Southern Illinois experienced planting delays this spring due to excessive rainfall, which pushed field activities into late May and early June. Despite these challenges, soybeans are currently at the R2 (full bloom) growth stage, and the corn that was planted has also reached reproductive stages. One field I scouted showed significant defoliation caused by insect pressure from bean leaf beetle, Dectes stem borer, and striped blister beetle, all of which can continue to impact soybean growth and development if not properly managed. At the R2 stage, the defoliation threshold for bean leaf beetle is 15–20%, and for blister beetle, it is 15%. At these levels, an insecticide application is warranted to prevent economic yield loss.

The beans are TALL as they enter the mid-R stages of growth. All fields I scouted this week were between R3 and R5 (beginning pod to beginning seed), depending on planting date. Corn is currently around the R3 to R4 (milk to dough) stage.

Stephanie and I saw some red crown rot in soybean fields around the Shelby/Macon County area, specifically in fields where she found it two years ago. The disease shows very visible symptoms, including yellowing and browning between the leaf veins (interveinal necrosis) as well as reddish discoloration at the base of the plant near the root. When you look at the root of a soybean plant infected with red crown rot, you’ll often notice white fungal growth (mycelia). Warm soil temperatures (77–86°F) are ideal for this fungus to thrive, so the recent warm days have likely contributed to its presence.

Corn and soybean fields across McLean, DeWitt, and Sangamon Counties have now reached the reproductive stages, with soybean fields closing their canopies and tassels clearly visible across every corn field I’ve driven past this week. These reproductive stages, combined with recent hot weather, create favorable conditions for insect and disease pressure—both of which are likely present by now, especially where preventative applications weren’t made. The heat is expected to ease starting tomorrow, which is good news for corn yields, since elevated night temperatures can greatly impact production. In corn fields with nitrogen deficiency, lower leaves are firing and showing the characteristic V-shaped chlorosis/necrosis. While rainfall has been consistent across the region, it remains scattered, with some areas receiving several inches over the past week.

Some late vegetative corn fields (V12+) in Menard County and northwestern Sangamon County are severely lodged from the tornadoes that went through the area on Wednesday (6/18). While some fields lay flat, there seems to be minimal snapping. Other later-planted corn fields in the region range in their vegetative stages (V5–V10) and were left standing after the high winds.

Soybeans appear unharmed by the storms and are starting to flower, although later-planted fields are still around the V4–V5 stage. While scouting, we noticed that Japanese beetles and grape colaspis beetles were beginning to appear, but in very low populations, and leaf-feeding damage was few and far between. Many fields are still growing out of foliar damage from their post-herbicide applications.

A wheat field in Menard County was starting to turn and will likely be ready to harvest within the next couple of weeks.

Attending the Illinois Wheat Plot Tour provided valuable insights into wheat development and the progress of corn and soybean planting in Macoupin and Montgomery Counties. Overall, wheat is flowering and conditions appear favorable, with only minor occurrences of bacterial leaf streak and tan spot observed in the fields we visited. Based on head and spikelet counts, estimated wheat yields are 100.38 in Macoupin County and 89.59 in Montgomery County. Corn and soybeans are beginning to emerge and are in their early vegetative stages, although many fields have yet to be planted due to wet spring conditions.

Attending the Illinois Wheat Plot Tour provided valuable insights into wheat development and the progress of corn and soybean planting in Bond and Madison Counties. Overall, wheat is flowering and progressing well, with insignificant occurrences of lodging and disease. Wheat yields are estimated at 93.77 in Bond County and 75.15 in Madison County based on our head and spikelet counts. Wet conditions have had discernible impacts on corn and soybean planting progress as most fields appear to be untouched by farming equipment.