Avaliação dos parâmetros morfológicos da qualidade de mudas de Paubrasilia echinata (pau-brasil) em viveiro florestal

Abstract

Paubrasilia echinata is a perennial species occurring in forests of Atlantic forest and has a dense and resistant wood, threatened with extinction due to its inadequate exploitation. Considering the economic and environmental importance, it is necessary to produce quality seedlings with good parameters, which show a uniform growth and a lower percentage of mortality in the field. Thus, the present work had as objective to perform a morphological analysis for quality of pau-brasil seedlings produced in the nursery of the Federal University of Sergipe, besides the adjustment of equations for estimation of Dickson’s Quality Index (DQI), dry shoot weight (DSW) and dry root weight (DRW) as an alternative to the use of destructive methods for the specie. Three evaluations were carried out biweekly with 50 samples of the 540 sapwood seedlings produced. The variables used were: diameter at neck height (DNH), height (H) and number of leaves (NL), dry and wet weight of 10 seedlings at each evaluation. We also tested 15 equations, aiming to generate the general model for all variables of interest. For the DAC and H, the seedlings obtained values above 5 mm and 20 cm respectively. It was observed that the dry mass weight, in the DSW/DRW ratio, the mean value reached was 3.24 and the DQI was 0.53. The best equations for PMSPA and PMSR, respectively, were at 12 and 15. According to the morphological parameters presented, the pau-brasil seedlings are suitable for planting even though it presents a low DQI.