The bad news? Marestail is a problematic weed lurking in many fields. The good news? There are several control options, according to Kansas State University Extension specialists Dallas Peterson and Doug Shoup.
The two researchers tacked this subject in a recent edition of K-State’s “eUpdate” newsletter. The two write that the fall season is the No. 1 time to start addressing any marestail issues.
“Fall applications can be effective even into December, as long as applications are made to actively growing weeds during a stretch of mild temperatures,” they write. “In fact, for fall applications, it may be better to wait until November to allow most of the fall-germinating winter annuals to emerge.”
Exact herbicide options vary depending on what a farmer intends to plant next spring, but a variety of herbicides are effective against marestail, including 2,4-D, dicamba, Clarity, Sharpen, Canopy EX, Autumn Super or Valor XLT, according to Peterson and Shoup. Farmers can add glyphosate to the tankmix to help control other grass and broadleaf weed species, they note.
Should you consider adding a residual herbicide to the tankmix as well? It could hold the line through winter and early spring, but be aware of the limitations, according to Peterson and Shoup.
“Don’t expect a residual herbicide applied in the fall to provide good residual weed control through the spring and summer of the next year,” they write. “[And] if a fall treatment isn’t made, early spring treatments should be applied to help control fall-germinated marestail.”