Hybrid selection is a key step for profitable corn production. Since 1948, the average corn yield in Minnesota has increased steadily at a rate of 2 bu./acre/year. This has been due to a combination of improved hybrids and agronomic practices, emphasizing the importance of hybrid selection. When selecting corn hybrids for next year, consider the following:
- Relative Maturity. In the northern Corn Belt, maturity is one of the most important factors to consider when selecting hybrids. Hybrid relative maturity (RM) is closely related to the number of growing degree days (GDDs) required from planting to maturity. In general, a 95-day-RM hybrid needs between 2,350 and 2,400 GDDs from planting to maturity, with each one-day increase in RM increasing the GDD requirement for a hybrid by an average of 22 GDDs. Identify an acceptable maturity range based on the number of GDDs required for a hybrid to reach maturity. Selected hybrids should reach maturity at least 10 days before the first average frost (32°) to allow time for grain drydown and buffer against a cool year or late planting.
- Multiple Hybrids. Plant multiple hybrids of varying maturity to spread risk and widen the harvest interval. Full-season hybrids do not consistently out-yield mid-season hybrids in Minnesota. There is more variability in yield among hybrids within a given RM rating than there is between maturity groups.
- Consistent Performance. Select hybrids that are consistently top performers over multiple sites or years within a region. Consistency over multiple environments is critical, since we cannot predict next year’s growing conditions.
- Agronomic Traits. Hybrids should also be selected according to agronomic traits such as standability, disease tolerance, emergence and the need for transgenic resistance to insects and herbicides within a given production system.
More in-depth information on hybrid selection is at the University of Minnesota Extension. Past hybrid trial results are available from Extension and from the Minnesota Corn Growers Association. Results are posted soon after harvest each year. Printed versions of the University of Minnesota trials are available from regional Extension offices and as a special report published each December in Agri-News.