Efeito do substrato na germinação e crescimento em Adenium Obesum (rosa-do-deserto)

Abstract

Adenium obesum popularly known as mock azalea, impala lily and Desert Rose is an angiosperm species which belongs to the family Apocynaceae. It is widely used as an ornamental plant, but, in non-natural habitat it lacks a pollinator. Germination is a physiological phenomenon and is influenced by environmental factors such as temperature, light and substrate. The substrates used have influence on the germination time, since factors such as aeration, structure, water retention capacity and degree of infestation by pathogens can vary from one substrate to another. The present work has the objective of evaluating the ideal conditions in relation to the substrates used in the germination of the Adenium obesum seed. The seeds used were seeded on coarse sand (A), vermiculite (B), Bioplant® (C) and a mixture of 50% Bioplant® and 50% sand (D). Germination tests was carried out during 20 days, from May 9, 2019 to May 28, 2019, being observed every three days. After the evaluation of the tests on different substrates, it was observed that only the coarse sand substrate presents a lower capacity for germination (60%), height (1.01cm) and germination speed index of (0.144). The best result was that of Vermiculita, which presented 95% germination, higher seedling height (2.94 cm) and better germination index (0.228), which is almost double the value over the lowest measure. From the data performed during the period evaluated the results presented by the compound vermiculite were the most satisfactory substrate either in germination and growth rate.