AGRONOMIC UPDATE: July 30, 2026….Crops moving along quickly….

             

Topics:

– Growing Degree Day Update

– What’s going on in my fields?…..Corn Development, ET rates, Disease, etc. 

– Insect Update

– Soybean Development

TEMPERATURES & GDU ACCUMULATION:

As of July 29th, 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                  1853                          1663                                +208  (+10 days)                        1787

April 21                  1818                          1633                                +185   (+8 days)                          1754

April 25                 1749                           1604                               +145   (+6.5 days)                       1720

May 1                     1734                           1565                                +169   (+7.5 days)                       1674

May 8                    1689                           1503                                +186   (+8 days)                         1591

As we have been for much of the growing season, GDU accumulation continues to run ahead of normal and we have gained 2+ days since the last GDU update on July 17.  Based on the above numbers and with continued normal-to-above normal temps for the rest of the growing season, we would need 40+ days to reach maturity for a typical 113-114 day hybrid (2700 GDU to physiological maturity) planted April 21st, which would put a potential black layer around the second week of September.  105-110 maturity would black layer during the first week of September.  These projections are based off of total GDU listed for specific hybrids to reach maturity.

These are just projections….and projections are just that….projections.  The likelihood of this occurring as mentioned above is not great, but it does give us a sense of just how fast the crop is moving along…which is normally not a positive to final yield, as this shortens the grain-fill period, which leads to reduced kernel depth and lower test weights.

The maps and graph below give us a greater sense of why the GDU accumulation is happening like it is….

                       

The two maps show the average high and low temperature ranks by climate district for the last 134 years.  For average high temperatures, 2026 is ranked as the 31st hottest July for high temperatures out of the last 134 years.  For average low temperatures, 2026 is ranked as the 17th hottest for average low temperatures out of the last 134 years. Restated in another way, only 16 years out of the last 134 years have been seen warmer average low temperatures in July than 2026.

The graph below shows this in another way.

The graph shows daily high/low temperatures for July at Neligh, NE, along with the 30-year average for both.  Note the departure from average for both high and low.  July had 24 days above normal high temperature and 26 days above normal low temperatures….this is why GDU accumulation (stage-of-growth) is so far above normal….this is enhanced due to the April planting dates for both corn and soybeans.  Bottomline is, we need the temperatures to cool off some over the next few weeks, so that the grain-fill period can be extended….best yields come from an extended grain-fill time….all else being equal, of course.

                           

Last comment on current conditions….the above maps show the total precipitation rank for July 2026 and 2025.  Note the big difference in just two years.  From the 2nd wettest out of 134 years in 2025 to the 100th wettest July in 2026.  Big swing, this will impact N-efficiency, rooting depth & overall rootzone mass, and disease development between the two years.

WHAT’S GOING ON IN MY FIELD?…..Corn Development, Disease, Crop Water Use..

Most of the corn crop is in the early-R3 (Milk) to R3 (Milk) stage.  This matches the above GDU numbers, as this is 7-9 days ahead of normal and 4-5 days ahead of 2025, which was also slightly above normal.

