Farmers quickly gobbled up corn and soybean transgenic traits when federal regulators first approved them in the 1990s. Initially, those traits zapped weeds and insects with nary a hitch.
For the most part, genetically modified traits still work. “Some have struggled with resistance issues, but these traits do what they say they will,” says Joe Lauer, University of Wisconsin (UW) Extension agronomist. “Conversely, they are expensive, but with all the licensing and regulations, companies have to make a buck, too.”
Therein lies the rub. As a rule, traited hybrids cost more money than conventional ones.
SO ARE THEY WORTH IT?
Superficially, the decision seems simple. “Buy the traits you need,” says Lauer.
If you farm in east-central Illinois where corn rootworm can swarm cornfields like flies on a rotting animal carcass, a rootworm trait needs to be part of your rootworm-management program. If resistance to one trait has developed, another trait in a pyramid package will do, coupled with tools like crop rotation and a soil-applied insecticide.
Meanwhile, farmers in northern Wisconsin who rotate alfalfa and soybeans every so often with their corn, where rootworm is seldom a problem, likely don’t need a corn rootworm trait. That’s because by themselves, traits don’t increase yields.
Since corn traits hit the market 20 years ago, U.S. annual corn yield gains have clipped along at around 2 bushels per acre. Compare that with the mid-1950s yield gain from .8 bushels to 1.9 bushels per acre as a result of widespread use of hybrid corn, pesticides like 2,4-D, commercial nitrogen fertilizer, and on-farm mechanization.
Although traits have maintained the annual rate of U.S. corn yield gain, they haven’t increased it, says Bob Nielsen, Purdue University Extension agronomist.
“Current transgenic traits protect yields,” adds Lauer. Sill, yields won’t increase if pests are not present.
Seed price, though, complicates matters. Hybrids with trait packages don’t always cost more than conventional hybrids. Often, though, they do.
“With a $100- to $200-per-bag hybrid difference, I question if you can make up that difference through traits,” says Lauer.
YIELD IMPACT
Lauer bases these findings on the Wisconsin Corn Hybrid Performance Trials dating back to 1973. Each year, this trial tests more than 500 hybrids at 14 sites around Wisconsin with the goal of providing unbiased performance comparisons of hybrid seed corn for the state’s farmers. Lauer began including traited hybrids in the trials when they debuted in 1996. Along with UW agricultural economists Guanming Shi and Jean-Paul Chavas, Lauer conducted a statistical analysis showing that yields of hybrids with genetically modified traits varied widely.
In most cases, higher yields did result with traited hybrids. That was particularly true with European corn borer (ECB)-resistant hybrids. On average, ECB-resistant hybrids outyielded conventional hybrids by more than 6 bushels per acre.
“Hybrids with this trait had no yield drag,” says Lauer. “It (the ECB trait) did well right from the start.”
That’s not the case with corn rootworm traits, though. On average, yields of hybrids with these traits trailed the trial average by 12 bushels per acre.
“As a group, growers need to be careful with rootworm-resistant hybrids,” says Lauer. “Some years they do well, but most years, they don’t.”
Stacked traits helped. One example is a triple stack in which a herbicide-tolerant hybrid is teamed with traits that resist ECB and corn rootworm. In these cases, yields were 2 to 3 bushels per acre higher than those of conventional ones.
Still, that’s good, isn’t it?
On a yield basis, it’s questionable, especially if you’ve paid a hefty premium for the trait package.
“Yield increases have been underwhelming,” says Lauer.
“Yield increases have been underwhelming,” says Lauer.
Let’s say you have a triple-stack hybrid that gleans a 10-bushel-per-acre corn yield edge over a conventional one. With $3-per-bushel corn, you can pay up to $30 per acre more in seed costs – or $69 a bag. (This assumes one bag plants 2.3 acres.) If seed costs more than that, be wary.
“The bottom line is that if there is a price difference between hybrid A and B that is greater than $75 per bag, be careful about buying the more expensive hybrid,” says Lauer.
