Impact of salinity and media on growth and flowering of a hybrid Phalaenopsis orchid.

摘要

The effects of water salinity (0.05, 0.40, 0.75, 1.10 and 1.40 dS/m of electrical conductivity (EC)) on plants of hybrid Phalaenopsis cv. TAM Butterfly grown in 100% fine-grade fir bark, or in a combination of 80% bark and 20% sphagnum peat, were investigated. In both media, flower diameter decreased slightly as salinity increased. Plants in bark had more flowers as salinity increased, but had fewer flowers than those grown in bark + peat. In either medium, salinity had no effect on the number of new leaves produced. As salinity increased, plants in bark had increasingly larger total leaf areas, with a maximum at EC=1.10 dS/m. The leaf area of plants in bark + peat was greater than that of those in bark, but was unaffected by salinity. Root freshmass was lower with increasing salinity in both media. Growing media had no effect on mineral concentration in the leaf. In bark, increasing salinity increased Ca and Na, but had no effect on the concentration of other minerals in leaves. As salinity increased in the bark + peat medium, leaf P, Fe and Cu decreased, K, Ca, Mg, Na and Zn increased, and leaf N was unaffected. Leachate from bark + peat had twice the EC and of a lower pH (4.9) than leachate from bark (5.7).