I have been getting alot of questions about goose grass control in cotton. Below are a few words from Stanley Culpepper on this subject.
For years, we have been discussing how science suggests that goosegrass populations are likely to explode in cotton systems that are heavily dependent on Liberty or dicamba, especially when residual herbicides are not used wisely. This year it seems that science is proving to be correct with goosegrass issues more prevalent across our state. This late in the season, there is little that can be done to control the huge goosegrass plants that have already escaped control but understanding how to improve the management program for the future will hopefully help. Keep in mind that those plants surviving in the field are likely producing seed that are more tolerant to Roundup (and other herbicides); thus, future management will be more difficult.
First to be successful, one must understand that goosegrass needs to be managed similar to Palmer amaranth…………the goal is to never see an emerged plant. Starting clean by planting into fields free of goosegrass (and pigweed) is ideal. Herbicides such as Prowl (preplant/at plant) or Warrant (preemergence) are the backbone of a sound system. Prior to these herbicides breaking down, additional residual herbicides need to be applied thereby creating an overlapping barrier of control preventing emerged plants throughout the season. Residual activity of Caparol, diuron, Dual Magnum, Outlook, Prowl, Treflan and/or Zidua will
be beneficial as long as the product is activated prior to goosegrass emergence. If (when) goosegrass emerges and is very small, an application of glyphosate + a grass herbicide (example being Select) is the best option. Always use the full rate of Roundup and treat when goosegrass is less than 2 inches! Making applications of Roundup + Liberty or Roundup + Dicamba will almost always provide much less control on this weed than that noted with Roundup alone. Understanding that follow up applications to control emerged plants are often not successful, special emphasis should be placed on a timely initial application.
