Expanding the Seeding Window of Winter Wheat in Western Canada.

Seeding date is one of the key management steps to growing a successful winter wheat (Triticum aestivum) crop in western Canada. Several factors are now limiting the ability of farmers to plant winter wheat within the optimum seeding window. These factors include continuous cropping, limited use of summer fallow, selection of longer season varieties, and the introduction of new late maturing crops, such as soybean (Glycine max) and corn (Zea mays). Although late planting of winter wheat has been demonstrated to reduce winter wheat yield and increase winterkill, farmers are planting winter wheat later in western Canada. A study was initiated in 2013 at 11 sites across the Canadian Prairies (Manitoba, Saskatchewan, Alberta) to re-evaluate the seeding window of winter wheat in light of the recent release of more cold tolerant varieties as well as the introduction of fungicide seed treatments. Winter wheat (cv. Flourish) was planted on five fall planting dates (Sept 1, Sept 15, Oct 1, Oct 15 and Nov 1) in the fall of 2013, 2014, and 2015. At each planting date, winter wheat treated with a fungicide seed treatment (Tebuconazole and Prothioconazole) was compared to an untreated control. The Nov 1 date represents a dormant seeding strategy for winter wheat, that could not be planted in all site years. Initial findings from this project confirm that the optimum seeding window for winter wheat remains within the month of September across western Canada.