Introducing Winter Canola to the Winter Wheat-Fallow Region of the Pacific Northwest

Abstract

Growers in the low-rainfall, winter wheat (Triticum aestivum L.)–summer fallow region of the Pacific Northwest (PNW) need an alternative crop to diversify markets, manage pests, and increase wheat yields. Winter canola (Brassica napus L.) may be a viable option for this region. However, agronomic research for winter canola in this region has not been conducted, and growers are reluctant to produce winter canola because of poor stand establishment. This study evaluated various winter canola planting dates and rates on stand establishment and yield. Research and grower experience has indicated that winter canola needs to be planted in August with postplant temperatures ≤85°F for successful stand establishment and an acceptable yield (>1500 lb/acre). Canola planted in September (or very late August), unless covered by snow, either did not survive freezing temperatures or yielded <900 lb/acre. Winter survival ranged from 56 to 83%. In general, the 4 lb/acre seeding rate was sufficient for stand establishment and yield, and higher seeding rates did not improve yield. A spring plant population of 2 to 4 plants/ft2 will yield optimally. Integration of winter canola into the low-rainfall, wheat-fallow region of the PNW will increase farm sustainability by improved pest management strategies and diversified production systems and markets.