DORMANCY-BREAKING, GERMINATION, AND PRODUCTION OF SEEDLINGS OF Mimosa bimucronata (DC.) KUNTZE

Abstract

Mimosa bimucronata is a pioneer, easily adapted, fast growing species used in restoration programs. The objectives of this study were to experimentally compare (1) methods for dormancy-breaking; (2) suitable temperature and substrate for germination; and (3) suitable light intensity and substrate volume for seedling production. In the first two experiments, the variables percent of germination, speed of germination and average germination time were analyzed. In dormancy test, seeds were submitted to ten methods divided in three groups: hot water, sulfuric acid, and control. In the second experiment, effects of five different temperatures and four substrates were evaluated. In the third experiment, morphometric and biomass variables of seedlings were evaluated in two substrate volumes and two light intensities. The most effective method for breaking dormancy was hot water at 80 ° C for 1 minute with post-treatment immersion in water at room temperature for 24 hours. The most suitable substrates and temperatures for germination were germitest paper at 25-35°C alternating temperatures and sand at constant 30°C. The most adequate volume of substrate for seedling production was 280 cm³ in both 50% shaded and full sun conditions.