Alternative substrates to substitute xaxim in the cultivation of the primary hybrid Miltonia regnellii Rchb. f. X Oncidium concolor Hook. (Orchidaceae)

Abstract

The paper had the purpose of evaluating root formation and vegetative development of the acclimatized plants of the primary hybrid Miltonia regnellii Rchb. f. X Oncidium concolor Hook., using alternative substrates to substitute xaxim. Seedlings, with approximately eight months, obtained by in vitro culture with medium height of 6.4 ± 0.5 cm, were grown up in greenhouse with 60% of shadowness, using pots of polipropilene number one, containing the following substrates as treatments: XD= defibered xaxim (control); PBC= sugar cane bagasse powder; PBC:I= sugar cane bagasse powder: estruted polystyrene (1:1, v:v); PBC:E= sugar cane bagasse powder: sphagnum (1:1, v:v); PBC:PC = sugar cane bagasse powder: husk pinus (1:1, v:v); CP= coconut powder and PBC:PC= coconut powder: sugar cane bagasse powder (1:1, v:v). The experimental design was randomized blocks, with seven treatments, and ten replications. Growing parameters evaluated after 12 months were: height of above ground part (APA), length of the heigher pseudobulb (CMP), diameter of the heigher pseudobulb (DMP), length of the heigher root (CMR), number of roots (NR), number of buds (NB), total fresh mass weight (MFT) and substrate pH. All the studied substrates, except the sugar cane bagasse powder with sphagnum, can be recommended to substitute xaxim on the hybrid Miltonia regnellii Rchb. f. X Oncidium concolor Hook. crop.