Efeito da aplica??o de ácido giberélico no crescimento da palmeira-ráfia

摘要

Lady Palm is of great economic importance due its commercial interest. It is an ornamental plant growing in shadowy places, resistant to sun exposure and very appreciated for its beauty and ornamental value. Its commercial value is associated to plant height and shoot number. The aim of this work was to stimulate lady palm growth by applying the plant growth regulator gibberellic acid. Plantlets of R. excelsa approximately one year old were sprayed every 21 days (4 applications) with gibberellic acid solution at concentrations of 0; 75; 150; 225 and 300 mg L-1. The results showed that gibberellic acid was efficient in promoting the growth of the species and was statistically significant for petioles, leaf length and plant height. Petiole dry and fresh mass did not show any significant difference between treatments for stem diameter, with root dry and fresh mass having a higher value for the control than for the 225 and 300 mg L-1 treatments. Due to the higher height and leaf architecture changes observed, gibberellic acid can be used as a tool to stimulate Lady Palm growth, adding commercial value to the plantlets.