The aim of this study was to evaluate the interference caused by Slender amaranth (Amaranthus viridis) and Milkweed (Euphorbia heterophylla) at different densities and distances in the common bean (Phaseolus vulgaris) cv. Pérola. The experiment was carried out using asbestos cement boxes, with 50 liters of capacity, filled with dark red Latosol. Seeds were put to germinate in a board of 128 cells filled with horticultural substratum. When the seedlings reached the V2 stage, they were transplanted to the boxes at densities of 8, 16, and 32 plant m-2, distanced 0, 12, and 24 cm from the bean plants and equally among themselves. Growth and yield characteristics of the plants and weeds were evaluated. The data obtained were submitted to analysis of variance using the F test and the means were compared by the Tukey test. Weeds were found to present a greater development when far from the culture. Slender amaranth caused reductions in the number of pods and in the estimated yield of the bean plants .Increase in density only intensified the competition and reduction in crop yield when the bean plants were distant at least 12 cm, in the slender amaranth case. At 0 cm, the bean plants became more competitive and did not suffer competition from the weeds, regardless of their density.
weed; competition; Phaseolus vulgaris
