- Yield trials from multiple sources should be used for selecting hybrids in similar growing environments.
- Use multi-year, multi-location yield trial information that matches your environment (crop rotation, tillage system, soil, and drainage).
- Choose hybrids with characteristics that fit the individual field and/or cropping system.
- Hybrid characteristics can influence other aspects of the cropping system that need to be considered when choosing hybrids.
Choosing corn hybrids is one of the most, if not the most, important crop management decisions to be made. It is a hard decision to make because it is typically made months before the growing season begins, and there are many factors yet to be determined, most notably the weather.
Interpreting yield trial information
The objective of hybrid selection is to predict how well a hybrid will do next year, not evaluate past performance. The difference here is that selecting a hybrid requires having enough information from many yield trials to predict future performance. To make predictive decisions, use yield trials that have single location as well as multi-location averages. Multi-location averages are required because they can account for a range of environmental conditions such as weather, nutrients, insects, and diseases. When choosing which yield trials to use, consider crop rotation, tillage, soil type, and drainage that are similar to your fields. These factors interact with yield potential in ways that affect how well the yield trial will predict hybrid performance specific to your field and management.
To use yield trial data confidently, do not rely on the yield value itself. Use information like least significant difference (LSD) to tell if a hybrid is statistically different than another. Even using simple quartiles can be useful when combined across multiple yield trials. For example, a hybrid that is in the top quartile for every yield trial has consistent performance whereas a hybrid that lands in a top quartile at one location and a middle location at another location is not a consistent hybrid with predictive performance. Looking for high performing hybrids that perform consistently across many locations and yield trials will lead to making hybrid selection decisions that are predictive for the next growing season.
Characteristics to consider
- Yield and yield consistency: high yield hybrids have the potential to have high yields every year, while low yielding hybrids rarely have the potential to be high yielding. Evaluate hybrids yearly for yield potential since hybrids are typically only on the market for 2 or 3 years. Look for hybrids that consistently have a high performance from location to location and year to year.
- Disease tolerance: knowing what diseases are common for your area is a key to choosing hybrids with disease tolerance to minimize disease risk. Disease tolerance is especially important for diseases that do not have other viable control options, such as bacteria diseases like Goss’s wilt. Consider management practices that have higher disease risk potential such as continuous corn where diseases that overwinter in residue are more prevalent or early planting where cool, wet soils may promote seedling disease. Another consideration is how likely you are to apply a fungicide. If a fungicide is not a likely option, look for hybrid disease packages with above-average disease ratings.
- Transgenic traits: this option can provide insect protection as well as herbicide resistance. When deciding on transgenic traits, consider whether you need all the traits being offered with the hybrid. Transgenic hybrids have been very successful where insect and herbicide resistance has not become an issue. While insect and herbicide resistance is becoming more of an issue, transgenic traits can still be a powerful management tool if used judiciously across the crop rotation.
- Early season vigor and emergence: these characteristics are extremely important to achieve the desired harvest population. A high seedling vigor rating helps manage risks when hybrids are selected months before planting and the knowledge of what weather conditions will be. Rapid emergence and vigor can minimize disease risk, while uniform emergence is important for high yield potential.
- Standability and lodging: often hybrids have ratings to indicate how well a cultivar will be to harvest. This characteristic may be key for fields that are typically wet in the fall or are harvested later in the field order. While some cultivars have better standability than others, weather also greatly influences how well plants will stand after maturity.
- Greensnap: weather events, landscape position and plant development stage influence the occurrence of greensnap. Hybrid selection can reduce the severity or occurrence of greensnap when hybrids have been characterized, or past hybrid knowledge can be accounted for. Avoiding more susceptible hybrids is recommended if greensnap is a common occurrence.
- Grain drydown: the ability of a hybrid to drydown quickly can lead to earlier harvest and/or lower grain drying costs. Choosing hybrids with rapid grain drydown is most important for farm operations with little to no on-farm drying capacity. Using grain drydown ratings can reduce the need for planting an earlier maturity and potentially losing yield potential.
- Seed costs: prices have been steadily increasing as seed technology and genetics have improved. Balancing the cost of seed with the yield potential can be tricky. Seed discounts should be considered, but do not compromise cultivar selection to obtain a discount on seed costs. Limiting the transgenic traits can reduce costs, but there must be consideration of the cost for alternative management strategies in the absence of traits.
Where to find public yield trial information
- Iowa State University / Iowa Crop Improvement Association
- University of Illinois
- University of Nebraska – Lincoln
- University of Minnesota
- University of Missouri
- South Dakota State University
- University of Wisconsin
It may be valuable to look at university trials in neighboring states with similar growing environments. Consider other public and private strip trials from FFA clubs, FIRST Seed Tests, cooperatives, and seed companies. These sources may or may not have entries from multiple brands and often are not replicated.