On-line version ISSN 1806-9088
BRANCALION, Pedro Henrique Santin; MONDO, Vitor Henrique Vaz and NOVEMBRE, Ana Dionísia da Luz Coelho. Chemical scarification to overcome dormancy on Colubrina glandulosa Perk. (Rhamnaceae) seeds. Rev. Árvore [online]. 2011, vol.35, n.1, pp.119-124. ISSN 1806-9088. http://dx.doi.org/10.1590/S0100-67622011000100014.
This work aimed to evaluate different immersion periods of Colubrina glandulosa seeds in sulfuric acid for overcoming dormancy. The experiment was divided into two phases. In the first, five seed lots harvested in different localities (two recently harvested and the others in 2004, 2005 and 2006), were chemically scarified in concentrated sulfuric acid for 30, 60, 90, 120 and 150 minutes. In the second phase seeds from recently harvested lots were immersed in acid for 20, 30, 40, 50 and 60 minutes. Germination of scarified in acid and non scarified seeds was evaluated daily (paper roll, 25ºC, darkness and four replicates of 25 seeds per treatment) and, with the data, germination percentage and speed were calculated. In the first phase means were compared by the Tukey test (P<0.05) and in the second the treatments were compared by regressive equations. Results showed that dormancy percentage varied among seed lots (higher intensity for recently harvested seeds) and that scarification in acid for a period between 30 and 90 minutes was favorable for overcoming dormancy. Germination was negatively affected when seeds were scarified for 120 or 150 minutes. In the second phase the maximum values of germination percentage and speed were obtained after immersion for 60 minutes. Based on such results, seed storage for 1 year and immersion in sulfuric acid for a period between 30 and 90 minutes can be efficiently used to overcome C. glandulosa seed dormancy.
Keywords : Forest seeds; Storage; Germination; Seed hardness; Impermeable seed coat.