It’s hot! Temperatures exceeding 90 degrees for consecutive days in NE Illinois. Despite the ambient temperature both corn and soy fields are holding up well, but additional rainfall would be welcome. Most corn fields are at or near R3, the milk stage. Some ears have visible aborted kernels at the ear tip. There has been minimal to no leaf disease in corn fields that I have visited, but plan on staying diligent and listening to local reports and regional reporting resources including the Corn ipmPIPE for Tar Spot https://corn.ipmpipe.org/tarspot/ to be aware of areas where crop disease has been detected. The soy crop has responded to recent rains with increases in vegetative growth and most fields are at or near R3 or Beginning pod. When scouting fields, it is still not too late to look for symptomology of herbicide damage in fields.

Wheat harvest has mostly wrapped up in NE Illinois. This week fungicide applications started in earnest, I observed fields sprayed by plane, helicopter, ground rigs and a drone! Many growers simply include a fungicide application in their management plan; however, we still encourage scouting to determine disease pressure before committing to a fungicide application. Being aware of requirements and favorable conditions for certain diseases. Examples include Northern Corn Leaf Blight and Tar Spot, both require extended periods of leaf wetness (6 – 7 Hours) for establishment. With recent rainfall many have noted early morning mist settling over some fields, facilitating the leaf wetness requirement. For those still considering an application, the Fungicide Efficacy Guides (from Land Grant Universities) have been updated for 2023 and can be accessed at https://cropprotectionnetwork.org/news/fungicide-efficacy-guides-updated-for-2023
Will the dry weather in June and resulting shorter corn plants have an effect on final yield? One of the things I have noted scouting some corn fields is the amount of light reaching the ground. In my experience during good growing seasons very little light reaches the ground at R1. As the picture demonstrates, that is not the case in all fields this year.

Another week with precipitation, July has been much more favorable than June for northeast Illinois crops. Even with the rain, some no-till soy fields are noticeably lagging in growth behind tilled fields in our area, especially on lighter ground. Those scouting fields have an opportunity to evaluate their post herbicide applications. For many, these applications took place under very dry and unfavorable conditions. Post control and residual activity or lack thereof is evident in some fields. Waterhemp is pushing through the soy canopy and growing well in corn fields as well. Most corn fields are at or near the critical R1 or silk stage, most soy is at or near R2 or full flower/bloom stage. While scouting I noted my first Northern and Western corn rootworm adults in the area. Local wheat harvest has started and stopped between recent rains.

Welcome and timely precipitation this past week in NE Illinois. Some areas had 3+ inches of rainfall but most had less. Adequate for now, but continued precipitation would be welcome for many. Some of the earliest planted or shorter season hybrids are starting to tassel. The emergence of tassels visibly illustrates the lack of uniform growth in some fields, likely due to earlier season stresses. Soybean are currently R1 nearing R2 (full flower). Japanese beetle adults can now be found leaf feeding. Recent rains have mostly halted the wheat harvest in northern Illinois. Potato leafhopper damage clearly detected in Alfalfa fields.

Some fortunate NE farms received up to an inch of rain this past week. The rainfall helped our soy crop initiate new trifoliates, improving field aesthetics by hiding leaves present when post-herbicides were applied, giving some fields a “dinged” appearance. While recent rainfall was welcomed, signs of a very dry early vegetative season, and drought conditions, persist. Corn and soy are smaller than normally expected as we near July in our region. The competition for early season soil moisture is evident in corn fields having trees on their perimeter. Wheat harvest has yet to start in northern Illinois.

Another week without a hint of precipitation in most of NE Illinois, soy has basically stopped growing and corn fields are struggling to canopy between rows. My thermometer is registering 99 degrees this afternoon. I truly hope to share a different story next week, there is concern on how long these crops can hang on before suffering significant yield consequences.

In Northeast Illinois fortunate farmers and farms received measurable rain, those that didn’t continue to watch their crops struggle in drought conditions. While most are familiar with a corn plants defense mechanism of leaf wrapping to lessen moisture loss, soy has defense mechanisms as well. Under moisture limited conditions or excessive temperature, soybean plants will flip over their leaves. This exposes their silvery-green underside which reflects more light. This process can reduce temperature stress for the plant until it experiences more favorable conditions. Even under stress, I noted the first flowers on Soy plants this week. While our preference is to have a stress-free growing season, stress during the vegetative stages of both corn and soy are less likely to have yield impacts when compared to the reproductive stages if conditions improve. Scouting V10 corn, I noted an insect egg mass on an upper leaf hatching nymphs. What did I find? Confirmed by Dr. Nick Seiter, University of Illinois entomologist, as Stink bugs.

Many areas in Northeastern Illinois are experiencing a level of drought conditions. Corn is wrapping in some fields during the day in response to temperatures and lack of moisture. Soybean growth has slowed and most are hoping for more favorable conditions before applying post herbicides in this crop. When applied under the dry conditions post corn herbicide conditions were less than ideal. We encourage growers to evaluate the effectiveness of the applications within 1 to 2 weeks. Wheat in the area appears to be hastening to maturity, it may be an early wheat harvest in northern Illinois.

Northeastern Illinois is turning dry. Post herbicide applications are taking place in corn fields. Despite dry conditions weed growth and diversity of species has been impressive in some fields, including robust vining weeds including Burcucumber and Morningglory. Early planted corn is at V6 and Soy at V2. I received reports of heavy Alfalfa weevil feeding and below average tonnage from the first cutting of hay in the region. A reminder, mechanical harvest is an effective cultural control of this pest. The Alfalfa weevil has one generation per year and overwinters as an adult. Mowing and harvesting the field removes the insect’s food and shelter. In addition, harvesting the crop can expose the larvae to sunlight which can be lethal. While the Alfalfa weevil window of damage is nearly over, farmers are encouraged to continue to scout for other forage pests that can cause damage in future cuttings including Potato leafhopper.

Much of Northeastern Illinois has had a precipitation-free week. Soils are drying rapidly. Soy planted just before the most recent rainfall event is struggling to emerge in some fields. The soy hypocotyl cannot push through the crusted soil surface. Fields planted in this time period warrant a field scouting trip to evaluate emerged plant population. Most corn is near the V4 stage, Waterhemp has also emerged and is growing quickly in fields. Be aware of size restrictions on both crop and weeds with planned post herbicide applications. Sidedressing of corn with nitrogen and harvesting the first cutting of hay is underway in the region.