Biometric characterization and dormancy overcoming of seeds of Pithecellobium diversifolium Benth.

Abstract

Pithecellobium diversifolium Benth. it is a native shrub with wide occurrence in the states of Northeast Brazil. The growing interest in the propagation and cultivation of native forest species demands basic information about the biometric and germinative characteristics of their seeds for their propagation. With that, the objective of the work was to characterize the seeds and evaluate the germinative process of P. diversifolium submitted to dormancy overcoming methods. The experiment was conducted at the Vegetable Production Laboratory of the Federal Institute of Alagoas, located in the municipality of Piranhas-AL, where the seeds were collected. The physical characterization of the seeds was carried out, determining the water content, the weight of 1.000 seeds, and the length, width and thickness of the seeds. Five treatments were used to overcome dormancy: (T1) intact; (T2) mechanical scarification with sandpaper nº 80; (T3) fragmentation of the integument; (T4) immersion in water at 90 °C for 1 min; and (T5) immersion in water for 24 hours. The germination test evaluations were performed daily, for 26 days. The parameters evaluated were first germination count; germination percentage; germination speed index; shoot and main root length; dry mass of shoot and root. The completely randomized design was used with four replications of 50 seeds per treatment. In this way, the seeds have variability in their evaluated biometric characteristics, and mechanical scarification with sandpaper is the recommended method to overcome the dormancy of P. diversifolium seeds.