With the delayed corn emergence this year, I had a grower inquire the other day about corn seed size and whether a specific seed size emerges any quicker than another. It’s a great question and one that tends to come up in years when field emergence is erratic due to cool wet temperatures. The short answer to the question is no. Many of the well-known agriculture schools that researched corn emergence have noted there is no difference is emergence between the different corn seed sizes growers plant.
The biggest difference with kernel size really boils down to the position of the kernels on the production ear of corn. Small rounds originate from the ear tip, flats are located on the middle of the ear, and large rounds are found on the butt of the ear. The majority of seed produced are medium rounds and medium flats found on the middle of the ear. Here is an article from Pioneer’s website with a more information on seed corn sizes. There is a great picture indicating the position on the ear of the various seed sizes Pioneer offers. One thing to note is different hybrids with the same seed size will vary in weight and seeds/lb.
Growers who want to ensure the best emergence of their corn fields, should pay attention to the seed sizes they are planting, the bag weights, and the seeds/lb. Adjusting your planter based upon the manufacturer’s recommendations might be necessary as you change hybrids from field to field to ensure uniform spacing of your final stand. It is also noteworthy to mention, planting depth and planting speed should also be closely monitored as all three factors greatly contribute to even emergence.
Pioneer.com, Agronomy Library