Planting can be a time of lost opportunity if you miss your seed target. Irregular stand spacing can mean reduced corn yields of 5 to 7.5 bushels or $10 to $15 per acre. Uneven emergence is also a yield-robbing problem that can be related to planter performance. Here are six tips to help you improve planting accuracy:

Years ago Dundee, Kentucky, farmer Darren Luttrell decided to have the seed meters on his 12-row corn planter calibrated after he heard about potential yield improvements from better planting accuracy. When Luttrell got a $1,300 bill for the cost of calibration and replacement of worn-out meter parts, he felt foolish about spending money on something so intangible.

"But I had the best stands and yields I'd ever had that year," recalls Luttrell, who farms 3,000 acres of corn and soybeans with his family.

"With costs as they are, we've got to take advantage of every seed kernel we plant," says Luttrell, who now calibrates about 400 to 500 meters each winter for other farmers. Seed meter manufacturers estimate that for every 1% improvement in meter accuracy, farmers reap about $4.50 to $5.00 per acre in better performance.

John McGillicuddy of McGillicuddy-Corrigan Agronomics, Iowa City, Iowa, suggests growers calibrate finger pickup meters after every 100 to 125 acres of operation per row. New meters should also be calibrated because settings by the manufacturer may not match your planting situation.

During calibration, Luttrell often spots worn meter backing plates on finger pickup meters where the agitator or bump that keeps extra kernels from getting into the seed belt has worn flat. That can cause doubles or even triples, he says. Fingers wear out, too, flattening near the meter cam and causing metering skips. A complete rebuild for a finger pickup planter costs about $120 per row, says Luttrell.

Certain new technologies might also be worth a look, says Pioneer agronomist Brad Sherwin, Algona, Iowa. If you own a vacuum planter, consider upgrading to seed disks designed without dimples, he says. The design (recently introduced by Precision Planting) releases seed kernels directly over the seed tube, eliminating the risk of the seed bouncing from side to side and going off target.

"The new design is more accommodating for different seed sizes," Sherwin says.

Check disk openers on planters to make sure they are sharp and at least 14.5 inches in diameter for most planters, says Kevin Kimberley, implement consultant from Maxwell, Iowa. Deere, Kinze, and White should be 14.5 inches; Case IH should be 14 inches.

Before you attach scrapers and gauge wheels, check the spin on disk openers to make sure they do not wobble, says Kimberley. Disk openers should be touching about 2 inches at the base of the vee and should be that way before and after spinning.

Worn disk openers can rub the bottom of seed tubes and cause a small point of friction, says Sherwin. Heat buildup can reshape the seed tube, forming a small lip at the bottom where seed can hit and be flipped out of the furrow. A new tube from Precision Planting has carbide in the tip to help prevent this wear.

Off-kilter closing wheel assemblies can contribute to variable emergence, which agronomists say can cut yield by 8% to 10%.

Uneven emergence is particularly a problem where there is pressure from insects, says Sherwin.

Later-emerging plants face more insect damage, interfering with pollination and yield.

Basic seed shape, size, weight, and surface quality are all important factors in planter performance. Bob Nielsen, Purdue University agronomist, suggests you jot down each lot's seed weight when seed is delivered from the seed supplier. Then look up the recommended seed disk and air pressure in your planter operating manual for each weight to create a planting guide.

This simple task can help deliver seeds closer to their targets, says Nielsen, because it simplifies making planter adjustments as you go. "By getting (the recommendations) written down ahead of time, you can refer to your list and avoid the mental gyrations on the day of planting."

Kimberley says seeds treated with insecticide have caused plant-spacing headaches in recent years because they had gravely, rough surfaces compared to smooth, untreated kernels. Most planters are designed to handle smooth surface seed, he says.

"If your seed is not slick, you gotta make it slick," he says. Kimberley recommends producers add talc for vacuum planters or graphite for seed planted through finger pickup planters.

"Don't just dump it in," says Kimberley. Mix about 1D2 to 3D4 cup slickening agent per bag of seed using a cordless drill with an auger tip. For bulk seed, an inoculator can be attached to the auger to mix the slickener in as seed is filled into the planter. In warm or humid weather, less talc may be needed.

Kimberley also cautions that if you get caught in a rain shower driving back from the field, immediately run all seed out of your meters and dump your planter boxes. "It will turn into cake mix and screw up plantability."

Implement consultant Kevin Kimberley (kneeling) recommends that farmers add talc to seed for vacuum planters or graphite for finger pickup planters.

"The biggest effect on plant-to-plant spacing is vibration," says Sherwin. The faster you go, especially in rough or cloddy fields, the more vibration youll get. Going 6 vs. 5 mph might save one day in planting time, but the difference in yield could be 20 bushels. "There's really no good reason to go too fast," he says.

Nielsen encourages growers to pay close attention to planters on a field-by- field basis. Changes in parameters, such as planting depth and down pressures, have to be monitored and adjusted according to field conditions in order to maximize planting accuracy.

Kevin Kimberley
Phone: 515/967-2583

Darren Luttrell
Phone: 270/298-7861
E-mail: luttfarm@aol.com

John McGillicuddy
Phone: 319/354-2985

Bob Nielsen
E-mail: rnielsen@purdue.edu

Brad Sherwin
E-mail: brad.sherwin@pioneer.com

Precision Planting
www.precisionplanting.com