Transforming the Prairies: the third act

Transforming the Prairies: The third act

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Photo by David Stobbe

U of S crop breeders are not just developing pulse varieties for the northern plains, they are quietly revolutionizing agriculture in Western Canada.

First came King Wheat, and then canola—the Cinderella crop—turned the land golden. And now the rise of pulse crops has the Prairies on the brink of a third agricultural make-over.

“Our goal is to have pulses in a one-in-four year rotation—let’s say 20 per cent of the landscape,” said U of S plant scientist Kirstin Bett. “We’re at 12 per cent, so we’re not there yet. But we want to offer every producer at least two species of pulses so they can include these legumes in their rotation.”

Pulses (dry peas, lentils, dry beans, chickpeas, and faba beans) pack a triple punch: affordable protein for a global population heading towards nine billion, a ‘superfood’ with multiple health benefits and a nitrogen-fixing crop that builds soil.

It’s a win-win-win with just a teensy problem—plant breeders will need to develop new varieties that are better yielding, can thrive in areas where pulses are not traditionally grown and are resistant to a host of diseases.

It is a tall order, until you consider the record of Bett and her colleagues at the U of S Crop Development Centre (CDC). Since releasing its first pulse—the Laird lentil—in 1978, the centre has produced more than 200 pulse varieties.

“There were no pulses to speak of in the 1970s until Al Slinkard (the centre’s first pulse breeder) came and began breeding peas and lentils suitable for Saskatchewan,” noted Bett, a dry bean breeder.

That work fuelled an explosion of pulse acres on the Prairies—about 3.9 million acres of lentils and 3.7 million acres of dry peas were grown last year. But Bett and her fellow breeders (Bert Vandenberg, Tom Warkentin, Bunyamin Tar'an and plant pathologist Sabine Banniza) can not rest on their laurels if pulses are going to capture one-fifth of the West’s 70 million crop acres.

And there is always the danger of going backwards. One of the centre’s earliest successes was chickpeas, which went from 10,000 acres in 1996 to more than a million in 2001. By last year, it was just one-tenth of that amount.

“Declining prices were a factor, but disease played a major role,” said Banniza. “We had major infestations of ascochyta blight.”

Disease is literally a problem that comes with the territory: plant millions of acres of any crop and disease pressure skyrockets, especially if you plant the same crop on the same field every two or three years. Today, one of the biggest threats is a root rot (first discovered in Saskatchewan in 2012 and now known to be widespread) caused by an organism called Aphanomyces that attacks peas and lentils.

“If you go into areas where they have a lot of problems, you can see a very clear trend between how often they grow a pea crop and the incidence of root rot,” noted Banniza. “The more frequently you grow a crop, the greater the chance you’ll have disease problems.”

Still, farmers’ practices don’t lessen the pressure on Banniza, Bett and their colleagues. Growers continuously demand improved disease resistance, varieties better suited to the northern plains and a host of other things (such as larger chickpeas, which fetch higher prices on world markets). And the challenge is made all the greater by the fact that pulses originated in tropical or subtropical regions.

Bett laughed as she describes the challenges of growing beans on the Canadian Prairie.

“First of all, you can’t plant them before the ground is warm enough, so you have to wait until the last week of May, and then you need them to come out of the ground quickly,” she said. “Because traditional varieties are often sensitive to day length, they typically don’t flower until there are 12-hour days—and guess what?—we don’t get those until the day before harvest. They’re also super sensitive to frost. So yeah, they’re a lot of fun.”

Lentils have the opposite problem—the long days of June make them want to flower soon after emerging from the soil. But obviously neither crop would be grown here if the day-length sensitivity issue could not be solved. In the case of dry beans, there is a gene that turns off that function but in turn presents a new challenge: that gene must be present in every breeding line of new potential varieties.

But the CDC pulse team has a secret weapon: each other.

“We’re not the largest pulse research team, but we’re one of the most concentrated teams anywhere,” said Banniza. “Australia has more pulse breeders, but they’re spread across the country.

“Because we see each other all the time and our breeding programs are integrated, we sort of pollinate each other with new ideas.”

She points to genomic sequencing as an example.

“I’m surrounded by plant breeders and one of the things all plant breeders do these days is map genomes,” she said. “So one day, I thought, ‘Why don’t I try this with a fungus?’ It’s not something that’s normally done and if I didn’t work with plant breeders, I probably never would have thought of that.”

It was an inspired idea. One of the biggest banes of plant breeders is that resistance can be incredibly short-lived, especially when farmers tempt fate by growing a variety too often.

“If you understand what makes a fungus virulent, what genes are involved, and how quickly they change, then you have a better understanding of how good your resistance is and how long it might last,” said Banniza.

Another example of their team approach is KnowPulse, which Bett described as “a breeder-friendly web portal you can use without knowing anything about databases.”

“It’s basically a whole suite of tools that allow us to look at data in a whole bunch of different ways,” she said.

Although knowpulse.usask.ca is never going to rival Google, even a non-scientist can appreciate how useful it could be. Just as you might want to find a store in your neighbourhood, a plant breeder might be interested in a gene that inhibits a particular enzyme. Type that into its search engine and you can not only find all the genes in the database that are similar, but also their base-pair sequences and even, in some cases, where they are located on a chromosome of a similar plant.

The old saying is plant breeding is like a lottery, said Bett, adding that 99 per cent of all the crosses you make “will break your heart.”

But having a tight-knit group that is constantly looking for an edge has allowed CDC pulse breeders to punch well above their weight.

“It’s not cheap to develop a variety,” said Bett. “It takes a good 10 years from the time I make a cross to getting it out on the landscape. So the more you can increase efficiency—either in costs or time—the better.”

Ushering in the next big transformation in Prairie agriculture is no small task, and while wheat, corn and rice will remain the world’s main food staples, the future for pulses is bright, adds Banniza.

“There is more awareness of food in general, and pulses have so many benefits—they have a very good chance of being right up there.”