Potencial de controle dos herbicidas 2,4-D e dicamba, sobre espécies daninhas tolerantes na cultura da soja

Abstract

The species Commelina erecta (trapoeraba), Commelina benghalensis (trapoeraba), Euphorbia heterophylla (dairy), Ipomoea Indivisa (viola string), Ipomoea grandifolia (viola string), and Ipomoea purpurea (viola string) and Richaridia brasiliensis (whitepoaia). ,are among the main spontaneous weeds in the Brazilian productive system. With the overuse of glyphosate herbicide problems began to arise with the successful control of these species. The aim of this study was to evaluate the control ability of the active ingredients belonging to the synthetic auxins group (2,4-D and dicamba), post-emergence in certain species. The experimental design was completely randomized, with three replications. The treatments were arranged in an 11 x 2 x 6 factorial scheme, in which the first factor was the species / biotypes, the second the herbicides and the third the doses of each herbicide ( control, 150, 225, 433, 650 and 974 g ai-1). At 7, 14, 21 and 28 days after herbicide application, the control efficiency of the plants was evaluated by giving a score from 0 to 100%. After the last evaluation the plant materials were collected to determine fresh and dry matter. Among the data obtained, it can be established that the species of Commelina erecta (trapoeraba) and the resistant biotype of Euphorbia heterophylla (dairy) are more easily controlled with the use of the herbicide dicamba, while the other species / biotypes are more easily controlled. the herbicide 2,4-D is used.