REDUCING RISK
There’s more to your seed decision than yields, though. You’d probably have steam churning out of your ears akin to the cartoon character Yosemite Sam if a hybrid that yielded 250 bushels per acre dropped to 100 bushels the next year.
That’s another perk of traits, as they can reduce this variability. The UW scientists found that even if transgenes produced only slightly higher yields in hybrids, they lower year-to-year yield variability. In a sense, this mimics a slight yield increase. Shi, Chavas, and Lauer found the downside risk of lower pest pressure mimicked a 0.8- to 4.2-bushel-per-acre yield spike, depending on the hybrid.
That’s another perk of traits, as they can reduce this variability. The UW scientists found that even if transgenes produced only slightly higher yields in hybrids, they lower year-to-year yield variability. In a sense, this mimics a slight yield increase. Shi, Chavas, and Lauer found the downside risk of lower pest pressure mimicked a 0.8- to 4.2-bushel-per-acre yield spike, depending on the hybrid.
“Reducing yield extremes is one route in which transgenics can help,” says Lauer.
Lower variability that translates into more consistent yields between years eases agronomic and economic farm planning.
This variance reduction is most pronounced in low-yielding environments, says Lauer. The UW trials show that grain yield rises among lower yielding hybrids with transgenic traits compared to conventional hybrids.
Thus, the more transgenes a hybrid contains, the lower the variance, he says.
Thus, the more transgenes a hybrid contains, the lower the variance, he says.
PESTS STILL EXIST
Pest pressure also can determine the trait payoff.
“Last year, we didn’t see a lot of rootworm pressure in the heart of the Corn Belt,” says Jeff Hartz, director of marketing for Wyffels Hybrids. “That can push some growers toward a double-stack trait (herbicide-tolerant and European corn borer-resistant).”
Just don’t get caught. Corn rootworm still lurks in cornfields, and it can slice yields.
In 2016, the Iowa Soybean Association (ISA) On-Farm Network found many eastern Iowa fields had high beetle numbers. If eggs laid last summer hatch this year, it could set the stage for infestations. In some fields last summer, beetle numbers were more than seven times the threshold for adult beetle numbers.
Ditto for ECB. Although it’s almost vanished, ECB can overwinter on 200 types of plants.
“It is still there,” says Hartz. In eastern Iowa, there have been cases where ECB has sliced non-GMO yields by 30 to 40 bushels per acre, he says.
Hybrids high in traits like SmartStax, which contains eight herbicide-tolerant and insect-resistant traits, will be under scrutiny by farmers for 2017, says Hartz.
“It will be a harder sell in 2017,” he says. “But farmers also have to make sure they don’t cut too many corners.”
In the case of Noah Hultgren and his family, who farm near Raymond in central Minnesota, a diverse rotation (sugar beets-kidney beans-sweet corn-field corn-soybeans) has helped keep insects at bay.
“We have not had to face as many issues as some,” he says. “We have had some glyphosate-resistant weeds, though.”
“We have not had to face as many issues as some,” he says. “We have had some glyphosate-resistant weeds, though.”
To counter them, the Hultgrens have planted Liberty Link (glufosinate-tolerant) hybrids on some corn acres before planting LibertyLink soybeans for the first time in 2016. In their Roundup Ready sugar beets, they also have resorted to some cultivation and hand weeding due to glyphosate-resistant weeds.
In the more intensive rotations of the Corn Belt, though, resistance has been more severe.
“We’ve considered cutting down or going without traits, but the risk of yield loss is still too great,” says Ron Moore, a Roseville, Illinois, farmer. In his own neighborhood, ECB infestations have occurred in non-ECB-resistant corn and caused yield losses.
Moore’s concern also extends to weeds. In 2017, Moore plans to plant some Roundup Ready 2 Xtend soybeans accompanied by an approved dicamba herbicide formulation.
“We are seeing some herbicide-resistant weeds,” he says. “Preventive treatments that prevent weed escapes are cheaper than rescue treatments. Traits cost money, but the benefits are more than the cost of seed,” he explains.
