Winterhardiness Genetics for the Northern Rockies In 2003, Charlie Rife from KSU sent a collection of Russian winter canola lines that he hoped was the ‘Holy Grail’ for winterhardiness to test in Montana against his most winterhardy K-State genetics. This rainfed trial was sown directly into standing wheat stubble using low-disturbance disk openers. Fall rain arrived late so seedlings were only at the 1 to 2-lf stage at dormancy. Overwinter survival was very low (Fig. 2). Bad News: The Russian germplasm collection was not the ‘Holy Grail’. Good News: Winterhardiness of K-State genetics was likely the best in the world. Importance of Fall Irrigation In the 2004 trial it was obvious that we were going to lose yet another rainfed trial due to insufficient fall rain. We decided to rescue the trial with a single application of sprinkler irrigation in mid-Sep 2003 (75 mm = 3 inch). The K-State genotypes showed superior winterhardiness compared with the European checks (data not shown) and the yield of the 7 highest entries averaged > 2500 kg ha -1 (50 bu/ac) (Fig.3). In 2005 we tested the importance of fall irrigation at Bozeman. Significant rain (1.4 inch) fell in September leading to timely emergence and fall growth, and thus, only minor differences among water regimes (Fig 4.). Strategies for High Yielding Winter Canola in the Northern Rocky Mountain Region Perry Miller 1 and Duane Johnson 2 Rationale  A successful bio-oil industry will depend on feedstock oil crops with a low cost per unit of production.  Winter canola has high yield potential due to synchrony of plant growth with the environment of the northern Rockies.  Preliminary research has shown that soil water in early September is a key constraint to winter canola survival.  The advent of RR winter canola removes a major source of agronomic risk related to weed management. Objective To test the relative importance of 1) fall irrigation, 2) fall seeding date, 3) plant density, and 4) cultivar, for winter canola survival, seed yield, and oil production. Methods 1)Bozeman (southwest MT) and Kalispell (northwest MT) represent mild winter climates in the Rocky Mountain Front region of Montana average annual precipitation was 421 and 516 mm, respectively. Bozeman has a deep silt loam soil and Kalispell has a deep sandy loam soil. 2)Preliminary research has been underway since 2000 at Bozeman and 2002 at Kalispell. It has included cultivar evaluation and agronomic factors such as fall irrigation and seed density. 3)The current 2007 sites were established in Sep 2006 under line- source sprinkler irrigation gradients at both locations. Agronomic factors in the experimental design are: i.Seeding date (early vs late September) ii.Cultivar (European RR vs winter hardy non-RR KS line) iii.Seeding rate (25, 50, 100, 200, and 400 seeds m -2 ) We will collect data on emergence rates, plant development rates, crop yield, and oil yield. Preliminary Research During at Bozeman, winter canola cultivar evaluation trials were seeded using low disturbance direct-seeding methods in dense cereal stubble. Our goal was to test the adaptation of winter canola in rainfed no-till systems managed for optimal snow cover. Due to dry fall conditions, the stands emerged late each year and small desiccated seedlings entered the winter in the 0 to 2-lf stage, strongly limiting winter survival. In some years green seedlings were present for hr after snowmelt, then quickly rotted.  We concluded that winter canola was not a viable option for rainfed no-till cropping systems because seedling establishment was not timely during drought-prone fall environments. 1 Dept. Land Resources and Environmental Sciences, Montana State University, Bozeman, MT; 2 Dept. Research Centers, Montana State University, Kalispell, MT We gratefully acknowledge support from the Montana Ag Experiment Station, the Pacific Northwest Canola Research Program, and the MSU Bio-Based Institute. Collaboration with Charlie Rife at Kansas State Univ. was invaluable. Technical expertise was ably provided by Jeff Holmes, Louise Strang, and Bernard Schaff. Figure 2. Winter canola stand densities measured 14 Apr 2003 at Bozeman, MT. Purple bars represent genetic lines from K- State and red lines represent genetic lines from Russia. European Yield Potential An unexpected result of the 2005 cultivar evaluation trials in Montana was that the European checks posted greater yields than the K-State genetic lines (Fig. 5). Excellent winter survival occurred at both locations. Managing Plant Density for Winterhardiness The 2005 trial at Bozeman showed that the greatest yield came from the lowest plant density (80 plants m -2 ; Fig. 4). Measurements of seedling biomass in the fall showed that total seedling biomass increased with plant density but that individual plant weight decreased with plant density (Fig. 6). Understanding this relationship may be critical to managing winter canola for optimal winter survival and oil yield in the northern Rockies. Figure 3. Seed yield of winter canola at Bozeman, MT, The 7 entries with dark blue bars were in the highest statistical group. The 3 lowest yielding entries with red bars were from Germany and had limited survival but thin stands were harvested due to weed management with the RR trait. The pink bars were also European entries. LSD (0.05) was 9 bu/ac. Figure 4. Seed yields in the Fall Irrigation x Rate of Seeding trial, at Bozeman, MT, The genetic line KS A-MT was used for this trial. Figure 5. Winter canola seed yields at Bozeman (top) and Kalispell (bottom), MT. The two highest yielding entries were European in both trials. Figure 1. RR winter canola in agronomy trial at Bozeman, MT. This plot was sown at 200 seeds m -2 and was sprinkler irrigated (3.8 inch) to initiate germination on Sep 8. Volunteer spring wheat was controlled with 12 oz/ac. Photo was taken Oct 5, Figure 6. Total seedling biomass and plant weight had inverse relationships with plant density (plants m -2 ), measured 46 das at Bozeman, MT, Oct 27, All differences P < 0.01.