Influência de diferentes substratos na produção de mudas de flamboyant Delonix regia (Bojer ex Hook.) Raf

Abstract

Delonix regia is a forest element used in reforestation and in the forestation of squares, parks and streets of many Brazilian cities. The aim of this study was to evaluate different compositions of substrate for seedling production in the flamboyant, Delonix regia. The experiment was carried out at the Forest Nursery of the Federal University of Tocantins, Brazil. A completely randomised experimental design was used, with ten treatments and eight replications. The treatments under evaluation were: T1-Control (Commercial Substrate), T2-Commercial substrate + Coconut fibre (70:30), T3-Commercial substrate + Carbonised rice husk (70:30), T4-Commercial substrate + Coconut fibre (50:50), T5-Commercial substrate + Carbonised rice husk (50:50), T6-Commercial substrate + Coconut fibre (30:70), T7-Commercial substrate + Carbonised rice husk (30:70), T8-Commercial substrate + Coconut fibre + Carbonised rice husk (50:25:25), T9-Commercial substrate + Coconut fibre + Carbonised rice husk (25:25:50), and T10-Commercial substrate + Coconut fibre + Carbonised rice husk (25:50:25). Evaluations were made at 30, 60 and 90 days after planting. The parameters under evaluation were: root collar diameter (DC), height (H), ratio of height to diameter (H/DC), shoot dry weight (MSPA), root dry weight (MSR), shoot dry weight/root dry weight (MSPA/MSR) and Dickson Quality Index (IQD). At 90 days, T6 presented better results for the parameters: DC (4.60 mm), H (11.22 cm), MSPA (3.71 g), MSR (3.99 g), MST (7.71 g), and IQD (2.28). T5 achieved the best result for MSPA/MSR (0.974 g). The treatment consisting of 30% commercial substrate and 70% coconut fibre was therefore considered the best treatment for seedling production in Delonix regia.