We received some much-needed (if sporadic) rainfall in the last week that has crops looking much better than in previous weeks. Areas of Bureau County reported over 5 inches on Friday night, though that storm system petered out by the time it reached LaSalle County. LaSalle County did receive about 2 inches of rainfall on Wednesday night. Thankfully, temperatures have also cooled off a little bit for the time being, and there is more rain in the forecast for this weekend and early next week.

Overall, crops are looking healthy. Wheat in LaSalle County was harvested the first week of July. Most corn is now reaching VT/R1. Most soy is entering reproductive stages, with many fields at R3. I have not seen any serious disease or pest concerns in the fields I have scouted, but tar spot has now been reported in LaSalle, Bureau, and Marshall counties, so growers should continue to scout fields and be on the lookout for this disease. Corn is reaching the growth stages where it could benefit from a fungicide application, and I have seen both ground and aerial sprayers at work in the past week.

I have received a few reports of corn leaf aphid. This insect should be scouted prior to tasseling, during late vegetative stages; if you have colonies of aphids formed on around 50% of plants at this time, you should consider an insecticide. Beneficial insects and fungal pathogens usually do a number on this pest, and it takes extremely large populations to impact yield.

Last week brought sporadic pop-up showers that benefited some fields needing a shot of rain to support growth and development in the reproductive stage. A few corn fields are still in the late V-stages, while nearly all have tasseled and ears are beginning to show. The same can be said of soybeans, with nearly all fields across the county at least in the R2 stage.

The rains have finally arrived in northern IL, with a handful of widespread storm events and more starting this weekend and pushing into next week. Most areas have reverted to D0 or D1 drought status, and crops are doing well. Will County is the only area still in a D2 drought. With the rain and cooler temperatures in the forecast, disease may finally start to creep into our corn and soybean plots. This late in the season generally won’t have a large impact on yields, but scouting is still recommended through ear fill in corn, as well as scouting for white mold and frogeye in soybeans.

Corn is tasseling across the I-80 corridor. The DeKalb area was around 80% of fields at VT/R1, with the stragglers around V12/13 and spiking. Corn blotch leafminer is showing up in the lower leaves of multiple fields I scouted between DeKalb and Crystal Lake. This is also the kind of weather tar spot thrives in — wet, with intermittent rains and cooler temperatures overall. I would not be surprised if it is already in fields in northern IL or develops quickly with the upcoming forecast. Scouting is your best measure to know if it’s in your fields, as always. Corn overall is healthy, and I have not seen any fields with wind or hail damage despite the severe weather we have been seeing.

Soybeans are pushing quickly through growth stages. Most bean fields I scouted are in R3 and nearing R4 very quickly, if they aren’t already there. Disease pressure is low currently, with small amounts of Japanese beetle damage, but nothing that will lead to economic loss. I will be scouting heavily for white mold, SDS, frogeye, and other fungal diseases in the coming weeks if the water has turned on and stays on.

Spotty storms this week have dumped 1″–3″ of rain across Marion County after our longest stretch without precipitation since March. Our soils didn’t get dry exactly, but this moisture will help see the crop through the heat. This rain also helped even out some stands of double-crop soybeans in spots where the seed didn’t quite make it through the straw down into the soil and had yet to germinate. Most double-crop soybean fields I’ve seen are at V2 and looking good. First-crop soybeans are R1–R2 unless they were planted or replanted late. There were still planters rolling the first week of July, and those are more on pace with the double crops.

Corn in the area is still in vegetative growth stages, but you can feel the tassel forming down in the whorl, so VT is on the horizon.

For a more upbeat report, I would encourage you to read my coworker Steve Brand’s report. Last week, in the area Steve covers in Northern Illinois, many fields received between 3 and 5 inches of rainfall. In areas including Kendall, Grundy, and Will, the rainfall totals measured in tenths. As many corn fields are at or nearing VT and R1 (tassel and silk stage), an expected result of the moisture stress is kernel abortion. Moisture stress at this time can interfere with pollen shed and silking synchronization. In addition, high temperatures coupled with low humidity can desiccate exposed silks.

Can farmers evaluate the pollination process? After successful pollination and fertilization of the ovules, the silk will detach from the developing kernel. Evaluating pollination success can be done with the ear “shake test.” Carefully unwrap the husk and gently shake the ear; the silks from the fertilized future kernels will readily drop off.

As long as we have kernels and green tissue for photosynthesis, we can remain hopeful for the corn crop. Our soy crop, while visibly shorter this year in the dry fields, can recover more readily if forecast moisture alleviates growing conditions in this area.