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.