PRODUCTION OF Eucalyptus urophylla x Eucalyptus grandis SEEDLINGS WITH DIFFERENT FERTILIZERS

Mineral fertilization is an important practice that contributes to the production of seedlings with satisfactory quality . This study aimed to evaluate the effect of the application of potassium chloride (KCl) and monoammonium phosphate (MAP) on growth and nutrition of Eucalyptus urophylla x Eucalyptus grandis seedlings. The experiment was conducted in full sun, with direct sowing in tubes containing composite substrate (Pinus bark, coconut fiber, bovine manure and vermiculite). The experimental design was a randomized block design in a 5 x 2 factorial scheme, with five doses of KCl (0.0, 0.025, 0.050, 0.100, and 0.200 g seedling -1 ) and two doses of MAP (0 and 0.10g seedling -1 ), with four replicates. At 120 days, the effect of the interaction between the KCl and MAP doses was verified for the variables: diameter at root collar, dry mass of the aerial part (DMAP) and total (TDM), Dickson Quality Index, N content, P K in the aerial part, K content in the roots, absorption efficiency (AE) of N and P. For the variables: height (H); leaf area; root dry mass (RDM); H/DRC and DMPA/RDM ratios; and N and P content in the roots, only effect of the application of MAP is observed, whereas for AE_K the effect was only of KCl. Thus, there is variation in the effect of KCl doses as a function of morphological and nutritional variables evaluated. In general, the best seedling growth and nutrition occurs with the applied dose of 0.100 g KCl + 0.10 g MAP seedling -1 .