Control of Ivyleaf Morningglory In GlyTol® + LibertyLink® Cotton

Trials were conducted in Lubbock, TX in 2010 to determine optimum tank-mix and sequential applications of glyphosate and glufosinate in Glytol® + LibertyLink® cotton to control ivyleaf morningglory.  Tank-mix trials included glyphosate and glufosinate applied at varying tank-mix proportions (1X:0X, 0.75X:0.25X, 0.5X:0.5X, 0.25X:0.75X, and 0X:1X) and varying tank-mix rates (1X:1X, 1X:0.75X, 1X:0.5X, 1X:0.25X and 1X:0X for each herbicide) to two different weed sizes.  Sequential EPOST followed by (fb) MPOST fb LPOST applications of glyphosate or glufosinate applied in all possible timing combinations were also evaluated for effectiveness of control.  Results indicated that glufosinate alone or tank-mixes with higher rates of glufosinate were most effective for suppressing ivyleaf morningglory.  Proportional treatments were only effective when rates of glufosinate exceeded 0.75X.  Applications made to smaller weeds were more effective than applications made to larger weeds.  Sequential applications of glufosinate only were most effective at controlling ivyleaf morningglory.  Sequential applications in which glufosinate was applied before glyphosate were more effective at controlling ivyleaf morningglory than applications which delayed glufosinate applications.