Of course this can be done with either tillage or a herbicide.  The most consistent control of Palmer amaranth regardless of size is paraquat (Gramoxone Inteon).  In our research over the past several years it has performed well in burning down Palmer amaranth as large as 6” tall. 

Judging by phone calls a number of folks have applied Reflex in with their burndown within the last 7 days or so.  A pint of Reflex will typically provide about 5 weeks (give or take a few days) of residual control of Palmer amaranth. Many of these growers plan to use Cotoran or Caparol right behind the planter to overlay a second residual.  I like this plan as it also overlays another mode of action that is effective on Palmer amaranth.  The Reflex applied that has received rain this week will be very safe to plant into.  The only time Reflex will injure cotton is when no rain has incorporated it. Then an untimely rain event splashes Reflex up onto newly emerged cotton plants.  We saw some of this last year where it would burn the cotyledons off the cotton.  Fortunately, most of this injured cotton recovered fine.  However, once Reflex is worked into the soil with rainfall prior to cotton emergence there is no chance for the splash injury.  Of course, if you have applied the Reflex within the last 7 days or so then you will not likely have any Palmer amaranth up as you plant cotton.  However, be on the lookout for grassy weeds or even morningglories as they can slip through the residual Reflex provides.