Initial growth and quality of jussara palm seedlings cultivated in biosolid-based substrates

All palms present ornamental appeal and may be widely used in landscaping, especially the native ones because of their ecological importance, such as the jussara palm (Euterpe edulis Mart.). In this sense, aiming at maximum plant development in the urban environment, it is necessary to use high-quality seedlings; the substrate is one of the key factors that directly influence it. The objective of this study was to evaluate the initial growth of jussara palm seedlings cultivated in biosolid-based substrates, which is a material of good characteristics besides attending sustainability issues. The experimental design was entirely randomized with six treatments consisted of substrates composed by biosolid (BIO) and subsoil (SS) at different proportions (v:v): 100% SS - control; 20% BIO + 80% SS; 40% BIO + 60% SS; 60% BIO + 40% SS; 80% BIO + 20% SS; 100% BIO. Seedlings were cultivated in a greenhouse and evaluated according to the following variables: height of aerial part; root length; collar diameter; leaf number; dry mass of aerial part and of roots; total dry mass; chlorophyll content; height of aerial part/collar diameter rate; dry mass of aerial part/dry mass of roots rate; and Dickson Quality Index. There was a significant effect (p < 0.05) for all evaluated characteristics. The biosolid, combined with subsoil, may be used for 20% and 40% substrate composition, as it is potentially appropriate for jussara palm seedling production. Higher proportions were toxic to seedling growth.