There are many factors to consider when choosing which soybean varieties to plant in 2015. Where should you start when making your decision?
A major differentiator between soybean varieties is maturity levels. Many growers plant a range of different maturities to spread out harvest time. However, there is a bit of a misconception that early maturity soybeans for your area have a lower yield potential. According to Dan Bjorklund, Syngenta agronomic service representative based in Fort Dodge, Iowa, this is not necessarily true.
"The thinking in the past was the fullest season varieties for your area would have the highest yield potential. In reality, the variety genetically developed to best handle area-specific soil types and diseases will have the highest yield potential," says Bjorklund. "It's more about the agronomics of the variety and how consistent it will be than the maturity length."
Disease resistance is high priority when choosing varieties
Although it is important to plant a range of maturities in preparation for different possible field conditions due to weather, disease resistance is a higher priority when choosing seed. Researchers at the Iowa State University Extension agree that disease resistance should be a higher priority. In the wake of a season that saw high levels of disease pressure, choosing a soybean variety with resistance to these threats should be top of mind for growers in 2015.
According to Bjorklund, preparation for the following three diseases will best protect yield potential: sudden death syndrome (SDS), Phytophthora and early-season Pythium. The first step to defend against SDS and Phytophthora is to choose a soybean variety that has resistance to these diseases, such as NK Soybeans. Bjorklund notes that many NK Soybean varieties have built-in resistance to both of these diseases. SDS in particular is becoming a more of a problem in Iowa and NK Soybeans offer increased SDS resistance compared to competitive varieties. According to Bjorklund, growers who planted varieties with excellent resistance to SDS this past season saw better overall yields.
Compare results in yield trials to your field's need
This information raises another question: What is more important, planting seed with resistance to potential threats or making a decision based on field trials? According to Bjorklund, both of these factors need to be considered when choosing soybean varieties. "I think the genetic yield potential of the variety is determined by looking at a plot and seeing how a variety has adapted to a particular soil type," Bjorklund notes. "You need to look at the agronomic package of the variety; its resistance to diseases like SDS should be weighed because you don't know when those diseases are going to become a major factor."
However, when it comes to early-season Pythium and some other disease pressures, picking the right variety only goes so far. The best way to defend against Pythium, says Bjorklund, is to apply a fungicide seed treatment for additional protection. Choosing an effective seed treatment can provide protection that leads to healthy crops throughout the season. Although treating seed is not a universal practice for Iowa soybeans, it is consistently expanding each year. Bjorklund cautions against trying to cut costs by skipping seed treatments.
New seed treatments help boost soybean yields
"I know of growers who treated their seed with Clariva Complete Beans seed treatment and averaged 70 to 75 bushels per acre across fields, and experienced the best yields they've ever had," says Bjorklund. "There were other growers in the area who did not treat their soybeans and were disappointed. People are looking at ways to cut back on input costs, but it would be a big mistake to not treat your soybean seed."
Although there are up-front costs associated with seed treatments, he advises that the return on investment is generally greater when growers take the extra care to defend soybeans before a disease or pest, like soybean cyst nematode, becomes an issue.
Choosing soybean seed is often the first of many choices throughout the growing season, and with all of these factors it can be a complicated decision to make. Although there is something to be said for planting what has worked in the past, it's crucial to stay on top of developing regional threats and to reevaluate the best varieties for your fields each season.