One reason you tune up your planter each spring and perhaps run planting units on a test stand is so you can minimize the number of doubles and skips in the field. Data from Bob Nielsen, Purdue University Extension corn specialist, indicates that if spacing isn't uniform, yields will suffer. Up to 5 bushels of corn per acre could be sacrificed due to uneven spacing, according to his data.
Doubles and skips usually happen when something in the planting process is worn, or isn't working correctly. In finger pick-up planters, it may be that the brushes that help knock off extra kernels are worn and no longer 100% effective.
Worn or damaged parts impact what's called singulation, or dropping one single seed each time, every time. Some modern monitors, such as Precision Planting's 20/20 monitor display not only planting population, but also singulation rates in the cab.
Pete Illingworth, employee at Purdue University's Throckmorton Research Center, though he was excellent at achieving good spacing and singulation, until he installed a 20/20 Seed Sense monitor three years ago. Then he discovered that the singulation, especially when planting big seed, wasn't always as good as he liked. By making adjustments on the planter, singulation now runs closer to 98 to 100%.
Many people are promoting twin rows these days. Often they are 7 inch rows with a bulk between. Harry Stine and Stine Seeds in Iowa announced twin 20-inch rows this year. John Deere is actually making planters so people can try the concept. It's moving another step toward equidistant spacing, which plant breeders theorize should produce maximum corn yields.
When skips occur, a kernel is dropped too soon, and usually winds up one to four inches from its closest neighbor.
The camera captured a rare sight in this field. The double is side-by-side- but that's not a twin row! Somehow due to bounce or other factors, the kernels reached the bottom of the seed tube and entered the soil trench at exactly the same time.
From the corn hybrid you select to the seeding rate and row width you choose, every decision you make influences the size and scope for corn yields. Download our FREE report: Maximizing Your Corn Yield.