Eeffect of Plant Density and Row Spacing on Seed Yield and Water Use Efficiency of Canola in the Southern Great Plains of USA: Hybrid Vs. Open Pollinated Variety.

Winter canola production area is increasing in the Southern Great Plains. Rotational benefits, increasing demand for canola oil and protein rich meal make it ideally fit in the predominately cereal based cropping systems of the region. Selecting appropriate variety, plant density and row spacing make canola production successful. A field study was conducted at the Agricultural Science Center, Clovis, New Mexico in 2015-16 to study seed yield and water use efficiency (WUE) responses of a winter canola hybrid (Safran) and an open pollinated variety (Riley) to plant densities (100% vs 75%) and row spacing (25.4 vs 50.8 cm). Target plant density (100%) for hybrid and open pollinated variety were 400000 and 800000 ha^-1 (seeding rate of 2.8 and 3.64 kg ha^-1, respectively). Seed yield and WUE were affected by variety (P<0.01). However, neither plant density nor row spacing had effect on seed yield or WUE.  Both seed yield and WUE of hybrid were 11% higher than open pollinated variety. Reducing plant density by 25% had no effect on seed yield (3953 vs 3850 Kg ha^-1) or WUE (5.0 vs. 4.9 Kg ha^-1 mm^-1). Seed yield of 25.4 and 50.8 cm row spacings were 3937 and 3866 Kgha^-1 with the same WUE value of 5.0 Kg ha^-1 mm^-1.  The results indicate hybrid’s superiority over open pollinated variety in achieving higher seed yield and WUE but no impact of increasing plant density and row spacing on these variables. Thus, producers can take advantage of hybrid’s potential to achieve both higher yield and water productivity with just 75% plant density and row spacing that fits their operation for successful canola production in the Southern Great Plains. The study will be repeated in 2016-17 season.