Mike Marshall Clemson Comments Weed Control Peanut Notes No. 92 2021

— Written By

Mid-Season POST Herbicides in Peanut 6.9.21

Mike Marshall, Extension Weed Specialist

With most of the state getting an abundance (some places an over-abundance) of rain over the past week, expect weed flushes to begin in earnest. As most plantings are approaching or past the 28-to-30-day mark, there are several options for us once field conditions permit over-the-top spraying. A paraquat program in peanut either tank mixed with Storm or Basagran is permitted up to 28 days after ground crack. Be sure to tank mix a residual herbicide with the POST combination (i.e., Dual Magnum, Warrant, Zidua, Strongarm, Outlook). If you are past the cut-off time for paraquat, Anthem FLEX can be applied after 28-day mark and has POST activity on several small weeds (remember small, 2 to 4 inches in height) including Palmer amaranth, sicklepod, and morningglory. Basagran or Storm are also options for small broadleaf weeds. For nutsedge, Basagran should be applied before nutsedge reaches 8-inches in height. A follow-up application 14-days later is recommended. Do not add any additives (adjuvants) if tank mixing 2,4-DB with Basagran. Strongarm POST at 0.45 oz/A is recommended at this stage if Benghal dayflower is a problem in your field. Two applications of 2,4-DB are permitted during the growing season (up to 12 weeks after planting). As I mentioned in my previous update, residual herbicides are important when considering your POST program. Tank mix Warrant, Outlook, Zidua, or Dual if applying a POST herbicide without a residual component (like Basagran, Storm, or Cobra). A note about managing annual grasses (think Texas panicum), treat them when they are not under stress and before significant tiller production begins (this is when the grass clump gets wider). In addition, a minimum spray volume of 15 gallons per acre is recommended when spraying Select or Poast. Check label(s) for recommended additives for each herbicide program. For additional information, consult the 2021 Pest Management Handbook or the 2021 Peanut Production Guide.