EFEITO DA TEMPERATURA E ESCARIFICAÇÃO SOBRE A GERMINAÇÃO DE SEMENTES DE Caesalpinia pulcherrima

Abstract

The objective of this study was to evaluate the effect of temperature and scarification on the germination of Caesalpinia pulcherrima (L.) Sw seeds, and to determine the seedlings biometrics. The treatments were: intact seeds submitted to a temperature of 25^oC (T1) and 35^oC (T2), mechanically scarified under 25^oC (T3) and 35^oC (T4) and chemically scarified 25^oC (T5) and 35^oC (T6). Germination seeds (%) were determined, and the roots length and diameter were measured, and the aerial part length. Dormancy breaking methods, at both temperatures tested, were efficient, with germination close to or equal to 100%. The isolated temperature effect was observed in the intact seeds, because the seeds exposed to 35^oC showed an increase of 126% in the germination of C. pulcherrima seeds, in relation to those submitted to 25^oC. In scarified seeds, the root diameter of seedling did not differ between treatments (equal to or greater than 1.75mm), regardless of temperature. Both the radicle length and the aerial part were superior to the other treatments after T4. The scarification methods and temperatures tested are efficient to increase the germination of C. pulcherrima seeds, however there was greater growth of seedlings in T4, especially in aerial part.