Plant breeders aren’t the only people who produce the seed corn you plant each spring. Once a hybrid is ready for release, agronomists plan where seed will be planted and in what planting scenario. Then they hope for spring weather that will allow them to plant on time.

“We’re planting two inbreds in each field to make the cross as the breeder prescribes,” says Darin Lucas, production location agronomist for Beck’s at Atlanta, Ind. “The goal is tweaking male and female inbreds, so each one pollinates at the correct time. Throw in uncertain weather, and it can be challenging.”

At the end of May, planting was still ongoing. Rain interfered with seed corn planting across the Corn Belt, Lucas says. “We’re confident that we will catch up and be OK,” he adds.

Overcoming challenges

If you’ve grown seed corn before, you know there are a range of techniques used to match up pollinating dates between inbreds, depending on the inbreds. If you haven’t raised seed corn, Lucas provides this quick refresher about different techniques:

Growth regulator. The easiest scenario occurs when you can use a growth regulator to delay germination of male rows. Beck’s uses BioNik from Valent for this purpose when possible. “Then you can plant female and male rows at the same time, more like normal planting,” Lucas says. “However, not all male inbreds get along well with S-abscisic acid, the active ingredient in BioNik. There are several inbreds where we can’t use this product.”

Missing row units? If they can’t delay germination of the male, they plant female rows, then come back and plant male rows. When they only need one male row to pollinate adjoining female rows, it is a four-female-one-male row pattern, Lucas explains. “The planter we use for planting male rows only has a planter unit on every fifth row,” he says.

DOUBLE TAKE: Agronomist Darin Lucas says it’s no accident that there are two rows of inbred male corn together. The row was planted at two different times to widen the pollination window.

More male power. For male inbreds that have smaller tassels or don’t produce as much pollen, the choice is alternating four female rows with two male rows. The double dose of male rows provides enough pollen to fertilize all female rows, Lucas says.

Double delay. With certain male inbreds, the pattern is four female, one male row, but the male row is planted at two different times — into the same rows. “We base when to plant male rows each time on how many heat units accumulate after planting female rows,” Lucas says. “The interval will be longer in cooler weather. We plant a lower population each time to reach the desired final stand. This process helps with inbred pairs where we need to spread the pollination window.”

So, why grow inbreds that require more tweaking? “Those crosses are often some of our best hybrids,” Lucas notes. “Plant breeders determine that part of the equation. Our task is producing hybrid seed, even in years when the weather doesn’t cooperate.”