Mauritia vinifera Mart Substrates and Nitrogen Doses in Acacia mangium Willd Growth

The objective of this study was to evaluate the effect of the combination of a substrate formulated with decomposed buriti stem (Mauritia vinifera Mart.) and nitrogen doses in the production of Acácia mangium Willd seedlings. A completely randomized design was used in a 3 × 5 factorial scheme, being the factors constituted of substrates formulated from decomposed buriti stem (DBS) mixed with dystrophic yellow oxisol in three proportions (0; 25 and 50%) and nitrogen doses (0; 100; 200; 300 and 400 mg dm-3) applied in cover. After 60 days from the emergency, it was made the following evaluations: Plant Height (PH), stem diameter (SD), internodes number (IN), dry mass of the shoot part (DMA), length and dry mass of the roots, robustness quotient through stem height/diameter relation, roots/dry mass relation and Dickson Quality Index (DQI). The multivariate analysis of variance showed a significant difference (p < 0.01) among averages vectors of treatments. The grouping analysis for the evaluated treatments allowed the division into four distinct groups. In the bi-dimensional plane formed by the first two canonical variables (Can.1 and Can.2) that withheld 99,47% of the total variance contained in the nine original variables, it is observed that the group II of treatments, composed of substrates formulated with 50% of soil + 50% of DBS supplemented with the doses of 200, 300 and 400 mg dm-3 of nitrogen, has provided a greater initial growth of A. mangium plants, as stated by the highest averages in all evaluated variables.