In order to evaluate the use of controlled-release fertilizer in the production and quality of Acacia mangium seedlings, this experiment was conducted in randomized blocks, and treatments consisted of five levels (0, 2.5, 5.0, 7.5 and 10.0 kg m–3 of substrate) of Osmocote Plus® in six replicates. After 130 days of sowing, the production and quality variables of Acacia seedlings were analyzed. All production and quality variables, height/shoot ratio (HSH) and Dickson quality index (DQI) were influenced by the fertilizer doses. The greatest mean values of stem diameter, total height, shoot dry mass, root dry mass, the best HSH and the highest DQI, were obtained for doses ranging from 7.1 to 7.8 kg m–3 of substrate. The largest leaf area was obtained using a dose of 9.3 kg m–3 of substrate.
