Winter Canola Yield and Survival as a Function of Environment, Genetics, and Management

Successful winter canola (Brassica napus L.) production creates diversity and provides crop rotation alternatives for producers. Stand establishment and winter survival are among the main determinants of success in winter canola production. The objective of this research was to investigate the impact of environment, crop management, genetics and their interactions on canola stand establishment, survival, yield, and oil and protein content. Two datasets were analyzed: results from the National Winter Canola Variety Trials conducted from 2003 to 2012 and data from experiments conducted for 3 yr (2010-2012) in Manhattan, KS, to assess the impact of planting date, tillage, and cultivar on canola yield and survival. Canola has the potential to yield up to 7 Mg ha(-1); however, actual yields were usually in the range of 0 to 4 Mg ha(-1). The average oil content of canola seeds was 40%, but the potential extended to 47%. Environment, defined as a combination of year and location, was responsible for the majority of variation in yield, oil content, stand establishment, and survival of winter canola. Planting in mid to late August and early September benefited yield most of the time compared with planting late in September or October in the Great Plains and Midwestern United States. Only with extremely early or late planting did tillage improve winter survival and yield compared with no-till. Crown height of canola was greater in no-till treatments compared with conventional tillage treatments, but a significant relationship was not observed between crown height and winter survival or yield. Cultivars differed significantly in yield, survival, and crown height, but no cultivars were consistently superior in no-till conditions or with plantings outside of the recommended time frame.