Growth of Chrysanthemum Cultivars as Affected by Silicon Source and Application Method

Abstract

The effect of different silicon (Si) sources and methods of application on the growth of two chrysanthemum cultivars grown in a soilless substrate was investigated. Rooted terminal cuttings of Dendranthema grandiflorum ‘Lemmon Eye’ and ‘Pink Eye’ were transplanted into pots containing a coir-based substrate. A nutrient solution containing 0 or 50 mg?L -1 Si from calcium silicate (CaSiO₃), potassium silicate (K₂SiO₃) or sodium silicate (Na₂SiO₃) was supplied once a day through an ebb-and-flood sub irrigation system. A foliar spray of 0 or 50 mg?L -1 Si was applied twice a week. Cultivar and application method had a significant effect on plant height. Cultivar, application method, and Si source had a significant effect on plant width. Of the three Si sources studied, K₂SiO₃ was found to be the best for the increasing number of flowers, followed by CaSiO₃ and Na2SiO₃. In both the cultivars, sub irrigational supply of Si developed necrotic lesions in the older leaves at the beginning of the flowering stage as compared to the control and foliar spray of Si. Cultivar, application method, Si source, and their interactions had significant influence on leaf tissue concentrations of calcium (Ca), potassium (K), phosphorus (P), magnesium (Mg), sulfur (S), sodium (Na), boron (B), iron (Fe), and zinc (Zn). The addition of Si to the nutrient solution decreased leaf tissue concentrations of Ca, Mg, S, Na, B, Cu, Fe, and Mn in both cultivars. The greatest Si concentration in leaf tissue was found in ‘Lemmon Eye’ (1420 μg?g -1 ) and ‘Pink Eye’ (1683 μg?g-1) when K₂SiO₃ was applied through a sub irrigation system and by foliar spray, respectively.