The battle between crops and weeds often reminds Dr. Byron Irvine of the ice dance competition at the last winter Olympics - it's over before it starts.

"The competition in most species happens extremely early," explains Irvine, an integrated agricultural management researcher at the Agriculture and Agri-Food Canada (AAFC) Brandon Research Centre. "With weeds, if there's too many of them and they come up early, most of the 'competition' is already finished even before they're competing for light or nutrients."

To help farmers win this fight, Irvine and AAFC wheat breeder Dr. Stephen Fox have launched a new research study to understand the genetics of wheat competitiveness. Wheat genetic improvement at AAFC is supported by farmers through the Wheat Check-off Fund, administered by Western Grains Research Foundation (WGRF).

There's growing evidence that plants can detect the presence of other plants around, Irvine points out. "Right away, the weeds signal their presence and the emerging crop restricts its growth. Thus if weed removal is delayed, the crop growth is still restricted and never recovers."

That's why it's critical to get herbicide spraying done quickly and at the right time, he says. Allowing weeds such as wild oats to get a head start on the crop can reduce genetic yield potential by as much as 50 percent.

The challenge for farmers, especially larger operators with a lot of ground to cover, is to get spraying done on time. The window is already very tight and wind and rain can make it tighter or even impossible to hit.

Irvine and Fox believe having varieties that compete better with weeds can give farmers a larger window for spraying and limit overall yield loss potential.

"Our first step is to evaluate current wheat varieties to see which ones compete better," says Irvine. "That alone might provide farmers with some valuable information. Then we can look at how to use the best material to breed new varieties that are stronger weed competitors."

This represents a brand new area of research, says Fox, a wheat breeder at the AAFC Cereal Research Centre in Winnipeg. "It's not like looking for resistance to a disease, because a disease is actually living on the plant. The problem with weeds is indirect - they deplete the resources that the wheat plant needs. So the key is competitiveness - competitive plants are going to make it more difficult for weeds to survive and cut into their productivity."

The genetics of competitiveness are likely very complex, he cautions. "But if the genetic variation is there, and there are certainly indications of that, this is definitely something that can be improved over time."

Improvements in herbicide management, crop rotations and sprayer technology will all help farmers provide more effective, efficient and sustainable weed protection, says Irvine. Genetics can provide a key support to the overall system. "In a year like this one, where the weather particularly in Alberta and Manitoba has played havoc with spraying, it's not hard to see the value of having a more competitive crop and an expanded window to get things done."

More information on the potential for genetic weed protection is available in the July edition of Western Grains Research Magazine, available on the WGRF Web site, www.westerngrains.com.