The black sucupira (Bowdichia virgilioides H.B.K.) trees have been declining in
numbers in their natural habitat, due to, amongst other reasons, the occurrence of seed dormancy
(water impermeability of the seed coat). The effect of the immersion time (0, 2, 5, 8, 11 and 14
minutes) of black sucupira seeds in concentrated sulfuric acid (95-98%) was evaluated through
the percentage and speed of seedlings emergence, height, ?colon? thickness, wet and dry weight
of the plants. The experiment were performed under nursery conditions with an experimental
design of completely randomized blocks, with six treatments and four replications, using eight
planted bags per experimental plot. The seeds were planted in plastic bags (3 seeds/bag) of an
organic soil. The height of the above ground part, ?colon? thickness, wet and dry matter of the
plants were recorded 30 days after planting. The pre-conditioning of the black sucupira seeds with
immersion in concentrated sulfuric acid, was efficient in overcoming seed dormancy, increasing
the percentage and speed of emergence, the ?colon? thickness, wet and dry matter of the plants.
The efficiency of this chemical treatment with concentrated sulfuric acid was shown to be dependent
on the immersion time, being eight to eleven minutes the most adequate immersion time.