Chemical and mechanical scarification on dormancy Adenanthera pavonina L. (Fabaceae: Mimosoideae)

Abstract

The Adenanthera pavonina seeds present dormancy caused by impermeability of water tegument. Aimed to determine the best methodology for the species dormancy superation, seeds were distributed within 25 units groups, in four Petri dishes and submitted to mechanical scarification  treatments by using metallic brush and scissors, on the hilum opposite region, and chemical, by using sulfuric (H₂SO₄) and chloridric (HCl) acids by 30 and 40 minutes. The experiment was conducted inside a B.O.D germination chamber under 25° Celsius degrees and 120 µmol.m^-2.s^-1. The collected data was used to calculate the Germinability (G%), Germination Velocity Index (GVI) and Deteriorated Seeds (DS%). The imbibition curve was also calculated to analyze the dormancy type presented by those seeds. The curve presents the triphasic model where the phase FI was completed in 3 hours and the FIII initiated after 12 hours of imbibition. The results showed that the pre-germinative treatments provide the A. pavonina germination, meaning that the 30 minutes sulfuric acid and scissors scarification revealed to be the most effective methods to overcome this species dormancy.