"We try to push the limits, but if we go too fast we will have issue with ear count," she says. "Planter bounce causes variability with spacing and then uniformity. This all hurts ear count."

She walks through an example of planting at 6 mph and 4.5 mph.

"When we do the stand counts, in both rows we had 30,000 plants per acre, but by ear count, we lost 4,000 ears. Every 1000 ears are worth 5 to 7 bu. That means we lost 20 to 28 bu. per acre because we were driving 6 mph.

Learn more in this episode of Corn College TV.