Glyphosate-Resistant Palmer Amaranth Control in Enlist Cotton Systems

New ways to manage Palmer amaranth in cotton are needed.  Dow AgroSciences is developing traits in cotton that bestow tolerance to 2,4-D, Ignite and glyphosate.  The name of this new herbicide trait package is Enlist®.  Research was conducted on this new herbicide tolerant trait cotton in Georgia, North Carolina and Tennessee in 2010 and 2011.

Sequential glyphosate applications only provided 39% GR Palmer amaranth control compared with 82 and 78% control by sequential applications of 2,4-D and Ignite, respectively.  Greatest control (94%) was achieved with sequential applications of 2,4-D plus Ignite.  Cotton lint yield reflected the weed control ratings. Yields with sequential 2,4-D and sequential Ignite applications exceeded yields with sequential glyphosate application by over 300% (Figure 2). Yields with the sequential applications of 2,4-D plus Ignite were greatest and 475% greater than yields with glyphosate applied sequentially.