Effect of potassium and calcium concentration in the nutrient solution on growth and nutrient uptake of rose plants

In order to make clear a relationship between plant growth and nutrient uptake, the effect of K and Ca concentration in the nutrient solution on growth and nutrient uptake of rose plants was investigated. Potassium and Ca uptakes were greater in higher concentrations, but the concentration in the solution did not affect the growth of rose plants. The amount of K uptake per 100 g FW increased from 0.32 to 0.47 g when K concentration increased from 25 to 200 ppm. The average amount of N uptake per 100 g FW was 0.66 g. The amounts of P and Mg uptake per 100 g FW averaged for all K treatments were 0.09 and 0.08 g, respectively. Calcium uptake decreased from 0.16 to 0.11 g per 100 g FW when K concentration increased from 25 to 200 ppm. Increasing the Ca concentration in the solution from 20 to 160 ppm led to an increase of Ca uptake from 0.12 to 0.20 g per 100 g FW. The amounts of N, P and K uptake per 100 g FW averaged for all Ca treatments were 0.47, 0.10 and 0.50 g, respectively. However, Mg uptake decreased from 0.06 to 0.03 g per 100 g FW as Ca concentration increased from 20 to 160 ppm. Rose plants should be fertilized on the basis of this relationship between growth and nutrient uptake.