Pretreatments to overcome seed coat dormancy in Dimorphandra mollis

Dimorphandra mollis Benth. is a multipurpose tree species providing importa nt subsistence and economic benefits to rural communities of the Brazilian cerrado. Seeds of D. mollis were collected to test for germination followin g one of 24 pretreatments intended to overcome seed coat impermeability. Th e tests were conducted for 21 days at 28 degreesC under a 24-hour constant light regime. Seeds without a pretreatment resulted in only 4% germination while immersion in sulfuric acid for 45 min to 1 1/2 hours and mechanically scarifying the seeds with a file improved germination to over 90%. A sulfu ric acid treatment for 1 1/2 hours followed by a 2 hour water soak was the most efficient method of accelerating germination rate. Seeds exposed to su lfuric acid for longer than 1 1/2 hours showed marked decreases in viabilit y. Though several heat pretreatments with boiling water provided germinatio n responses of over 50%, fire was not successful in eliciting germination s ignificantly higher than the control. These results provide viable pretreat ment options for both large and small-scale reforestation efforts.