Potential lies in native prairie perennials

CARMAN, Man. — Farmers have wanted more perennial crops since the earliest days of cultivation.

There are numerous benefits if commercially viable cereals and oilseed crops can advance to the state of sophistication reached in forages.

Perennial crop breeder Doug Cattani of the University of Manitoba plant science department is exploring commercializing or extracting favourable genetics from intermediate wheatgrass and perennial sunflower, cereal rye and wheat.

The ideal perennial cereal would be able to fix nitrogen, but Cattani said that’s not in the cards for intermediate wheatgrass.

“It will still require some sort of nutrient input,” said Cattani.

“You could probably fix some nitrogen if you intermixed with a legume, but that will reduce your yield because the legume reduces the density of your main crop. But theoretically, such a mix could take care of itself.”

Cattani said the main advantage of intermediate wheatgrass is that it regrows after seed harvest, making it a good crop for baling or fall grazing after the seeds are taken.

It has not been bred like wheat, where most of the nutrients go up to the seeds. That means there’s a lot of nutrient left in the straw.

The animals would digest the nutrients and excrete them back onto the field if it were fall grazed, said Cattani.

“We’re just beginning to work with intermediate wheatgrass as a grain crop, so we don’t know yet what our major roadblocks will be.

“We do produce seed here in Western Canada, but it’s strictly the forage variety. The best yield we’ve seen so far is 800 pounds per acre. Given it has a bushel weight of 15 lb., we only have 16 bu. per acre.

“But keep in mind that’s a forage variety. Hopefully, we can make significant gains in these yields if we concentrate on breeding for grain production,” he said.

Cattani said breeders have already increased grain size in only three generations. Breeding annual cereals proceeds quickly with two generations per year. Each generation of intermediate wheatgrass takes three or four years.

The tall plants have excellent resistance to lodging, but that extra biomass also consumes nutrients that could go into the seeds. Cattani said breeding will try to reduce plant height while maintaining stalk strength.

The intermediate wheatgrass nursery was established at Carman in 2011. The first seed harvest is this fall, with two more harvests in the next two years.

Those seeds will be analyzed to find genetic traits that can be moved toward commercialization. They will also be evaluated for resistance to stress factors commonly occurring on the Prairies.

Canada wild rye has not been fully explored, said Cattani.

“It grows up to seven feet tall here in Manitoba, mainly in shaded areas. Here at Carman, it grows up to three feet tall. It’s a self-pollinating species, so the breeding program can move along quickly.

“We also have a native legume that grows well. It’s called prairie turnip or Indian Breadroot.”

This legume was a staple in the diet of Native North Americans. It’s edible raw, can be dried for storage, ground into flour, plus it’s quite palatable and nutritious.

“It’s a legume, so it fixes its own nitrogen. It has a large seed, up to one centimetre in length.

“Of course, if you harvest the root for food, you kill the plant. So we’re looking at it mainly as a nitrogen fixing legume.

“We also have a perennial flax that’s native to Western Canada, and that could be very useful in a perennial rotation.”

The Land Institute in Salinas, Kansas, is a partner in a number of these U of M projects, including intermediate wheatgrass and the evaluation of perennial wheat.

The wheat nursery was established in 2011 with plant materials developed at the institute. The Carman component of the project is simply to evaluate the viability of these strains of perennial wheat.

Cattani cautions against over-optimism. He said these and other alternatives all have potential to help bring food production on the Prairies closer to real sustainability, but each species represents only a small step.

U of M masters student Sean Asselin, who is evaluating perennial sunflower species native to Manitoba, said commercial viability of these genetic traits may be 15 years away, but thinks intermediate wheatgrass, perennial rye and the perennial wheat are closest to commercialization.

He said native perennials have a distinct advantage because they grow throughout the growing season and create more biomass.

Their roots penetrate into the soil profile to access water and nutrients, allowing them to maintain their leaf matter through the growing season. This makes them ideal for grazing in a drought year.

“Native salt-tolerant perennials will be good for reducing high water tables and reducing soil salinity.

“They can help clean up your soil. For example, if sclerotinia has infected one of your fields, you put in a sclerotinia-resistant native perennial on that field for five years to break the disease cycle and clean up that field,” said Asselin.

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