Pioneer - Corn kernel size has little effect on yields, research shows

Growers have a number of decisions to make prior to planting.

But according to agronomy science researchers at Pioneer Hi-Bred International, Inc., seed size is the least critical. Recent research there shows the selection of corn kernel size has the least impact on grain yield of any seed-related choice.

"Kernel size is a decision that concerns some growers," says Pioneer agronomy research scientist Tom Doerge.

"However, the choice of kernel size must be kept in proper perspective with overall crop management goals and year-to-year fluctuations in seed availability. Extensive field research by Pioneer and university scientists has found that kernel size has minimal effect on seed vigor, field emergence or final yield."

Choosing the best crop genetics has the highest impact on corn yield -- followed by insect resistance and seed treatment selection.

Corn seed comes in seven kernel sizes based on seed size (small, medium or large) and shape (round or flat).

Kernel size is determined by position on the seed parent ear, hybrid genetics and in-season growing conditions.

The most common kernel sizes are Precision Design Round (PDR), Precision Design Flat (PDF) and small flat (F16). This can vary greatly, however, across hybrids and years.

"Growers should remember that with a greater number of hybrids planted there is the likelihood that they will be planting several kernel sizes," Doerge says.

Virtually all kernel sizes can be successfully planted with all planter types -- air, vacuum, finger pick-up and plate-type; however, adjustments may be required in some cases.

"Pioneer has developed a rating system that describes the expected plantability for each combination of kernel size and planter type," Doerge says. "The system has three classifications that we use to advise our customers on seed size selection."

Kernel size/planter type combinations given this classification are expected to have acceptable plantability with normal planter adjustment and maintenance. A majority of cases falls in this management category.

Some of the larger and smaller kernel sizes necessitate additional adjustments to attain acceptable plantability.

Accessories may be needed in conjunction with proper adjustments -- examples include installing a small disk on vacuum planters when using F16 seed or adjusting finger tensions when planting flat kernel sizes.

In rare cases, certain kernel sizes, specifically PDR seed on plate planters, may not achieve satisfactory plantability.