Desempenho agronômico de cultivares de feijoeiro-comum em função de densidades populacionais, no Norte de Minas Gerais

Abstract

The objective of this work was to study the effects of sowing densities on growth and yield of grains with its primary components in of common bean cultivars sown in different crops. The experiment was carried out at Experimental Farm of the UNIMONTES, in Janaúba city, MG, in the spring and fall of 2011. The treatments were in a factorial scheme 4 x 5, involving four common bean cultivars and five population densities. The used experimental design was of blocks at random, with four repetitions. The sowing was manual one, being each parcel composed of 6 lines of 5 m length, with spacing of 0.5 m between lines. Every 10 days were evaluated the dry matter mass and the plants height. At harvest, the grains yield and its primary components were evaluated: final stand, average number pods per plant, average number of grains per pod and mass of one hundred grains. The effects of sowing density and the age of the collected plants were studied by means of regression analysis, choosing the models appropriate to represent them for the biological behavior of the studied characteristics, for the significance of the equation coefficients and for the value of the determination coefficient (R²). In turn, the effect of the crops and cultivars were studied, respectively, by the F and Tukey tests to 1 and 5% of significance. The gotten results allowed concluding that the increment in the sowing density increases the shoot dry mass, the mortality of plants, also decreases the number of pods per plant, but it does not cause alterations in the grains yield of the common bean in the most situations. With the increase of the plants' age, there is an increment in the dry mass and plants height of all of the evaluated cultivars, being the 'Ouro Negro' which presented greater height. The spring provides to studied cultivars greater dry mass in the most situations, greater number of grains per pod and mass of 100 grains, whereas the winter provides greater plants height. In the winter, the 'Ouro Negro' cultivar has the grains yield influenced by the sowing densities, being observed greater yield in the density of 305 a thousand plants ha¹.