Influência do sombreamento no crescimento de mudas de cumaru (Dipteryx odorata (Aubl.) Willd. - Fabaceae), cultivadas em viveiro

Abstract

This paper presents results of an experiment carried out in the nursery at the Tropical Silviculture Experiment Station of Inpa, in Manaus, Amazonas, Brazil, with Dipteryx odorata (Aubl.) Willd. seedlings. The objective was to assess the growth of the species in the nursery under different levels of shade. The experiment used fully randomised blocks with five treatments: two treatments with temporary shading which was removed later to provide full sun light (0%) and three treatments under shade (30%, 50% and 70%) using black polypropylene mesh. Stem diameter, height, root length, leaf, root, stem dry weights, shoot/root ratio and height/diameter ratio were assessed at three and five months after sowing. Height and root length were unaffected by shade levels at three and five months. Stem diameter was larger in full sun light, being statistically superior to the treatment with 70% shade, in both periods. Dry weight obtained under 70% shade was less than for other treatments at three months. At five months, there was a trend to increase dry weight as shade levels decreased. Smaller values of root/shoot ratio and height/diameter ratio were obtained in full sun. Dipteryx odorata, a species typical of the terra-firme (non-flooded) high forest, grows better under full sun light.