Silicon Fertilization Affects Growth of Hybrid Phalaenopsis Orchid Liners

Abstract

Experiments were conducted during two different time periods to determine if hybrid phalaenopsis orchid (Phalaenopsis spp.) liners accumulate silicon (Si) and if this element can affect liner growth. A total of 800 liners were evaluated and Si fertilization was performed by applying potassium silicate (KSiO3) as a drench with three treatments (0.5%, 1.0%, and 2.0% v/v) and a control (water, no Si fertilization). The application of KSiO3 affected overall growth of phalaenopsis orchid liners, where Si content of the plant ranged from 0.5% to 1.7%. Overall, Si applied at 0.5% and 1.0% increased fresh weight and dry weight (DW) and at 1.0% Si significantly increased DW of root, shoot, and whole plant over the control. Increases in DW ranged from 27% up to 118%. Results from the second experiment were similar. Other plant parameters evaluated such as leaf number and size, root number, and length were unaffected by Si application. Although leaves of phalaenopsis orchid liners treated with Si appeared darker green when compared with the control, no significant differences were observed in chlorophyll content of leaves. Reduced growth was observed when 2.0% Si was applied affecting Si tissue concentrations and substrate electric conductivity. The data obtained from this study indicate that hybrid phalaenopsis orchid liners are Si accumulators and that this element influences their growth. Further studies are warranted to address the long-term effects of Si fertilization on the complete life cycle of hybrid phalaenopsis orchids.