It was conduced field trial with the objective to study the effects of herbicides, isolated or combined, in cotton crop (Gossypium hirsutum L.) and weeds control, in a soil previously occuped by cerrado vegetation, at Selviria, MS, Brazil. The experimental design used was randomized block with 12 treatments and four repetitions. The treatments, dosis at kg a.i./ha, were: alachlor at 2.15 and 2.58 and diuron at 1.6 on preemergence application, trifluralin at 0.96 on preplant incorporated isolated or combined with MSMA at 1.89, or bentazon at 0.72 or diuron at 1.2 on postemergence applications; MSMA at 2.52, linuron at 1.0 and diuron at 1.6 on postemergence application and checks with or without hoeing. The treatments alachlor, diuron on preemergence application and trifluralin combined with diuron controlled Digitaria sanguinalis (L.) Scop and Amaranthus viridis (L.) during 90 days after the sowing of cotton, decreased 80% or more of dry matter of weeds. The herbicides did not caused phytotoxicity on crop. The weed competition reduced 58.9% of cotton yield.
cotton (Gossypium hirsutum L.); weeds; herbicides