Topics:

– Temperatures & GDU Accumulation

– Corn Update/Disease/Water Usage/Weather Update

– Corn/Soybean Insect Update

TEMPERATURES & GDU ACCUMULATION:

As of August 24th, we have accumulated approximately the following for Growing Degree Units in 2026:

Planting Date     GDD’s2026          Average GDD          Departure from 30-yr average           2025

April 16                  2427                          2200                                +227  (+11 days)                        2375

April 21                  2384                          2169                                +215   (+11 days)                        2341

April 25                 2323                           2140                               +183   (+9 days)                         2307

May 1                     2315                           2100                                +215   (+11 days)                        2262

May 8                    2256                           2039                                +217   (+11 days)                        2179

It’s hard to believe, but we have gained 3 days since the update on August 10th.  On August 10th, we were 7-8 days ahead of the 30-yr average and now we are 9-11 days ahead.  This gain came from warmer than average nighttime temperatures.  Nighttime temperatures have averaged 2-4 degrees above normal for the month of August, while daytime temperatures have been normal to 1 degree below normal. While August felt cooler to us, it wasn’t necessarily so….it just FELT cooler than July!  August moisture has also been above normal.  See maps below:

     

The first map shows Total Precipitation Ranks by Climate District so far in August.  NE Nebraska district has had the 4th wettest August in the past 134 years.  This is also reflected in the Percent of Normal Precipitation map for Nebraska over the past two weeks, where we are running 200-300% above normal.

CROP UPDATE/WATER USE/WEATHER UPDATE

• Crop conditions: Much of the Corn crop in the area is in the Full Dent to 1/4-1/3 milk line….some 1/2 milk lines on fields planted April 16th or so, and early maturity.  Last year at this time, corn was Full Dent to 1/8-1/4 milk line, so we are currently slightly ahead of 2025.   Soybeans are running ahead of normal as well.  Early planted soybeans are in the R6-R6.5(full seed), with May planting dates in the R5-5.5(Beg. Seed) stage.  These stages-of-growth track with the above GDU accumulation of one week ahead of normal.
• The hybrids that we currently plant today, perform best with a long grain-fill period….we like to 3-4 weeks of good fill weather once crop reaches full-dent for highest test weights, kernel depth, and good late-season plant health.  So far, we are seeing good kernel depth in area fields and early grain color also looks good.  Late-season plant health will be dependent upon the ‘race-to-the-end’ with disease and spider mites….more on this below.
• Relative Humidity – With all of the foggy mornings over this past month, it doesn’t surprise anyone that RH has been much-above normal for August.  See graph below:
• 
• The graph shows daily maximum RH for Norfolk for 2026.  The black line represents the average.  Note the far end of the graph for the month of August….note how everyday in August has been above average.  This helped to lower ET rates over the past few weeks, but has the potential to increase disease severity.  Next few weeks will tell the story on this….
• Total Water Needs to Finish:
•          
• The above charts show water still needed for corn and soybeans.  At current crop stages, corn is needing anywhere from 3-5″ to finish and soybeans are needing 4-6″ to finish, depending upon weather and planting dates.  If no rain, we are not done irrigating….
• Sunlight – As always sunlight becomes a major player during grain-fill for both yield and late-season plant health.  See graph below for the month of August:
• 
• The above map shows the daily solar radiation anomaly for Elgin so far this year. Note the far end of the map which shows the month of August. So far, August has been, on average, below normal for sunlight.  Not surprising considering the fog, etc., we have been experiencing.  We always stress how important sunlight is for kernel depth and test weights, and it plays a big role in overall plant health.  Hopefully, we will get back to more sunlight to finish the grain fill period!
• Diseases – So far the 2026 growing season has seen much reduced leaf disease pressure overall when compared to 2025.  We are starting to see Southern Rust show up, but this is coming in very late, and is not anywhere near the yield-robbing levels it was in 2025.
• We continue to monitor for Tar Spot.  We continue to see this disease show up in higher levels than last year, but we are now starting to see it greatly increase in area fields, especially further west of Elgin. Greatest impact from this disease will most likely be on late-season standability. We will update for any impact on harvest as the growing season progresses to the finish line.  See link below for the recent Kick n’ Dirt podcast on Tar Spot….worth a listen.  Bottomline, disease will impact both final yield and harvestability for 2025.
• Tar Spot in Corn: When is Fungicide Still Worth It?
• For Soybeans, we are just now seeing a little White Mold show up in some fields.  Overall levels of this disease are very low considering the growing season so far.  This disease should not be an impact on irrigation management.  However irrigation management moving forward in soybeans this year, will have more to do with lodging than disease.   SDS is showing up in our area once again, heavier than in 2025 overall.  We continue to see increased levels of this disease each year.  Monitor fields for this disease and plan on seed treatment for next year in those fields showing high pressure….which is a fair amount of them now.  See discussion below on new product for SDS Victrato that will be offered for 2027.  In general though, overall disease in soybeans is low….
• Victrato: Introducing Victrato seed treatment as an enhancement to the LumiGEN seed treatment lineup for 2027. Victrato provides broad spectrum protection against early-season soybean nematodes and diseases, such as SDS and Red Crown Rot. This will replace Ilevo for SDS control and soybean cyst nematode control.  Has shown a 1.5 bu yield advantage over Ilevo, while providing superior plant vigor and protection against SCN, SDS and RCR, for the past two years in trials. This will be a great offering for SDS in our area!

CORN/SOYBEAN INSECT UPDATE

• Spider Mites – Currently we are finding spider mite colonies in many area fields.  Overall numbers are low in heavy soils, however, in conventional corn/white corn/popcorn fields we are seeing higher numbers due to earlier treatments for corn borer and western bean cutworm. Also seeing higher numbers in many sandy soil fields.  Some fields have been treated for this pest, so keep an eye on this insect over the next 7-10 days or so.
• Corn Leaf Aphids – These can be found in most fields.  They proliferate in high humidity conditions.  They are not a cause for concern….just more of a nuisance when walking through fields.
• Soybean pests – so far, insect activity in soybeans continues to be very light.  We are seeing some soybean aphids, but low numbers overall.  Expectations for major outbreaks of these pests are low….or, really outbreaks of any kind in soybeans, at this stage.

Reminder: The Pioneer Plot tour is scheduled for Wednesday, September 2nd….at the Jim/Dave Schiltmeyer Farm – 1/2  mile east on 838 Rd.

All for now!  Stay safe and thanks for your time!