Influence of temperature and water on Paricá (Schizolobium amazonicum Huber ex Ducke - Leguminosae-Caesalpinioideae) seed germination

Paricá (Schizolobium amazonicum Huber ex Ducke) is a tree species of the Leguminosae-Caesalpinioideae botanical family. This species has been used in rehabilitation programs for of degraded areas and it has good acceptance at local timber markets as well. This study aimed to evaluate the effects of different water contents in the substrate and temperatures on germination of S. amazonicum. Seeds were immersed in sulfuric acid for 50 minutes in order to break the impermeability of the seed-coat. After this, they were seeded over Germitest paper rolls wetted with water contents (mL.g-1 paper) equivalent to 1.5, 2, 2.5 and 3 times the substrate mass without new water addition, and they were maintained in chambers at constant temperatures of 25, 30 and 35ºC. In addition to the germination percentage, the speed of germination index and length of primary roots and hypocotyl of normal seedlings were also evaluated. A completely randomized design was used with a 4x3 factorial. The best germination performance was observed at temperatures of 25, 30 and 35ºC combining with water contents of 2.5 and 3 times the paper mass. The germination speed was favored by temperatures of 30 and 35ºC as well as by the largest water content, which corresponded to 3 times the paper mass. The best results related to root and hypocotyl development were observed in treatments involving water content 3 times the paper mass at a temperature of 25ºC.

forest species; seeds analysis; water volume