ABSTRACT
Stizolobium aterrimum, known locally as mucuna-preta, is a legume used in the recovery of degraded soils. However, dormancy has a negative impact on seed germination and establishment of the seedlings. The aim was to select treatments to eliminate dormancy in seeds of mucuna-preta, thereby accelerating and synchronising seedling emergence. The experiment was carried out in a completely randomised design with 10 treatments, each with four replications of 25 seeds. The treatments were a control (intact seeds), immersion in water heated to 60 ºC, mechanical scarification with an electric emery scarifier for one second in the distal region of the seed, and scarification with sulphuric acid (H2SO4 98%) for 5, 10, 15, 20, 25, 30 and 35 minutes. The evaluations were made with tests for seedling emergence, average time of emergence, speed of emergence index and relative frequency of emergence. Seedling emergence in mucuna-preta is increased, and the average time of emergence reduced by scarification in the distal region of the seed and immersion in sulphuric acid for periods of 5 to 35 minutes. Treatment with the acid for 10 to 20 minutes increases, accelerates and synchronizes seedling emergence in black mucuna, but 10 minutes will reduce the period of contact with the H2SO4.
Key words:
Stizolobium aterrimum; Hardness of the integument; Germination
