Doug Cattani is working on a long-term investment that will pay dividends down the road.
The University of Manitoba plant sciences professor is currently in year five of a now much-publicized 15- to 20-year perennial wheatgrass breeding project.
Perennial grain is something of a holy grail in plant breeding: a cereal crop that delivers high yields year-in, year-out, improving soil health and increasing carbon sequestration while saving farmers seeding costs. According to Cattani, the vision is not so far from reality.
Currently, Cattani’s program is evaluating the adaptation of intermediate perennial wheatgrass to Manitoba production environments.
The team started in 2011 by planting thousands of individual wheatgrass cultivars sourced from the Land Institute in Kansas as well as from collections around the world. They immediately eliminated any grasses that could not overwinter in Manitoba or withstand the province’s unpredictable spring conditions. “Our main problem was not necessarily overwintering but beginning growth too early in the spring and getting hit with a hard frost — a similar problem for winter wheat,” says Cattani.
The next step was evaluating how individual plants performed in terms of yield over a multi-year period. “We wanted to see whether, if a plant yielded well one year, it would be bad the next year,” he says. “We had to look at this, because if you sell it to a producer, and they get a good yield the first year and it’s a forage crop thereafter, they will not plant it again.”
Cattani’s team found that after the first year, many plants dropped off in yield in the second year and “tanked” in the third year — 99 per cent of the material they’d started with.
But the one per cent that remained included about 50 plants that were hardy enough to withstand Manitoban winters and yielded well three years in a row.
“We took the good ones and began the next step of the program, which is where we are now,” says Cattani.
Any breeding project takes years from genesis to commercialization, and Cattani’s project is right on schedule. Each of the 50 individuals — of which a promising 20 are under special scrutiny — will be evaluated both as individuals and to see how well they perform together.
“Perennial wheatgrass plants have to have pollen from a different genotype in order to set seed, so we have to evaluate how suitable they are together,” explains Cattani. “We want to find ‘parents’ that will give a high yield, and then we’ll limit the number to eight to 10 to make a population going forward.”
It’s a slow process, but an essential one. The best contenders out of the first round of selection will have to be evaluated again in a second round of three consecutive harvests to ensure they retain productivity.
Average yields of the first round of contenders are in the 1,200 kg/ha range (18.8 bushels per acre), although figures are approximate as the researchers must extrapolate individual plant yields to a crop basis. But Cattani says some of the best crosses will likely yield much higher.
In addition, most individual plants are relatively competitive with weeds once established. Disease-wise, the plants seem hardy, and have had no observable problems with leaf rust or stem rust.
“We haven’t tested for it, but a group from Minnesota has found that many of the intermediate wheatgrasses they looked at have had moderate tolerance to fusarium head blight. We want to look at that as well,” he says. “That’s probably a strength of the wheatgrasses — they appear to have tolerances our other wheat varieties don’t have.”
In 2016, Cattani’s team will start looking at nutrient needs and evaluating some of the basic agronomy that will go into managing perennial wheat stands over time.
The program is growing the wheatgrass under organic conditions with no added nutrients, but Cattani estimates that in a conventional system 50 kg of nitrogen per hectare (44.6 pounds per acre) will be required to keep the stand competitive and max out production.
It’ll be 10 to 15 years before a cultivar is released. “The project is still in its infancy, but I’m optimistic about what we’ve found out so far. This next stage will be critical in helping us make more rapid advancement, but we still need to test each generation over long periods of time to make sure we’re not selecting for high yield in one year and decreasing its life expectancy in the stand,” says Cattani.
“Whenever something new comes out, if the early adopters have good things to say, it’s promising, and if they have bad things to say, you’re done. So we’re being cautious,” he says.