AGRONOMIC UPDATE: July 31, 2024….Quick trip into the furnace…and maybe back out again….

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 30th, we have accumulated approximately the following for Growing Degree Units in 2024:

Planting Date     GDD’s2024          Average GDD     Departure from average

April 23                   1800                           1779                                + 21 (+ 1 day)

May 4                      1722                           1697                                +25  (+1 days)

May 14                    1517                           1606                                +11 (even)

From the above numbers, we see that we have gained just a little from last update….overall crop is still moving along at an average pace.  Even the mid-May planting dates are average.  We are currently 3 days behind 2023.  Still need 800-900 GDU’s to finish the crop, so we still need some heat into August and September….

The above map is the departure from normal temperature for July 2024.  We continue to trend 1-2 degrees below normal.  Temperatures are forecasted to stay hot into mid-next week, but it looks like a significant cool down is coming end of next-week….more typical of what we experienced in June for temps.  This will give us a break from the heat, but will keep us needing most of September for good fill.  It will also lead to increased disease outbreaks…more on this below.

 

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

Most of the corn crop is in the late-R2 (Blister Kernel) to early-R3 (Milk) to R3 (Milk) stage.  The heat last week really pushed the crop along.  The late planted fields (ie. after rye, etc.), are just starting to tassel.

  • Pollination overall seems to be good so far.   Finding the usual checkerboard pattern on the butt of the ear in some fields, but overall looks good.  Some fields had delayed pollination, so we are seeing some unevenness in pollinated kernels in some cases.  This was due to the cooler temps and dewy conditions during pollination, along with very little wind to help move pollen around.
  • Plant height this year seems to be normal overall.  Seeing shorter corn in the sand on the first-planted fields.
  • At R1, potassium uptake is essentially complete, and nitrogen and phosphorous uptake are rapid.  Last round of N should be on, or going on shortly.    
  • Blister Kernel occurs approx. 10-14 days after Silking.  Starch has begun to accumulate in the watery endosperm and the kernels are beginning a period of rapid, steady, dry matter accumulation that will continue until physiological maturity in approx. 50-60 days after silking.
  • At Blister Kernel, maximum ear length is achieved.  Although not as severe as at Silking, stress over the next two weeks can still have a profound effect on yield through kernel abortion, which is why this last rain was such a Godsend….
  • 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 and sunlight will play a role here….
  • As far as sunlight is concerned, we are currently running about 10% percent below normal over the last month.  Sunlight, of course, is now a much bigger yield factor, since we are now beginning 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 (which is not predicted).  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.  The forecasted cooler temps next week, will give the crop a nice break.
  • Relative Humidity over the past month has been 8-10% above normal, with a daily average RH in the low-to-mid 70’s%.   While this leads to decreased ET rates; it increases the potential for more disease in corn and soybeans.  The two graphs below show daily maximum RH for Jan-Jul.  Frist graph is 2023 and second graph is 2024 up to July 31st.  Main thing to note is the comparison of the time period July-August between the two years.  2024 looks to be even more humid than 2023….and 2023 was a very humid period from July to mid-August.  We continue to have a disease breeding environment….
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  • ET rates for the past 15 days have been averaging .27 inch/day, which is normal.  The forecasted cooler temps next week will keep overall ET rates normal to slightly below normal….keep in mind 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.  Last Friday/Saturday were tough ET days, as one can see from this daily maximum RH graph.  Just look at the far right and notice the drop in humidity.  That, coupled with winds, led to high ET rates….
  • Soybeans are now at peak usage at R3-R4 stage….over .30 inch/day normal.  Maintaining an adequate soil moisture profile will be key over the next three weeks or so.   As you think about irrigation needs over the next two weeks, keep temperatures and relative humidity in mind as we move forward to see what actually occurs to help reduce potential water stress or potential over watering.  If dew points are low (dry mornings), that means relative humidity is low, and ET rates will stay up higher than normal.  On the flip side, if heat indices are high in which a 95 degree actual temperature feels like 110 degrees (which is what we experienced for most of the last 10 days), then relative humidity is high and ET rates will be average to below average.  Forecasts for the next few days week are calling for hot temperatures and higher humidity….
  • So far corn leaf diseases continue to be on the low side, however, we are seeing first signs of Southern Rust lesions in some area fields. 
  • This disease can ‘blow up’ quickly, so highly recommended to watch your fields for outbreaks….better yet, recommended to apply a fungicide to halt the disease.  One does not need a lot of residual now, and there are some ‘lower priced’ products – less than $7/A for the product…well worth it if southern rust explodes!  Otherwise, seeing mainly Bacterial Leaf Streak, and Grey Leaf Spot is increasing, and we have seen a few Northern Corn Leaf Blight lesions around.  Have yet to see Tar Spot in the area, but it has been confirmed in the counties to the east and south of us.
  • Fungicide application should be on, or going on now, and into next week on the later planted fields.  You want to protect the plant when it is working the hardest, which is silking through milk stage (which is  NOW!).  Reminder, a fungicide will not help control Goss’s Wilt or Bacterial leaf streak.

