It feels very fall-like with low humidity and temperatures in the low 80s. The crop is proceeding well, and some corn and soybean harvest will begin next week, mainly March corn and late group 2 soybeans.

Conditions remain dry. We haven’t had significant rainfall since mid-July, and while some subsoil moisture is present, the area’s high clay content limits plant availability. After several weeks of heat, corn is showing stress, with leaves firing in areas of thin soil or earlier-season ponding. Corn is beginning to dent.

Most first-crop soybeans are in the R4 to R5 stages, depending on planting date. Later-planted and double-crop beans are still in R2 to R3 and could benefit from late-season rainfall, similar to the inland hurricanes from the Gulf that have boosted yields in recent years.

Rain showers earlier this week brought much-needed moisture to the area, giving some fields a boost. Most of the corn in Logan County has entered the R5, or dent, stage, with some fields still in R4, or dough. Soybeans are showing similar progress, with most fields in the R5 stage. The growing season is nearing its end, and some plants are beginning to show signs of full maturity.

After a wet couple of weeks in Northern Illinois, precipitation levels are nearly back to normal for the season. Most areas received 1 to 4 inches of rain over the past weekend, depending on storm tracks, which has primed plants to finish strong through ear and pod fill. Disease has become more prevalent as rainfall increased and temperatures dropped from the 90s.

Corn across the region is entering the dent, or R5, stage, with kernel development varying by planting date. Tar spot is usually the primary concern, but early southern winds this season brought in southern rust. While southern rust generally does not cause major yield loss, it may slightly reduce yields in fields that were not treated with fungicide. Because the disease does not overwinter in northern climates, it is not expected to be an issue next season. Tar spot is moving into upper canopies, but spraying this late is not recommended due to limited return on investment. Another issue observed in multiple fields is tip-back on corn ears, likely caused by poor pollination during extreme heat and drought earlier in the season.

Soybeans continue to look strong. With their height later into the season, some fields experienced slight lodging after severe storms over the weekend. Disease pressure remains low overall. White mold was found for the first time this season in some lodged beans, but incidence is expected to remain low due to drought and high temperatures during flowering. Overall, soybean yield potential looks very good.

Soybeans in many fields are reaching the R6, or full seed, stage, and late-season insect and disease pests are beginning to appear. A few fields are nearing R7, or beginning maturity.

Precipitation this past week brought substantial rainfall totals to some fields in Northeast Illinois. Isolated corn fields are showing significant disease pressure but are also nearing maturity. In the R5 stage, the corn kernel contains both “soft” and “hard” starch. The transition, or hardening, of the soft starch into hard starch begins at the top of the kernel and progresses to the tip. This progress is visible as the kernel’s “milk line.” Corn is typically about 55 percent moisture at the beginning of R5 and 30 to 35 percent at its conclusion. Corn plants generally complete the R5 stage in about 30 days, during which they accumulate dry matter content.

The soybean crop is nearing the R6 stage. At R6, or full seed, plants have a green seed that fills the pod at one of the top four nodes on the main stem. Once soybeans reach R6, new leaf growth ceases, and lower leaves begin to yellow and drop. We are encouraging growers, especially those with a history of the disease, to monitor their fields for white mold.

For those attending the Farm Progress Show next week, visit Illinois Extension at the University of Illinois College of ACES tent on West Progress Avenue.