Selectivity of herbicide isolated and in associations for RR2/LLTM maize

Abstract

Maize with tolerance to the herbicide glyphosate (Roundup Ready^TM) (RR2^TM maize) has been increasingly used, since it favors the use of this herbicide to control weeds. Thus the objective of this study was to evaluate the tolerance of the hybrid 2B810PW (RR2/LL), submitted to the application of isolated and associated of glyphosate, glufosinate and atrazine at post-emergency (V4). The assay was carried out in the field, in the harvest 2013/14, and the design adopted was a randomized block with four replications. The treatments consisted of the application of glyphosate (1080 g ha^-¹ of acid equivalent - a.e.), glufosinate (500 g ha^-¹ of active ingredient - a.i.), atrazine (2000 g ha^-¹ a.i.), glyphosate + glufosinate, glyphosate + atrazine, glufosinate + atrazine, glyphosate + glufosinate + atrazine, plus the control without application. Crop injury was evaluated at 7, 14, 21 and 28 days after application (DAA) and SPAD index, at 21 and 28 DAA. Were also evaluated variables related to agronomic performance: height, ear height, stem diameter, thousand grain weight and yield. In general, the variables were not affected by treatments. The maize hybrid 2B810 PW presented is tolerant to the application post-emergence (V4) of the herbicides used.