Desenvolvimento inicial de sangue-de-dragão (croton lechleri müll. arg.) sob diferentes classes de solos, corretivos e níveis de luminosidade na Amazônia centra

Abstract

The specie dragon s blood (Croton lechleri) having been calling international attention due the presence of an alkaloid in its latex called taspine known for its antinflammatory, antibiotic and cicatrizing properties, being largely used in the healing of gastric ulcers, diarrhea and different types of viruses. The latex indiscriminated extraction from native plants, elimination of specimens in cultivated areas ceding these areas for another kinds of crops, and the low occurrence of small populations in the north of Brazil (Rondônia and Acre States), shows that more researches are necessary for a viable domestication making possible the conservation of the specie and sustainable utilization. Due to the lack of studies about dragon s blood propagation in Brazil, an experiment was conducted with the objective of testing its viability in Amazon State, evaluating different soil classes and correctives under different luminosity levels, during the plant initial growing. The experiment took place in the Agricultural Science Researches Department Campus of the National Institute for Amazonian Research. The experiment was set up in a completely randomized design, in a factorial scheme 4x5x2, with three repetitions, compounded by the factors: Soil class (gleysoil, argisoil, yellow latosoil, Amazonian dark earth soil), soil chemical correctives (none, 50 mg of dolomitic calcareous, 20% of saw dust, 20% of aviary manure and 20% of saw dust plus 20% of aviary manure) and shading levels (none and 50%). The experimental block was compounded by ten plants. The data begun to be reported after the unfurling of the first true leaf and continued until the 140th after the sowing. In a 14 days interval, were determined morphological variables as, plant height from the base of the stem until the last leaf insertion in the stem apex, stem diameter and number of emitted leaves. Croton lechleri grows in a satisfactory way in places with 100% or 50% of photosynthetical active radiation. Results shows a tolerance to the more acid soils (latosoil and argisoil), however results shows a preference for more naturally fertile soils (gleysoil and Amazonian dark earth soil) or the fertilized ones with organic corrective rich in nutrients (manure). The gleisoil treatment fertilized with aviary manure exposed to full sun radiation and 50% of shading proportioned seedling with a better quality in a shorter period of time.