Métodos para quebra da dormência das sementes de Leucaena leucocephala e Flemingia macrophylla

The aim of this study was to evaluate methods to effect seed dormancy breaking of Flemingia macrophylla (flemingia) and Leucaena leucocephala (leucena). The seeds were submitted to the following treatments: a) Manual scarification with sandpaper; b) Immersion in 98% H2SO4 for five minutes; c) Immersion in H2O at 80° C for 3 minutes; d) Preheating at 60 °C for 150 minutes; e) Potassium nitrate (KNO3 0.2%); f) Gibberellic acid (AG3 0.5%); g) Control (without breaking dormancy). For the seeds of flemingia, treatment with H2SO4 obtained a higher percentage of germination, followed by immersion in H2O at 80°C and manual scarification with sandpaper. Leucena seeds submitted to immersion in water at 80°C and H2SO4 showed a higher percentage of germination in relation to the other treatments. Thus, the use of hot water for leucena seeds and immersion in H2SO4 for flemingia seeds were the most adequate methods to overcome the dormancy of their seeds.