Improving inflorescence quality of Oncidium 'Gower Ramsey' by calcium supplement.

The objective of this study was to investigate flower developmental stages of Oncidium 'Gower Ramsey' plants grown in various growing media after treatments of different calcium supplementation, either alone or together with a kinetin spray. The results indicated the growth of Oncidium pseudobulb was obviously enhanced and accumulated more nutrients inside when grown in rockwool medium. Compared with other treatments, Oncidium plants in rockwool developed the healthiest and largest pseudobulbs with a fresh weight of 31.0 g, total soluble sugar and starch contents of 45.1 and 35.5%, respectively. Supplementation of calcium nitrate at 300 mg/L greatly improved inflorescence quality of Oncidium with highest stalks and most florets in contrast with other calcium treatments. In addition, calcium supplement plus a kinetin spray at 100 mg/L slightly improved inflorescence quality with more branches and flowers as well.