Does the sowing depth affect crateva tapia l. seedling vigor?

The low seed germination index reduces the propagation of Crateva tapia L. Adequate sowing position and depth can maximize the stand and emergence speed of C. tapia seedlings. The objective of this study was to determine the adequate position and depth of sowing for emergence and growth of C. tapia seedlings. C. tapia seeds were sown in plastic trays containing sterile sand. Sowing at the depths of 0, 1, 2, 3, 4 and 5 cm were performed in three positions (upward, downward and side-facing hilum). The emergence, first counting, emergence speed index and seedling length were evaluated. The emergence percentage of C. tapia, with seeds in the position side-facing hilum, was higher at a depth of 3.4 cm. The emergence speed index reached the maximum for seeds sown at 3.7 cm deep and in the upwards hilum position. The seedling length reached the maximum with seeds sown upwards at 3.2 cm depth. The dry matter content reached the maximum with the seeds sown in the side-facing hilum position at 3.3 cm depth. The average depth of the substrate provided sufficient moisture for the seed to rehydrate its tissues and achieve maximum emergence when sown in the side-facing hilum position. The higher emergence speed and seedling length obtained with the hilum upwards position is attributed to the fact that this position and depth provide absorption and distribution of water by the seed, increasing seed volume and tegument rupture for the seedling development. The higher dry matter content obtained when sowing was performed at the depth of 3.3 cm and the side-facing hilum position is due to the higher seedling growth when the seeds were placed under optimal depth and position conditions. C. tapia L. seeds can be sown at depths ranging from 3.2 to 3.7 cm with the side-facing or upwards hilum position.