Growth of tamarind seedlings in different levels of shadowing and substrate composition

ABSTRACT Tamarind (Tamarindus indica L.) is a species with promising potential for commercial production; therefore, studies involving practices of conducting culture in the initial stage are essential. The present study aimed to evaluate different shading levels and substrate compositions in the seedling production of tamarind. The experimental design was completely randomized in a 4×4 factorial scheme, four levels of shading (0%, 18%, 30%, and 50%) and four substrates (pine bark-based substrate pure and mixed with 50% vermiculite, and sphagnum peat-based substrate pure and mixed with 50% vermiculite), with four replicates of four seedlings. Growth and biometric relationships were evaluated at 40 and 98 d after transplantation (DAT). The results reported that seedlings formed on the sphagnum peat-based substrate on pure or associated with vermiculite at 98 DAT had a height greater than 35 cm and a total 8.5 g DM. In contrast, seedlings produced in pine bark-based substrate did not reach 20 cm in height and had less than 3 g total DM. The condition of 30% and 50% shading promoted greater growth in height, reaching an average height greater than 40 cm, while in the full sun environment, seedlings showed an average of less than 35 cm; however, for the other variables, full sun environment did not differ from 30% shading, producing good quality seedlings. Thus, the cultivation of seedlings in an environment with 0% or 30% shading, associated with the sphagnum peat-based substrate pure or mixed with 50% vermiculite promoted the production of tamarind seedlings with vigorous growth. In the best environments, the best substrates increased, on average, 41.3% number of leaves, 80.5% shoot dry mass, 56.8% root dry mass, and 71.0% total dry mass. In the best substrates, the best environments increased, on average, 18.0% number of leaves, 20.7% shoot dry mass, 8.7% root dry mass, and 14.3% total dry mass.