Influence of light, natural ventilation and cultivation flask size on the growth and development of denphal (Orchidaceae)

Abstract

This study aimed to evaluate the growth of denphal orchid, in function of the light, micropropagation system and size cultivation flasks. The experimental design was completely randomized and treatments arranged in factorial scheme 2 x 2 x 2 with five replicates. Seedlings cultivated in vitro for 90 days, from the beginning of the experimental period, were removed to the flasks, washed and evaluated for the number of leaves, seedling height, diameter of the largest pseudobulb, number of the shoots and roots, length of the largest root and largest leaf, and fresh mass. Then they were planted in substrate (pink sphagnum + coconut fiber) and transferred to ex vitro environment. In order to investigate their increases, after 90 days the plants were evaluated for the same initial characteristics. The different light spectra weren’t decisive for the growth of denphal. The use of natural ventilation system in larger flasks was the factors that provided favorable conditions in promoting growth both in vitro and ex vitro cultivation.