Effects of plants arrangement on two second-crop maize hybrids on the interference relations with weed community

Abstract

This work aimed to study the weed control and coexistence periods interference in crop yield characteristics of two maize hybrids, NK ‘Somma’ and NK ‘Impacto’, in two densities, sowing in the second-crop in two row spacing, resulting in the estimated density of 100.000 plants ha^-1 in the 0.7 m row spacing, and 78.000 plants ha^-1 in the 0.9 m row spacing. The experiment was carried out in a completely randomized blocks design, with four replications, with treatments disposed in a 2x18 factorial scheme (2 densities and 18 periods of weed interference). The control and coexistence periods were 0, 15, 25, 35, 45, 55, 65, 75 and 85 days after the emergency. The weed community was composed mainly of eudicotyledons, especially Alternanthera tenella, with average relative importance of 70% in both situations of this research. Under these conditions, the maize hybrids NK ‘Somma’ and NK ‘Impacto’ shows higher competitive ability with the weed community in secondcrop, except for ‘Somma’ in the row spacing of 0.7 m, in which the weed interference reduces its yield in 15.3%. Therefore, it is not possible to determine the weed interference periods on the crop.