Effects of Light Intensity and Nutrient Solution Strength during Short Day Treatment on the Growth and Nutrient Absorption of Kalanchoe blossfeldiana 'Rako' in Ebb and Flow System and the Accumulation of Nutrients in Growing Medium

• Published in: Journal of Bio-Environment Control Vol. 20; no. 3
• Main Authors: Noh, E.H., Seoul National University, Seoul, Republic of Korea, Choi, J.M., Chungnam National University, Daejeon, Republic of Korea, Son, J.E., Seoul National University, Seoul, Republic of Korea
• Format: Journal Article
• Language: Korean
• Published: 01.09.2011
• Subjects: CONDUCTIVIDAD ELECTRICA; CONDUCTIVITE ELECTRIQUE; ELECTRICAL CONDUCTIVITY; nutrient composition; photosynthetic photon flux
• ISSN: 1229-4675

The objective of this study was to investigate the effects of light intensity and electrical conductivity (EC) of nutrient solution during short day treatment in an ebb and flow systems on the growth and nutrient uptake of potted Kalanchoe blossfeldiana 'Rako' and the nutrient accumulation of growing medium. Nutrient concentrations in the growing medium were also analyzed to investigate the accumulation rates of macro-nutrients such as T-N, P, K, Ca, and Mg, respectively. To achieve the objectives, plants were fed with a nutrient solution with 1.2, 1.8, or 2.4 dSㆍm-¹ under three daily photosynthetic photon flux (PPF) of 4.26, 5.51, or 9.75 molㆍm-²ㆍd-¹. Both light intensity and EC of nutrient solution significantly influenced the crop growth. The elevation of PPFs resulted in the increase of plant growth. For each light condition, plant growth, such as dry and fresh weight and leaf area, was the highest when the electrical conductivity of nutrient solution was controlled to 2.4 dSㆍm-¹. However, growth was acceptable in the EC ranges from 1.8 to 2.4 dSㆍm-¹. Both light intensity and EC of nutrient solution significantly influenced the uptake of nutrients in the solution tanks and the accumulation of nutrients in the growing medium. As the EC of nutrient solution was elevated, the absorption rates of NO₃-, PO₄-³, K+, and Mg²+ by crops and accumulation of those in growing medium increased, but the light intensity did not significantly influence the absorption rates. Based on the above results, the regression models were suggested for anticipating the macro-nutrient accumulations in growing medium.