Abstract

ZANATTA, F.S.; RIZZARDI, M.A.; LAMB, T.D.  and  JOHANN, L.B.. Influence of nitrogen doses on maize (Zea mays) during weed control. Planta daninha [online]. 2007, vol.25, n.3, pp. 529-536. ISSN 0100-8358.  http://dx.doi.org/10.1590/S0100-83582007000300012.

The objective of this study was to quantify the effect of nitrogen fertilization on weed interference in maize. The experimental design used was a split-plot, in randomized blocks, with four replications. The treatments consisted of five rates of N (0, 50, 100, 150 and 200 kg ha^-1) and four weed control times (maize in V₂, V₃, V₄ and V₅), two more controls without and with weeds. Chemical control was performed at post-emergence with association of the herbicides nicosulfuron and atrazine. The N rates influenced the determination of weed control time. When weed control was conducted at a later time, the use of high N rates minimized the negative effect of weed interference. In the absence of N application, chemical control exerts a greater influence on maize grain yield.

Keywords : Zea mays; management; interference.