Optimize Corn Hybrid Selection for 2021

 By Jeff Coulter

Hybrid selection is one of the most important factors affecting corn yield and profitability. In trials where many corn hybrids are compared, it is common for grain yield to vary by 30 to 50 bushels per acre or more among hybrids.

Seed costs should also be considered when selecting corn hybrids, as several hybrids often produce yields that are among the highest in a trial. Additionally, it is important to stay current with corn hybrid selection, as the rate of genetic yield improvement by year of hybrid commercial release is nearly 2 bushels per acre.
Hybrid trial results
To select corn hybrids, consider trial results from many reputable sources including universities, grower associations, cooperative elevators, technical colleges, farmer groups, and seed companies. Trials that have all hybrids replicated at least two or three times and compare hybrids from multiple companies are of particular value.

Select hybrids that consistently perform well across multiple locations or years with soils and growing conditions similar to those of your fields, because these hybrids will likely perform well in the future in your fields. When possible, use statistical results such as a least significant difference (LSD) value to determine whether the measured variable, such as yield, is significantly different among hybrids of interest. Additionally, percentiles can be used to assess the consistency of hybrid performance. For example, a hybrid whose yield is within the top 25% in all trials under consideration would have consistent performance. Be wary of hybrids with inconsistent performance.

Results from the University of Minnesota corn grain and silage performance trials are available at http://z.umn.edu/corntrials. The 2020 corn grain trial results have recently been posted and the 2020 corn silage trial results will be posted soon.

Results from other corn trials are available at the links below.

• Minnesota Corn Growers Association
• Iowa State University
• University of Wisconsin
• South Dakota State University
• North Dakota State University

Additional hybrid criteria for corn grain

• Plant multiple hybrids of varying maturity to widen the time for harvest. Planting hybrids with a range in maturity also widens the time for pollination, thereby reducing the risk that one’s entire crop will experience dry and hot conditions during pollination. Consider choosing two to three hybrids in each of two to three maturity groups, where a maturity group represents a set of hybrids that have grain moisture within 2% of each other at harvest. Within a maturity group, look for hybrids that have high and stable yield, lower grain moisture, and less stalk lodging.
• The growing degree unit requirement of the selected hybrids should be at least 100 to 200 growing degree units less than that of your growing season to allow time for in-field dry-down of grain before harvest and to provide a buffer in years with below-average air temperature, delayed planting, or an early freeze in the fall.
• Full-season hybrids do not consistently out-yield mid-season hybrids, particularly in central and northern Minnesota, and full-season hybrids usually have higher grain moisture than mid-season hybrids at a given time in the fall. Typically, the range in grain yield among hybrids within a maturity group is greater than the range in grain yield between maturity groups.
• Also consider agronomic traits such as suitability for a given crop rotation, emergence, root strength, and tolerance to diseases, drought, insect pests, and herbicides.

Additional hybrid criteria for corn silage

• Longer-season hybrids typically produce higher silage yield. Hybrids planted for silage should be about 5 to 10 units greater in relative maturity than hybrids planted for grain. However, longer-season hybrids may not be optimal if one wants the option of harvesting corn for grain rather than silage.
• Select multiple hybrids with varying maturity to widen the time for harvest, as harvesting at the correct moisture level is critical for high-quality silage. This is especially important in years when dry late-season conditions cause corn to dry rapidly.
• Other important considerations for selection of silage hybrids include suitability for a given crop rotation, emergence, root strength, standability, and tolerance to diseases, drought, insect pests, and herbicides.
• Consider both silage quality and yield when selecting hybrids. Milk per ton is an overall indication of silage quality, and is estimated from forage analyses for crude protein, neutral detergent fiber (NDF), NDF digestibility (NDFD), starch, and non-fiber carbohydrate. Once a suitable group of hybrids has been identified based on milk per ton and yield, further selection within this group can be based on specific forage quality and agronomic traits. Consult with a livestock nutritionist when selecting silage hybrids to ensure that the selected hybrids will have the necessary nutritional value.