Supera？？o da dormência em sementes de paineira-branca

cotton-silk tree ceiba glaziovii (kuntze) k. schu belongs to family bombacaceas and is locally known as barriguda. it is widely used in landscaping and reforestation, neverdeless seed dormancy affects reproduction in this species. the objective of this study was to evaluate the effectiveness of different methods to overcome dormancy in the germination process. treatments included mechanical scarification with 85-grit sandpaper, chemical scarification with concentrated sulfuric acid for 5, 10, 15 and 20 minutes, physical scarification with hot water at 60o, 70o, 80oand 90o c for one minute, imbibition in distilled water for 24, 48 and 72 hours, oven heating at 65o c for 1, 2, 3 and 4 hours, and a control treatment. each treatment included four replicates of 25 seeds, using a completely randomized experimental design, and means were compared by the scott-knott test at the 5% probability level. assessed parameters included emergence percentage, emergence rate index, dry matter and length of plants. the most recommended treatments were mechanical scarification, immersion in sulfuric acid for 5, 10 and 15 minutes and immersion in distilled water for 48 hours.