Respostas morfofisiológicas de cultivares de feijoeiro em competição com buva

Abstract

When weeds infest the bean plant, they are responsible for great losses in productivity and also in the quality of the harvested grains. Thus, studies that portray the competitive interaction between bean and weeds in substitute experiments are important to adopt more efficient management in crops and at the same time reduce the use of herbicides. Thus, the objective of this work was to evaluate the competitive ability of bean cultivars (BRS Estilo, IPR Urutau, IAC 1850 and IPR Tangará) in the presence of buva (Conyza bonariensis), in different proportions of plants in the association. The experiment was conducted in a greenhouse in a randomized block design with four repetitions. The treatments were arranged in proportions of feijoeiro and buva plants: 20:00; 15:5; 10:10; 5:15; 0:20 plants vase-1. The analysis of species competitiveness was performed by means of diagrams applied to substitution experiments and through relative competitiveness indices. At 40 days after emergence (DAE) the diameter of the stalk, plant height, leaf area, variables related to plant physiology and dry mass of the aerial part were measured. There was a negative effect on the species, with the bean cultivars and the weed being negatively affected, since they competed for the same resources available in the environment. Interspecific competition causes greater damage to CD, EP, AF, and the DM of the species than does intraspecific competition. Bean shows better for photosynthetic rate and efficient water use in the presence of the weed. Bean cultivars show greater competitive ability with respect to the weevil.