Emergence and vigor of Cedrela fissilis L. seedlings in function of the sowing position and depth

Cedrela fissilis L. are Meliaceae, popularly known as cedro. This species is native to Brazil, and owing to its qualities for the timber industry, it is being exploited progressively at its place of occurrence until the point of exhaustion. It is now listed as a species under threat of extinction, making it necessary to carry out studies in order to help in its preservation. The objective of this work was to determine the effects of the position and depth of sowing on the emergence and vigor of C. fissilis seeds. The experiment was accomplished in an entirely randomized design, with four replications of 25 seeds in different positions in sand substrates: I – hilum pointing downwards (HD) and II – hilum pointing upwards, forming an angle of 90o in relation to the imaginary axis (HA). The tested depths were: 0, 1, 2, 3, 4 and 5cm. We evaluated the percentage emergence, index of emergence speed (IES) and length and dry mass of the seedlings. The sowing depth of 2.2cm in the position of the hilum pointing downwards provided seedlings with a better response for the percentage of emergence (66.18%). The depth of 2.17 and the position of the hilum pointing downwards were responsible for a higher emergence speed (IES). The seeds of C. fissilis should be sown with the hilum pointing downwards at a depth of 2.0cm.