This essay compared three container volumes, conventional fertilizer, recommended and half recommended slow release fertilizer, and the way of mixing fertilizer in the substrate on the initial growth of Peltophorum dubium seedlings in a nursery. The statistical design was a randomized factorial 3 x 3 x 2, using 180 and 100 cm³ plugs for containers filled with commercial substrate and plastic bags of 10 x 15 cm filled with soil and vermiculita in equal parts. For fertilization, a slow release fertilizer (FLL) was tested in the dosages of 3.5 and 1.75 kg m-3, as well as NPK in 1.0 kg m-3 of substrate. The adopted mixture form was based on a cubical substrate volume or individually for each container. A destructive analysis was done 12 weeks after emergence, evaluating leaf number, plant height, stem diameter, aerial, radicular system and total dry matter. The results indicated that, during the nursery phase, the reduction of container volume caused a reduction in dry matter, diameter and height. The leaf number, aerial and total dry matter was similar in seedlings under fertilization with NPK independent of container volume, which did not occur in those under FLL, where this parameter decreased with container volume. The calculated Dickson Index indicated superior values in seedlings with the conventional mixture form in relation to the individual one, and the biggest one in those under fertilization with NPK compared to the ones under FLL.
Container volume; Slow release fertilizer and Forest seedlings