In some cases, trait use transcends agronomics. “We have producers who have 50,000- to 60,000-acre grain farms in western Canada,” says Jay Bradshaw, president of Syngenta Canada. “They want technology to control disease, weeds, and insects. But when you talk more with them, it is also about time management. There are fewer people available to do on-farm work. Traits can help them manage their farms.”
SEED FIRST
Think of buying seed like buying a pickup. “You have different options, but at the start, you focus on the truck itself,” says Cole Hansen, portfolio marketing leader for Mycogen Seeds. “You can buy all the traits there are, but it won’t mean increased yield without pest pressure. Selecting the correct hybrid for that individual farm is key before addressing pest concerns.”
Low corn and soybean prices have caused seed firms to ramp up offerings of less-expensive seed.
“We have expanded our trait choices, which include lower-priced options,” says Duane Martin, Syngenta commercial traits lead. When pest pressure is high, stacked traits with multiple modes of action are a sound agronomic choice. Where pest pressure is low, though, a single trait can provide the needed protection, he says.
“With margins like they are, I think farm managers can make a difference by employing field-by-field insect infestation history and by putting the best fitting soybean varieties and corn hybrids on those acres,” he adds. “There are cases where growers want to focus more on genetics and less on traits, and vice versa. We want to make sure those choices are available to growers to help make sound and cost-effective trait decisions.”
TRANSGENIC WILD CARD
Transgenes inserted in seed offerings can often be a yield wild card. “There can be a tremendous yield difference when we switch transgenes in and out of a hybrid,” says Joe Lauer, University of Wisconsin Extension agronomist. Swings of 20 bushels per acre or more have occurred either way between conventional and assorted trait packages in Wisconsin Corn Hybrid Performance Trials.
“There will be interaction between transgenes and underlying genetics,” he says. “The point is, there are yield interactions (including yield drag) that go on. Within trait technologies, there are good and bad hybrids. Each hybrid has to stand on its own.”
MULTIPLE LOCATIONS KEY HYBRID SELECTION
Each year, you spend time deciding whether or not to use products promising to coax just a few more bushels per acre out of your corn. Just don’t let these distract you from spending time on the decisions like seed that can literally cost you your family’s farm.
Each year, the Wisconsin Corn Hybrid Performance Trials test more than 500 hybrids at 14 Wisconsin sites with the goal of providing unbiased performance comparisons of hybrid seed corn for the state’s farmers. Year in and year out, there’s a 72-bushel-per-acre difference within relative maturities between top and bottom yielding varieties, says Joe Lauer, University of Wisconsin Extension agronomist.
So how do you sort out the diamonds from the dogs?
“Use independent yield-trial data and multilocation averages to pick hybrids,” says Lauer. Picking multiple locations is more accurate than on-farm trials, he says.
On-farm trials do have merit. A random hybrid pick has a 50:50 chance of beating the trial average. Meanwhile, planting the best hybrids from on-farm trials can beat trial averages 67% of the time.
However, findings in the Wisconsin performance trials show hybrid selection with a multi-location assessment can beat trial averages 71% to 74% of the time. The more locations you have, the better the odds have been of hybrids beating the trial average, he adds.
Gleaning these results can enable you to concentrate on the top-performing hybrids. “Don’t care about all hybrids, just care about the top-yielding top 20%,” he says.
Look at individual hybrids, too, whether or not they are traited. Lauer notes when traited hybrids were first introduced in 1996, their yields eclipsed those of conventional hybrids.
“But in the last three to five years, conventional hybrids have come back,” says Lauer. We still always find conventional hybrids in the top 10 of the same relative maturities.”
Don’t be distracted by a hybrid family. Seed companies will often sell a new hybrid as belonging to an outstanding family. Like your own family members, though, there can be stark differences among them.
“We see a big difference among individual (trait) technology packages within a hybrid family,” he says. “Each one has strengths and weaknesses. Try to measure just genetics. Hybrids within a family are not the same.”
