Palmer amaranth is getting away from us quickly! A considerable amount of the Palmer pigweed in soybeans is now 2 to 4” tall.  

We are finding in our research here at Jackson this week that the Palmer in that 3 to 5” range is being burned by the fomesafen (Flexstar). Unfortunately, in 5 days many are well on their way to growing back.  I have had a number of reports from the field of similar results.  What can you do to improve control of Palmer amaranth that is borderline too big?  Increase the gallonage to at least 15 GPA. Use spray tips that are designed to provide good coverage, not drift reduction. Move from a pint to a pint and a 1/3 of a fomesafen (Flexstar, Rhythm) product. Add 1 % MSO to Flexstar or Flexstar GT.  Even doing all the above will not control a 5” Palmer amaranth.  However, it should help the fomesafen products become more consistent in controlling the borderline too large, 3 to 4” tall Palmer amaranth.