Seeds of Schizolobium amazonicum present physical dormancy which can be broken through different scarification methods.  In this work, the effects of sandpaper and hot water seed scarification on physiological aspects related to seed germination and seedling quality were evaluated.  Seeds of S. amazonicum were scarified by (i) immersion in water at 100°C/2 min and (ii) by scrubbing seeds on sandpaper.  Non-scarified seeds were used as control.  The following variables were evaluated: tissue viability (by using tetrazolium test), germination rate, speed germination index (SGI), seed imbibition rate, endosperm depletion, and seedling emergence rate, uniformity and biomass accumulation.  Seeds from both treatments were equally dyed by tetrazolium.  Seeds scarified on sandpaper showed higher germination rate, higher SGI, faster seed imbibition and endosperm depletion than those scarified in water at 100°C/2 min.  Seeds scarified on sandpaper presented higher seedling emergence rate and emergence index, and their seedlings were more uniform and with greater biomass than those obtained after scarification in water at 100°C/2 min.  Therefore, scarification of paricá seeds on sandpaper is more efficient in promoting germination and production of uniform seedlings. 
Source