How high can spring wheat yields go? With unprecedented gains in crop yields in general, heightened economic pressure for producers and farmers'expanded role as investors in wheat breeding research, it's a question Western Canada's wheat breeders are hearing more often.

The answer, say two leading wheat breeders, is that wheat yields have come a long way and will continue to steadily increase within the confines of Canada's balanced approach to yield and quality

"In the 1960s when I was a student, people thought the theoretical maximum yield for wheat might be 10 to 12 tonnes per hectare (150 to 180 bushels per acre)," says Dr. Ron DePauw, wheat breeder and head of cereal research at Agriculture and Agri-Food Canada in Swift Current. "In those days a 10 tonne per hectare yield was unheard of. Within a few years the theoretical maximum had moved to 15 tonnes per hectare. Now we're looking at a theoretical maximum of about 20 tonnes per hectare."

Canadian wheat yields have increased about 10 to 15 percent over the past 20 years, and DePauw and fellow breeders expected a continued increase of around 0.5 percent per year over the next decade. In Western Canada, the major public wheat breeding programs are supported in part by farmers through the Wheat Check-off Fund, administered by Western Grains Research Foundation (WGRF).

"We've seen about a 0.5 percent increase in yield per year in recent years, which means we should expect to see at least another five to six percent improvement over the next 10 years," says Dr. Pierre Hucl, wheat breeder at the University of Saskatchewan's Crop Development Centre.

DePauw agrees with Hucl's forecast. "The rate of genetic gain will vary, but we are in that 0.5 percent range now, whereas we used to average more like 0.2 percent, so our breeding efforts over the past years are paying off."

Success depends on more than breeding strategy alone, notes DePauw. "Genetic gain in grain yields depends on many factors. Financial resources is the biggest factor."

Along with yield, breeders aim to improve a wide range of agronomic and quality traits in new wheat varieties, says Hucl. Yield isn't necessarily the first priority. Breeders realize that a number of factors, from disease, pest and drought resistance, to high quality, all must combine to get the best production and market results for farmers.

That hasn't been the strategy used in other wheat growing jurisdictions, Hucl points out. In Europe and the United States, yield potential has been a greater focus than improvements to other traits such as quality. "If wheat breeders in Canada were to just focus on yield, we would lose our funding and be shut down because we wouldn't be successful in meeting the quality targets required for variety registrations." For example, with some varieties, it may be possible to hit dramatic yield targets, but doing so usually means a corresponding drop in protein content.

Canada's more balanced approach may have slowed the rate of increasing yield in Canadian wheat varieties compared to some countries, says Hucl, but it has given Canada a better overall package of wheat traits and helped build the country's reputation as a high-quality supplier.

Some of the brightest lights among recently registered varieties include an amber durum, the yet to be named DT712, which features seven percent higher yield, higher protein, good colour and an important human-health trait for marketing - low cadmium content. This durum is expected to set the new standard for durum yield and quality. As well, AC Superb, a hard red spring developed for the southern Prairies, boasts improved yields in the 15 to 20 percent range compared to varieties of 10 years ago

More perspective on yield potential from DePauw and Hucl is available on the WGRF Web site, www.westerngrains.com, in the April, 2004 edition of WGRF's Industry Report newsletter. WGRF is funded and directed by Western crop producers, and allocates approximately $5 million annually to research through the Wheat and Barley Check-off Funds and a separate $9 million Endowment Fund.