While changing the weather is beyond anyone’s control, farmers can make the most of the canola that does grow by selecting varieties that increase harvest management options, says a researcher with Corteva Agriscience.
Making the decision on whether to swath or straight cut the crop often depends on how the crop looks heading into late summer or early fall — usually just before harvest, says researcher Chad Koscielny, North American canola breeding lead for Corteva. More producers (somewhere around 60 per cent of Prairie farmers) are adopting straight cutting of canola for a number of reasons, with the elimination of one field operation leading the list.
“Selecting varieties that provide farmers flexibility in making that decision at harvest is a valuable risk management tool,” says Koscielny. “Especially in a dry growing season, producers can end up with a lot of variability in crop maturity.”
For example, perhaps the crop on the drier mid- and upper slopes of a field matured sooner, somewhere around 80 or 90 per cent seed colour change, compared with the lower lying areas of the field where the crop likely has more yield potential, but it is in the 60 to 70 per cent seed colour change. How do you handle that? If you wait for the whole field to be mature, you might run the risk of increased shatter losses in the crop in those early-maturing zones. On the other hand, if you combine too soon, you increase the risk of harvesting immature crop with too much green seed.
- Read more: Taking a look at canola harvest options
That’s where selecting varieties that have built in pod shatter resistance, such as Corteva’s HarvestMax trait, take some of the decision-making pressure off, says Koscielny. “Whether a farmer is straight cutting or swathing, varieties with the HarvestMax trait reduce the risk of pod shatter in both standing and swathed crops,” he says. “You can time your swathing or combining so that the majority of the crop has reached maturity, with increased confidence that you’re putting more crop in the bin.”
The HarvestMax trait can now be found in virtually all of Corteva canola varieties whether they be varieties available under the Pioneer or Brevant brands. While there may be a couple of the older varieties without the HarvestMax trait still available, going forward all new Corteva canola varieties will offer pod shatter resistance.
It's about the whole package
Koscielny points out that while HarvestMax shatter resistance is an important trait on its own, it is only one feature that contributes to optimizing yield when choosing a canola variety.
While Corteva has excellent varieties across the major herbicide tolerance platforms, Roundup Ready, LibertyLink and Clearfield, a new variety under the Pioneer brand P505MSL is an example of where Corteva canola breeders are headed with variety development.
“P505MSL has the whole package,” says Koscielny. “It has the LibertyLink herbicide tolerance trait, along with an excellent disease resistance package that includes blackleg, sclerotinia, clubroot and fusarium wilt, as well as the HarvestMax trait. From a breeding standpoint, it is a challenge to get all these protector-type features in a new variety while still maintaining excellent yield. It takes more time. But we hope to introduce more varieties that include all of these traits.”
Koscielny says some of the top hybrid canola varieties have the genetic potential to produce 80- to 90-bushel yields, but the western Canadian average — most years, not necessarily in a drought year — is more in the 40- to 50-bushel yield range.
“As we develop new varieties with more of these crop protector features, such as improved disease resistance and pod shatter resistance, hopefully that will help producers achieve more of that genetic yield potential,” he says.
While pod shatter resistance has been proven to reduce canola yield losses, it has limits under extreme growing conditions, such as a drought year, Koscielny says. If the canola develops into an extremely thin stand, for example, and plants nearing maturity get whipped around by hot, dry winds, those plants could still experience some degree of pod shatter losses. But, he says, hopefully those growing conditions are rare.