Tratamentos térmicos para a superação de dormência em sementes de uma espécie arbórea brasileira

Abstract

Enterolobium contortisiliquum (Vell.) Morong., known as tamboril, is a promising species in the recovery of degraded areas. However, it presents integument dormancy in its seeds and it is necessary to find methods to overcome it. Therefore, the present study aimed to evaluate the dry heat efficiency on the viability and vigor of E. contortisiliquum seeds, as an alternative and practical method for overcoming dormancy. The experiment was conducted in the house of vegetation of the Specialized Agricultural Sciences Academic Unit of the Federal University of Rio Grande do Norte. The fruits, obtained from different matrices located in the municipality of Macaíba-RN, were manually processed. The heat treatments obtained through a drying oven during five minutes used: 60 (T1), 80 (T2), and 105ºC (T3), the mechanical scarification (T0) of the seeds were used as a mediating treatment of the efficiency of the others. The emergency, first emergency count, and the emergency speed index were evaluated. Observing the results obtained, the best performance corresponded to the scarified seeds. The thermal treatments in dry heat were not efficient to overcome the dormancy of E. contortisiliquum seeds when compared with the traditional method of mechanical scarification. However, the methodology presents practicality in its execution which can be considered advantageous. Therefore, new studies with different combinations of time and temperature for the species are encouraged.