  • Pollination overall seems to be good so far.  Finding the usual checkerboard pattern of missing, or late pollinated kernels, on the butt of the ear, or scattered on the ear, but overall looks good.  Rows around look to be normal by hybrid as well.
  • Plant height this year is taller than a year ago, even the light sand is taller than last year.  While there are differences in plant height within a field due to heavy crop residue and/or rye cover spots, and/or dry conditions during and after planting, overall field uniformity for plant height and color is good.
  • Kernel abortion from stress can occur through the Milk stage(18-22 days after silking), however when the plant reaches Dough, kernel abortion will no longer take place, and any yield reduction from then on out will be from lower test weight.  We are currently in the ‘tip-back’ stage of growth.  This stage will last over the next two weeks or so.  Temperature, sunlight and moisture play a role here….currently, drought conditions will have the greatest impact overall here.
  • As far as sunlight is concerned, we are trending above normal. Sunlight, of course, is now a much bigger yield factor, since we are now in the crucial grain-fill period.   As such, how much sunlight, and when it occurs during the grain-fill period, will play a role in overall yield and late-season plant health.   Lack of sunlight early in the grain fill period (i.e. right now) can increase potential for the ear to tip-back.  Extra stress will occur if sunlight is reduced and temps (especially nighttime) are higher than average (so far, we have had good sunlight in this time of high nighttime temps).  This stress occurs because, since temps are high (especially nighttime temps), the energy demand on the plant is higher than average.  Couple this with reduced photosynthesis, and this leads to greater energy in the plant just going to maintain itself and not to filling the ear.  It is an axiom in corn production that when you have to run your air conditioner at night, it is not good corn growing weather. See graph below for sunlight for Elgin, NE in 2026. Note that we have had good sunlight so far since pollination….
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  • Relative Humidity for most of July has been average to slightly-below average.  It is only the past 7 or so days that RH had been above normal.  The lower humidity helped to slow disease development, but raised ET rates.  However, the higher humidity as of late is doing the opposite….increasing potential for disease development, but lowering overall ET rates.
  • Currently, corn leaf disease has been on the low side for much of the area.  We expect this to change over the next week or so due to the higher humidity, and if temps cool down.
  • Main leaf disease to currently watch for is Tar Spot.  This disease is just starting to increase in severity, and we are seeing the heaviest levels in the Bartlett area so far.  This disease is still an ‘unknown’ quantity for its overall impact, especially in the dry and hot conditions we have had over the past weeks.  However,  it can be a ‘fast mover’ once it gets established, and heavy irrigation can play a role by increasing development.  Northern Corn Leaf Blight is more noticeable this year in most fields due to the cool and wetter conditions of late-June.  If temperatures cool off for August and September, this disease will likely ‘get going’ again.  So far, we have not observed Southern Rust in our area, but it has been confirmed in the counties to the south and west of us.  Keep monitoring for leaf diseases, (even if field is already treated) over next few weeks for sudden outbreaks….
  • Fungicide applications should be on, or going on now.  Reminder, a fungicide will not help control Goss’s Wilt or Bacterial leaf streak.  We will soon reach the time for a second treatment if one is planned…especially if the 1st treatment went on mid-July.
  • ET Rates: Corn at Blister Kernel is average of .28/inch per day and Milk stage is .25″/day in normal weather….we are closer to .30+/day when hot & windy.  It has been hard to keep up irrigating in almost all soil types over the past two weeks.  However, some areas have received MUCH needed rain today, hopefully the whole area will receive a nice, general rain….
  • All things consider, much of the irrigated crop is in good shape…and even the heavy ground dryland has been hanging on relatively well….

SOYBEAN UPDATE

  • Much of the crop is in the late-R2(full flower) to R3(pod set) to late-R4(full pod) stage-of-growth, depending upon planting date and variety maturity. Much like last year, overall stage-of-growth is ahead of normal.  Overall plant height will be average to tall…the beans have really taken off as of late.  Keep this in mind when irrigating….already starting see some lodging in spots….
  • Peak water use, nutrient demand, and overall energy demand in the plant occurs at R3 and into R4 stage….i.e. right now and into the next couple of weeks!
  • ET rates in soybeans reach peak at R3 into R4 stage (.30+ in/day) and will continue to stay high through R6(full seed).   Soybeans have been ‘pulling’ just as hard as corn over the past couple of weeks. See comments above on corn ET rates, as the same applies for soybeans.  One will need to be careful not to water constantly to help reduce disease potential (see below on white mold) due to a constantly ‘wet canopy’.  Potential for a heavier outbreak of white mold has grown with the recent foggy mornings and higher humidity over this past week. If White Mold becomes a problem, it will be best to water at night and leave off during the day so the canopy has some chance to dry out.    In heavy soils, when irrigation is needed, we recommend running a heavy irrigation amount (.80 to inch+) and then leaving it sit for a while.
  • We are just starting to see the first signs of White Mold in a few area fields.  Weather conditions over the past week have been conducive for increasing development of this disease.  How much this disease will impact this year’s crop is unknown, however, if the high humidity of the past week stays through most of August, this will greatly increase the potential for this disease….lodged beans will also increase the likelihood of this disease as well. Any second treatments for White Mold should really be on by now.   See the attached link for White Mold management.    Managing White Mold in Soybeans   High temps and dry mornings will slow the disease down.
  • Sudden Death Syndrome – so far not seeing much for SDS in area fields.  We would expect to see more of this show up as the weeks progress.  Soil conditions at planting were conducive for development of this disease.  Soybean SDS Management
  • We are also seeing first signs of Frogeye in soybeans….just a lesion or two.  Keep an eye out for potential increase in this disease under these humid, wet conditions.

