We are well behind the burndown pace of most Tennessee springs, where at least some would have burndown applications applied by this time. However, this was not a typical winter and as such we are not behind with respect to weed maturity.

The winter Tennessee experienced is not unlike what happens in the Midwest.  They typically see high mortality rates of fall germinated horseweed (marestail).  In walking a few fields it appears this is the case for us as well this spring.  The bulk of the horseweed we will have to manage will be spring germinated. 

New horseweed germination started about two weeks ago and I would expect that to continue over the next few weeks.  It should be easier to control with it being much smaller than what we typically spray this time of year.

Does a residual make sense this spring? That depends on if a follow-up burndown is planned at planting, the expected planting date and what is the intended crop. If the expected planting date is 3 weeks or so off and the plan is to burndown with something at planting then a residual in with the burndown now is probably not warranted.

Read:

Dicamba shortage looms on Tennessee farms, but other options available

Wheat herbicides: Time running out in some Southern fields

However, if the intended planting date is more than 30 days away, then a residual can provide the advantage of not having a large grown up mess to have to plant into later this spring. If corn is the intended crop then a residual added to an early burndown often will not add much as most of the popular Pre and Post applied corn herbicides will also control newly emerged horseweed.