may struggle to fill pods with the lack of available soil moisture.

Over the past few weeks, weather conditions have been fairly dry—so much so that many were hopeful for a shower or two to help finish grain fill. Thankfully, our territory caught a few nice rains, ranging from ¼ inch to 1 inch. Temperatures went from unbearably hot to super comfortable and fall-like, which has been a blessing after a long, abnormally warm spell.

In my opinion, as I’ve revisited corn fields after pollination, the ears have filled very nicely, leaving me anxious for harvest to begin. Last week, most of our cattle producers who chop silage put theirs up. A few growers have also started harvesting their early-maturing varieties, like 106–108-day corn, with moistures as low as 24–25%. Many of the hand-shelled moisture tests I’ve taken have been in the 28–36% range, so we may be a week or so away from broader harvest. I anticipate many more starting next week for sure.

As for soybeans, they are starting to change—and seem to change by the day. Early last week, we flew on the majority of our cover crop mixes that will be used for grazing this fall and into the spring. More planes will be rolling tomorrow, spreading rye and radish mixes over corn going to soybeans.

Harvest has begun, and very dry conditions are moving back in. Fire risk is becoming an issue as harvest picks up speed. Late-planted corn is in real trouble, and all crops are ripening fast.

Onward! Corn and soybeans both are marching toward season’s end. Fields in my area are really starting to have that “late-season” look this week. Much cooler temperatures arrived on 9/3, and daytime highs in the mid-60s really made it feel like fall. Walking through corn, I’ve noticed a significant uptick in foliar disease across the board. Some fields are showing quite a bit of GLS, and others NCLB, on and above the ear. Most notable to me, however, was the amount of late tar spot I’ve seen. Natural leaf firing from the bottom is a normal part of filling out the ear, but there’s a difference between that and earlier-than-normal leaf death from the culmination of tar spot plus two to three other leaf diseases. I’ve been in some fields that really need to be watched closely as harvest approaches, and I hope they don’t get a significant wind event. Stalks in the worst fields are already weak and prone to breaking just by crossing rows. Most ears look good and are well into dent stage, with milk lines ranging from ¼ to ¾. I expect black layer to be a couple of weeks away yet in most fields.

Soybeans are mostly into the full seed stage, and you can see the leaves beginning to yellow. Early-maturity fields are into leaf drop now, and some are probably 50–60% dropped. Pockets of Sudden Death Syndrome are beginning to show up a little more, but it does not appear to be as widespread as in some years. I have not seen any red crown rot in my area. Cooler overnight temperatures have led to some very heavy dews in the mornings. Lingering moisture on green leaves, plus a blue sky and sunshine, has caused a fair amount of sunscald on the bean leaves, but at this point I would not expect that to have any significant impact on the plant.

The earlier heat and lack of rain over the last 4 to 5 weeks brought an earlier senescence for both corn and soybeans. Some areas received a few tenths with the last storm that came through with the cold front, but it was too little, too late. Corn is just about at black layer, with some testing at 19.5 to 24% moisture. Many in the surrounding counties are getting ready to start harvest. The 3.5 maturity soybeans are just starting to turn R7, but the 4.0s are mostly green or at R6.

Cooler temperatures have arrived this fall (late summer, really) as we move through the waiting period of the growing season for corn and soybeans. Temperature averages in the 70s and low 80s have brought much relief after a very hot stretch across northern Illinois. Nearly every corner of Illinois north of I-80 is at normal rain and water levels, while downstate areas are beginning to enter into a slight drought, and plants continue to work through ear and pod fill. I have noticed diseases starting to really ramp up with temperatures dropping and heavy dews every morning.

Corn is still green and starting to fire as it reaches maturity. Most fields I visited were full dent, with the milk line in the ear around 50%—maybe a little further along in some places (west of DeKalb was scouted this week). With the cooler temperatures and daily dews, tar spot and ear mold in particular have taken off in corn. Every field I visited had lesions well into the upper canopy, with lower leaves turning brown, necrotic, and dying. The upper third of plants above the ear are still green, so ear fill is still occurring even as the bottom dies out. Ears are starting to see small amounts of mold on the ear tips as well. Black layer is most likely 10–14 days away, based on the milk line and cooler temperatures.

Soybeans are still mostly green, with select fields either planted early or of an earlier variety starting to turn and enter senescence. For as disease-free as we were early in the season, SDS has flared up across many fields and is starting to take off in hot pockets. This year is a very important year to scout your fields if you see SDS symptoms. Red crown rot is a new disease seen in the area that has the exact same foliar symptoms. The key characteristic to look for is a bright red color on the soybean stem just above the soil layer, and in some cases, red spore balls called perithecia. If you find what you think could be red crown rot, please contact your local extension office so we can work with you to get that sample tested for identification.

Other than that, we are moving along and marching toward harvest. Northwest Illinois and Joliet are a bit ahead of the DeKalb area in terms of maturity, and harvest will be right around the corner!