Biotemas (Jun 2012)
Breaking the tegument dormancy of Senna silvestris (Vell.) H. S. Irwin & Barneby seeds
Abstract
Senna silvestris (Vell.) H. S. Irwin & Barneby is a tree native to Brazil that has the potential to be used in urban forests and has seed coat-imposed dormancy. Considering the need to better understand native forest species, and more specifically the processes of overcoming seed dormancy, the objective of this study was to verify the behavior of S. silvestris seeds exposed to sulfuric acid (98%), over different time periods (0, 0.5, 3.0, and 5.0 minutes), using four replications of 25 seeds and a completely randomized design. The parameters evaluated were the following: emergence percentage, mean emergence time, emergence rate index, and mean emergence rate of seedlings. The results of the experiment revealed that soaking the seeds in sulfuric acid between 0.5 and 5 minutes led to the highest emergence percentage, which was statistically equal for the seeds soaked in acid and different from the control treatment (0 minutes). There was a moderate positive correlation between emergence percentage and the emergence rate index of the different exposure times. It is therefore recommended that the chemical scarification with concentrated sulfuric acid be between 0.5 and 5 minutes to break the dormancy of S. silvestris seeds.doi: 10.5007/2175-7925.2012v25n2p25Biotemas, 25 (2): 25-31, 2012
