Westfield, Indiana, USA
August 27,2025
Defaulting to a generic kernel-per-bushel figure can lead to misses.
As corn approaches black layer, many farmers head out to their fields to estimate yields. They walk rows, pull ears and count kernels. Once they’ve collected data specific to the field, they’ll divide it by the number of kernels per bushel. Historically, that’s been a ballpark figure around 90,000 kernels per bushel.
But in today’s precision-driven world, generalities rarely cut it. The number of kernels it takes to make a bushel of corn can vary widely depending on the seed, weather, management, soil, irrigation and the list goes on. A better understanding of that can help you make more accurate corn yield estimates.
AgriGold Agronomist Sam McCord draws from his work studying kernel flex to share pointers on adjusting from the 90,000-factor.
Accuracy aids planning
An accurate corn yield estimate better prepares farmers for decisions regarding storage, marketing, planning, and assessing seed and management choices. “It gives you a starting point for determining if certain management practices were successful or how you can improve in the future,” McCord explains.
“We’ve used the 90,000 kernels per bushel as a dividing factor for decades, and it wasn’t always as accurate as we’d like,” he continues, detailing it can make a difference of 10 to 20 bushels per acre in your average corn yield estimate. This motivated him to get a better understanding of when to adjust the dividing factor.
Corn’s flex type impacts kernels per bushel
Dialing in your kernel-per-bushel figure based on corn hybrid and weather can result in a more accurate corn yield estimate. Pictured: A642-76 (left) and A647-42 (right).
Corn hybrids build yield in different ways. Some are more based on kernel count, flexing earlier in the season by length or girth. Others put on yield by flexing in kernel size later in the season during grain fill, packing more weight into each kernel and generally using fewer kernels to make a bushel.
Understanding whether you’ve planted a product that predominately flexes in terms of kernel count or kernel weight can help you determine the most appropriate kernel per bushel figure.
This knowledge can also help you optimize corn crop management. “Kernel-flex products are the ones that often surprise you because they can pack on weight late if conditions are favorable during grain fill,” McCord says. “They also tend to have higher late-season nutrient needs.”
When it comes to corn yield calculations, McCord says a factor of 65,000 is a likely average kernel-per-bushel figure for kernel-flexing products under good growing conditions. In contrast, a kernel-per-bushel factor of 85,000 to 90,000 is more appropriate for more of a kernel count product.
Don’t make the mistake of assuming one of these will outyield the other. It largely depends on how each handles the growing season, among other factors.
Weather, environment and management also come into play
Weather is another major factor when it comes to kernels per bushel. “If you have a healthy plant and you didn’t face much drought stress, you can take that factor down a bit,” McCord says.
He also recommends breaking a few ears in half to evaluate kernel depth and paying attention to whether ears are filled all the way to the tip when figuring corn yield. “A deep kernel is a good indicator you have some heavy grain in the works and can lower your kernel count number from 90,000,” he says.
Higher rainfall typically favors lower kernel counts to make a bushel than drier years. The timing of any stress also comes into play. Stress early in the season can result in fewer kernels around, while ears with less length can signal mid-season stress, McCord explains. “If kernels per bushel are higher across the board, it can indicate late-season stress.”
Irrigation is another scenario where a lower kernel-per-bushel factor can be used. On the other hand, challenging soil types or lower-performing fields typically warrant a higher kernel-per-bushel number, according to McCord.
AgriGold Agronomist Sam McCord says adjusting your kernel-per-bushel factor to the seed product and growing season can improve your corn yield estimates.
Many ways to make a bushel
Many of today’s corn seed offerings are kernel-flex products that typically add weight late in the growing season. But that doesn’t mean a farmer should shy away from a product that uses more kernels to make a bushel. At the end of the day, yield is what counts — not how the corn plant got there.
A better understanding of how flex type, environment and management impact kernels per bushel can help you estimate yield with greater accuracy, leaving you better prepared for decisions on things like grain storage and marketing.
Your local AgriGold agronomist can help you dial in corn yield estimates.
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