The topic of weed control for oil-seed rape has come up in the past few weeks. The labeled options are very limited. Treflan is labeled for pre-plant incorporated application. There are no herbicides labeled for application after planting or for no-till production. If you are inclined to try no-till, be cautious of what you include with your burndown herbicides.
Sharpen and 2,4-D are often used as tankmixtures with glyphosate to broaden the control with no-till burndown. But Sharpen can injure oil-seed rape if used as burndown application; it is used in some areas to manage volunteer canola/rapeseed.
Dr. Curran at Penn State examined 2,4-D ester before planting canola and found significant injury if canola was planted within 1 to 2 days of application, but no injury if the herbicide application was made 14 days before planting.
Postemergence options include Stinger for broadleaf weeds and Assure II, Poast, or Select for grasses. Be sure to read the Stinger label for rotational restrictions (minimum of 10.5 months to nonlabeld crops, including soybeans).
If growing oil-seed rape for the first time, select a field with a low density of winter annual weeds since you are very limited in herbicide options.