SOYBEAN UPDATE

  • Much of the crop is in the late-R3(pod set) to R4(full pod) stage of growth.  This is normal in my opinion.   The heat has also pushed the soybeans along as well.   Overall plant height will be tall…the beans have really taken off as of late.  Keep this in mind when irrigating….
  • 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 few 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).    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’.   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 seeing first signs of White Mold in a few area fields.  Weather conditions of the past few weeks have been conducive for development of this disease.  Too early to tell yet, but if the above forecasts hold true, expect to see higher amounts of white mold begin to show up.   Any 2nd treatments for White Mold need to go on at R3 and should really be on by now.   See the attached link for White Mold management.    Managing White Mold in Soybeans    We recommend Aproach, Viatude, or Delaro fungicide for any white mold control.   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.

INSECT UPDATE – Corn & Soybeans

  • Overall it has been a ‘quiet’ insect year in both corn and soybeans.  Much of this can be attributed to the wet conditions experienced this spring.
  • Seeing historically low levels of Corn Rootworm adults.  This is due to the wet spring, I feel.  Compared to prior number of years, seeing very low numbers.  We don’t expect to see numbers increase much over the next few weeks, as the heat of the past 10-14 days should’ve ‘pushed’ them out.  However, keep an eye on them through August, in case an odd field shows up that needs treating for next year….if a treatment has not already happened.
  • Western Bean Cutworm numbers are historically 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 the first 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 as well.  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
  • Seeing 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 we may see their numbers increase in the area.   They are not an economic concern, but you may begin to notice them as you walk through your fields.
  • So far not seeing much for Spider Mite colonies.  However, if temperatures turn out as forecasted (cooler temps and higher relative humidity), infestation levels should be on the light side.  Keep an eye out for this insect over the next month or so.

Please mark your calendar for the Pioneer Annual Customer Appreciation Supper  which is set for Friday, August 23th.  Invite will be coming out soon!  The Pioneer Plot Tour is tentatively sent for, Wednesday, September 4th.

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

Starman Seed Service, Inc.

 

 

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AGRONOMIC UPDATE: July 10, 2024…wet spring into cool summer so far….

 

Topics:

– Growing Degree Day Update/Forecast Maps

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

– Fungicide/Disease in Corn

– Insect Update

– Soybean Development

As of July 9th, we have accumulated approximately the following for Growing Degree Days in 2024:

TEMPERATURES & GDU ACCUMULATION:

Planting Date     GDD’s2024          Average GDD        Departure from average

April 23                  1288                         1298                               -10 (even)

May 5                     1192                          2012                                -20 (-1 day)

Current GDU’s are running average, to slightly behind average.  Last year at this time we had 1374 GDU’s accumulated, which means that we are 4 days or so behind 2023.  The first week of July in 2024 has seen much below average temperatures, 6-8 degrees below average to be in fact.  This is delaying tassel/silking by a few days compared to the last few years.  We will be tasseling more like normal, to slightly behind normal.

What’s the forecast for the next two weeks?

     

The above maps are the temperature and precipitation forecasts for the next 6-10 and 8-14 day periods.  The maps (which were issued July 9), are forecasting an increase in heat with normal precipitation through this period.  This would be good as it ‘feels like’ we are behind in crop development….

What’s going on in my fields?

