Impact of Starter Fertilizer On Winter Canola Grown in Oklahoma.

As acres of canola increase across the Great Plains, producers are left asking more questions about fertility for canola production in Oklahoma. This study was conducted to determine the impact of applying Diammonium Phosphate (DAP) (18-46-0) directly with seed, on stand, grain yield and oil quality. Additionally the impact of delaying further nitrogen applications until top-dress was also evaluated. This trial was located at two locations; North Central Research station West of Lahoma (low soil test P), Cimarron Valley Research Station West of Perkins, OK (low soil pH). The study consists of 13 treatments replicated 3 times arranged in a randomized complete block design. Six rates of DAP 0, 33, 66, 99, and 135 kg ha^-1 where applied directly with seed at planting.  Each rate of DAP was implemented two N management strategies; 40% yield goal N pre-plant 60% top-dress and only the N from DAP at planting and remainder of the N at top-dress. At crop maturity the center 2 m of each plot was harvested with a combine. Grain was collected, and plot weight was recorded and sub samples were analyzed for oil quality. In 2012, at both sites the check plots with no application of DAP they had a slight decrease in plant population. In the 33 and 66kg ha^-1 rates of DAP had an  increase in plant population, while the 99kg and 135kg ha^-1  rates of DAP, had a significant decrease in plant population and a substantial decreases in plant population was observed for the 168kg ha^-1  rate.