MORPHOGENIC CHARACTERISTICS OF TWO TILLERS TYPES AND BIOMASS PRODUCTION OF MASSAI GRASS UNDER NITROGEN FERTILIZATION DURING THE ESTABLISHMENT

The experiment was conducted with the objective of evaluate the morphogenic characteristics of two tillers types (main and primary) and the biomass production in massai grass during the establishment in greenhouse under five nitrogen fertilization levels. A completely randomized in the split-plot design, with five nitrogen levels (0; 150; 300; 450 and 600 mg N dm(-3) of soil) and five replicates (plots) were adopted. The level of nitrogen for each treatment was divided into two parcels, the first half applied immediately after the roughing final (13 DAE) and the second half applied 14 days after the first. We identified six tillers (three main and three primary) in each experimental unit, for further monitoring and determining the variables biomass flow. The leaf elongation rate was increased with the nitrogen fertilization levels and the primary tiller showed highest value in relation than main tiller. The fertilization level at 600 mg N dm(-3) presented increment of 17.4% in the leaf elongation rate at 0 mg N dm(-3). The culm elongation rate was not influenced by nitrogen fertilization and the primary tiller showed highest value for this variable. The leaf senescence rate after cut was not influenced by nitrogen fertilization. However, it was showed highest value for the main tiller. The number living leaves per tiller and leaf appearance rate were increased with N levels and the main tiller was superior in both variables, being the inverse occurred for the phylochron. There were observed values estimated of 0.135 and 0.154 leaf day(-1) tiller(-1) for the leaf appearance rate and 7.49 and 6.56 days/leaf for the phylochron for 0 and 600 mg N dm(-3)levels, respectively. The total herbage dry biomass increased with nitrogen fertilization levels. The nitrogen fertilization influences positively the morphogenic characteristics and biomass production of the massai grass until the fertilization dose of 600 mg N dm(-3).