Emergência e crescimento inicial de plântulas de Swietenia macrophylla (King) em função da posição da semente e presença do endocarpo

Abstract

Mahogany (Swietenia macrophylla King) is a high economic potential Meliaceae found in an upland forest of the Brazilian Amazon, one of the most exploited species in Brazil and because of that is endangered. The study aimed to evaluate the effect of sowing position and presence of endocarp in the emergence and initial growth of S. macrophylla seedlings. The design was completely randomized with four replications of 25 seeds, arranged in a factorial 3 × 2 (positions and endocarp). The treatments consisted of different positions of the seed on the substrate with reference to the germ pore: 0° – germ pore turned up – PGC; 90° – germ pore turned to the side – PGL; 180° – germ pore turned down – PGB. Were evaluated: the percentage of emergency, emergency mean time, stem diameter, number of leaves, shoot height, root length, dry weight of shoot and root dry mass. The seed positions affect the percentage and the mean time of seedlings emergency of S. macrophylla. The position 0º provides greater emergence rates and lower mean time of emergency. To encourage the emergence and initial growth of S. macrophylla seedlings, sowing should be performed with the seed germination pore turned up without the presence of endocarp.