  • Baring the fields that were caught in Sunday’s hail event, much of the corn crop looks good overall.  However, most all fields in the area have spots of reduced stand from erosion, waterholes, etc., from the spring rains. Much of the corn crop is in the V13-V16 stage to almost VT, this is slightly behind last year.   From V10-VT, corn gains a new color every 50 GDU’s, or about every other day.  During last week’s cooler temps, it was taking three day for a new leaf to emerge.  Many fields will begin tasseling the end of this week, with most fields reaching full tassel mid-next week.  Majority of tasseling will occur from July 12-20th, which is behind last year by a few days.
  • Kernels per row began around V12 and is continuing 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#.  Due to the increased rainfall this spring and into June/July, it is safe to assume that some N leaching occurred on the sandy soils.  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 over the next 5-10 days.
  • 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 next week for most fields.  Expect some unevenness in tasseling/silk emergence in most fields due to the spring rains moving crop residue around and slowing emergence.
  • 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.
  • 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 should give us a GDD accumulation of 25-30 GDU’s per 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.  The weather conditions experienced so far this year has increased the likelihood of seeing higher incidence of disease for the 2024 crop.  Keep in mind that if we continue to see cool temperatures and wet conditions, potential disease outbreaks will increase exponentially.  We will also see a wider range of different diseases.
  • Begin scouting now and through the next few weeks for disease infestations.  So far, leaf disease load in area cornfields is very low, mainly bacterial leaf streak, however, we have seen some Northern Corn Leaf Blight lesions and, with the wet conditions, we are starting to see the first Common Rust show up.
  • We are not seeing any Tar Spot in the area, however it has been confirmed in the counties just east of us.  So, we expect that we will see some lesions moving forward.  Hybrid tolerance is first line of defense with a fungicide giving added protection.  We will keep you posted on this disease if we find it….   See slides below:
  • If you are planning on only one fungicide application, the best timing for this application is after pollination, 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 P05466, P0622, P0924, P0908, P0995, P1185, P1278, P1366, P13050, P14830, & P1563 are hybrids to focus on first for higher probability of response from foliar fungicides, especially if gray leaf spot infestations are high…..2024 Corn Fungicide Management Guide ….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.  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….
  • See attachments on disease and fungicide management – Maximizing Foliar Fungicide in Corn
  • Fungicide Efficacy for Control of Corn Diseases     This attachment shows efficacy and posted residuals by active ingredient.

Water Management

2024 has seen above normal rainfall from planting up to now….in many cases 200% above normal.  This means that we have excellent soil moisture profiles into pollination, which is a real positive to the dryland and limited irrigation acre.

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 under cool and cloudy conditions.
  • ET rates over the past two weeks have been average…. .20-.25/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.
  • At present, we are seeing fairly good root depth according to the soil moisture probes….sandier soils are 20-32″, very similar to last year, and heavy soils are 28-40+” (average) depending upon plant date, conditions and soil type.  Remember that maximum plant height and root depth are achieved once the plant tassels.

Insect Update

Just beginning to see Western Bean Cutworm egg masses in sandy fields.  They are just getting flying.  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 again have pheromone moth traps located west of Elgin.   Current numbers are slowing trending upwards, but too early to tell how heavy the flight will be.
  • 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 P0622AML, P0908AML, P1122AML, P12904AML, P1366AML, P14830AML, P1563AML, & P2042AML.

Corn Rootworm

Adult beetle emergence is also beginning right now, 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 and this is what we are mainly seeing right now.
  • 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.

Grasshoppers….seeing very small grasshoppers in many sandy fields.  Numbers are low and defoliation is very minor….

Soybean Development

  • Most of the soybeans in our area are at late-R1 (Beg flower) to late-R2 (Full flower).  I would not be surprised to see early R3 (pod set) on some fields end of next week.   Most fields are finally coming around and growing.
  • 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 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 during the upcoming heat and will 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 on or going on) and/or a later R3 (pod set) stage of growth.  Environmental conditions over the next two months will determine disease incidence and overall level of disease infestation.  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.   If current weather trends continue into August, expect White Mold outbreak to be as high as a year ago.    For White mold management see attachment:  Managing White Mold in Soybeans
  • The below picture shows precipitation and temperatures for the past 30 days.  This year has HIGH potential for white mold outbreak….every bit as heavy as we saw in 2023 or worse.  Highly recommended to apply a fungicide for white mold to most acres.  Apply Viatude, Aproach, or Delaro for best control…really, only control….for white mold….

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

Starman Seed Service, Inc.

 

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