Efeito da luz no crescimento de mudas de Hymenaea parvifolia Huber

摘要

The objective of this work was to determine the effect of light intensity on the growth of Hymenaea parvifolia Huber seedlings as well as to infer on their degree of shade tolerance. Thus, an experiment was carried out in a completely randomized design, with four treatments (light levels): full sun (FS), 50% shading, 70% shading and natural shading (NS). The 50% and 70% shading levels were reached with the use of black polypropylene screens and the natural shading consisted of natural luminosity under a closed forest canopy. Each treatment had ten replications. Plants under 50 and 70% shading presented greater height, leaf area and leaf area ratio and few differences in dry mass accumulation, compared with plants kept under full sun. As a consequence, few differences were observed in the relative growth rate of the seedlings under these treatments. However, seedlings kept under natural shading showed lower relative growth rate and net assimilatory rate. The results as a whole showed that Hymenaea parvifolia was capable of adjusting itself to maximize the acquisition of light under very limiting conditions as that provided for natural shading and that the production of seedlings of this species can be carried out in nurseries under full sun and 50% or 70% shading.