INSECT UPDATE – Corn & Soybeans

  • Western Bean Cutworm numbers are low this year.  They can be found in sandy fields, but overall infestation levels are low versus what we have seen in prior years.  Any treatments now will be strictly rescue…
  • We are just starting to see 2nd brood ECB moths start to fly.  Keep this insect in mind on your conventional and popcorn acres over the next two weeks….
  • Overall insect pressure in soybeans has been very light.   Very little defoliation going on yet.  Begin scouting for Bean Leaf Beetles as they will begin feeding on developing pods over the next few weeks.  So far we are not finding any Soybean Aphids.   If you have made an insecticide application already, or are going to, this should give you season long control unless a severe outbreak of one of these insects occurs.
  • Dectes Stem Borer – be on the lookout for this insect starting now and into harvest.  We have seen the adult beetles in some area fields over the past few weeks….actually pretty heavy amounts of adults overall.  Watch field edges first and let us know if you are seeing wilted and dying plants, as they move in from the grassy edges.  If you see this, keep these fields in mind for earlier harvest.  Dectes Stem Borer in Soybeans
  • Beginning to find a few small colonies of Corn Leaf Aphids (dark green aphid) in area corn fields.   They tend to proliferate under cooler and damper conditions, so numbers should be on the low side….unless August turns cool and wet.
  • So far just starting to see a few areas of Spider Mite colonies.  Expectations are for this insect to increase in numbers over the next several weeks due the hot, dry conditions we have had, and if the hot, dry weather stays.  Watch closely those fields that were treated with an insecticide over the recent weeks.

Please mark your calendar for the Pioneer Annual Customer Appreciation Supper, which is set for Friday, August 21st.  Invite will be coming out soon!  The Pioneer Plot Tour is tentatively set for Wednesday, September 2nd.

Please contact us with any questions or comments you may have!   Thank you for your business!!

Starman Seed & Supply, Inc.

 

 

 

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AGRONOMIC UPDATE: July 2, 2026….Have a great 4th of July….

             

TOPICS FOR THIS UPDATE:

  • Temperatures & GDU accumulation update
  • What’s going on in my fields right now…
  • Fungicide/Diseases in Corn,
  • Insect Update
  • Soybean Update

TEMPERATURES & GDU ACCUMULATION:

As of July 1st, 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                  1161                          1036                                +125                                                1116

April 21                  1117                          1005                                +112                                                1083

April 25                 1057                          976                                 +81                                                   1049

May 1                     1048                          937                                 +109                                                1003

May 8                    990                            875                                 +115                                                 920

Overall GDU accumulation has slipped some from the last update on June 11th.  The second half of June average temperatures were off by 4 degrees.  So far, 2026 is currently running 4-5 days above the 30-year average and very similar to 2025 and the 10-year average.  Even though the last half of June was cooler than normal, we are still on track to tassel/silk at normal dates.

         

Above are the 6-10 and 8-14 day temperature outlooks as of July 1st.  These change every day, so take with a grain-of-salt.  However, temperatures are trending to be above normal for the next two weeks.  Warm temperatures and full sun are always a positive….

What’s going on in my fields?

