No skips, no doubles for sunflowers
By Loretta Sorensen
Carefully calibrating the planter is one of the most important steps sunflower growers can take to realize optimum yield and quality at harvest.
John Smith, former University of Nebraska machinery systems engineer, says growers shouldn’t underestimate the complexity of their planter.
“Don’t take for granted that every aspect of your planter is operating exactly as it should,” Smith says. “Thoroughly inspect the drive mechanism, the meter unit and the seed tubes. Significant planting issues can often arise in these areas. Something as simple as a worn seed tube can result in significant seed spacing problems.”
Smith notes that planters are made up of sprockets, chains, clutches, couplings, transmission and, typically, some accessories such as granular applicators. A small problem with any of those elements can quickly affect uniform seed spacing.
“Uniform, consistent seed spacing within the row is very important for confection sunflowers because uniformly spaced plants produce uniform-sized heads with consistent-sized seeds,” Smith says. “Confection seed buyers often object to small or inconsistent seed size. Two plants spaced far apart within the row will produce the desired large-sized seed, but yield will be reduced. Two plants spaced too close together will often result in small head size and small seed size.”
Smith recommends that growers begin inspecting their planter by testing its drive mechanism. In order for the meter unit to operate properly, the drive unit must turn uniformly and smoothly.
“Picture the rotation of the seed plate, dropping a lot of seed quickly,” Smith says. “If you’re planting at 5 miles per hour with 9-inch seed spacing, the planter drops 10 seeds every second — machine gun speed. There’s a very short time between each seed drop. Any jerking or hesitancy in that drive will affect seed spacing.”
One way to get a close look at a planter’s drive system is to attach the planter to a tractor and raise the planter drive wheels off the ground. Then turn the planter drive by hand and determine if the planter drive system rotates easily and uniformly.
“Block the planter, for safety purposes, then turn the drive wheels by hand,” Smith says. “That way, you observe firsthand how the drive mechanism is functioning.”
In his research, Smith has encountered an instance where frozen bearings seized up a planter, causing the drive mechanism to cyclically jerk and stop. Close inspection revealed the bearing problem, but it took time and several inspections to identify that problem had also severely bent the teeth on a sprocket that had to be replaced before the drive worked properly.
Smith’s research has also revealed that even minimal wear of seed tubes can affect how consistently seed drops from the planter.
“We think the sharp edges of corn seed cause seed tube erosion, which feels slightly rough, like sandpaper, if you run your hand over it,” Smith says. “That seems like a small thing, but I just about guarantee that seed spacing for any crop will be affected by that. You don’t have to replace the sensor, but check that seed tube every season and replace it if you find any wear.”
Precision planting tools assist growers in monitoring planting activities. Smith recommends using a model that shows individual seed spacing rather than averages.
“If your monitor shows your seeds are averaging the correct number, it could still mean you’re not achieving the correct singulation, or correct individual spacing,” he says. “You could be planting two seeds, skipping one, planting two, etc., and still have the correct average seed spacing. When you monitor individual seed spacing information, you know for certain your planter is operating as it should.”
Some planter models will singulate and space sunflower seed, especially confection seed, much better than others.
“Some planters may be a little less sensitive to seed size and seed shape, which can affect seed spacing performance,” Smith says. “Review your planter manual, talk to your equipment dealer and visit with your seed company representative. They know their seed better than anyone.
The National Sunflower Association has an excellent library on its website and a network of people with extensive growing experience. University Extension Service is another good resource. Blend all the information you obtain to get the best possible planting performance.”
Sorensen is from Yankton, S.D.
ON TARGET: Uniform plant spacing — no skips, no doubles — is critical for high sunflower yields.
This article published in the February, 2013 edition of DAKOTA FARMER.
All rights reserved. Copyright Farm Progress Cos. 2013.