Goosegrass Persists In Too Many Fields

DR. LARRY STECKEL

JACKSON, TENNESSEE

 Serious infestations of goosegrass have proven to be way too persistent in many cotton and soybean fields (Picture 1).  Many are getting frustrated with the lack of control seen with tankmixes that contain glyphosate and/or clethodim.  Some have asked if maybe some of these grasses have developed resistance to glyphosate and/or clethodim.

 Resistance is indeed part of the reason for the lack of grass control with glyphosate. We documented glyphosate resistance in some Dyer and Lake County goosegrass populations back in 2012. We have yet to find clethodim-resistant goosegrass in Tennessee.  However, the number of reported failures controlling this grass in recent years does warrant investigation.

 We plan to screen for clethodim resistance in goosegrass this winter.  If you suspect resistance in a grass population in your field please contact me.

As far as management goes, at this date a tankmix of Liberty at 32 ozs plus clethodim at 16 ozs of a 2lb product has provided the best results in most fields.  ∆

DR. LARRY STECKEL

UNIVERSITY OF TENNESSEE