Xtendflex, Liberty Link, and Widestrike/Roundup Flex Tolerance to Glufosinate and Metolachlor

Reports of phytotoxicity have been received over the past few years after glufosinate has been applied over the top.  The objective of this research was to evaluate varietal response to labeled herbicides within the XtendFlex, Liberty Link and Widestrike/RoundupFlex traits.  Field trials evaluating traits from each of these platforms and five herbicide regimes were conducted during 2015 and 2016 in Jackson, TN.  Varieties selected for the study included DP 1522 B2XF, ST 4946 GLB2, and PHY 333 WRF.  The five herbicide treatments included an untreated control, one 29 oz applicaiton of glufosinate, (2) 29 oz applications of glufosinate, (3) 29 oz applications of glufosinate, and (3) shots of glufosinate plus (2) applications of 16 oz of metolachlor.  Results suggest the LibertyLink trait may be more tolerant to applications of glufosinate than the Xtendflex trait, which is in turn more tolerant than the Widestrike/RoundupFlex trait; however, this injury may or may not impact yield.