Nitrogen Management for Carrot Seed Production.

Carrot (Daucus carota var. sativus) seed production in central Oregon represents approximately 85% of the carrot seed grown in the US. Rapid advances in carrot breeding have resulted in carrot plants that are quite different from the varieties available 20 years ago when nitrogen rate research was last conducted on carrot seed production. In particular, hybrid European Nantes type carrots have become popular with consumers yet unpopular with seed growers due to unreliable seed yields. Therefore, in an effort to evaluate N rate recommendations in European Nantes type carrots, an N rate field trial was conducted to access the impact of N rate on carrot seed yield. Large-scale field plots (0.26 ha^-1) were placed in two commercial fields with four replications and four N rates (0, 45, 84, and 123 kg N ha^-1) at each location. Nitrogen treatments were applied at bolting in May of 2015. Soil samples (0-15 cm) were collected monthly from each plot from fertilization until after harvest. Plant samples were collected every two weeks from each plot. Seed yield at location 1 did not correlate with N rates. At location 2, seed yield decreased as N rate increased.