Texas Panicum Control in Corn and Soybeans

Mark VanGessel, Extension Weed Specialist; mjv@udel.edu

Below are a few key points from a two years of research funded by the DE Soybean Board:

  • Herbicides applied at planting in either corn or soybeans generally do not provide full-season control and required a postemergence herbicide. The large seeds of Texas panicum allows it to emerge from relatively deep in the soils, and so results with residual herbicides applied at planting have been inconsistent.
  • Postemergence control in corn was highest with two applications of glyphosate (97%) or single application of Accent Q (89%). A single application of glyphosate provided only 78% control. The addition of Resolve with glyphosate did provide residual control resulting in improved full-season control (83%).
  • Postemergence control in soybeans was 100% with either glyphosate or Select Max in one of two years. In the other year, when Texas panicum emergence was delayed, one application of glyphosate was not adequate and required either a second glyphosate application, or tankmixing glyphosate with Zidua extended residual control.