According to university field trials, hybrid selection is the number one factor in determining yield. Four years of yield data from the University of Minnesota illustrate the impact hybrid selection has on a corn grower's bottom line.
"We identified key agronomic practices that impact a grower's success including hybrid selection, crop rotation, tillage systems and relative maturities," says Jeff Coulter, University of Minnesota extension agronomist. "Selecting proven, well adapted hybrids with high yield potential can make a large impact on overall performance."
According to the research, return to the grower was between 37% to 64% when comparing highest to lowest yielding hybrids. "No other decision can make that large of an impact," says Fritz Behr, vice president of research at Wyffels Hybrids.
Bill Jay, who farms just west of Champaign, typically makes his hybrid decisions shortly after harvest. He plants corn from several different companies, bases a lot of his decisions on what has worked well in the past on his ground and focuses on base genetics.
"We have corn rootworm pressure in this area, so I plant some traited seed with above- and below-ground insect control, but I mostly concentrate on good base genetics," Jay notes. "That means a lot more to us than what's stacked on to it."
Behr suggests reviewing the following factors when selecting corn hybrids for next year:
•Your geography, number of growing degree days, soil type and drainage
•Prevalent disease and insect problems
•Local yield / performance data across multiple years and multiple sources including universities, grower associations, seed companies and on-farm strip trials
•Available data, products and new technology from a knowledgeable seed representative
•Harvestability and root lodging resistance
•Stalk strength and greensnap resistance
•Disease resistance that matches your past disease pressure
•Reaction to drought stress
~~~PAGE_BREAK_HERE~~~Behr also recommends planting a selection of hybrids with different maturities and genetics to help manage both the risk of summer heat stress with pollination timing and the workload at harvest. "Since we can't predict what kind of growing season we'll have, it's best to plant 25% early maturing hybrids, 50% mid-range and 25% late maturing hybrids," he adds.
The second-ranked practice in the university trials, crop rotation, affected 4% to 19% of yield. Research generally demonstrates a yield improvement for corn following soybeans or alfalfa. However, some growers take advantage of the high yield potential that continuous corn can offer when prices are right.
A relatively small percentage of Jay's fields are continuous corn, but he understands the extra steps needed when selecting hybrids. "You really have to be particular with your corn-on-corn hybrids," he says. "Some are stronger, can withstand the stress and have better disease resistance. We manage those acres a lot more carefully, not just with the hybrids we select, but also applying fungicides and other practices."
Management decisions that make a difference
Rank % Yield Impact Agronomic Factor*
1 37-64 Hybrid selection
2 4-19 Crop rotation vs. continuous corn
3 6-15 Tillage system for continuous corn
4 6 Uniform emergence vs. 1-leaf stage delay
5 4 Late- and mid-season hybrids vs. early hybrids
The next four factors had much less impact on performance:
6 2-5 Planting date
7 1-2 Population of 34,000 vs. 30,000 plants/acre
8 1-2 Within row plant spacing
9 0-4 Narrow or twin rows vs. 30-inch rows
*Two factors not mentioned are soil fertility and insect and disease management. Researchers considered these to be prerequisites for high yield corn. Courtesy of University of Minnesota.