A concern of many growers with late planted corn, and replanted corn, has been: will the corn reach black layer or physiological maturity? Many growers across the Midwest planted corn late, or had to replant many acres. With the month of May being very wet for many areas, this pushed many growers into June planting dates some even mid to late into the month.
The concern if corn will reach black layer is one that can impact harvest greatly. A few things that could be impacted include grain quality, test weight, and yield. The main reason for corn to not reach physiological maturity is frost. When a killing frost occurs before the corn plant can reach physiological maturity the grain quality and yield can be impacted depending on the crop’s stage. When a frost kills the plant prematurely the ear production cannot be completed affecting the ear. The plant is unable to provide to the ear so kernels may shrink reducing both test weigh and yield.
The picture (right) from Michigan State University shows what can happen to an ear, if a killing frost occurs when the ear is not fully developed. One ear is in early dent stage so a grower should not see as much of yield loss compared to the other ear in the picture. The second ear was in late milk/ear dough stage and yield loss can be much greater, up to 35% for this stage.
This chart from the Michigan State University shows GDD and average calendar days to maturity based on growth stages. A chart like this one could be a useful tool to help determine how your corn could be affected. This is a general chart and would be different depending on hybrids and their maturities. The chart also shows what % of Max yield you could expect if the whole plant is killed by a frost. Using information like this along with historical weather data, and long-range weather data, can help determine if your corn will reach black layer, and if not, what impact you should expect.
The question if your corn will reach black layer is not one that is easy to answer. Corn, as the season goes on, will adapt to the weather and the time needed to reach black layer can change from that of what it normally takes. With this said however the main factor that will impact corn reaching maturity is the weather, which we cannot control.
If you have any questions about your specific hybrids or our concerned about this topic please contact your Agronomist or DSM, as they will be willing to help answer your questions. I hope everyone has a safe harvest and thank you for your continued support of the LG Brand.
Sources and Additional Information:
Note: The information in this issue is based upon field observations and third party information. Since variations in local conditions may affect the information and suggestions contained in this issue, LG Seeds disclaims legal responsibility therefore. Always read and follow label instructions.
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Download a copy of this Technical Bulletin: Tech_352 - Will Corn Make Black Layer