Effect of Cultural Medium and Hydroponic Culture on Growth and Flowering Quality of Oncidium Gower Ramsey

Oncidium Gower Ramsey ‘Valcano Queen’ grew in rockwool, moss, and mixed medium containing crashed stone, fern chop and coconuts chop to test. The total fresh weight of plants which grew in rockwool was 60.9 g and pseudobulb thicker with fresh weight at 31.0 g gained higher weight compared to other treatments. The total soluble sugar (TSS) of pseudobulb which was part from plants cultured by rockwool showed TSS existed 43%, starch 32% respectively, compared to plants grew in mixed medium with four-folds in TSS, and 1.5 folds in starch. Consequently, Oncidium grew in rockwool promoted pseudobulb growth and accumulated storage of starch. Moreover, higher root activity presented in plants cultured in rockwool. The enrichment of calcium in cultured solution applied in fertigation, calcium nitrate 300 ppm could improved the quality of cut Oncidium, flower stalk length at 117.07 cm, 9.5 branches and 108 florets. Introduction Oncidium which is a tropical epiphytic orchid was original come from Spanish-America. Oncidium has special flower shape and rich of flower color. These characters of oncidium promoted oncidium industry had expandable potential in Taiwan. Pseudobulb is a major storage organ of oncidium. It will enlarge gradually with plant growth and development until reproductive growth. However, cultured medium will affect plant growth and development seriously, advance to affect flowering quality. The experiment cultured oncidium plantlets by various media, investigate the growth and development of oncidium during vegetative growth stage. Used various concentration of calcium supplement in rock-wool nutriculture system, investigate flowering quality of oncidium during reproductive stage.