Truths or myths of seed selection
Coffee-shop talk about seeds often contains a mix of truth laced with, well, whoppers. Here’s a truth assessment about some of these claims.
Some hybrids naturally resist insects.
TRUTH. A 2021 Syngenta corn rootworm trial found a 67 bushel per acre (bpa) difference existed for one hybrid protected by a rootworm-resistant trait and/or a soil-applied insecticide when compared with the same unprotected hybrid. Another hybrid, though, had just a 15 to 20 bpa yield loss in the trial.
“Some hybrids are just more tolerant of yield loss from corn rootworm,” says Bruce Battles, Syngenta technical agronomy manager. Identifying these hybrids and incorporating them in fields prone to corn rootworm infestations can provide natural protection, he says.
Seed size predicts yield potential.
MYTH. A bulging soybean seed bursting at the seams and ready to germinate and generate a bountiful yield is beautiful.
Still, save that wistful gaze for another time. Falling in love with a seed lot based on size is misplaced time that you could instead spend sleuthing more pertinent characteristics. Excellent yields can come from both small and large soybean seed, says Marc Hoobler, northern region agronomy lead for BASF. “Today’s planter technology has come a long way and can plant seed whether it’s small or large,” he adds.
Defensive characteristics can lower a soybean variety’s yield potential.
Goss’s wilt is gone.
MYTH, although breeding technology has lessened this bacterial disease’s severity. Significant breeding advances have created hybrids with a high degree of tolerance, says Andy Ackley, corn portfolio manager at Golden Harvest.
“Because of these advances, it’s become less problematic,” he adds. “You may give up a bit of yield with disease tolerance, but you’ll give up more without tolerance. In some severe cases of Goss’s wilt, a grower [with no tolerance] could experience a 100 bushel per acre yield loss.”
Defensive characteristics can lower a soybean variety’s yield potential.
TRUTH, but consider context. “We’ve noticed that when you put a lot of defensive traits into a variety, it tends to limit the yield ceiling,” says Shawn Conley, University of Wisconsin Extension agronomist.
Still, put this into proper context.
“You will want to plant a defensive bean into fields where you have SCN [soybean cyst nematode], SDS [sudden death syndrome], and other diseases,” he says. Meanwhile, farmers can aim top-yielding varieties with minimal defensive characteristics on well-drained fields with little disease history, Conley adds.
Plant bushy soybean varieties in wide rows and erect varieties in narrow rows.
MYTH. Agronomists used to recommend bushy varieties for soybean rows 30 inches or wider and erect ones for narrower rows or drilled soybeans, says Conley.
However, soybeans automatically compensate to whatever spacing they encounter, says Conley. Whether a soybean is erect or bushy has no impact on yield potential.
Precision placement benefits soybeans.
MYTH (most of the time). Those straight picket-fence evenly emerging stands can make corn farmers salivate akin to a beagle begging for a biscuit. That’s because precision placement for corn works well, says Conley.
Soybeans? Not so much.
“Considering the phenoplasticity of soybeans and their ability to branch and fill in, there is no evidence to indicate you need it in soybeans,” Conley. “There is some evidence that precision placement may benefit double-cropped or later-planted soybeans, but not for the majority of beans we plant at current recommended seeding rates.” In the Upper Midwest, that is around 140,000 seeds per acre, he says.
Conventional hybrids and varieties capture premiums with few drawbacks.
HALF-TRUTH. Premiums garnered by planting nonGMO hybrids and varieties can boost a farmer’s bottom line. Still, they’re akin to former professional quarterback and football announcer Don Meredith’s trademark line: “If ifs and buts were candy and nuts, we’d all have a Merry Christmas.”
“You can go the non-GMO route, but you have to manage for it,” says Brent Tharp, Wyffels Hybrids technical product manager.
Pests that insect-resistant traits have alleviated for decades, such as European corn borer (ECB), can strike non-GMO corn hybrids with a vengeance. “ECB numbers are way down, but they are not extinct,” reminds Tharp.
Weed control is also a challenge, particularly in soybeans because of fewer postemergence herbicide options, says BASF’s Hoobler.
“If you are considering planting conventional soybeans , make sure you know your weed populations and have access to the chemistries to control them,” says Hoobler.
- READ MORE: Do seed treatments pay off?
Herbicide-tolerant traits boost soybean yields.
MYTH, MYTH, AND MORE MYTH! True, some attractive herbicide-tolerant trait options exist for soybeans. They include:
- Roundup Ready 2 Xtend soybeans that tolerate dicamba (Group 4) and glyphosate (Group 9).
- XtendFlex soybeans that tolerate dicamba, glyphosate, and glufosinate (Group 10).
- Enlist E3 soybeans that tolerate 2,4-D choline (Group 4), glyphosate, and glufosinate.
Joining these packages is Alite 27, a Group 27 (isoxaflutole) preplant/preemergence herbicide. Farmers in selected counties may apply Alite 27 to GT27 (tolerant to isoxaflutole and glyphosate) and LibertyLink GT27 (tolerant to glyphosate, glufosinate, and isoxaflutole) soybean varieties.
Still, herbicide-tolerant traits and the accompanying herbicides are solely weed control tools.
“Spraying a herbicide never increases yield,” says Aaron Hager, University of Illinois Extension weeds specialist. “Spraying a herbicide only allows the crop to express its inherent genetic yield potential.”
“Pick a herbicide trait platform that fits your farm, and then pick a good high-yielding variety in that platform,” adds Conley, “All trait platforms have good high-yielding genetics.”
Automatically discount a problem hybrid.
MYTH TO A DEGREE. Granted, a poor-performing hybrid should always be suspect. Still, poor performance could be due to an interaction between a specific hybrid and weather.
For example, sudden temperature drops spur silk balling, a phenomenon where silk is trapped in the ear, says Andy Heggenstaller, head of agronomy, U.S. seeds for Syngenta.
“By the time it breaks out of the ear, the plant doesn’t fully pollinate,” he says. “The ear portions that don’t pollinate don’t produce grain.”
Recognize this for what it is — a weather quirk.
“By never growing that hybrid again, you’re doing yourself a disservice, because there are good hybrids that just happen to be in the wrong place at the wrong time,” says Heggenstaller. Before nixing such a hybrid, view its performance in areas where the same weather event didn’t occur, he says.
Hybrids with the same relative maturity mature equally.
MYTH. “There’s not a lot of regulation around [relative] maturities,” says Isaac Anderson, WinField United technical seed agronomist. “Companies are at their discretion to assign a maturity, such as a 99-day hybrid vs. a 101-day one.”
This variance can lead to a hybrid that is excessively wet because it didn’t fully mature, says Anderson. It also could create a scenario where a hybrid matures too early without realizing its anticipated yield potential, he says.
One factor that is uniform as published by companies is growing degree units to maturity. This enables farmers to better assess maturities between two hybrids, he says.
Hybrid response to inputs can be predicted.
TRUTH, but verify. One trend in seed selection is measuring how responsive hybrids are to nitrogen and fungicide applications, says Anderson. Still, ask how extensive the testing is behind the claim.
“To truly vet responsiveness, you need a high volume of testing that adheres to specific protocols,” says Anderson. In WinField United’s case, its responsiveness scores are backed by trials in its 200 Answer Plot locations using stringent protocols replicated at each site, he says.