Crescimento e produção da couve-da-Malásia submetida a adubação nitrogenada

Abstract

The aim of this work was to evaluate, through the growth analysis, the effects of nitrogen doses on the development of Brassica campestris var. chinensis (Pak Choi). The experiment was carried out in a greenhouse, from October to November, 2007, in Marechal Cândido Rondon, Parana. The experimental design was the randomized block, with five treatments (0, 60, 105, 150 and 195 kg ha-1 of N) and four replications. The hybrid used was Chouyou. The nitrogen was equally applied in three times, when in transplantation, and at seven and 14 days after the transplantation. The dry mass production, and the foliage area were weekly evaluated reaching the following indices of growth: relative and absolute growth rate, net assimilation rate, leaf area ratio, and specific leaf area. The fresh mass of the aerial part was also evaluated in the last collection. The increase of nitrogen fertilization positively affects the growth parameters, and provides an increased production with emphasis on the dose of 195 kg ha-1 of N.