Spring planting is the culmination of weeks of seed selection by compiling field profiles, disease presence and desired product at harvest.

By Dave DeValois

Farm News staff writer

Using one part science, one part word-of-mouth advice from fellow farmers, and one part gut instinct, farmers across Iowa for the most part have already decided what varieties of corn and soybean seeds they’ll plant in their fields this spring.

Most farmers choose their varieties in the late fall shortly after that year’s crops were harvested. Selecting seed varieties at that time ensures that the varieties they seek will be available and also locks in the lowest price of the season. Other than price, farmers know that nothing else in the complicated equation of choosing varieties is ensured.

Field specific

Yield potential, maturity date, soil condition suitability, disease and pest resistance, weather conditions, and cost are just part of the factors corn and soybean growers must evaluate to determine the best variety for each particular field.

Jim Legvold farms near Vincent and is a seed dealer for Kruger Seeds. Legvold said rather than looking first at yield potential he looks at the yield limiting factors for his soybean crop, such as sudden death syndrome, white mold and soybean cyst nematode.

“Yes, yield should be the number one factor. But I use the metaphor of will this racehorse run on a fast track and a muddy track,” Legvold said. “Buying traits is like buying an insurance policy.

“It may cost you in yield to have those traits. But you’re banking on those traits to stabilize your yield if the conditions rear their ugly head.”

To filter through the various combinations of seed varieties, Legvold said he starts with the soil map for each field and likes to study independent yield trials, such as those released by universities, as well as research within Kruger, the company he represents.

But he also asks neighboring farmers how they did with a particular variety. “I don’t know if I have a science to it,” Legvold said “I take it all into account and make a decision.”

End product specific

Jim Stillman, who farms near Emmetsburg, said with his soybean varieties, he looks carefully at protein and oil content, to keep those within the ideal levels of 35 percent and 19 percent respectively.

“Yield always comes first, but I need for the protein and oil content to be right up there, too. We sell to processors and they’re looking at the foreign market,” Stillman said, referring to South American growers, who generally have higher protein and oil content for their soybeans.

Stillman said he relies on his seed company’s agronomist to help him filter through the scores of choices for varieties.

“You have to rely a lot on your agronomist. They’ve got the upper hand in knowledge that everybody needs to have,” he said.

On the soybean side, Stillman said brown stem rot is the disease that concerns him most and that he will use a variety with resistance to it.

Compiling data

Roger Vander Veen raises cattle and grows corn-on-corn on his farm near Hartley. He also is a Pioneer seed dealer. Vander Veen said he takes the same approach to selecting his own seed that he uses with his customers.

“The data I use for picking varieties for their farm is the same way I do it for my farm,” he said.

Vander Veen said many of his customers are older farmers who want to use the same varieties they used in years past.

“They are creatures of habit,” he said. But he tries to get customers to look at three years of data on roots, stock, emergence, yield and other factors and evaluate whether the corn variety they used is the best one for them.

He also is careful to look only at research that applies to his specific area in northwest Iowa, which he said can have much different weather patterns than other parts of Iowa

“That affects a lot of what we do,” he said. Many farmers, for example, choose 98- to 104-day corn maturity, which is a shorter season than most of Iowa.

If weather conditions or disease patterns change substantially between the time farmers ordered their varieties and spring planting, seed orders can be changed.

“We always do a plan ‘A’ and plan ‘B.’ We’re always willing to adjust,” Vander Veen said.

Contact Dave DeValois at dwdevalois@yahoo.com.