AGRONOMIC UPDATE MAY 8, 2023…
This is just a quick update on planting and initial emergence….
What a beautiful rain we received this past weekend….very blessed! It was desperately needed and it appears that significant amounts were received throughout our area.
As of May 7th, we have accumulated approximately the following for Growing Degree Units in 2023:
Planting Date GDU’s2023
April 17 139
April 24 116
May 1 71
This past week we saw warmer temperatures. This is finally allowing for both soil temperatures and GDU accumulation to increase. Corn typically requires about 120 GDU’s to emerge from a depth of 2”. Once the seed is in the ground, we begin to accumulate GDU’s. Under cool conditions (which is what we experienced in April) it can take up to 130-150 GDU’s to emerge. The more consistent soil temperatures stay, the faster and more uniform emergence is. As temperatures increase, the process required for germination to proceed occurs at a faster rate, leading to more rapid emergence. Under ideal conditions, corn will emerge in ten days or less, but with cooler soil temperatures, like the seedlings that were planted the week of April 11-17th , the process takes longer. This is showing up in the above GDU accumulation numbers. Corn planted April 17th is just starting to spike after three weeks in the ground….see video link below. The first planted corn will emerge over the next few days with the later planted emerging by the end of this week into first of next, depending, of course, on temperatures. As you begin checking for emergence, if the kernel is firm and shoot looks healthy, there are no concerns. There is a 1-2 day difference between the bare soil and heavier residue.
Checking Corn Emergence…April 17, 2023 planting date
The above photos are from the same field in the video link….planted April 17th. The first photo shows progress on May 4th and the second is from May 7th….showing the difference heat makes. The third photo is from May 7th, showing the planting depth of 2″ and the coleoptile spiking through the soil.
The first planted soybeans are also starting to emerge. Watch for seed corn maggot as the GDU’s indicate we should see hatching beginning 5/4/2023 in Madison county, which means just a few days later in our area. Hopefully, the warmer temperatures will allow for quick emergence with little impact from this insect.
Environmental Factors that contribute to uneven corn growth:
- Soil Temperature –
- Darker soils and reduced surface residue will tend to warm more quickly
- When soils are less than 50 degrees, emergence will occur more slowly and unevenly
- Heavy residue areas will be cooler which will make emergence uneven this year on continuous corn
- Cold soils can increase deformed mesocotyl elongation due to chilling injury
- Soil Moisture –
- Planting too shallow or uneven planting depth can lead to uneven emergence
- Seed-To-Soil Contact –
- Residue in the seed furrow and planting too wet/dry can lead to improper seed-to-soil contact contributing to uneven emergence
- Insect/Disease Damage
- Herbicide Injury
Weather Outlook…
The above maps are the 6-10 day and 8-14 day forecasts for temperature and precipitation. The maps were issued May 7th. As you can see we are potentially entering into a warmer and drier period beginning in mid-May. The warmer temperatures will help crop emergence and growth and allow the last part of the corn and soybean crop to get in the ground. Hopefully the moisture and warmer temps will allow the pastures to ‘take off’ and the rye to get some height for forage.
Overall soil conditions are in good shape after the recent rains. No crusting and nice moisture in the seed zone. Rainfall should’ve incorporated herbicide and fertilizer. As of right now, the moisture we received has put overall conditions in good shape for emergence….way better than we were thinking last week….
Please let us know any questions or comments you may have. Thank you and stay safe…..
Starman Seed Service, Inc.
