Spontaneous sunflower control with selective herbicides for soybeans

Abstract

One field experiment was carried-out during 1989/90 at Estação Experimental Agronômica of Universidade Federal do Rio Grande do Sul, in Eldorado do Sul, RS, Brazil, in order to evaluate the control of sunflower plants with herbicides applied in post-emergence in a soybean culture. The herbicides acifluorfen, acifluorfen+bentazon, bentazon, clomazone, chlorimuron-ethyl, imazaquin, imazethapyr, fomesafen, and lactofen, used at the recommended rate, were applied to sunflower plants at the 4 and 10 leaf-stages. A stage dependent sunflower control was observed when clomazone, chlorimuron, bentazon+acifluorfen and bentazon were used. Efficient control was obtained when these herbicides were applied to plants with 4 leaves. Imazaquin and imazethapyr gave satisfactory sunflower control when sprayed to plants at both growth stages. Acifluorfen, fomesafen, and lactofen, did not control efficiently sunflower plants at either stage.