Effects of extraction methods and pretreatments for germination on the physiological quality of Cassia carnaval Speg. seeds

Abstract

Parameters related to fruits and seeds, and related to the manual and mechanical extraction of Cassia carnaval seeds were determined. The seeds obtained by those two extraction methods were submitted to the following pretreatments for germination: immersion in distilled water for 6, 12 and 18 hours under normal temperature of laboratory; immersion in boiling water for one, two and three minutes; mechanical scarification (a cut of the tegument in the position opposed to the radicle) and mechanical scarification followed by immersion in water for 20 minutes. After the treatment, the seeds were sowed in sand and the germination tests were carried out at 30ºC, with photoperiod of eight hours a day. The seeds physiological quality was represented by the percentage and speed of germination. It was suggested that the improvement of the equipments and of the techiques can make possible the mechanical extraction of the seeds, in substitution to the manual extraction. The results of the germination tests showed that (a) the seeds physiological quality was not affected by the tested extraction methods; (b) the immersion in boiling water caused a decrease of the seeds physiological quality; (c) the immersion in water under normal temperature of laboratory was not efficient to accelerate the germination; ( d) the mechanical scarification was the best treatment, increasing the speed of germination; (e) the immersion in water after the mechanical scarification did not favor the seed germination.