Strategies to Improve Brassica Napus L. (Canola) Establishment and Winter Survival in Conservation Systems

Abstract

The introduction of winter canola to the U.S. has allowed producers to diversify their winter wheat systems by offering an additional rotational crop. Canola acreage has been on a steady incline in the southern Great Plains as it has proven beneficial to removing grassy weeds from continuous wheat systems. Winter canola production has also proven to be a challenge with winter kill particularly in no-till systems within the southern Plains. There is little data available to evaluate the impact of wheat residue and freeze intensity on the winter survival of canola in the southern Plains. Therefore a study was conducted in Fairview and Chickasha, OK to evaluate the effects of shallow tillage and burn on the winter survival of canola during and following the winter. There are few studies investigating the screening of varieties in a controlled environment for winter hardiness. The majority of winter survival assessment is conducted in the field, mainly in the National Canola Variety Trials. Therefore a study was conducted in Stillwater, OK to develop a variety screening program for cultivars commonly used in the southern Plains. Residue management methods impacted canola plant density at both locations but only resulted in yield differences in Chickasha. Canola subjected to a three hour freeze at -4.4C� and -8.8C� did not result in any conclusive winter kill however a six hour freeze with the same temperature resulted in complete plant loss. This data will provide insight into the potential need of a residue management method in canola to increase productivity and provide a better understanding of how freeze intensity and duration impacts canola survival.