Herbicides Work With Soil Management to Combat Resistant Palmer Amaranth

Yesterday we heard from NC State Extension Associate in Crop Sciences, Matthew Vann on using deep tillage as well a rotation with tobacco in the war against resistant Palmer Amaranth. Today, Vann discusses adding herbicides into the tillage program, and the results:

“On top of the tillage treatments we have herbicide treatments. So we have a combination of herbicides like Spartan and Command which is a very good pigweed herbicide and Command gives us very good weed control. So we have that combo compared to just Command. We are comparing herbicide treatments that control pigweed and those that don’t. Then we have treatments were we are hand weeding.

Based off of those and our tobacco, we are seeing where we have our tillage implemented out there, when we are burying seed with a deep tillage, we see about a 50% stand reduction with palmer amaranth.”

Vann explains how the weed control systems are different between tobacco, soybeans and cotton:

“Spartan is not labeled in cotton production. There is a rotational restriction, about 18 months, when you use Spartan. But with beans, there may be a label and they are using herbicides with similar chemistry. There may be similar products in beans, but in most systems today, beans and cotton are genetically modified and they can stand applications of RoundUp or Liberty, so glyphosate type herbicides. Those herbicides are applied after the weeds emerge. In tobacco we are applying even before we transplant tobacco.”

And while the study is incomplete, Vann says some things are apparent now:

“We have two locations for this study. At one location we are moving into the 3rd year of the rotation and the other location it’s the 2nd year. I anticipate that by the end of next summer we will start telling growers what to expect in terms of weed control. Now we are able to tell them that in tobacco production, when we use deep tillage, we can reduce weed stand by 50%. When we use the combination of Spartan and Command we reduce the overall weed population by about 80%.”

To see Vann’s presentation from the 2013 Tobacco Day, click here

Matthew Vann, NC State Extension Associate on Today’s topic.


A native of the Texas Panhandle, Rhonda was born and raised on a cotton farm where she saw cotton farming evolve from ditch irrigation to center pivot irrigation and harvest trailers to modules. After graduating from Texas Tech University, she got her start in radio with KGNC News Talk 710 in Amarillo, Texas.

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