Early-maturity soybean fields are turning yellow and shedding leaves as they approach the R8 (Full Maturity) stage. Most soybean fields are just beginning to show a little yellow.
Corn harvest has just started, with a few farmers taking out end rows and taking advantage of local elevators offering reduced drying charges for corn at moisture levels under 30%. Corn root and lower stalk samples from fields with lodging issues were submitted to the U of I Plant Clinic and were diagnosed with both Rhizoctonia crown and stem rot and Pythium crown and/or root rot. Corn ears are varying quite a bit in size within fields.

Entering September an intense shift in weather as a “heat dome” became established in Northeast Illinois. While fields near the Wisconsin state line received precipitation, most areas did not. The ninety degrees plus days provided ample Growing Degree Days (GDDs) for crops finishing grain fill. On lighter soils the temperatures are causing a water deficit reflected by the wilting/yellowing plants. As mentioned in previous reports, there is very good corn, and not as good, depending on where you collect samples. This week I collected from fields that should be very high yielding.

Few things are left to surprise me in this growing season, but a sunflower field in Kendall County did just that! Not sure when the field was planted or harvest plans for the crop, but an interesting rotation option. Several winter wheat fields that had been harvested earlier in the season are now supporting a robust weed population. Farmers should consider mowing, tillage or a chemical option to prevent these weeds from adding to the weed seed bank. For those considering a third or fourth cutting of alfalfa, an often asked question is when? Adequate time is needed for regrowth of alfalfa to replenish root carbohydrates to increase overwintering ability of the perennial crop. Our general answer has been four to six weeks before a killing frost for the hay crop. Newer recommendations encourage farmers to look at GDD’s, with a minimum of 500 GDD’s between last cutting and a killing frost.

After a week of some welcomed dryer weather, and perhaps less welcome heat, the crop in southern Vermilion County is progressing quickly towards maturity.

Most soybean fields in that part of the county were somewhere in the full seed (R6) growth stage, with a couple fields starting to drop leaves and close in on beginning maturity (R7). Some pockets with disease issues could be found and are relatively easy to spot at this point in the season, as they tend to be a bit stunted and yellowing/dropping leaves faster than surrounding areas. But for the most part, most fields are relatively clean of disease as they near maturity.

Most corn fields are somewhere in the dent (R5) stage. I did not find any kernels at black layer in the fields I surveyed, but there were at least a couple fields that were very close. As these fields senesce, more foliar disease can be seen in the canopy as well. Even if it won’t impact this year’s management decisions, now is a good time to scout your fields to determine how well your disease management plan worked this year. Over time, these observations can help you determine which diseases may be more prevalent in certain fields as well as help you determine the influence of genetic resistance in your chosen hybrids to different diseases. Another reason to scout now is to asses the levels of stalk rot and lodging in your fields. I found a couple fields during my survey with some localized lodging due to crown and stalk rots. The use of drones or recent satellite imagery, if you have access, may help to assess extent and severity of lodging and help with prioritization of harvest activities.

Harvest season is coming in HOT! Literally… as temperatures are reaching 100°F in many areas of central Illinois this week.

It seems that September 1 hit and soybean fields started turning, as many full-season beans in these counties are hitting R7 (beginning maturity) or pushing R8 (full maturity). A few farmers have begun dipping their toes in corn harvest, as I saw a few guys stripping off end rows. This high heat will accelerate crop dry down, especially since early-planted crops were already pushing maturity in many areas of Sangamon, Christian and Montgomery counties. Fall is definitely whispering to us and I expect harvest to be in full swing within the next couple weeks.

Black layer is near for some corn fields in the Northeast region. Utilizing the U2U Decision Support Tool – Corn GDD suggests a 108-day Hybrid planted April 25th in Grundy County will reach black layer between September 1st and the 6th. In corn fields scouted, especially those that did not receive a fungicide application, foliar leaf diseases continue to hasten leaf area necrosis and yellowing of plants. This is going to be a challenging year for accurate corn yield prediction from the perspective of in-field variation. Growers are encouraged to sample multiple locations within the field, accounting for pollination differences in ears to more accurately assess predicted yield. Some soy fields are starting to show very limited disease symptoms including Sudden Death Syndrome. This fungal pathogen can survive the winter in both corn and soy residue. Infection takes place early in the growing season, enhanced by cool and wet soil conditions. The visible symptoms we see are the result of a toxin produced by the disease that is translocated to upper canopy leaves. There are several other diseases including Red Crown Rot and Brown Stem Rot that exhibit similar leaf symptoms.

Earlier-planted soybean fields are beginning to turn color, signaling the Beginning Maturity (R7) stage. Other soybean fields are mostly in the Full Seed, R6 stage, and no longer blooming.
Earlier-planted corn fields are looking ugly with areas of the fields showing severe N-deficiency symptoms and dead plants, which is indicative of a root or stalk disease issue. Corn crown rot is suspected to be the cause in some of the fields. I currently have several corn plant roots and lower stalks being analyzed at the U of I Plant Clinic in the hope of determining the cause or causes. Local farmers are preparing for a challenging beginning to their corn harvest in the area.