Efeito das secagens lenta e rápida em sementes de ipê-roxo (Tabebuia impetiginosa (Mart.) Standl.)

Abstract

This work studied the physiological answers of Tabebuia impetiginosa seeds to desiccation when dried at climatized room (20oC/40%RH) (slow dry) and at oven (38o C) (fast dry). At different times during slow and fast dry samples were taken for determination of the physiological quality which was done through the germination test, germination index speed and electric conductivity. The slow drying method reduced the water content from 51.33% to 6.33% in 840 hours of drying, under theses conditions the germination percentage was 53% and germination index speed of 1.37. During fast drying there was a faster reduction of the seed water content to a minimum of 1.87% in 240 hours, under these conditions the seeds had shown germination percentage of 47% and germination index speed of 1.78. Independently of the drying method used the electric conductivity reached a maximum value up to 37 hours and levels off thereafter. The drying methods used were efficient in reducing the water content of the seeds without interfering on seed quality. In addition, the results indicated that ipê-roxo seeds presented orthodox behavior during storage.