Pioneer Research Shows Impact of Lower Seeding Rate, Seed Treatment on Soybean Yield

Reduced seeding rates of up to 7 percent show same or better yield outcome

DES MOINES, Iowa.- Research from Pioneer Hi-Bred, a DuPont business, shows that soybean growers can get the same or better yields using a lower seeding rate with an insecticide-fungicide treated seed as opposed to planting at a higher rate with an untreated seed.

“Results from research conducted at five locations in the Midwest in 2006 and 2007 have shown planting at a lower seeding rate with a treated seed increased yields,” says Jim Trybom, Pioneer agronomy research scientist. “In some cases, seeding rate was reduced up to 7 percent, which can help growers offset the input cost of treated seed.”

Targeted seeding rates were 50,000, 100,000, 150,000 and 200,000 viable seeds per acre. The actual seeding rates achieved were 55,000, 110,000, 165,000 and 220,000, respectively. All plot locations were conventional tilled and in a corn-soybean rotation.

Increased soybean commodity prices have driven growers to protect their crop through management practices. With recent yield threats, such as soybean rust and aphids, growers are looking to additional management inputs. Additionally, soybeans are being planted earlier every year which also brings possible risk of fungal diseases.

“As growers continue to plant earlier and earlier, treated seed becomes more common,” says Trybom. “Pests and fungal diseases are more of a threat when planting into cooler and moister soils. Planting treated soybeans is a form of insurance - protecting your crop until it gets out of the ground.”

Pioneer research shows earlier planting dates, from April to early May, have the highest yields. In addition, using a treated seed also proved to increase yields. CruiserMaxx® treatment, an insecticide-fungicide combination, showed increased yields up to 3.1 bushels per acre at the early planting dates, and 1.4 bushels per acre at the late planting date. ApronMaxx®, a fungicide treatment, also indicated higher yields than untreated seed.

“The optimum economic seeding rate for ApronMaxx and CruiserMaxx treatments were lower than the optimum economic seeding rate for untreated seed,” says Trybom. "Yields of both seed treatments were greater than untreated seed at all seeding rates. Among seed treatments, CruiserMaxx treatment out yielded untreated seed at all seeding rates.

“There are several factors to consider when deciding on a soybean seeding rate,” says Trybom. “These include the type of planting equipment, seedbed and weather conditions at planting and seedling disease history of the field. Seeding economics, such as the cost of incrementally higher seeding rates versus replant costs also factor in the decision-making process,” adds Trybom.

For further information about the effects of seeding rates and seed treatments, contact your local Pioneer sales professional. In addition to your local sales professional, Pioneer offers a national network of agronomists to provide assistance.