Monday, November 13, 2006

An Evaluation of the Effects of Planting Date and Seeding Rate on the Yield of Winter Canola Grown at Three Different Geographic Areas.

Nicole Fink, Shawn Conley, and Ellsworth Christmas. Purdue Univ, Agronomy Dept, 915 W State Street, West Lafayette, IN 47907

Winter canola (Brassica napus L.) is a winter annual and as such is seeded in late summer or fall. When commercial production was first considered in Indiana, site location was thought to be the most important cultural decision. Producers discovered that locations well suited to winter wheat production were also good sites for winter canola. Producers also found that planting date was one of the most important production decisions. To address this problem, three sites were selected for a planting date experiment, each representing a distinctly different climate in terms of severity of winter temperatures and snow cover. The three planting dates selected ranged from mid to late August, for the initial date in the North, to early to mid October for the last date in the South. Multiple cultivars were planted at each location at 10-14 day intervals. The northern site is the coldest of the three sites and generally once the canola goes into dormancy, it remains dormant until March and is usually protected with a blanket of snow during the coldest period. Many times the canola is slow going into dormancy at the central site. In these cases, temperatures may drop sharply and in the absence of snow cover can result in significant freeze injury. At the southern site, the long-mild fall season greatly delays the onset of dormancy. Each of the three sites included in this study exhibited distinctly different weather conditions. Due to the addition of four seeding rates, midway through the study, the number of cultivars was reduced. Optimal planting date time for the northern site was found between mid August and September 10th, for the central site was found between late August and September 20, and for the southern site was found between September 15th and October 10th.