News Story

Agronomy Notes for the week ending September 2, 2017

Brian Weller, Lead Agronomist

The week, much like many weeks this summer, had spotty showers move through the area, with a few days having more clouds than sunshine. Temperatures ranged from the 50°F’s for the lows, and 70°F’s for the highs. The week, on the whole, felt more like an early fall day than a late summer day.

 It seemed that we had a few sunrises and sunsets that had a slight haze to them, this could be attributed to the fires that are taking place in a some of the western states (Oregon, Idaho, Montana, and Washington). In conversations with some Agronomists in those areas these fires have devastated thousands of acres.

Much like the week of the August 26, we saw more trees starting to turn color, with many of the maple species having color or leaves on the ground. I did start to see some walnut trees starting to drop their mast.  I remember hearing them being called a squirrel’s green hand grenades with a few adjectives added for effect. I don’t recall when I normally have seen walnuts on the ground but I have been told by many that it is September and not August.

Corn plant development ranges from Milk and Early Dough, for corn planted in late May and early June, to Dent, for corn planted in mid to late April.

Planting Date

GDU'S

Growth Stage

Growth Stage

12-Apr

2090

Dent

R5

24-Apr

2025

Dent

R5

5-May

1989

Late Dough-Early Dent

R4-R5

12-May

1921

Late Dough-Early Dent

R4-R5

2-Jun

1704

Milk-Early Dough

R3-R4

 

At the beginning of R5, kernels have approximately 55-60% moisture content. As the Milk Line advances down the kernel, the moisture level drops and will be at 30-35% moisture content when the kernel reaches R6 or Black Layer. The closer you get to R6 prior to a frost, the less likely you are to experience yield loss.

The photo below and on the left, shows a corn ear at the R5 or Dent growth stage that has accumulated 2000 Growing Degree Units (GDU’s).  The photo on the right shows the advancing Milk Line on the kernel. I would estimate the Milk Line to be at 20-30% on this kernel.

 

               

We accumulated 99 Growing Degree Units (GDU’S) during the week, which is 25 GDU’s less than the 30-year average. For the month of August, we accumulated 461 GDU’s, which is 123 GDU’s less than the 30-year average. In comparing our daily GDU’s accumulation, we averaged 14.14 GDU’s for the week, which is 3.57 GDU’s less than the 30-year average. For the month of August, we averaged 14.87 GDU’s per day, which is 3.97 GDU’s less than the 30 year comparison.

Dates

2017 GDU Average/Day

30 Year GDU Average/Day

Difference/Day

August 27 to September 2

14.14

17.71

-3.57

August 1-31

14.87

18.84

-3.97

Dates

2017 GDU

30 Year GDU Average

Difference

August 27 to September 2

99

124.0

-25.00

August 1-31

461

584.0

-123.00

 

The table below compares our GDU’s by planting date to the 30-year average. We currently are 75 to 148 GDU’s behind the 30-year average for all planting dates.  The April 24 planting date is the furthest behind the average at 148 GDU less, and the June 2 planting date the closest at 75 GDU’s less. If we use the 30-year average of 18.8 GDU’s/day for August, we are currently 4 to 7.9 GDU’s behind the average.

Planting Date

2017 GDU'S

30 Year GDU'S

Difference

Day +/-

12-Apr

2090

2219

-129

-6.9

24-Apr

2025

2173

-148

-7.9

5-May

1989

2102

-113

-6.0

12-May

1921

2040

-119

-6.3

2-Jun

1704

1779

-75

-4.0

 

It normally takes 55-65 days from the Tassel/Silking date (R1) to Physiological Maturity or Black Layer (R6). The anticipated date of Black Layer by planting date is listed in the table below. This is calculated with the belief that a 100-103 day hybrid was planted, and that we will receive “normal” temperatures and GDU accumulation between now and R6.

**** The following data is based on GDU accumulation as of September 2, 2017****

Planting Date

GDU'S

GDU'S to R6

Days to R6

Date of R6

12-Apr

2090

385

20

22-Sep

24-Apr

2025

450

24

25-Sep

5-May

1989

486

26

27-Sep

12-May

1921

554

29

1-Oct

2-Jun

1704

771

41

13-Oct

 

With our below average GDU accumulation for the week, our anticipated date of Black Layer or R6 was pushed back another day or two, by planting date.

In comparing GDU information from 2001-2017, the average GDU accumulation for a planting date of April 25 is 2192 GDU’s. When comparing 2017 to that average we are about 205 GDU’s less than that, or 10.9 days. There are only 2 years that have fewer GDU’s than 2017, with those being 2004 and 2009. In comparing 2017 to 2016 we have 298 GDU’s less this year than last, which is about 15 days.

Year

GDU

2017

1987

2016

2285

2009

1897

2004

1909

 

Soybean plant development ranges from Full Pod or R4 (Pod is 3/4" of an inch long at one of the four uppermost nodes on the main stem with a fully developed leaf) for beans planted in late June, and Full Seed to R6 or Full Seed (Pod containing a green seed that fills the pod cavity at one of the four uppermost nodes on the main stem with a fully developed leaf)

Planting Date

Plant Stage

Growth Stage

25-Apr

Full Seed to Beginning Maturity

R6-R7

10-May

Beginning Seed

R5-R5.5

27-May

Beginning Seed

R5-R5.5

3-Jun

Beginning Seed

R5

28-Jun

Full Pod to Beginning Seed

R4-R5

 

We do have so early planted, early maturing varieties that are approaching Beginning Maturity or R7 (When one pod on the main stem has reached its mature pod color.)

                    

Insurance Reminders- Contact your Crop Insurance agent if you are chopping corn for silage, so your silage tons can be converted into bushel equivalents. This can also be used on revenue claims if Chicago Board of Trade (CBOT) future prices remain low.

Other Insurance reminders would be to contact your agent if you still have old crop in the bin prior to harvest and are going to put this year’s harvest on top of your old crop. If you do not measure prior to harvest it could be counted as new crop and would affect any claims, you may have.

Upcoming Events:

  • Central Advantage Field Technology Days September 6-7 Farm America Waseca
  • Answer Plot Tuesday September 12 Truman

 

Central Farm Service Website: Central Farm Service Agronomy Notes, Updates and Videos can be found on our website www.CFSCOOP.com at the bottom of the home page. Past Agronomy Notes and Updates can be found under the News tab and Agronomy News.

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