Technology | Summer 2008
Why hybrid vigor is a one-time event.
By Kieran Brett
With open-pollinated canola, growers have the option of holding back some seed to plant the following year. This leaves a little less canola to sell in the current year, but reduces seed cost the following spring.
Hybrid canola, however, does not offer this option and it's important to understand why. According to Bayer CropScience Canada's Stewart Brandt, the reason is that hybrid vigor is a one-time event that's lost in later generations.
"What we call F1, or first-generation, certified seed, has all the advantages of the two distinct parents," he says.
Second-generation seed, the crop resulting from F1 seed, is known as F2 seed. A grower who plants F2 seed, Brandt explains, loses all the advantages of the F1 hybrid seed. Lack of genetic purity in the F2 seed is reflected in crop performance. Yield, agronomic advantage, and disease resistance are all less than in crops grown from the original certified hybrid seed. And that's not all.
"In an F2 crop, a number of plants will be sterile - virtually weeds in the crop because they won't produce seed," says Brandt. "As well, many plants won't have tolerance to the herbicide. So, when sprayed, they'll be killed, which will create problems with crop uniformity."
These problems don't occur with open-pollinated seed. But over the past 10 years, faced with a choice between the convenience of open-pollinated canola or consistently higher yields from certified hybrid seed, growers have voted with their pocketbooks. It's hybrid canola by a long shot.
