Germination of Ormosia arborea (Vell.) Harms seeds submitted to different pre-germination treatments.

Abstract

Ormosia arborea is a tree belonging to the Leguminosae-Fabaceae family. It is in extinction risk due to the continuous devastation of native forests. The production of seedlings of this species is difficult because the seed germination percentage is low in consequence of the hard seed coat. Thus, this study was conducted in order to evaluate the efficiency of pre-germination treatments to overcome the seed coat dormancy. The experiment consisted of five pre-germination treatments (scarification with sandpaper; scarification with sulfuric acid; water soaking of the seeds for 24 hours; water soaking of the seeds for 48 hours; control) combined with four substrata (between blotters; sand; vermiculite; sphagnum). The substrata were moistened with nystatin supension (0.2%). The seeds were treated with the fungicide Thiram. The experimental design was a completely randomized with four replications of 25 seeds. The control seeds and those submitted to 24 and 48 hours of water soaking did not germinate. The values of the germination percentage of seeds scarified with sandpaper and with sulfuric acid were respectively: blotter substratum: 98.67, 8 days after sowing (DAS) and 97.33, 27 DAS; sand: 65.33, 27 DAS, and 90.67, 22 DAS; vermiculite: 92.00, 27 DAS, and 90.67, 27 DAS; sphagnum: 98.67, 20 DAS, and 97.33, 8 DAS.Additional keywords: dormancy; scarification; germination substratum.