Scouting Report for Tazewell, Woodford, McLean, Livingston, and Champaign counties in Illinois
(Scroll down for NE and SD counties)
Reported by Robert “Bob” Starke, Ph.D.
Currently the CropVoice network is not indicating an above-ground fungal foliar disease that warrants in-season treatment. We will continue to monitor plots daily and conduct regular tissue sampling and will send a Disease Alert if any of your fields are at risk.
This past weekend marked the solstice, a traditional benchmark for transition to flowering, however we observed initial flowers in the region as early as June 12. Most beans are well into bloom now.
June has also brought with it warm, damp mornings with leaf moisture that sticks around until 10AM. These extended leaf wetness hours create a potential environment for fungal growth. To date, we have noted limited Septoria brown spot symptomology on unifoliate leaves (see picture below). This is normal – the leaves will yellow and fall off soon without causing yield damage.
(Septoria brown spot. Credit: Crop Protection Network)
Through our tissue sampling and molecular assays of plants around our plots, we have detected the presence of other soybean pathogens, such as Pseudomonas (bacterial blight) and even a bit of Cercospera leaf blight. Of note, there were some rain events locally that caused a bit of splash onto the leaves, causing these results but plants do not appear to be defending themselves from any infections at any of the sites currently.
In our scouting these past couple of weeks we have also encountered a wide number of fields with herbicide damage patterns that could be confused with early fungal infections (see picture below). Here, the distinguishing factors are timing and the lack of fungal growth at the center of any lesions. Easy to think you’ve come across something on a first look though!
Leaf with herbicide damage – NOT frogeye leaf spot. (Credit: InnerPlant Scouting)
Over the next 10 days we see a marked increase in modeled frogeye risk, with the region’s odds of infection increasing by ~7%. This will move some of the region from its current low risk category into medium.
The next few weeks are also critical for white mold that will infect through the flower. However, we are seeing less of an increase in this risk in this region with the recent and forecast high temperatures. Beyond our forecasts and tissue tests, the team at InnerPlant will continue to monitor the InnerSoy plots daily and will send a Disease Alert if any of your fields are at risk.
(Modeled change in frogeye leaf spot disease risk for next 10 days based on weather, leaf moisture, and other variables. Credit: InnerPlant Modeling based on the work of Damon Smith at the University of Wisconsin)
In advance of a Disease Alert, it is also great to consider fungicide efficacy for soybean foliar diseases. Speaking with your trusted advisor or consulting this resource from the Crop Protection Network is a great way to start.
Scouting Report for Cedar, Knox, Pierce counties in Nebraska and Yankton County in South Dakota
Reported by Tristan Mueller
The last couple weeks have been a wild ride for the soybean crop in Northeast Nebraska with strong storms bringing hail and wind, to temperatures pushing 100 degrees. We are past the solstice and the crop is entering or is already flowering with the moisture and heat.
Radar image from June 16, 2025 indicating severe hail storm. (Credit: National Weather Service)
With the hail, one of our plots near Coleridge experienced a near total defoliation on June 16 (see picture above of radar image at the time). While our field equipment and some plants survived the storm, losses were significant enough to replant some of our site to match the farmers’ fields in the area. Monitoring the hailed crop and the replanted crop may generate interesting insights on the effects of reduced stand and late planting dates on disease susceptibility. Our thoughts are with all those who experienced losses in the storm.
Currently, there is limited disease pressure to report in the CropVoice network. Our scouting and tissue samples as well as our fluorescing plants have indicated Septoria brown spot (see pictures below) on the lower leaves. Those leaves will yellow and drop off. This is a common disease that has little effect on yield and the crop does not need to be sprayed with a fungicide unless the disease starts to infect the upper third of the canopy.
First image is through fluorescent lens (bright green indicates the InnerSoy plant fluorescing, or signaling) that shows limited fluorescence related to Septoria brown spot in the lower leaves, as pictured in daylight on the second image zoomed in. (Credit: InnerPlant)
Speaking of our tissue samples, in addition to monitoring the fluorescence of our engineered soybeans, we are also conducting routine tissue sampling of the areas we serve. We deploy two types of sampling methods: a molecular assay, where we identify pathogens from small leaf punch samples, and full traditional tissue tests where whole plants come into our lab and we plate and culture out the bacteria and fungi present. This helps us ensure we are providing you with the best and most accurate information on the threats in your area.
Plates currently being cultured in our lab for analysis from field samples. (Credit: InnerPlant)
Looking forward, the next few weeks are critical for white mold that will infect through the flower. The weather-based models that we have developed alongside our sensor plants and lab work indicate that for irrigated 15” row beans especially, the risk increases from low/medium to high especially near the Missouri River bottoms along the Nebraska border (see picture). Furthermore, almost the entirety of the region east of Highway 81 moves up to at least medium risk. Of course, the team at InnerPlant is actively monitoring the plots daily and will send a Disease Alert as the situation evolves.
Weather-based risk model of white mold risk. Red lines indicate major roads, with Highway 81 running down the middle of the image; Sioux City at right. The first image indicates current risk and second image indicates 10-day forecasted risk. (Credit: InnerPlant Modeling)
In advance of a Disease Alert, it’s great to consider fungicide efficacy for soybean foliar diseases. Speaking with your trusted advisor or consulting this resource from the Crop Protection Network is a great way to start. For white mold control specifically, not all fungicides are created equal and only one active ingredient is rated as “Very Good”. Recommended timing to spray is from R1 to R3, but often a single application with an efficacious fungicide at R3 will have the best return on investment.
Catch up with any scouting reports you missed by following the links below:
Scouting Report for June 12, 2025
Scouting Report for May 29, 2025
Scouting Report for May 15, 2025