The heat is on and it has sped up the growth stages of both corn and soybeans. The corn growth stages of VT – R1 can be the most sensitive to heat stress. Warm nights (72F – 75F) combined with hot days can increase stress on pollen, silks, and fertilization, potentially reducing kernel set. But the good news is that we don’t have moisture stress and cooler weather is in the forecast. It has finally dried up enough to harvest wheat, plant double-crop soybeans, apply post herbicide on late planted soybeans, and apply fungicide/insecticide on early planted corn.

What a turn of events over the last couple of weeks from the start of the season. Heavy rains, hail, strong winds, and even tornadoes have brought out of the early drought and well past into extremely saturated soils. Areas hit hard by storms have significant standing water. Established crops have begun to show signs of stress and are being drown out in low areas with long standing water. Those who avoided the flooding are enjoying great moisture. We are seeing significant growth across both corn and soybeans.

Early in the season, there was staggered emergence, and lots of variability within fields and that largely faded out as crops even out with ample water. Field to field is still showing high variability and that is mostly due to staggered planting with rain events in April and early May. I’ve seen soybean fields anywhere from V2, with some fields approaching R1 flowering in the next week or so. Fields looks healthy as far as the crops are (outside of aforementioned flooding and water logging damage). With delayed emergence and plenty of water recently, missed post applications could become a problem quickly as weed pressure is taking off. I have not seen much if any disease in soybeans yet. The dry conditions early on prevented a lot of soil-borne diseases from taking hold such as pythium or phytophthora. Once soybeans start to canopy, we will need to remain vigilant for late season disease such as white mold and SDS. Overall, soybeans look good with all things considered.

Corn has started to jump growth stages quickly. Other than low spots and fields with extreme flooding, much like soybeans and corn are looking great. Most fields I visited were in the V5 growth stage, with some a little further west near Amboy at V6 and growing quickly. One thing to really look out for in corn will be disease in the coming weeks. Many foliar fungal diseases (Tar spot, Gray Leaf Spot, and Northern Corn Leaf blight) thrive in cooler, wet conditions with extended leaf wetness. These are the exact conditions we are seeing currently before an end of week warm up. Many of these diseases, such as tar spot, can infect plants but won’t show symptoms until 10-14 days after the initial infection. I would highly recommend scouting vigilantly starting next week to catch any early signs of disease so you can act accordingly. Early infections of tar spot can wipe out fields of corn, so, it’s very important to be on top of.

I will touch on wheat quickly. Fields are drying down nicely, with many fields ready to harvest. They appear healthy and disease-free from what I have scouted. If we catch some breaks from the rain, early July could be in play for harvest.

For help identifying windows when weather conditions are optimal for diseases to replicate, using the Crop Protection Network crop risk tool can be very helpful. This site has a multitude of helpful tools, and I will link it below.

https://cropprotectionnetwork.org/tools

Last week brought another 3 to 4 inches of rain across Logan County. This has helped alleviate concerns about drought or dry conditions in the short term. Despite the high winds from some of the storm systems last week, there appear to be very few signs of wind damage to crops. Nearly all of the corn is at knee-height or higher, with some of the earliest-planted corn at V9-V10. Soybeans across the county also look healthy, with the earliest-planted fields in the V5 stage.

With the incoming heatwave, we expect to have corn tassels by the 4th of July. With rain almost every week, it is no surprise that gray leaf spot has started to show up, and a few lesions can be found on the second leaf from the ground. Early planted soybeans are full of blooms and at R2. Septoria brown spot is just starting to show up on lower leaves. Fungicide applications will need to be made soon on both corn and soybeans. Interesting to note that I have not been able to spot many Japanese beetles yet. Meanwhile, rain has hindered post herbicide applications on late planted soybeans. It has also put a damper on the wheat harvest and planting double-crop soybeans.

Field conditions are still wet in northern Champaign County, with 2.5-3 inches of rain falling across most of that half of the county since June 17. A large proportion of fields I saw during my survey on Wednesday (6/24) morning had at least some low-lying and/or poorly drained areas with stunted, dying, or dead crop from the inundation those plants have experienced over the past couple of weeks. For the most part, these areas were relatively isolated in fields, and standing water is no longer present. However, I did see several fields with large areas of dead or stunted crop, some still with standing water. Relief from the wet conditions may still be a few days away, with more rain in the forecast for the remainder of this week. But drier conditions and warmer temperatures in next week’s forecast offer some hope.

Because of the generally wet conditions we had in this part of the state so far this season, crop progress is variable both across the area and across the field, in many cases. Healthy areas of corn fields are generally somewhere around V8, with some fields getting closer to the V10-V11 growth stages. Most soybean fields are still in vegetative growth stages, but I did find a handful of fields that have started to flower (R1) and a couple fields getting closer to full flower (R2). Wheat fields I checked were nearing full senescence with grain in the ‘ripening’ stage (Feekes 11.3) and could likely be harvested next week if the hot and dry forecast holds. As can be expected, weed control was variable across the area, with some fields presumably missing their timely post-emergence application windows due to the wet conditions. That said, I saw several sprayers on the roads while doing my survey, so at least some of those acres may get covered today or tomorrow, if the rain holds off long enough.

Crops are generally doing quite well, although severe storms on June 17 did bring high winds and hail to portions of the 3-county area. The majority of the corn is in the V8 to V12 stage, and soybean fields are in the R1 stage. Presently, seeing only minor Gray Leaf Spot lesions in a few fields, and no Tar Spot so far. Japanese beetles are emerging. Low areas in fields are showing ponding and water-damaged plants. There will be cornfields tasseling by July 4.