Carinata Seed and Oil Yield Responses to Nitrogen and Sulphur Nutrition Under Rainfed Conditions.

Oilseed brassicas require relatively large quantities of nitrogen and sulphur for optimum growth and yield. Brassica carinata cv. A120 was planted on Dec. 1 2015 and harvested June 3, 2016 in a one-year field experiment that was conducted at the North Florida Research and Education Center, Quincy, Florida during 2015/2016 winter-spring growing season. The experimental design was a RCBD with four replications in a 4×4 factorial arrangement of nitrogen fertilization rates (0, 45, 90, and 135 kg N ha^-1 applied at planting, bolting and flowering) and sulphur fertilization rates (0, 17, 34 and 50 kg S ha^-1) applied at planting and bolting. Main effects of N and S rate was observed on seed yield, oil content and oil yield but no interaction existed between the independent variables. Averaged over S rates, maximum seed yield (3400 kg ha^-1) was produced at 90 kg N ha^-1 representing a 13% a yield increase over the non-treated control. The application of 30 kg S ha^-1 resulted 20% yield gain when averaged over N rates. Similar trends were observed for oil yield as a function of N and S rates. Oil yield increased from 1300 (0 kg N ha^-1) to 1400 l ha^-1 (90 kg N ha^-1). Sulphur application increased oil yield from 1100 (0 kg S ha^-1) to 1500 l ha^-1 (34 kg S ha^-1). These preliminary results suggest that the application 90 kg N ha^-1 and 34 kg S ha^-1 may be optimal for growth and productivity for rainfed carinata in the southeast.