AGRONOMIC UPDATE: JUNE 11, 2025….Strange year so far….

TOPICS FOR THIS UPDATE:

  • Planting and Early Spring conditions….
  • Temperatures & GDU accumulation
  • What’s going on in my fields right now…
  • Insect Update
  • Soybean Update

PLANTING AND EARLY SPRING CONDITIONS:

  • 2025 planting got off to a fast start with both corn and soybean planting much ahead of normal.  By May 1, 75%+ of soybeans were in the ground, and by May 5th, 90%+ of corn was planted.
  • This was due to above normal temps and dry conditions through much of April and 1st half of May allowing for no stoppage due to moisture.
  • Temperatures for April and 1st half of May averaged 2-3 degrees above normal leading to quicker emergence and what appeared to be rapid growth heading into June…
  • However, temperatures for last three weeks have been 2-4 degrees below average, causing slow emergence on last soybeans planted and slowed down growth….
  • There were a lot of windy days in May as well, which slowed up growth and gave much of the corn crop a ‘beat up’ look for a few weeks.  We are seeing more unevenness now in height and color from the winds, cool temps and wetter conditions…..
  • Overall stands for corn have been very good and soybean stands are the best they’ve been in last few years, especially on the tilled soils.

TEMPERATURES & GDU ACCUMULATION:

As of June 10th, we have accumulated approximately the following for Growing Degree Units in 2025:

Planting Date     GDD’s2025          Average GDD         Departure from average

April 17                  599                            608                                – 8 (-.5 day)

April 24                 548                            570                                 -14 (-1 day)

May 1                     502                            506                                 -13 (-1 day)

We were +4-5 days ahead of average for April and 1st half of May, but the cooler temps of last few weeks have caused the crop to lose that ground, to where we are now just even.  We are slightly ahead of last year yet, however.  The heat that has returned this week and forecasted to last through next week will help us to gain a little ground.

PRECIPITATION

     

We all know how dry it was in April and through most of planting.  The recent rains have been a godsend as we were getting beyond desperate for moisture.  The above map will help put things in perspective so far.  The above maps show percent of normal precipitation for April, May and the last two weeks.  This is why it was so important to run those pivots at planting and after as this really helped achieve good and uniform stands.  While we did get some good relief over the past few weeks, we could easily fall into severe drought conditions if rainfall turns below normal over next couple of months.

WHAT’S GOING ON IN MY FIELDS RIGHT NOW?...

As mentioned above, overall corn stands are very good.   The majority of the corn crop is in the 5-7 leaf stage.  From V1-V10, corn gains a leaf collar about every 83 GDU’s…this will be about every 3.5 days with current forecasted conditions.   This would put us in the mid-July time frame for tasseling….

  • At V5, leaf and ear shoot initiation will be complete and a microscopically small tassel is initiated in the stem apex tip, or top of the growing point.
  • At V6, the growing point and tassel will be above the soil surface and the stalk is beginning a period of greatly increased elongation.
  • Determination of potential kernel rows around will be completed around V7 (range of V5-V8)…all fields are now is this stage….
  • The corn root system is now rapidly transitioning to the main nodal root system.  When hot temperatures occur following a cool spell, crop growth at this stage can be uneven.  Areas of heavier residue will start to look shorter.  It will take a little time for that to catch up.  We are experiencing this right now.
  • At V9, an ear shoot will develop from every above-ground node, except the las six to eight nodes below the tassel.  Growth of most of the lower stalk ear shoots eventually slows, and only the upper one or two ear shoots will develop into a harvestable ear.
  • At V10, the time between the appearance of new leaf stages will shorten….generally every 2-3 days.
  • We are now heading into the rapid growth and accumulation of dry matter by the plant.  The window for brittle snap will start to grow exponentially over the next few weeks.
  • Pre-emerge herbicide control has been very good in both corn and soybeans considering the early, dry conditions.  Rainfall received over last few weeks has really helped here.  Palmer is really starting to come over last couple of days, so be scouting now for any potential respray as the window for application in corn will close quickly this week for the April planting dates.
  • Watch temperatures as you are spraying post-herbicides on corn or beans.  When temps are in the 90’s and humidity is very low, (or very high), the potential for crop response from post-application of herbicides will increase.  It is not recommended to be spraying during the heat of the day if temps are in the low-to-upper 90’s…both for potential crop response and herbicide control.  Contact only herbicides like Liberty need full sun, warm temps and high humidity for good control.

INSECT UPDATE:

Corn Rootworms –

It’s about that time to start seeing our annual rootworm hatch. When we see the cotton start to fly, or the famous lightning bugs, we will know rootworm hatch is underway because it takes about the same GDU’s (680-750 soil based degree days) for all of these things to happen….cotton has been flying for awhile now….

