Match the best hybrids and varieties to your management zones. By Jason Jenkins
Selecting the best corn hybrid or soybean variety for a field always has been a compromise. Seed that excels in one portion of a field may fall pitifully short in another, never reaching the full yield potential promised by trial results.
Prior to the advent of precision-agriculture management zones and multi-hybrid/variety planting technology, producers were essentially limited to planting only one hybrid or variety per field. They had few practical means of addressing multiple yield environments. Now, however, solutions exist to place the right seed in the right place at the right rate to boost productivity and profitability.
“There’s no perfect hybrid or variety, but you can’t just look for the yield contest winners when choosing your seed,” says Greg Luce, adjunct professor of plant sciences at the University of Missouri-Columbia and director of research for the Missouri Soybean Association. “Seed that performs in well-drained silt loam soils may struggle when planted into heavy clay. You need to consider what’s best for every zone in your field and account for characteristics such as soil type, slope, drainage and fertility.”
Racehorse vs. workhorse hybrids. While establishing management zones across a field allows for variable-rate application of inputs, it also provides direction toward selecting seed for multi-hybrid planting. “Every corn hybrid and soybean variety out there has a significant amount of genetic variability,” says Darren Goebel, AGCO Global Commercial Crop Care director.
“As the seed companies advance new genetic material, they see these hybrids and varieties in multiple environments,” he continues. “So, it’s important to select seed that performed well in the conditions in which it will be planted.”
Goebel explains that in the world of seed corn, there are “offensive” and “defensive” hybrids. Like racehorses, offensive hybrids have a lot of top-end yield potential and perform well in highly productive environments. However, these thoroughbreds can fall off when planted in low-productivity areas or when put under stress.
By contrast, defensive hybrids are more like workhorses. While they may not have the same yield potential and may even underperform in high-yield environments, they will put on ears despite stressful conditions.
“With the ability to switch between two hybrids on the go, you want to put those racehorse hybrids on your really productive soils,” Goebel says. “On your tougher soils, you want to select a workhorse hybrid, one that can get out there and perform, even if it’s in a management zone that’s not as productive.”
Beyond yield potential, other factors to consider when planting multiple hybrids in the same field include drought tolerance and disease tolerance. “You need to prioritize your individual stressors and field-level needs,” Luce says. “If you’re planting dryland corn in Kansas, you need to look hard at drought tolerance. If you’re planting in a river valley in southern Illinois, disease tolerance takes precedence.”
Luce adds that maturity date should be similar when pairing offensive and defensive hybrids in a single field. He also recommends that growers keep phenotypic considerations in mind when matching seed with field characteristics.
“If a hybrid has a tendency to lodge, plant it in a field you can harvest early,” he says. “If you’re planting two hybrids in a field that’s terraced, make sure they both produce ears at a height that’s high enough for harvesting.”
Varying varieties. Yield advantages also can be realized by planting multiple soybean varieties in the same field using management zones. As with corn, there are several factors to consider.
Luce says paired varieties should be relatively close in maturity group. “You don’t want a variety out there that’s ready to harvest for a long time when the other one isn’t; you’re risking loss,” he explains. “Several days apart in maturity is OK, but you don’t want them more than a week. Even a Group 4.0 bean and a Group 4.5 bean are too far apart.”
On soils with top-end yield potential, shorter beans are preferred over taller ones. “If you get a tall variety on productive soils, you can get lodging that causes harvest problems that negatively impact yield,” Goebel says.
The opposite holds true on soils that are more drought-prone, Luce adds. “Varieties with a little more vegetative growth have an advantage in a stressed environment.”
Disease resistance is perhaps even more critical in soybeans than in corn. Should a particular field have a history of developing sudden death syndrome, white mold or frogeye leaf spot, both varieties planted need to have resistance to these issues. The same holds true for fields impacted by soybean cyst nematode or Phytophthora.
“This is why it’s important to look at performance data from variety trials. Look at how individual varieties have performed in different environments over time, and then work with someone who understands your operation and what you’re dealing with,” Luce says. “These are things most producers have been doing for a long time, but now with precision agriculture, they can fine-tune it even further to improve their bottom line.”