Effects of some mechanical and chemical treatments on seed germination of Sabal palmetto and Thrinax morrisii palms.

Abstract

Sabal palmetto and Thrinax morrisii, Arecaceae, are important ornamental palms of socioeconomic importance. Experiments using physical, mechanical and chemical pre-sowing treatments were conducted to determine the germination response of these two palm species. Among various treatments, soaking of Sabal seeds in 500 ppm gibberellic acid (GA3) for 24 h resulted in a highest final germination percentage (FGP) of 95% in day 14 of culture and number of days lapsed to reach 50% of FGP (GT50) of 6.8 days. Nontreated Sabal seeds exhibited FGP of 75% in day 16and GT50 of 7.39 days. Soaking of Thrinax seeds in H2SO4 for 30 min resulted in a highest FGP of 90% in day 14 of culture and GT50 of 5.19 days. Non-treated Thrinax seeds exhibited FGP of 70% in day 16 and GT50 of 8.07 days. The results indicate that Thrinax seeds exhibit exogenous dormancy which is entirely imposed by the hard seed coat, whereas the Sabal seeds exhibit both exogenous and physiological dormancy.