Some CRW facts:

  • Larvae in sandy soils can become scratched and lacerated causing more mortality
  • Flooded or saturated soils will cause more mortality, we had a lot of this last spring which did lead to below normal adult beetle emergence last summer.  This should lead to lower CRW infestations for this year.
  • CRW will go through 3 growth stages (Each last 7-10 days)
  • 3rd Instar will create the most damage to corn roots
  • Begin scouting continuous corn acres now through the rest of the month of June.

There are many management practices that can help mitigate the risk of yield loss or lodging due to corn rootworm. The best recommended strategy is to rotate to soybeans.  Overall pressure was much less in 2024, so hopefully, overall larvae populations are starting from low numbers.  The new Vorceed Enlist technology from Pioneer is a new ‘tool’ in the toolbox for CRW control.    Vorceed offers three distinct modes of action for protection against CRW, with 98% reduction of adult beetle emergence.  If you planted a hybrid with a number that ended with a V (ie. P13777V example), that hybrid has the Vorceed technology.

Corn Rootworm Scouting and Management

European Corn Borer:

  • We have yet to see ECB moth flight begin. However, we should start seeing moth’s flying over the next two weeks with egg-laying starting next week of June and lasting through June.  For those of you who have conventional white or yellow corn and/or popcorn, begin scouting for this pest the week end of next week and scout over next few weeks.  We will keep everyone updated on this pest….
  • On premium priced acres, treat at 5-10% infestations.

Wheat Stem Maggot in Corn

  • We have had a couple of fields with this pest causing some weird growth and/or reducing stands.
  • Rare pest, but possible when corn follows rye cover.
  • Maggots feed in green stems of rye – when rye crop dies, they move into emerging corn.
  • Symptoms in Corn:
    • Dead center whorls
    • Stunted growth
    • Excessive tillering
  • Timing: highest risk when cover is terminated after corn is planted.  It is possible that early GDU accumulation may have ‘pushed’ the insect into being able to cause damage before the rye cover was terminated.  May want to consider applying an insecticide when terminating the crop….but very rare pest….very rare….
  • No rescue options.

SOYBEAN UPDATE:

  • As mentioned above, vast majority of soybeans were in the ground by May 1st which is the most ever by that date.
  • For the most part, soybean stands are better than prior years, especially on the tilled acres.  The early planted beans have better stands than those planted later in May when soil conditions were drier and temperatures cooled down.
  • Many no-tilled fields have the ‘usual’ look to them of uneven growth and color.  Much of this is due to soil structure conditions at planting and after….worse in the heavier residue, again very typical for no-till.  This year the tilled fields look better than the no-till, which was not the case last year.
  • Nexta Shield for soybeans – NEXTA Shield is a product in Pioneer’s lineup of Biologicals.  Shield is a product that mixture of growth hormones that promote plant growth under stress conditions.  This product can be tank-mixed with your post-application of herbicide.  This is a product that can help with uneven growth and heavy residue fields.
  • The early planted beans are reaching the stage where it will be time for a post-application of Enlist or Enlist/Liberty.
  • Maximizing Enlist Applications
    • Nozzles – TeeJet AIXR or AI-TTJ
    • Pressure – run in the high end of your nozzle’s pressure range
    • GPA – 20 GPA minimum with Enlist/Liberty
    • Enlist can be sprayed through R1 soybeans
    • Liberty Timing Tips:
      • Spray after dew is gone
      • Stop 2 hours before sunset
      • Ideal conditions are 70-85F, sunny and higher humidity.
  • No insect concerns in soybeans at present time.

Impact of Weed Height

Something to share that could easily get overlook is how much faster weeds grow per day in June than in April.   As you know well, Palmer amaranth grows rapidly; much faster in June than April

  • So how does the performance of Enlist One® herbicide + Liberty change with increasing weed height?
    • Multi-state study funded by Corteva & BASF – Enlist One 2 pt + Liberty 32 oz
      • 3-4” Palmer amaranth verses 6-8”
        • 90% vs. 78%
      • 3-4” Waterhemp verses 6-8”
        • 98% vs. 82%

Influence of Temperature

Most research suggests weeds are best controlled when air temperatures are between 75-86F

So what happens when air temperatures are colder or hotter than ideal?

  • Glufosinate performance declines under colder night/day temperatures

Please reach out to us with any questions or concerns you may have over the next few weeks.  Stay safe!   Thank you for all of your support!!

STARMAN SEED & SUPPLY, INC.

 

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