Revista Brasileira De Herbicidas 2010; 9(3): 100-108
Use of glyphosate associate to herbicides applied in post-emergence on soybean crop genetically modified
DOI: 10.7824/rbh.v9i3.82
Frequent utilization of associations among post-emergence herbicides has remained a lot of questions about the selectivity and effectiveness of weeds control in soybean crop. Thus, this study aimed to evaluate the selectivity and effectiveness of herbicides tank mixtures on weed management in Roundup Ready® soybean crop. For this purpose, the following treatments were evaluated: glyphosate (960 g ha-1), glyphosate + Agrus 200® adjuvant (960 + 200 g ha-1), glyphosate+chlorimuron-ethyl (960 +12.5 g ha-1), glyphosate+lactofen (960 + 96 g ha-1) and checks with and without weeds. The spraying of treatments in post emergence conditions occurred when CD 219 RR® soybean genotype plants achieved V4 leaf stage (third leaf stage). Control levels of Alternanthera tenella, Senna obtusifolia, Cenchrus echinatus and Commelina benghalensis species and crop phytotoxicity symptoms were evaluated at 3, 7, 14 and 21 days after application. The association between glyphosate+lactofen provided higher levels of phytotoxicity over the crop. All herbicide treatments evaluated were efficient in controlling Alternanthera tenella and Cenchrus echinatus, but showed unsatisfactory control of Senna obtusifolia and Commelina benghalensis, causing significant reductions in crop yield.
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