Avaliação do tempo de imersão de sementes em ácido sulfúrico para quebra de dormência tegumentar da Millettia stuhlmanii (Taub.) (Jambirre)

Abstract

M. stuhlmannii is exploited at unsustainable levels, and a rapid depletion of the species is occurring. It has slow growth and development (60 years). On the other hand, this species exhibits seed coat dormancy. The present study aimed to evaluate the effect of 98% sulfuric acid at different incubation periods on overcoming dormancy in M. stuhlmannii. The study was conducted in a completely randomized design with four treatments: T1 – control, T2 – incubation in sulfuric acid for 10 minutes, T3 – incubation in sulfuric acid for 20 minutes, and T4 – incubation in sulfuric acid for 30 minutes. After scarification, the seeds were placed to germinate for 30 days in cups with a previously sterilized coarse area. The germination rate (PG%), germination speed index (GSI), mean germination time (MGT), and mean germination speed (MGS) were evaluated, and intact and deteriorated seeds were expressed as a percentage. Chemical scarification with 98% sulfuric acid in the tested periods was not efficient in breaking seed coat dormancy of M. stuhlmannii, although significant differences were observed in the germination percentage (PG) and germination speed index (GSI) parameters. With these results, it is suggested to test shorter periods and lower concentrations, as well as other methods for breaking seed coat dormancy of the species under study for the production of you change faster than normal.(TRADUÇAO NOSSA)