Fruits and seeds biometry and pre-germination treatments in Cassia fistula L. (Fabaceae-Caesalpinioideae)

Abstract

This study aimed to characterize the morphology of fruits and seeds of Cassia fistula L. (Fabaceae) and study techniques, mechanics and physics as pre-germination of seeds of these species treatments. Measurements of length, diameter, thickness, fresh weight and number of seeds per fruit were taken at a sample of 100 fruits, selected at random from the lot of the municipality of Souza-PB. After extraction of seeds from fruits withdrew randomly sample of 100 seedlings for the determination of length, diameter, width, fresh weight, mass of 1,000 seeds and humidity. To overcome dormancy were used the following techniques: without scarification and scarified cheeks and side opposite to the hilum, and these mechanical treatments with and without soaking in distilled water for 12 to 24 hours, using 100 seeds per treatment divided in four replications. After application of the treatments, the seeds has been were sown in trays containing autoclaved sand. The effectiveness treatments measured by variables: first count, emergency, rate of emergence, mean time of emergence and length and dry weight of shoots and roots of seedlings. Fruits and seeds of C. fistula have, on average, 414 and 8.28 mm in length; 18.9 and 6.25 mm in diameter; 20.9 and 3.54 mm in thickness and; 67.3 and 0.1474 g of fresh, respectively. The scarification is efficient to overcome the dormancy of C. fistula, rising above 90 and 50% variables emergence and seedling growth, respectively. The soaking in water for 24 hours does not promote breaking dormancy. Scarification improves emergence and seedling vigor of C. fistula.