Canola response to boron and nitrogen grown on the southeastern coastal plain1

Canola has the potential for production in a doublecropping system in the southeastern Coastal Plain, but little information is known about its fertility reguirements when grown in this region. This two-year field study was conducted to determine the effect of boron (B) and nitrogen (N) on canola growth and yield. Nine combinations of five N rates ranging from 45 to 225 kg/ha, with and without 1.68 kg B/ha, were evaluated at Blackville SC, on a Plinthic Paleudult. Canola plants receiving foliar B had a 6.5% higher yield than those receiving no B for the combined 1990 and 1991 data. Compared to plants which received no B, whole plant tissue analysis at beginning bloom detected a 50% higher B concentration for plants receiving B application 25 days earlier. Seed yield was affected by N rate both years, and there was a significant year by N interaction. In 1990 yields increased as the N rate increased, whereas in 1991 yields peaked at 135 kg/ha N and declined at higher N rates. These data suggest that, on a typical Coastal Plain soil, canola will respond to the application of foliar B, and requires approximately 135 kg N/ha.