Analysis of the effect of ultrasound on Hymenaea courbaril L. seeds / Análise do efeito do ultrassom em sementes de Hymenaea courbaril L

Hymenaea courbaril L. popularly known as Jatobá is a native species of the Amazon. We selected 100 seeds for the morphometric analysis, for the water content of the seeds, four samples of 5 g each were used, for the germination test, four groups of seeds were evaluated: control group without ultrasound application and three other groups that were submitted to ultrasound application for 2 minutes (U2), 3 minutes (U3) and 4 minutes (U4) at a frequency of 3 MHz and an intensity of 2 W/cm² of exposure. Each group divided into four repetitions of 25 seeds each, were transferred to an incubator (B.O.D.) with a photoperiod of 12 h of light per day and 100% relative humidity, each group being repeated twice and tested at two temperatures (30 °C and 35 °C). The seed has 9.36% fresh mass, 23.62 mm, 14.1 mm, 65.59 mm in length, width, and perimeter respectively and 79.03% purity. The ultrasound waves applied for 3 minutes favored seed germination of 86.12% (30 ºC) and 83.04% (35 ºC) and mean germination time of 21.75 days (30°C) and 21.81 days (35°C) for two and three minutes respectively. Therefore, the ultrasound technique is considered useful and promising tool for breaking tegumentary dormancy in Jatobá seeds.