Michael Stamm and Kraig Roozeboom, Agronomy, Kansas State University, Manhattan, KS
A three-year study examined the effects of planting date, tillage, and cultivar on winter survival and yield of winter canola near Manhattan, KS. Eight commercial cultivars were seeded in conventional tillage and in no tillage with four planting dates. Results show that crown height decreases at later planting dates and it is generally higher in no tillage than tillage. Some varieties had lower crown heights across planting dates. Others, especially hybrids with vigorous fall growth, had higher crown heights. Across planting dates, four cultivars had higher winter survival in no-tillage compared to tillage in 2009-2010. In 2011-2012, three cultivars had better winter survival in no tillage than in tillage. Three cultivars had higher mean yields in no tillage than conventional tillage in 2009-2010. Overall, the study indicates that planting date may be less flexible in no tillage and varieties with lower crown placement and proven winter hardiness perform best under no tillage conditions.