NURSERY GROWTH OF Pinus cembroides ZUCC. IN DIVERSE SUBSTRATES AND FERTILIZERS

Abstract

Substrates based on raw pine sawdust and composted pine bark, with controlled-release fertilizers, are an alternative for producing forest plants in nurseries. The aim of this study was to evaluate the effect of substrate, controlled-release fertilizer (FLC) and water-soluble fertilizer (FH) on the growth of Pinus cembroides Zucc. in nursery. The mixtures evaluated were composted pine bark (P. douglasiana Martínez), raw pine sawdust (P. engelmannii Carr., P. cooperi Blanco and P. durangensis Martínez) and peat moss (Sphagnum sp. ): M1 (60:0:40), M2 (35:30:35), M3 (25:50:25), M4 (15:70:15), with three fertilization schemes based on selected combinations of doses 0, 4 and 8 kg m^–3 of FLC (Multicote®), and 0.0, 0.5 and 1.0 g L^–1 of FH (Triple 19® of N, P and K). The experimental design was completely randomized with a 4 x 3 factorial arrangement. The variables evaluated were: height, diameter, total biomass, Dickson’s quality index, root volume (VR) and concentration of N, P and K in the foliage. The mixture of substrates and the fertilization scheme significantly affected (p≤0.0001) the variables studied. The seedlings with greater height and total biomass were those treated with 4 kg m^–3 FLC plus 0.5 g L^–1 FH. The largest diameter and VR were obtained with 8 kg m^–3 of Multicote®. In most variables, the lower values occurred when only raw pine sawdust was applied and in mixtures with a higher proportion of sawdust. In treatments containing FLC and FH, plants with higher morphological attributes were obtained, regardless of the substrate.