Planter calibration study focuses on sunflowers
By Jennifer M. Latzke
There are many variables that influence sunflower seed production, but the one thing that growers can do to guarantee themselves a good sunflower crop happens before they even place the first seed in the ground. To get a good stand, they must set up their planters for success.
Larry Kleingartner, executive director of the National Sunflower Association, explained his organization recently sponsored a research project to determine the effects of planter calibrations on sunflower stands because of input from farmers. One of the top concerns of growers is seed spacing accuracy, he said.
"What growers want to avoid is having two or three seeds planted in the same spot," Kleingartner said. "You can have three plants come up and essentially become weeds and compete against each other for inputs. You walk a field in the fall and you'll see a six-foot space with weeds because a seed didn't drop or didn't germinate. Then, you see the impact on yield that big skips and doubles or triples can have in a field."
Planter maintenance is key
Sunflower producers like Cameron Peirce, who farms southwest of Hutchinson, Kan., know proper maintenance of a planter can go a long way toward boosting their bottom line at harvest. The research conducted by specialists at the University of Nebraska, and sponsored by the National Sunflower Association, shows just how much planter calibrations affect accurate seed spacing and overall production.
Peirce has grown oil sunflowers for about eight years, in a 100 percent no-till rotation with wheat, corn, soybeans, grain sorghum, and alfalfa. He knows how doubles, triples or skips in his field can affect his end harvest. So, each season, before his planter leaves for the field, he thoroughly checks it out.
"We usually go all the way through it and replace seed discs, openers, and check to see that there isn't any play in planter units; we look at the bushings and replace any questionable bearings," he said. "We make sure the closing wheels are properly aligned and centered over the seed slice and close uniformly. We make sure the fertilizer applicators are all calibrated and running correctly. There's a lot to do on the planter." Spending a half hour to an hour in the shop before heading to the field can pay for itself many times over, he explained.
The NSA study covered some of these maintenance aspects. The research was conducted by John Smith, professor and machinery systems engineer with the University of Nebraska, Panhandle Research and Extension Center in Scottsbluff, Neb.
Smith's research looked at both confection and oil sunflower seed spacing accuracy's, using three of the most popular planters used by sunflower growers-the Case IH 1200 series vacuum planter, the John Deere MaxEmerge Vacuum series planter, and the John Deere Finger Pickup Series planter. While the research study looked at these three specific planters, it's important to note that the findings are very general, and farmers can apply this information to their own planters and own situations. His research began in 2007 with confection sunflowers and continued through 2008 with oilseeds. He used 9 inches as the targeted in-row spacing for the oilseed study, with a standard ground speed of 4.5 miles per hour. Smith attempted to address variables such as the effect of field speed best plate selection, sensitivity to vacuum adjustment, planting with and without graphite and talc, the effect of seed size change, the best settings for each seed size, the effect of seed treatment, and the effect of worn seed tubes.
Results of the study were recently published in the National Sunflower Association's Sunflower Magazine, and several video clips are available on the association's website, www.sunflowernsa.com.
Three critical components to check
When looking at the planter, Smith explained there are three parts that growers should focus on maintaining and adjusting for more accurate seed spacing: The meter unit, the drive of the meter unit, and the seed tube that delivers the seed to the furrow.
"The drive mechanism must turn very uniformly for the meter unit to turn uniformly for accurate seed spacing," he said. The goal is for an even and consistent movement of the seed. Sunflower seeds, unlike pelleted sugar beet seeds, or other crops, tend to be flat, long and rough. This irregular shape can be difficult for planters to smoothly handle, he said.
"If you can picture a rotation of the seed plate, it's dropping a lot of seeds in a hurry," he explained. "If you have a five mile per hour speed, and nine-inch seed spacing, that translates to 10 seeds per second the planter must singulate and release. That's a short time, about six seconds between seeds. Anything that causes a difference in amount of time between seeds being dropped then causes irregular seed spacing."
To check to see if a planter has a problem with its drive system, Smith advised producers to attach their planters to their tractors and lift them up so that the drive wheels are off of the floor of the shop. For safety, he urged farmers to block the planter's wheels, and then they should be able to turn the drive wheels of the planter by hand. While they're turning the drive wheels, farmers should feel for a jerking motion, which may be caused by bearings that may have seized up or chains that may have a link frozen, he said.
Smith also emphasized producers should closely examine their seed tubes on their planters. Tubes that are too narrow, or are worn too rough, may catch a flat and long sunflower seed horizontally inside. This seed will then alter the trajectory and flow of the rest of the seeds through the tube and into the furrow, resulting in less than acceptable seed spacing accuracy, he said.
Smith attributed some of this wear to the sharp corners on corn seeds. He recommended producers to feel the inside of their seed tubes. Those that feel like sandpaper should be replaced. "They can't be repaired, and you don't need to replace the sensor, just the tube part," Smith said. If a seed tube is too narrow, Smith said, some farmers may consider using seed tubes that are designed for peanut planting. These are a bit larger and should be able to handle sunflowers just fine.
Peirce and his family take this advice by examining their seed tubes each season and replacing those that have been roughened inside. "You usually only get one chance at making a stand," Peirce said. Replacing seed tubes is less expensive than skips, or doubles or triples in a field.
A better monitor
Modern planters have seed monitors that give an average plant population or average seed spacing, but they don't give information on spacing between individual seeds, Smith said. He gave the example of a planter that's getting two seeds in every cell or hole in the plate, and then planting two seeds per hole, and the operator thinks that the transmission is set wrong. He can change it to get the right number of seeds, but then spacing is twice what it should be, and the field has skips and doubles.
"The top thing to improve accuracy for seeding sunflowers, because of a number of variables, is a monitor in the cab that will give us information on seed spacing between individual seeds," Smith said.
In summarizing the results, Smith explained there are many things that can also affect accurate plant spacing, including poor seed moisture, poor seed-to-soil contact, planting depths that are too deep, residue in the furrow, insects, diseases, and more. Peirce agreed and added he monitors the size of the sunflower seed he's planting to control his seeding accuracy.
"Sunflowers, much like corn, have to be evenly spaced," Peirce said. "You need to start with the right seed sized so that it matches up with your planter plate. If you get it too small, you can have doubles and triples and plant two or three seeds instead of one." He said he prefers to plant larger sized seed if possible because smaller seeds can get stuck in his particular planter.
"Changing the seed disc size for sunflowers to a small corn disc will help, too," he added. Lately, Peirce has seen a large amount of smaller No. 4 sized sunflower seed on the market, and he usually tries to plant with No. 1 and 2 sized seed.
"Last year, we didn't have terribly large seed size because we had too much moisture and it was too cool," he added.
Some seed companies recommend adding an adjuvant, such as talc or graphite, to sunflower seeds in the planter box. Peirce said talc or graphite can help when farmers have to plant in humid conditions, so that seeds flow smoothly. He recommended any farmer discuss adjuvants with their seed salesman or equipment dealer.
Smith advised farmers to first read their equipment operator's manual to determine their specific needs for their planter. Then, they should visit with their seed suppliers who should have the knowledge to recommend how to calibrate planters for their seeds. Equipment dealers and local university Extension Services should also be helpful, he added.
In the end, it comes down to farmers going over their equipment before taking to the field. "We're always tweaking our equipment," Peirce said. "It doesn't take too long to change seed discs in the field, if we need to; and a half hour here, or an hour there can pay dividends down the line."
Jennifer M. Latzke can be reached by phone at 620-227-1807, or by e-mail at firstname.lastname@example.org.