Effect of Silicon Source and Application Method on Growth of Kalanchoe 'Peperu'

Abstract

The effect of different source silicon (CaSiO3, K2SiO3, and NaSiO3) and their application methods (foliar application and subirrigation) on the growth of potted kalanchoe was investigated. Rooted terminal cuttings of Kalanchoe blossfeldiana 'Peperu' were transplanted into 10.5 cm plastic pots containing a commercial growing medium. Then, a nutrient solution, containing 0 or 50 mg.L-1 Si as K2SiO3, Na2SiO3, or CaSiO3 and adjusted to EC 1.4-1.6 mS.cm(-1) and pH 6.0, was supplied through subirrigation along with the nutrient solution or by a foliar application. Plants were grown in a glasshouse under a mean temperature of 23 degrees C and RH of 70-80%. After 12 weeks of cultivation, plant growth characteristics and leaf tissue contents of P, K, Ca, Mg, Na, S, and Si were measured. Both subirrigational supply and foliar application of Si decreased the plant height and flower stem length. However, the plant condition in the foliar application resulted in disease-like soft rot on the leaf. Among three silicon sources tested, CaSiO3 supplied through a subirrigation system increased shoot tissue contents of Si and chlorophyll as compared to the Na2SiO3 or K2SiO3 treatment. Shoot tissue contents of Ca, K, and Na increased when the plant was supplied with CaSiO3, K2SiO3, and Na2SiO3, respectively. Subirrigational supply of K2SiO3 and NaSiO3 decreased the shoot tissue contents of Ca and Mg, and K and Ca, respectively. Therefore, CaSiO3 supplied through a subirrigation system could improve plant quality of kalanchoe 'Peperu' making compact potted plants.