Avaliação de diferentes tratamentos pré- germinativos e biometria em sementes de Mimosa ophtalmocentra Mart. ex Benth.

Abstract

Seed dormancy is common in many species of the Caatinga, and tegumentary impermeability is one of the main factors that prevent water absorption. Thus, the objective of this study was to determine the best method for overcoming dormancy and biometry of seeds of jurema-de-imbira (Mimosa ophthalmocentra Mart. ex Benth.) in the Cariri region of Paraíba. The study was carried out at the Laboratory of Plant Anatomy and Physiology (LAFIV/CDSA/UFCG). The seeds were collected from adult matrices located in the Goiânia site, rural area of Itapetim - PE. Seven pre-germinative treatments were used for dormancy tests: T1: intact seeds immersed in water for 48 hours; T2: topping and immersed in water for 48 hours; T3: intact seeds immersed in water for 24 hours; T4: topping and immersed in water for 24 hours; T5: lopping; T6: manual scarification with sandpaper #80 opposite the hilum and T7: intact seed - control. The following parameters were evaluated: emergence (%), emergence speed index, seedling length (cm) and seedling dry mass (g). The experimental design was completely randomized, with four replicates of twenty-five seeds for each test. For the biometric data, the averages of length, width and thickness were calculated, which presented averages of 3.37 mm, 2.83 mm and 0.51 mm, respectively. Regarding the physiological quality data, it was observed that topping followed by immersion in water for 24 hours (T4) was the treatment that promoted the best results for emergence, emergence speed index and seedling length with values of 57%, 2.72 and 11.2 cm, respectively. For the dry mass data, it was observed that the treatments intact seeds immersed in water for 48 hours (T1) and (T4) topping with immersion in water for 24 hours were those that promoted the highest levels. On the other hand, the treatment topping and immersion in water for 48 hours (T2) did not present any emergence. Thus, (T4) topping followed by immersion in water for 24 hours is, considering the evaluated treatments, an adequate method for overcoming dormancy of M. ophthalmocentra seeds in the Cariri region of Paraíba.