Habilidade competitiva de cevada em convivência com populações de azevém

Abstract

Barley has been gaining ground in southern Brazil since it shows itself as a good option for crop rotation with wheat in winter. One of the main constraints to increasing its productivity is the competition with weeds, especially ryegrass. Therefore, the goal of this work was to evaluate the competitive ability of barley (Hordeum vulgare) grown in the presence of ryegrass (Lolium multiflorum) and measure in which ryegrass density the crop development is compromised. A field experiment was designed in randomized blocks, with four replicates (13,60 m2), where the barley cultivar BRS Elis was grown in the presence of different ryegrass densities (0, 4, 8, 16, 32, 64 and 128 plants m2). The variables analyzed were: plant height, chlorophyll content, leaf nitrogen content, number of barley and ryegrass shoots, dry mass of barley and ryegrass shoots, barley leaf area, number of ears, number of grains per ear, the thousand grain weight and the productivity of barley. Ryegrass interferes negatively in the development and productivity of barley, with more expressive damages in the greater population densities of the weed species. Ryegrass interferes in barley productivity even at low densities, and its control is necessary from four plants m2.