Substratos alternativos ao xaxim no cultivo do híbrido Cattleya intermedia X Hadrolaelia purpurata (Orchidaceae)

Abstract

The present work had the purpose of evaluating the efficiency of different substrates by vegetal origin, to grow species of orchids (Orchidaceae). Seedlings of Cattleya intermedia X Hadrolaelia purpurata, obtained by in vitro culture, and acclimated, with medium height of 5 cm, had the following substrates: 1 - Defibered xaxim (control); 2- Carbonized rice husk; 3- Coconut fiber; 4- Husk pinus; 5- Carbonized rice husk + Coconut fiber (1: 1); 6- Carbonized rice husk + Husk pinus (1: 1); 7- Coconut fiber + Husk pinus (1:1); 8- Husk pinus + Carbonized rice husk + Coconut fiber (1:1:1). A randomized design with eight treatments and ten replications. Results were submited to Variance Analysis and Tukey Test at 5%. Growing parameters evaluated after 17 months were: root length, roots number, height of above ground, buds number., leaves number, leaf length, leaf width, total fresh mass and root volume. Determinated substrates parameters were: pH, eletric conductivity and density. All studied substrates can be recommended to substitute xaxim but, coconut fiber was least efficient to develop roots and aerial parts of plants. Better results were showed by substrates only with carbonized rice husk + husk pine on culture of Cattleya intermedia X Hadrolaelia purpurata.