By Grant Mehring,NDCUC Contracted Research Director

At this time of the year it is getting less easy to walk through a corn field due to the height of the crop, however it is still important to be doing so. I want to touch on a precision planting issue today from an agronomic vantage point. It is not too late to take a look at your fields and gauge the final stand, or plant population, that you realized and compare it to the planted seeding rate. While doing so, take careful stock of skips and doubles. At this growth stage it is probably too late to measure emergence, specifically the impact late emerged corn has on the final yield. I cannot offer you any input into the machinery side of this issue, however there are numerous precision planting companies and dealerships who can guide you through this process if you need a change on your farm.

Let’s take a look at some research done at NDSU about this issue. A graduate student at NDSU, Lindsey Novak, carried out an exhaustive study under the advisement of Dr. Joel Ransom, on the impacts of skips, doubles, and late emerged corn plants on final yield at 16 environments throughout the entire state of North Dakota. This research was carried out with measurement made in producer’s fields with their machinery and management. Her research answers the question about what impact skips, doubles, and late emerged plants have on final plant yield.

The data in the table below is the percent of yield compared to a normal plant (100%), classified as one with normal spacing on both sides of the seed within the row. Plants that were next to a skip yielded 111% of the normal yield, however this is far from making up for the yield lost from having a skip. Plants that were planted as a double combined to yield 136% of normal, with one double at 86% and the other at 50%. This result shows that doubles can add to yield, however not at the rate of what that seed should have yielded with uniform spacing. Late emergence is another major question in the eyes of producers, as we have often heard that late emerged plants are a better weed than a corn plant. The data shows that a plant next to a late emerged plant adds 5% to its yield, however at a detriment to the late emerged plants of 59% of normal for 1 week late and 59% for 2 weeks late .

I hope that you take some time to really get a feel for how your planter and seedbed preparation did this season with providing a uniform stand. If you find that your stand was less than uniform, try your best to understand what variables affected the poor stand. The list of reasons for a poor stand is long, such as down pressure, tire track compaction, residue management, moisture, seedbed uniformity, poor seed lot, freezing temperatures, and more. Right now, the observations you make can greatly benefit your ability to get a better stand of corn next year.