Help is on the way for field pea producers who consistently face an uphill battle against their number one disease – Mycosphaerella blight.

A new three-year study led by Agriculture and Agri-Food Canada scientists in Morden, Man., will refine control options against this disease and lay the groundwork toward disease-resistant field pea varieties. This study is supported in part by the Endowment Fund, administered by Western Grains Research Foundation.

"Our goals are to identify farming practices producers can use to reduce Mycosphaerella blight, and to examine different pea lines for sources of genetic resistance," says researcher Dr. Bob Conner. "This will lead to a cost-effective, integrated program for improved disease control."

Field peas now cover more than 3 million acres in Western Canada, where they provide a source of high-quality protein for the rapidly growing hog industry. But improved disease controls are badly needed for the crop to reach its full potential, says Conner.

Recent surveys found the disease in 100 percent of the pea fields examined across the Canadian prairies. During severe outbreaks, yield losses can exceed 50 percent and significantly reduce seed quality. Losses have been particularly high in eastern Manitoba, and in other pockets of the prairies that experience wet growing conditions. Based on average yields of 37 bu/acre at $4/bu, a conservative estimate of 10 percent yield loss would cost producers over $44 million, says Conner.

The disease spreads through infected seeds and airborne spores, and is difficult to control, he says. The most resistant field pea cultivars are considered at best only moderately susceptible to the disease. A foliar fungicide is registered against Mycosphaerella blight, but is not widely used.

Conner will conduct the study along with colleagues Dr. Dengjan Bing of the Cereal Research Centre and Dr. Sheau-Fang Hwang of the Alberta Research Council.

"We have short term and long-term goals – to find farming practices farmers can use in the next year or two to cut their losses, and to help breeders with the development of more resistant field pea varieties for the future," says Conner.

In their study of farming practices, the researchers will examine the influence of cultural control measures, the effect of maturity and lodging and the potential for fungicide application.

For the genetics component, they will evaluate current field pea lines and search for additional sources of resistance. The researchers will study the effectiveness of stem, leaf and pod resistance, and then determine if these specific differences are most effective alone, or in combination. The top performers will be identified and included in field pea breeding programs.

Part of the genetic work will involve investigating untapped wild field pea subspecies for new sources of disease resistance, says Conner. "Not much research has been done on wild peas because they are unsuitable for commercial production, but sometimes the best genes can come from wild germplasm."

The Morden Research Station is part of Agriculture and Agri-Food Canada’s Cereal Research Centre. Western Grains Research Foundation’s Endowment Fund has contributed over $17 million to nearly 200 crop research projects in Western Canada since its inception in 1983.