  • General conditions and Silking: The corn crop in our area looks very good at present time.   Overall color is good, holding up much better than last year at this time. Much of the corn crop is in the V11-V14 stage, which is tracking very close to normal and slightly ahead of 2025.   From V10-VT, corn gains a new leaf every 50 GDU’s, or about every other day.  Cooler temps will delay this to 2.5 days/new leaf.  Majority of tasseling will most likely be from July 13-24th.  Keep in mind that hybrids silk early, or late, versus their maturity rating.  It always seems to take a little longer than expected….see graph below for predicted silk date, etc., using current conditions and the 10-year average….planting date for the graph is April 21st, using a 113 day maturity hybrid….this is showing a silk date of July 17th…
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  • Kernels per row begin around V12 and will continue through and up to tassel stage
  • Nitrogen needs will continue to grow through tasseling and into early reproductive stages.  Nitrogen uptake in corn is very rapid now through tassel (up to 4-8 lbs per day).  As we have discussed in the past, today’s hybrids use nitrogen later in the growing season and into the reproductive phases.  You will want to keep that last shot of N available for after tasseling….40-50#.  Keep in mind that the higher amounts of rain received this week in some sandy soil areas may have caused some N leaching to occur.  Keep this in mind as you determine your final N applications.  Overall color, however, looks very good throughout the area….We are now into the rapid growth and accumulation of dry matter by the plant.  The window for brittle snap is still open from now to tassel….
  • Tasseling/Silking: Under field conditions, pollen shed usually occurs in the late morning and early evenings.
  • Pollen shed will extend for one to two weeks, but if field is uniform in plant emergence and height, pollen shed is 80% complete in 5-7 days from full tassel emergence….this will take place the week of July 13-21st.  Expect some unevenness in tasseling/silk emergence in many fields due to the heavy residue/dry soils causing slow emergence this spring.
  • At tassel, vegetative development is now complete; maximum plant height and root depth is achieved.
  • VT overlaps with R1 (silking stage) when visible silks appear before the tassel is fully emerged.  By definition, growth stage R1 (Abendroth et al., 2011) for an individual ear is defined when a single silk strand is visible from the tip of the husk. An entire field is defined as being at growth stage R1 when silks are visible on at least 50 % of the plants. This whole field definition for growth stage R1 is synonymous with the term “mid-silk”.
  • A captured pollen grain takes about 24 hours to grow down the silk to the ovule for fertilization.
  • Peak pollen shed usually occurs in mid-morning.   Some research indicates that pollen shed decreases after temperatures surpass 86F.   A second “flush” of pollen often occurs in late afternoon or evening as temperatures cool.   Pollen shed may occur throughout most of the day under relatively cool, cloudy conditions….. Crop Focus – Corn Pollination Success
  • Weather conditions influence pollen shed.  If the anthers are wet, the pores will not open and pollen will not be released.   Thus, on an average summer morning following a heavy evening dew, pollen shed will not begin until the dew dries and the anther pores open.  Similarly, pollen is not shed during rainy conditions.   Cool, humid temperatures delay pollen shed, while hot, dry conditions hasten pollen shed.  We have seen more problems with pollination under cool temps vs. warm temps.
  • Generally 2-3 days are required for all silks on a single ear to be exposed and pollinated, with the silks on the butt of the ear emerging first.  The silks will grow from 1-1.5 inches each day and will continue to elongate until fertilized.  If not pollinated, silk elongation stops about 10 days after silk emergence due to senescence of the silk tissue. Unusually long silks can be a diagnostic symptom that the ear was not successfully pollinated.
  • Silk emergence and growth is dependent upon turgid pressure within the plant, in other words how much water is available in the plant to cover all of its needs.   If this is limited, (ie. dryland, low-gallon wells, etc.) silk emergence will be slowed and delayed with potential to miss the pollen shed.   Under severe water stress conditions pollen shed will still take place like normal, however, silks can be delayed, which means potential for poor pollination.
  • It takes approximately 55-60 days from silking (R1) to physiological maturity.  So if a field is silking on July 15th, it will need until September 15th to reach maturity, given average weather.  Current 6-10 and 8-14 day forecasts call for above normal temperatures which would give us an average of 23-26 GDU’s/day.
  • High nighttime temperatures (ie. any stress) begin to play a role in final yield during grain-fill as this causes the plant to work harder to maintain both yield and overall plant health, thereby lowering potential final yield.

