RED DEER – With hybrid canola seed costing as much as $5 a pound or more, some growers may be considering bin-run seed this spring to keep their input costs down.
“Certainly the most controversial topic I’ve dealt with this winter has been farm-saved hybrid canola seed, or bin vigour. The interest in bin-run seed is the cost-price squeeze,” said Murray Hartman, an oilseed specialist with Alberta Agriculture.
“You have the polarization of the seed industry versus some producer testimonials. There are extreme positions on both sides and I advise people to take a more moderate position, with an objective look at the data and positions of the other people.”
Read Also
VIDEO: Green Lightning and Nytro Ag win sustainability innovation award
Nytro Ag Corp and Green Lightning recieved an innovation award at Ag in Motion 2025 for the Green Lightning Nitrogen Machine, which converts atmospheric nitrogen into a plant-usable form.
Speaking at an Agronomy Update conference in Red Deer this winter, Hartman said saving seed grown from hybrid canola brings genetic concerns.
“F1 and F2 refers to the generations since the first cross. When dealing with hybrids, you usually want inbred parents, because they produce hybrid vigour when mated. When mated, all the F1 offspring are the hybrid,” he said. “The F2 offspring are when you cross all the F1 together and get certain recombinations coming out of there.
That bin-run seed, the F2 generation, can have genes segregated that are the ones you want, or genes that you don’t want in your crop.
“When we talk about segregation, what that means is all the possible gene recombinations in the offspring when you mate two parents. With one gene, there’s a ratio of 3:1 for the dominant trait. In F2, you end up with a ratio of 9:3:3:1,” he said.
“That means nine of the combinations have both dominant traits, three have one dominant trait, another three have the other dominant trait and one out of 16 has both recessive traits.”
Hartman focused on Invigor hybrid canola because he said those are mainly the ones farmers are interested in for the F2 segregation.
“They use a novel hybrid system that ensures cross pollination. They’ve got a male-sterile line that has a barnase gene in it that prevents pollen formation. That’s good for male sterility, but in that same construct they have Liberty tolerance. Because they’re in the same construct, they have to segregate together with genetic recombination. You can’t have male sterility and not herbicide tolerance with it,” he said.
“The fertility restorer site has a gene in it that inhibits the other gene and thus restores the pollen formation and fertility. It also has the herbicide tolerance in the construct. So in both lines, we have the herbicide tolerance.
“They both act as dominant genes and both follow the basic dominant inheritance. So when you buy certified Invigor hybrid seed, you’re getting the offspring from this cross.”
Hartman said the F1 has two genotypes: both are herbicide tolerant and fertile. The crop acts as if it’s fertile and herbicide tolerant, but has two different genotypes. That affects what segregates out in the farm-saved seed, or F2.
“Because there’s two genotypes in that F1, there’s going to be three possibilities in how they cross, from the F1 to the F2. The first one, 75 percent are herbicide tolerant and 25 percent are susceptible, but they’re all fertile. The second has 16 different possibilities. One out of the 16 is herbicide susceptible, three out of 16 are sterile. With the third (possibility), seven out of eight are herbicide tolerant and one out of eight is male sterile,” he said.
“When you calculate the proportions of male sterility and herbicide tolerance in farm-saved seed, we first assume it’s self-pollinated. That’s not too far off as it’s 70 to 80 percent self-pollinated. The F2 for herbicide tolerance is the average of 75 percent and 93.75 percent, which is about 84.4 percent herbicide tolerant and 9.4 percent male sterile.”
Hartman said even with 30 percent cross-pollination, the result is 84.8 percent herbicide tolerant and 9.8 percent male sterility.
“The main message here is theoretically, with the F2 Invigor hybrid, you’re going to have about 85 percent herbicide tolerance and about 10 percent male sterility. That’s two genes and how they work out.”
According to Hartman, textbooks say the more inbred the parents are, the higher the heterosis or hybrid vigour in the F1 generation and the greater the yield decline from F1 to F2.
