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On-line version ISSN 1806-9088
AGUIAR, Francismar Francisco Alves et al. Seed germination and seedling growth of Caesalpinia echinata Lam. (Brazilwood): shading effect. Rev. Árvore [online]. 2005, vol.29, n.6, pp. 871-875. ISSN 1806-9088. http://dx.doi.org/10.1590/S0100-67622005000600005.
Caesalpinia echinata Lam. (Brazilwood), Brazil's national tree, has ornamental potential, and due to years of exploitation this species has been reduced on the verge of extinction. This study was aimed to evaluate seed germination and seedling growth of brazil wood under shading conditions. The experiments were conducted at the IBt/SMA Ornamental Department, São Paulo-SP. Seeds were harvested from ripe fruits, from trees of the experimental arboretum of brazilwood at Mogí-Guaçu-SP. The germination tests were carried out in 1999, 2000 and 2003 with 4 replicates consisting of 25 seeds, the germination percentage and the speed germination index (SGI), subjected to five shading levels (0%, 20%, 40%, 60%, 80%) were evaluated. Nine-month-old brazilwood seedlings were submitted to the same shading treatments and the analyzed variables were seedling heights, stem base diameters and number of leaves. The experimental design was completely randomized with four replicates, and each experimental unit consisted of 24 plants, totaling 96 plants. The obtained results showed that shading levels did not the affect seed germination percentage and SGI. The stem base diameters were not statically significant for full sunlight, 20 and 40% of shading, but they were significant for the treatments with 60 and 80% of shading.
Keywords : brasilwood; germination; growth; shading.