Corn Leaf Disease/Fungicide

  • The next four to six weeks will be critical for disease infestations and fungicide applications.  So far, overall levels of disease are very low in the area…even bacterial leaf streak is below normal. Keep in mind that if we see cool temperatures and wet conditions, potential disease outbreaks will increase exponentially, and we will also see a wider range of different diseases.
  • Tar Spot has been found throughout our area, but lesions are very low at present time and not easily found.  Hybrid tolerance is first line of defense with a fungicide giving added protection.  Pioneer offers the best hybrid tolerance to this disease in the industry.  The two graphs below are related to Tar Spot and disease in general and give us something to watch for as we progress in the growing season:
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  • The first graph is daily GDU accumulation using an April 21st planting date.  Main thing to note is the lower temperatures in the last half of June.  These two weeks were very conducive for Tar Spot  and Northern Corn Leaf Blight development.  These two weeks have set up Tar Spot to be heavy in the area once again.  However, if temperatures stay high and humidity is low over next few weeks, development will be slower compared to last year.
  • The second graph shows accumulated leaf wetness hours for Elgin over the past ten years using April 21st planting date.  Leaf wetness is an indicator for disease development and severity. The more hours a leaf stays wet, the higher incidence of disease infestation.  Main thing to note is how 2025 was the worst year over the past 10 years…how it climbed all year long, this was due to both environmental conditions and high rainfall. Now note that as of July 1st, 2026 is trending in that same direction….                                                                In other words, our fields are set up for both development of, and high incidence for, disease, as the year progresses.
  • We will keep you posted on this disease as the year progresses….   See slides below:
  • We have yet to see much for Southern Rust.  Hopefully, we will not see the same levels in 2026 as we have seen for the past two years.  Remember that this disease does not overwinter in our area and much move up from the south….
  • If you are planning on only one fungicide application, the best timing for this application is VT-R1, as the crop is working the hardest at this time and has the highest demand for energy.  We want to protect as much of the leaf surface as possible in this time frame, which is from pollination and the two weeks after.   Corn on corn acres are always a good place to start with fungicide applications.
  • While any hybrid can have a response to foliar fungicides, hybrids such as P05081, P05466, P09944, P0995, P09076, P1185,  P13476, P13050, P1413, P14830, & P15517, P1742 are hybrids to focus on first for higher probability of response from foliar fungicides…..
  • 2026 Pioneer Fungicide Considerations for Corn ….This attachment is a list of Pioneer hybrids and their potential response to a fungicide application for Gray Leaf Spot and Norther Corn Leaf Blight and Tar Spot. The chart also shows staygreen and stalk strength ratings for each hybrid.   This chart can help with fungicide management decisions.  Highly recommended to fungicide corn with current weather conditions….and with Tar Spot now fully in the area.
  • See attachments on disease and fungicide management – Maximizing Foliar Fungicide in Corn
  • 2026 Corn Foliar Fungicide Efficacy  This attachment shows efficacy and posted residuals by active ingredient.

Water Management

With the recent rainfall over the past two weeks, 2026 has just now reached normal precipitation for the year.  Heading into mid-June we were still 4+ inches short of normal, however, we are up 200% over normal since then, which brings us close to the norm….and the rains have allowed for good penetration and fill into the second and third foot of the rootzone.

Below are some key water management tips to keep in mind:

  • The greatest yield loss from moisture stress occurs in the period two weeks prior to two weeks after pollination.  For the next two weeks, the corn crop will be at its peak water usage, with ET rates of .30+ inches per day – higher when temps are in the mid-90’s, and higher yet when combined with low humidity….lower ET rates under cool and cloudy conditions.
  • ET rates over the past two weeks have been slightly below average…. .20-.23/day depending upon temperatures, etc.  However, we are reaching peak water use in corn, and with the potential higher temps forecasted out two weeks, it will be important to stay on top of overall water needs by the crop, as ET rates will move to .30+ through the next few weeks.
  • At present, we are seeing fairly good root depth according to the soil moisture probes….sandier soils are 20-28″, very similar to last year, and heavy soils are 24-36+”, depending upon plant date, conditions and soil type.  Remember that maximum plant height and root depth are achieved once the plant tassels.  It does appear that plant height will be taller than last year….also hoping that rooting depth and root volume will be greater than last year.

Insect Update

Western Bean Cutworm egg masses should begin to be found in sandy fields this next week.  They are just starting to fly.

