Biometric characterization, post-seminal development and overcoming seed dormancy of Albizia polycephala (Benth.) Killip ex Record

Albizia polycephala (Benth) Killip, popularly known as angico-branco, belongs to the Fabaceae - Mimosoideae family, is a pioneer species used for environmental restoration, ornamentation and urban afforestation. Biometric characterization is an important tool to provide information on the type of germination, in addition to describing the morphology of the seed, it stimulates studies inherent to taxonomy, ecology and seed technology. For the production of seedlings, the most used form of propagation of this species is through seeds. Therefore, with the establishment of protocols to overcome dormancy of forest species, the producer will be able to choose the most efficient method and also the one that best adapts to his reality, both commercial and technological, providing an increase in the number of species destined to compose the models for the recovery of degraded areas to be implemented. Based on this, the objective of this work was to carry out the biometric characterization of the seeds, describe the post-seminal stages and verify the best way to promote the germination of A. polycephala using pre-germination treatments to overcome dormancy. The work was carried out at the Laboratory of Phytotechnics of the Campus of Engineering and Agricultural Sciences (CECA) of the Federal University of Alagoas (UFAL). The differentiation and development of A. polycephala seedlings was measured. In the dormancy breaking trial, the following treatments were used: i) control (intact seeds); (ii) chemical scarification by immersing the seeds in sulfuric acid for 5 min, followed by washing in running water; iii) cut (cut) on the side opposite the micropyle; iv) immersion in hot water (80°C) and cooling for 24 h; v) immersion in distilled water (room temperature) for 24 h; and vi) immersion in distilled water (room temperature) for 48 h. The seeds were incubated in a germination chamber at a constant temperature of 30°C. The design used was completely randomized, with 4 replications of 25 seeds per treatment, and the means were compared by Tukey's test at 5% probability. At the time of installation of the experiment, the seeds had a water content of 12.4%, with an average of 10.3 mm in length, 7.42 mm in width and 2.46 mm in thickness. Germination is epigeous and seedlings are phanerocotyledon. The physical rupture of the seed coat from the bud treatment contributed to the increase in permeability to water and gases, thus benefiting the germination process. Thus, topping can be recommended to overcome A. polycephala seed dormancy.