Ex Vitro Acclimatization of Laelia halbingeriana Plants Grown in Different Media and Fertilization Doses

In vitro plants of the orchid Laelia halbingeriana were obtained fromseed germination. The plants were grown and established in differentorganic substrates mixes. The substrates resulted from the mix ofcompost and charcoal, land of mount and Holm oak bark, and peat andvolcanic tuff. The plants were fertilized with four levels of nitrogen(0, 10, 30 and 50 mg L-1). Six months after the establishment, 64.84%to 80.22% of the plants were adapted to the climate conditions. Thehighest survival rates in plantlets were obtained in the adaptationconditions using peat-volcanic tuff and nitrogen doses of 30 and 50 mgL-1. These plants had an average of 8.01 cm height, 5.15 leafs, 2.66pseudo-bulbs, 77 to 89 mg of total accumulated dry matter, and 42 to45% of C in leaves and pseudo-bulbs. The fertilization had asignificant effect (P <= 0.05) on the plants growth and a highlysignificant effect (P <= 0.01) on number of leaves, width of the majorleaf and the number of pseudo-bulbs; The interaction substrates andfertilization had a highly significant effect (P <= 0.01) on thenitrogen content in leaves and pseudo-bulbs.