
Douglas B. Gucker
IL Extension
dgucker@illinois.edu

Douglas B. Gucker
IL Extension
dgucker@illinois.edu
DOUGLAS B. GUCKER UPDATES
The majority of the corn and soybean fields are in good to excellent shape. The exceptions are those fields that have suffered some type of weather issue – flooding, storm, or wind damage.
Soybean fields are mostly at the R5 stage, with some at the R6 (full seed) stage. I am noticing Japanese beetle feeding, but at levels below treatment thresholds. Also beginning to see bean leaf beetles showing up in the fields.
Corn fields are mostly in the R4 or R5 stage, dough to dent, but do see the occasional corn field in the R1, Silk stage. Corn leaves are showing minor leaf diseases currently, mostly a little gray leaf spot.
Corn and soybean crops are generally looking good, with the only exceptions being areas of fields that experienced flooding or waterlogged soils earlier in the season. Leaf disease pressure is low in fields except those fields where plants experienced stress from waterlogged soils.
Last week’s timely rains had a noticeable impact on fields with low soil moisture and plant vigor. Soybeans are midway through the R5, Beginning Pod stage, and corn is in the R4, Dough stage, with kernels beginning to dent.
Crops are looking good. Soybean fields are not showing any signs of disease symptoms in the upper soybean canopy. Corn is advancing to the dough stage in early-planted fields.The majority of central and eastern portions of Illinois have had below normal rainfall for the first 29 days of July, as evidenced by the brown grass in pastures, lawns, and roadsides.
Crops are generally looking good. The exceptions are fields that suffered earlier issues of waterlogged soils or storm damage. Amaranth weed control has been a problem for non-GMO soybean producers relying on Group 14 herbicides, with insufficient early-season herbicide control of these plants. Dr. Aaron Hager’s research shows improved amaranth control in non-GMO soybeans when metribuzin is applied at appropriate rates either PPI or at planting. Soybean fields vary from the R1 to R4 growth stages.
No-till double-crop soybeans are growing very well, reaching the V3 stage.
Corn fields vary from almost VT to R3 stage. Nitrogen deficiency is apparent in fields where there were waterlogged soils. Corn leaf diseases are beginning to appear – Gray Leaf Spot. Physoderma Brown Spot can be seen in a few isolated fields in the low areas where water stood earlier in the season.
Crops are growing well with soybeans in the R2 to R3 stages, and corn is in VT to R1 stages. So far, not seeing any leaf diseases in corn or soybeans. Japanese beetles are being seen feeding on tender vegetation, but are not yet evident in fields. I have not found any root feeding in corn, and root systems in fields planted under good conditions are looking healthy and strong.
The wheat harvest is quickly wrapping up in the wetter areas of the region, with double-crop planting following soon after.
Post-emergent soybean herbicide applications delayed by wet field conditions are wrapping up, with the target weed species larger than desired.
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.
Crops are growing well. Soybeans vary from growth stages V3 to R1. Corn fields vary from V4 to V12. Earlier in the week, farmers and custom applicators were trying to finish up post-emergent herbicide applications ahead of the forecasted rains and storms. Unfortunately, still seeing a few farmers attempting to control tall waterhemp that exceeds the 4-inch recommended height limit for effective control.
Soybeans vary from V2 to V5 in general, with some fields showing the effects of early crusted soils and reduced emergence in those areas. Tall waterhemp has reached the 4-inch stage by the middle of the week. Corn varies from V2 to V7. All the crops have good color in spite of it being dry for the past 14 days. NOAA shows that the 3-county area has 2 to 3 inches below average rainfall over the past 2 weeks. Grass is browning in the lawns.
First cutting hay is being made. Sidedressing of corn is wrapping up, and post-emergent herbicide applications are in full swing.
Planting is over 90% completed in my three-county area. The rains of the past week brought anywhere from nearly 3 inches of rain in the southern portions to just over 1/2 inch in the NE portion. Generally, the emerged crops look good, but areas of some fields are showing uneven emergence due to soil crusting. In an effort to get fields planted ahead of the May 15 rains, some fields were tilled when the soil was too wet, and they are now experiencing weed control problems due to incomplete control of emerged weeds.
In my three-county area, we are more than two-thirds planted, but that varies from area to area depending on rainfall amounts and field drainage. All plants are showing leaf damage from one or a combination of high winds, blowing soil and severe storms. This leaf damage can be seen in the photos.
With the high winds, we have experienced dust storms in select locations across the three counties.

