Produtividade do feijão-caupi cultivado após plantas de cobertura com e sem aplicação de herbicida sem pós-emergência

Abstract

The objective of this research was to evaluate the yield of the cowpea crop, when grown on cover crops straws, managed or not with herbicides applied in post-emergence. The experiment was conducted in the field, in a complete randomized block design with three replications. In a 5x2 factorial scheme, the first factor were featuredby five types of straw were tested: sorghum, congograss, Tanzania grass, palisadegrassand weeds. The second factor was characterized by the absence and application of the ready mix of bentazone + imazamox at the dose 600 + 28 g ha-1at 13 days after emergence (DAE) and the herbicide haloxifop-p-methyl at the dose of 62.35 g ha-1to 18 DAE. Weed density and dry matterwere evaluated at 20 and 85 DAE of the crop, plant height, stem diameter, chlorophyll content, dry matteraerial part and in the flowering of the crop (46 DAE). At harvest, the number of grains per pod, the number of grains per plant, the weight one hundred grains, the population of cowpea plants and grain yieldwereevaluated. The straws of congo grass, Tanzania grass and palisadegrasson the soil surface reduce the dry mass of weeds, constituting necessary management where chemical control has not been carried out. Regardless of the use of straw, the application of the herbicide is essential to guarantee the productivity of the crop. The cultivation of cowpea on sorghum straw, congograss, Tanzania grass and palisadegrassresults in higher grain yield.