Variety selection is one of the most important management decisions that influence soybean production.
Obviously, it’s key to select varieties that demonstrate the highest yield potential, although that’s only 80 percent of the equation. The other 20 percent is about identifying the best variety for each field.
Why field fit is important
While the genetic base for soybean is quite narrow, each variety has strengths and weaknesses. Properly positioning the best lines across your acres will increase yields by several bushels per acre.
You may meet people who’ll promise they can help choose these varieties for each field but, unless you work with a crop consultant who has scouted your fields, most will not have enough information to help position varieties.
The key is a detailed, well-organized inventory of all of your acres. A clear understanding of the diseases that impact soybean yields on each farm is an essential ingredient for variety selection. Knowing where and when diseases have been present will help.
How to assess your fields
Walk through your fields throughout the season and note any troublesome issues. If plants have diseases you can’t readily identify in the field, send them to a lab. Map the areas and take notes to identify associations between disease and environmental factors or management decisions.
For instance, “Disease X was present in the south half of the Y 80. Planting conditions were excellent and variety Z was treated with A+B+C.” Paired with soils and yield maps, these observations can be quite powerful.
Without truly understanding which organisms impact your soybean yields, it’s difficult to select among the hundreds of available varieties. Keep in mind genetic resistance is only available for a small number of diseases. You’ll need additional soybean management to reduce risk from all diseases.
When choosing among varieties, it’s also important to keep seed compositional quality in mind.
Although it’s unlikely you’ll be directly penalized for your soybeans’ low protein or oil content, your entire crop will be marketed at a small discount for historical low protein levels typically found in the upper Midwest.
This penalty is embedded within the basis. Choosing high-quality soybean genetics will allow Minnesota soybeans to remain competitive in local and international markets.
The most practical selection criterion among varieties is maturity.
Selecting soybeans across a range of maturities will help hedge against some extreme weather events, but can lead to overlap with corn harvest. In general, select the longest-season varieties that fit with your operation’s logistics.
Some final tips:
Select six or more unique varieties to spread the risk across the farm.
If possible, purchase from different companies with different genetic backgrounds to ensure you’re really utilizing unique genetics.
All varieties are rated good to excellent for most traits, so carefully identify any potential weaknesses and keep these varieties off of acres where those weaknesses may show.
Ignore red herring traits like “hypoctyl length,” “bushy vs. thin-line,” “leaf shape,” “seeds per pod,” “seed size,” “standability” and “shattering.” These measures rarely differentiate varieties in the real world.
Most importantly, use multiple information sources when choosing varieties. Look for independent support for each variety you choose. Use the Minnesota Variety trials and the FIRST test results in addition to local strip trial data.
Courtesy Minnesota Soybean Research & Promotion Council
Reviewed in 2018