Substratos e níveis de sombreamento na produção e qualidade de mudas de cedro (Cedrela fissilis L.).

Abstract

Aiming to understand the behavior of the C. fissilis species during the nursery stage, this study aimed to evaluate the response of this species to different substrata and shading levels in the semi-arid region of Brazil. Cedrela fissilis L., is a tree classified in the family Meliáceas, with a wide natural distribution, occurring in almost all forest formations of Central and South America, popularly known in Brazil, as; cedro, cedro rosa, it is found in most Brazilian biomes. The study was conducted at the Forestry Nursery of the Forest Engineering Academic Unit of the Rural Health and Technology Center of the Federal University of Campina Grande (CSTR / UFCG), Patos Campus. The experiment was distributed in a completely randomized design, 3x9 factorial scheme, with three levels of shading (70% 50% and 0%) and nine substrates, with five replications and four plants per sample unit, totaling 540 plants. The substrates were formed from soil (S), coconut powder (PC), charcoal rice husk (CA), vermiculite tailings (RV) and tanned bovine manure (EB) in the proportions of (S 70% + EB 30%, S 70% + CA 30%, S 70% + PC 30%, S 70% + CA 15% + EB 15%, S 70% + PC 15% + EB 15%, S 70% + RV 15% + EB 15%, S 70% + CA 7,5% + PC 7,5%+ RV 7,5%+ EB 7,5%) plus a commercial substrate Plantmax®. The plants kept at 70% shading, regardless of the substrate employed, provided the highest values of plant height, collection diameter, leaf area and dry mass of the seedlings. The 0% shading level had a negative influence on the growth and quality of the seedlings, which were favored by the 50% level of shading in the SCAEBsubstrates, SPCEB, because it had a higher IQD value. The use of carbonized rice hulls, coconut powder and vermiculite tailings has the potential to be used in the composition of substrates for seedling production of C. fissilis L.