2023 PAR (Product & Agronomy Research) Report: Corn Emergence Study - So. Minnesota 2023 Adjusted
BY Dairyland Seed Agronomy Team
Description:
The decision to replant a crop due to less-than-desirable plant populations and emergence patterns caused by equipment malfunctions, obstacles Mother Nature has thrown our way or both, can be one of the most difficult and agonizing decisions a farmer or agronomist can make. The spring of 2023 planting season posed many challenges for producers and agronomists in the upper Midwest, due to cold and varying amounts of precipitation around Mother's Day. Areas in southern Minnesota had 7 to 13 inches of rainfall during this time frame, which caused many replant decisions to be made. Another impact of this Mother’s Day weather event caused fields slow to be planted thus delayed further.
The field we will be looking at for this report was planted on May 20, 2023, to Dairyland Seed’s DS-4219AM™. Portions of the field were slightly tacky when doing tillage with a field cultivator. This caused areas of the field to become cloddy which did not provide the best seed-to-soil contact in those areas. This lack of proper seed-to-soil contact affected planting depth to vary which also impacted soil temperature and moisture of the seed. The result is that upon scouting the field on June 10t we had plants that varied in growth stages from just emerging or VE to V5 (collar on 5th leaf).
The vast majority of the field had plant populations ranging from 28-31,000 plants per acre with most of those plants being at the V3-V5 growth stage. The decision not to replant was made based on plant population and growth stage of most of the field, coupled with the late date (June 10 or later) and dry soil conditions with no measurable rainfall predicted. An area of the field which had two 1/1000th of an acre portion back-to-back with variable growth stages was flagged and monitored during the remainder of the growing season.
On November 16, a day or two prior to harvest, ear samples were pulled from the two 1/1000th back-to-back blocks and yield was calculated from the 50 plants and 56 ears that were collected in those areas. Ear heights, plant populations as well as kernel rows and length were counted, as was estimated kernel size. The ear number as well as growth stage and plant height were written on tape on the ear to help organize the data.
Results:
Ear heights ranged from 25 to 40 inches with the average ear height being 31.9 inches. Kernel seed size ranged from very small to very large and we did vary the factor to calculate yield based on seed size. Kernel rows around varied from 8 to 18 with the average rows around being 14.4 rows. Kernel row length varied from 2 to 45 with the average being 29.5 kernels long. Plant populations were 25,000 plants in both blocks. Yield estimations ranged from 7 to 189 bushel per acre.
Summary Table of Observation Variability
Photo of all 56 ears harvested from block.
Photo of ear and seed size variability.
Conclusions:
The area we used for this test validates a commonly held perception that if a corn plant and its neighbors emerge on a timely basis it tends to equate to a higher yield.
Summary Table of Growth Stage Variability
In reviewing the data and categorizing the plants based on the stage of growth at the first observation date, we can show the number of ears and break down the low and high range of yields and the averages per growth stage. By doing this, it does show the general trend of early and more timely emergence equating to more yield.
Consolidated Table of Growth Stage Variability
If we consolidate the growth stages from V.5 to V2.5 and V3 to V5, we more consistently show that timely emergence with neighboring plants does equate to higher yields.
Photo of potentially unharvestable ears and seed size variation.
We did harvest every ear that we found on plants knowing full well that not all the ears on the plants would be harvestable and make it from the head to the combine due to their width or length. We did have six plants that did put on an additional ear, with that additional ear a node or two below the dominate node or ear.
Other factors that may have influenced results are that not all kernels were counted. If kernels were smaller on any part of the ear those kernels were not counted, on the belief that they would not make it into the hopper on the combine.
Kernel weight is a factor that we could not accurately estimate or predict. Individual kernel weight can impact yield, with higher weights of the same kernel count yielding more than those kernels weighing less.
Standard Deviation of plants (change in the average distance between plants) was not measured and could have impacted yields but was not measured. We did encounter instances with a skip or double which did affect ear size.
Lastly, any study increasing the number of replications increases the validity of the information. It would also be nice to try this study with different hybrids, row widths as well as increasing and decreasing plant populations.
Brian Weller
Western Region
507.456.3034
Rod Moran
Western Region
507.456.3034
Dan Ritter
Central Region
219.863.0583
Branden Furseth
Northern Region
608.513.4265
Mark Gibson
Eastern Region
260.330.8968
Amanda Goffnett
Eastern Region
989.400.3793
Ryan Mueller
Eastern Region
989.400.3793