Weed phytosociology in the cultivation of black beans under seeding densities in semi-arid

The objective of this study was to characterize the phytosociology of weeds in irrigated cultivation of black beans, under different sowing densities in semi-arid region of Minas Gerais, Brazil. The experiments were conducted in the autumn-winter harvest. The treatments consisted of four bean sowing densities (50, 100, 200, and 500 thousand seeds ha-1), in a randomized block design, with four repetitions. Weed plants with complete structure were collected using the standard method of the square inventory and phytosociological parameters were estimated, studied using descriptive analysis. Lower sowing densities favored the development of species with C4 metabolism, while higher density suppressed their diversity, especially promoting Sena obtusifolia. The sowing density of black beans alters the dynamics of weeds in semi-arid conditions in Minas Gerais, Brazil. The density of black beans at 500 thousand seeds ha-1 suppresses the diversity of weed species, especially those with C4 metabolism. The species S. obtusifolia, Eleusine indica, Amaranthus spp., and Brachiaria plantaginea have higher importance value indices (IVI) and coverage value indices (IVC) in different densities of black beans in the semi-arid region of Minas Gerais, Brazil.