Field Trials Say 32,000 Corn Seeding Rate is Best

Looking for the ideal corn seeding rate for 2015? Seven years and 55 field scale trials have shed some light on the best rate for normal growing conditions, according to Purdue Extension corn specialist Bob Nielsen. He tells HAT the trials scattered all across Indiana with a range of different hybrids and farm conditions, “those trials indicate that a final population somewhere in the low 30’s, around 32,000 final stand seems to be good for quite a range of conditions. It seems to be something close to an all-purpose population and to go higher than that even in a good year doesn’t really seem to result in higher yields. So even in a good year a final population in the low 30’s seems to do pretty well.”

There are also 12 trials from the drought year of 2012. Those trials suggest the optimal final population drops to 24,000-25,000 plants at harvest in times of severe stress. You can’t plan ahead for drought, but Nielsen says, “If you’ve got sandy fields that are perennially challenged with moisture deficits or maybe folks running a center pivot and non-irrigated corners are under perennial drought stress, well then we can sort of apply this to variable rate seeding and say if you’ve got these areas in fields that are always terribly challenged, maybe we can drop the seeding rates in those areas. Or if you have entire fields that are just simply drought challenged almost every year, there again we probably need to be dropping to lower populations.

Based on their experience of a 95% stand, and a target of 32,000 plants per acre at harvest, Nielsen says the seeding rate would need to be about 34,000. He encourages farmers to walk the fields each summer and document stand counts compared to seeds planted.

Nielsen says they would like to at least double their nearly 70 field trials, so he is interested in more farmer participation. If you want to be included, contact him at 765-494-4802, or rnielsen@purdue.edu, and learn more in the HAT interview:Bob Nielsen on plant population

Nielsen’s Chat ‘n Chew Café newsletter is available at https://www.kingcorn.org/cafe.