If the F1 is an excellent hybrid compared to the parents, the F2 will perform poorer than if the F1 had more mediocre hybrid vigour. Every hybrid will show different yield drops in the F2. Unfortunately, Hartman added, he doesn’t have much data on the parents’ inbred nature.
As a result, while there may still be a significant amount of herbicide tolerance and a relatively small percentage of male sterile plants, that’s only part of the picture.
“Some populations will segregate with combinations of desirable traits like yield, but also undesirable traits like late maturity,” he said.
“Some disease resistance is based on a single gene, like fusarium wilt. If we did know the parental genotypes, we could predict the segregation in the F2. But other disease resistance is based on many genes, both race specific and non-race specific. Therefore it’s difficult to predict the disease resistance in the field, for diseases like blackleg.
“You can see that when you start to segregate for other traits like yield, disease and maturity, they’re controlled by a lot of different genes. Not only we don’t know what all these genes are and where they are, we also don’t know the exact mechanisms of how they’re expressed. Dominance is one simple explanation, but there’s a lot of others. So genetic predictions are very difficult.”
Another aspect of planting bin-run F2 seed is the availability of seed treatment. While many seed treatments are still available for on-farm application, the popular product Helix can only be applied in commercial seed treatment facilities. The lack of a seed treatment such as Helix for bin-run seed is also a factor.
Hartman said all these issues add up to more questions than answers when it comes to the final yield differential between F1 and F2 seed.
“Farmers want to know how much,” he said. “If it’s five to 10 percent, they often say, ‘I can live with it’. Fifteen to 20 percent is probably too much.”
To help them, researchers from Alberta and Saskatchewan have been running comparisons between F1 and F2 seeds.
“We started these trials because the Alberta and Saskatchewan canola producer groups had members interested in this,” said George Clayton, a research scientist with Agriculture Canada in Lacombe, Alta.
“We compared the hybrid versus open pollinated; certified versus farm-saved, which is seed grown from hybrid plants, so it’s not a hybrid; and sized seed that’s bigger than the rest. Those are some of the questions we had, so we developed treatments to (investigate).”
In 2004 researchers established plots at Lacombe, Alta., and Scott, Sask., and later expanded them to Beaverlodge, Alta., Lethbridge, Melfort, Sask., and Canora, Sask.
They used Invigor 2663 for the hybrid, 46A76 for the open pollinated variety and seed saved from each for the F2 trials.
For seed sizing, the canola was passed over a 5/64th screen to extract the larger seeds.
“Our objectives were quite simple. Is there a reduction in yield potential in the F2 generation from high yielding hybrids compared to the actual hybrids?” Clayton said.
“Seed sources can vary, so to eliminate that aspect, we took a number of different seed sources, bulked them together and developed a new seed lot for each year.”
Clayton said the average yield difference from a variety of locations in Alberta and Saskatchewan was about six bushels per acre less when growing F2 seed. The yield ranged from zero to 10.5 bu. per acre less if the researchers did not use certified seed.
He said the yield advantage of certified hybrid seed over farm-saved F2 from hybrid seed was always greater than potential cost savings associated with farm-saved seed.
In the research summaries, Clayton said yield of certified hybrid was greater than farm-saved seed in 21 of 25 comparisons. However, the farm-saved seed from open pollinated varieties performed well, as was expected.
With the unavailability of Helix for on-farm treatments, the trials included comparisons with and without the seed treatment.
“For the F2, the yield loss without Helix typically exceeded any potential savings, even with $5 canola. The hybrid seed is likely most beneficial under stress.”
The study also compared sized seed to unsized to see if larger seed would yield more.
“In our study, sizing seed did not increase yield in any comparison. We didn’t see that as a benefit, and it’s a major cost,” he said. “We found under weedy conditions, increased seeding rates increase yield for both certified and farm-saved seed. So increasing seeding rates didn’t have a big impact.
“With our certified hybrid, we had a vigour index of 4.03, which is germination times seed weight. The F2 grown from hybrid plants, we had good germination and decent seed weight. The open pollinated were quite similar.”
Clayton said the researchers are also looking at other questions: oil profile, trials for disease resistance, seed quality, integrated weed management opportunities and managing risk.
