My understanding is that Tennessee may have as many as 100,000 acres of canola planted this fall.  Weed management in canola can be difficult, but is fairly straight forward for 2 reasons.

The first reason for weed control to be less complicated is that Tennessee historically has not grown much canola.  This results in less weeds in the soil seed bank that best fit the niche of effective competitors with this crop.  An exception that could be an issue in some fields is horseweed. It has a wind-blown seed so could show up in any given field.  There really are no herbicides from a POST applied stand point that can control horseweed in conventional canola. The best control measure for horseweed would be to get a good canola stand as shade greatly mitigates horseweed germination.

The second reason is that there are only a few herbicides labeled in canola that would have efficacy on our most common winter annual weeds (ryegrass and poa).  The herbicides are Command, Treflan and clethodim.  Since Treflan will photo decompose it must be quickly tilled in to provide efficacy.  In all our no-till acres this is not an option.  In those cases, the 4 oz/A rate of Command applied PRE is likely a better fit.  The best option though would be clethodim applied in November to take out young ryegrass and Poa.

In regions where canola is commonly grown, broadleaf weeds like wild radish and thistles are most problematic. In those areas most grow Liberty Link or Roundup Ready canola in order to control those broadleaf weeds.  My understanding is that Tennessee contracts are for conventional canola so it does not have these traits, therefore glufosinate and glyphosate are not options.