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.