Phalaenopsis cultivation in different media. Part II. Nutrients and chlorophyll concentration in leaves and roots.

Effect of growing media on macro- and microelements, as well as on chloro- phyll concentration in Phalaenopsis orchids were investigated. In the years 2006-2008, an experiment on Phalaenopsis orchids cultivation was carried out. The plants were planted into New Zealand sphagnum moss, mixture of expanded clay pellets and New Zealand sphagnum moss (v:v = 1:1), or into expanded clay pellets only. Orchids were grown in translucent plastic pots. Total macro and micro elements concentration in leaves and roots were determined. Furthermore concentrations of chlorophyll a and chlorophyll b in leaves and roots were measured. Growing media exert a significant influence on the nu- tritional status of Phalaenopsis orchids. The highest concentration of magnesium, iron and copper was found in plants grown in expanded clay, less in orchids grown in the mixed medium and the least in plants grown in sphagnum moss. A higher concentration of nitrogen, phosphorus, potassium, calcium and manganese was found in leaves. In- versely, in roots, there was a higher concentration of magnesium, iron and zinc. Growing media did not affect chlorophyll concentration in leaves and roots of Phalaenopsis.