Developing Roots Agronomic Insights for Northeast Iowa May 30th, 2025
I thought we would see some heat this last week, but we didn’t accumulate very many heat units. The crop that was planted just before the rain is still slowly emerging because of the lack of heat units, only accumulating 72 in the last 10 days. We are starting to post spray the fields that got their pre spray in mid-April as the herbicides have been on for 6 weeks and are starting to weaken.
Uneven Stands
I am still seeing uneven stands in numerous corn and bean fields. The seed that laid in dry soil is now starting to emerge. Spike corn vs V2 corn in most cases. And most of the time there was a row or two on the planter that was shallower planting than the others, so you can see a pattern in the fields. Older, wore out planters are mostly the culprits, showing how important planter maintenance is.
Weed Pressure
Some fields are showing weed pressure right in the corn row where the herbicide was sprayed before planting. In this case the row cleaners moved the treated soil out of the row, leading to less activity in the row. This is one concern with spraying ahead of planting.
Seminal Root System
When corn gets to the V3/V4 growth stage it starts to transition from the seed (seminal) root system, circled in red in the picture, to the primary root system. Sometimes at this stage corn growth stalls out while developing the main roots. If corn is sprayed at this time under poor growing conditions, it can make the corn even more stressed. Try to make herbicide applications when conditions are good for growth
Root Nodules
Soybeans are starting to show the nodules on the roots. This happens starting around V 1 /V2, but on the earlier side of that if you have an inoculant applied to your seed. Our Launch Point Complete seed treatment contains a full rate of a high quality inoculant.
Seed Treatment Trial
We have an independent research company conducting some tests for us this year. One of them is comparing seed treatments in beans. I took some stand counts from the April 17th plant date. Untreated beans had a population of 60,800, Launch Point F&I was 72,800 (+20% stand), and Launch Point Complete was 78,750 (+28% stand) These are all below what we would like to see, but it definitely shows the differences seed treatments can make, especially under stressful conditions. These replicated plots will be taken to yield as well.
As always, reach out to me with questions or concerns you have or come across out in your fields. Everyone, Stay Safe! Connect with your agronomist >
Northeast Iowa Heat Units Accumulated
April 14 Plant Date: 382 (-10 to 30-year average)
May 7 Plant Date: 241 (+0 to 30-year average)
Northeast Iowa Rainfall Data
April 2025: 4.8″ | 30-year average 4.2″ |
May 2025: 2.8″ | 30-year average 4.8″ |