Keep these tips in mind over the next few weeks:

  • To scout for this insect, check the sandier fields first and look on the upper side of the leaf for a white, or purple, egg mass.  These will be found on the upper 1/3 of the plant.
  • We will again have pheromone moth traps located west of Elgin.
  • Treat when the fields are 95% tasseled.  Use high rates (5-6oz) of a Capture-like product to give you 3-4 weeks of residual control.
  • WBC are attracted to those fields that are closest to tasseling, so this means the later planted and later silking fields have the highest potential for infestations.  Cool conditions will delay and extend their flight, so what may appear low numbers now can pickup in two weeks, which is why we recommend the extra residual.
  • Once a field has been tasseled, any egg masses that hatch will see the larvae move straight to the ear tip, so treatment soon after tasseling is critical.
  • AML versions of Pioneer hybrids offer control of WBC/Corn earworm.  No need to treat these hybrids for WBC – these include P05081AML,P14830AML, & P2042AML and Enlist hybrids that end with PCUE behind the hybrid number.

Corn Rootworm

Adult beetle emergence will begin soon….and will continue over the next few weeks.  Monitor your continuous corn acres for adult beetle populations to:

  • Prevent high numbers interfering with pollination through silk-clipping.  Males emerge first.
  • Help with rootworm control in your continuous corn acres.  Strongly recommended to use Steward insecticide (by FMC) for control of adult beetle populations to help with next year’s control of rootworm.  This product has shown excellent results for both kill and residual, which can be upwards of 30 days.  As far as timing for control, it is best to wait until there are pregnant females present.  The new Vorceed CRW technology has been shown to give 98% beetle control.  We will watch for this trend over next few weeks.
  • We are seeing some rootworm feeding from larvae in a few fields.  This may contribute to increased chances for root lodged corn under saturated soil conditions.

Dectes Stem Borer.…Be aware that adult beetles have been emerging over the past week and have been migrating into area soybean fields….much as they have in the past few years….no treatment guidelines at this time….just more for you to be aware and watch as the year progresses.

European Corn Borer….Much of the conventional yellow and white corn hybrids and popcorn have seen low-to-moderate levels of ECB larvae.  If you have not treated yet, recommended that you treat ASAP.

Soybean Development

  • Most of the soybeans in our area are at R1 (Beg flower) to R2 (Full flower).  Most fields are finally coming around and growing.  No-till and later-planted fields have been slow to ‘get going’ this year, as normal….
  • Soybeans should be nodulating heavily at this stage.   At the beginning of the reproductive stage, soybeans will still put on 50% of their vegetative growth.
  • Crop water use in soybeans starts to increase rapidly at full flower, peaks at R3 and will stay high through R6, or full seed  Flower stage is usually the time when the soybean plant begins to pull from the deeper root zones….we usually see this happening on the soil moisture probes in the area.  Heavy soil moisture profiles are full enough that very limited irrigation will be needed on soybeans through July, unless temps turn off hot.  Sandy soils will need monitoring as area rains have been somewhat spotty over the past two weeks or so, and they may need a shot of irrigation to keep growth moving.
  • We continue to see a yield response from a fungicide application in soybeans, either at R1/R2 for white mold (applications of which should be going on the first planted, and going on this upcoming week for later planted acres) and/or later at R3 (pod set) stage of growth.  Environmental conditions over the next two months will determine disease incidence and overall level of disease infestation….so far, we have had weather conditions conducive for higher outbreaks of disease, both soybeans and corn.  Just a reminder, keep an eye out for Frogeye Leaf Spot  in soybeans as not all fungicides control this disease.  This disease is normally not an issue in our area and many varieties have very good tolerance to this disease.  See attachment for more info on this disease….Frogeye Leaf Spot in Soybeans
  • Recent weather conditions have increased the potential for White Mold. For White mold management see attachment:  Managing White Mold in Soybeans  Highly recommended to apply a fungicide for white mold to most acres, especially those fields with a history of white mold in the past.  Apply Viatude, Aproach, or Delaro for best control (really, ONLY control)….for white mold….2026 Foliar Fungicide Efficacy in Soybeans

Thank you for your business!!   Please let us know any questions or concerns you may have!!

Starman Seed & Supply, Inc.

 

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