It is nearly September, which means that the first contacts for varietal selection and seed purchases for next year are soon to begin. Between now and the end of harvest, you will likely be visited by your local seed dealers or company representatives concerning what you will be planting next year. These initial commitments are often requested before a combine has entered the field for you as a grower and most likely for the seed companies as well. The importance of deciding what varieties you will grow next year cannot be overstated. As you receive these visits, I’d like to encourage a few considerations.
1. Understand the yield information you are receiving: Most of what is available this time of year in terms of yield data is from the previous growing season. Knowing that will tell you how individual lines performed in last year’s environment, but may not indicate how they have performed this year. It is imperative that decisions are made looking at data from as many replicated environments as possible. Best data is replicated and over multiple years to cover performance over a range of environmental conditions such as rainfall, growing degree days, pest pressures and more. When looking at commercial seed yield data, consider another look at the University of Minnesota yield trail data from Dr. Jim Orf’s breeding program from last year as well. (http://maes.umn.edu/prod/groups/cfans/@pub/@cfans/@maes/documents/asset/cfans_asset_464952.pdf) The trials cover locations from Roseau to Waseca and include evaluations of multiple lines and new material to give you valid comparisons for those lines included at each location in the trial. When reviewing these or commercial variety trial data, it is not valid to compare performance between independent trials since the environmental influence on yield cannot be fully accounted for between individual data sets. A top performer in one trial environment may have performed differently in another soil/rainfall/pest pressure/etc. environment even if it is in the same relative maturity range.
2. Make decisions on multiple criteria: Yield is the trait most equated with profitability and thus it is at the top of the list in terms of importance. However, coupled with that is maturity rating, pest resistance, herbicide tolerance, standability, and quality or end use parameters and others. As you consider these, you have begun to fit a variety to your field, performance expectation, and market requirements.
3. Land history: The notes and records you or your field scouts keep on each field should serve as the basis for future production goals. In that regard, variety selection should be done on a field basis as much as possible. Soil type, weed, pest, or disease pressure, crop history, rotation plan, previous herbicide use, fertility and others all impact which variety might be the best performer on that field. A one-variety-fits-all decision may cost in maximizing profit potential of individual fields.
4. Pest resistance: When considering pest resistance, rotation is the best technique. Monoculture in crop choice or pest management scheme has always led to increased pest populations and build-up of resistance mechanisms within those pests. All living organisms adapt, so using a rotation of crops, chemicals, or genetic resistance mechanism, if more than one resistance option exists, will give you better management options in the long run.
5. Special needs: Because each field is different, include special production needs into varietal selection. If you have high SCN counts, IDC, herbicide resistant weeds, consistent disease pressure etc., matching the best performing variety to that unique field environment will provide improved performance potential in your soybean rotation system. Highest yielding lines coupled with best management practices for production challenges provide the greatest potential for yield and profitability. Become well informed on what lines perform well in trials most closely matching your scenario. Contact other growers on how their choices performed, review U of M research and talk to extension faculty and us at Minnesota soybean. If you can’t find a source of information, I’ll work to help you get there.
6. Yield: When choosing a variety, yield data is of greatest importance. It is the measure of profit potential and often, in replicated trials over years, provides anecdotal performance under coincident stress or pest pressures that may have occurred in individual environments.
In the meantime, keep taking notes, use all of the information you can find, and make the best informed decisions on next year only when you are ready.