Fungicide season is wrapping up for both corn and first crop soybeans. Varying reports of corn pollination issues which could be attributed to weather conditions during pollination or early grain fill. Soybeans look great and double crop soybeans are really taking off!

Most corn and soybeans in Douglas County have progressed into flowering stages. The primary exceptions to this are areas of fields where early season inundation led to crop stunting as well as a handful of fields where planting was delayed due to wet conditions, which now contain soybeans. These fields, as well as the few wheat/double-crop soybean fields I found, have soybeans ranging from late VC to early V4. Corn that has entered reproductive growth is still in the early stages, generally R1 (silking) to early R2 (blister). Developing pods can be found in the lower canopy of many soybean fields (R3). Foliar disease issues still appear to be minimal in the county. Low spots in soybean fields still have a visibly lighter color as they try to recover from saturated soil conditions and possible soil-borne pathogen pressure. In corn, I found a couple fields with some Physoderma brown spot/stalk rot symptoms starting to show. This pathogen doesn’t generally cause economic losses, but it may be taken into consideration when prioritizing fields for harvest to minimize loss potential from lodging (https://cropprotectionnetwork.org/encyclopedia/physoderma-stalk-rot-of-corn).

A favorable week for crop growth in the northeast region of Illinois. Corn is pollinating, despite predicted 90 degrees plus highs this week, most fields have adequate moisture and should not suffer despite elevated temperatures at this critical stage for the corn crop. I enjoy my early morning coffee looking across several corn and soy fields. This past week I noted most mornings start with a mist or fog. The mist does not come directly from the corn and soy crops, even though both put water vapor in the air through the process of transpiration. The morning mist is the result of the cooling of the moist air. As the air cools overnight, it reaches its “dew point” and can no longer hold water as a gas, causing water vapor in the air to turn into liquid droplets. Of significance to those scouting for crop diseases, the morning mist extends periods of leaf wetness, a favorable requirement to several fungal leaf diseases. This week, with the appearance of brace roots in the corn crop, the question of underground root expansion was raised. There are many limiting factors to root growth, too much or limited moisture, soil compaction or other natural barriers. However, the general suggestion is that root expansion in the corn crop continues through pollination. At this point the crop redirects energy toward grain fill. By this time with favorable soil structure, it is not uncommon for corn roots to extend to six feet in depth. Our soy plants tend to generate roots further into the vegetative stages, to R5 and R6, beginning and full seed.
The corn crop is R1 with kernel fertilization underway. Soy is between R2, full flower and R3, or beginning pod. Despite favorable conditions for leaf diseases, I have yet to see an outbreak of tar spot on corn or soy leaf disease in fields I have scouted. Growers are encouraged to remain diligent with both field visits and local reports.

This small area around the Kaskaskia River near Vandalia has been greatly affected by flooding. Both corn and beans in the floor plain are far behind, with large areas not able to recover. Large acres of soybeans were covered in mud and had corn residue stuck halfway up the plant. This has delayed the growth that would have normally been seen with the heat the area has received. The last rain on the 11th cleaned most of this up. It will be interesting to see how much if any is replanted. Double-crop beans are well under way.

Continued rain has been the story in south-central Illinois, with 0.63″ for the week ending 7/11/2026 and 1.83″ month-to-date for July. This has led to some prevented planting claims for soybeans in the area, including double-crop soybeans. This will provide an opportunity to close some combine ruts, manage residue, possibly clean a drainage ditch later in August. Have to figure out a good cover crop solution for the stubble, probably spring oats and crimson clover in August.

Early corn has reached R1-R2 growth stage, with good yield potential and fairly consistent pollination. Mid-season corn should tassel in the next week to 10 days. Replant corn is still at least a couple weeks away from pollination and has struggled to grow in wetter zones of fields. The ear leaf picture above illustrates how little disease pressure we see in early corn this year – no evidence of southern rust or tar spot yet and very little grey leaf spot (well below thresholds to trigger spraying). But recency bias from southern rust and tar spot in 2025 is leading many growers to make prophylactic/preventative fungicide applications to corn, even in the absence of disease. My suggestion would be to continue scouting and wait – we can still see a benefit from an application as late as R3 if disease shows up. And keep a close eye on the late-planted or replant crop, as the early corn could serve as incubation chambers for the late crop.

Early soybeans are R3-R4 and looking better now that rains have tapered some. Still some slow growth and general yellowing in low-lying areas that received too much water. Late season weed pressure could be a challenge this year, as high rainfall has allowed waterhemp to recover more effectively from post applications and has led to some degradation of residual herbicide. Some defoliation is present in the upper canopy but below threshold. And septoria brown spot is very prevalent in the lower canopy, as is commonly the case this time of year. I don’t see anything that would lead me to apply fungicide/insecticide to beans at this time.

Fungicides and disease scouting is our focus this week to ensure we are ahead of these yield robbing diseases. Corn and soybeans have had a great week with plenty of moisture in the soil and sunlight to keep growth and development active especially soybeans. They have turned from a visual yellow color to more of a dark green color across the region with the break in rainfall we have had this week. Aerial fungicide applications have kicked off with corn, and some ground fungicide applications have been sprayed in early planted soybeans. In the upcoming weeks fungicide applications will be in full flight.