RESUMO: Um estudo de campo de três safras foi conduzido para avaliar o potencial de uso de herbicidas pré-emergentes misturados com glyphosate como meio de controlar as espécies de plantas daninhas na cultura da soja. Nas safras 2011/12, 2012/13 e 2013/14, o cultivar Brasmax Apollo RR foi semeado sob resíduos de colheita de centeio. Os tratamentos herbicidas foram o glyphosate (gly) (1.296 g i.a. ha-1), gly + S-metolachlor (1.296 + 1.920), gly + imazaquin (1.296 + 161), gly + pendimethalin (1.296 + 1.000), gly + metribuzin (1.296 + 480) e gly + 2,4-D (1.296 + 1.209) aspergidos em pré-emergência (PRE) dois dias antes da semeadura da soja. Além disso, foram incluídas as testemunhas capinada e sem capina. Gly + S-metolachlor e gly + pendimethalin reduziram a densidade de buva de 48 para 3 e 6 plantas m-2, respectivamente. A mistura contendo gly + metribuzin e gly + 2,4-D amina e o gly aplicado isoladamente não apresentaram controle dessa planta daninha. As misturas contendo gly + metribuzin, gly + 2,4-D amina, gly + imazaquin e gly aplicado isoladamente não mostraram qualquer efeito no controle de milhã. Em contraste, gly + S-metolachlor e gly + pendimethalin reduziram a densidade de milhã de 70 para 0 e 1 planta m-2, respectivamente. O rendimento de soja foi maior na testemunha sem capina, gly + S-metolachlor e gly + metribuzin. O uso de herbicida com efeito residual teve impacto no manejo de plantas daninhas e na produtividade da soja. Os maiores níveis de controle de buva e milhã ocorreram com os herbicidas S-metolachlor e metribuzin.

ABSTRACT: A 3-year field study was conducted to assess the potential for using pre-emergent (PRE) herbicides tank mixed with glyphosate as a means of controlling weed species in soybean. In 2011/12, 2012/13 and 2013/14 growing sessions soybean cultivar Brasmax Apollo RR was planted under residues of rye. The herbicide treatments glyphosate (gly) (1,296 g a.i. ha-1), gly + S-metolachlor (1,296 + 1,920), gly + imazaquin (1,296 +161), gly + pendimethalin (1,296 + 1,000), gly + metribuzin (1,296 + 480), gly + 2.4-D amine (1,296 + 1,209) was applied in pre-emergence (PRE) over rye crop residues two days before soybean sowing. In addition, full season weed-free and weedy control plots were included. Gly + S-metolachlor and gly + pendimethalin reduced the horseweed density from 48 to 3 and 6 plants m-2, respectively. The mix containing gly + metribuzin and gly + 2.4-D amine and gly applied alone had no effect in the horseweed control. The mix containing gly + metribuzin, gly + 2.4-D amine, gly + imazaquin and gly applied alone had no effect in the crabgrass control. In contrast gly + S-metolachlor and gly + pendimethalin reduced the crabgrass density from 70 to 0 and 1 plant m-2, respectively. The soybean yield was higher with weed-free, S-metolachlor and metribuzin treatments. The use of an herbicide with residual effect had impact on weed management and soybean yield. In conclusion, a greater control of horseweed and crabgrass occurred when S-metolachlor or pendimethalin was applied PRE.