Effects of K/Ca ratios of Nutrient Solution on Some Physiological Traits and Cut Flower Vase Life of Rose Cultivars (Capitol and Magic Red)

An experiment was conducted to investigate the effects of K/Ca ratios of nutrient solution on physiological traits, cut flower vase life and postharvest changes of rose. The main experiment was factorial based on completely randomized design with two cvs. of rose (Magic Red and Capitol), five K/Ca ratios in the nutrient solution (4:4, 6:4, 6:3, 8:3, 10:2) and three replications. Increasing the K/Ca ratio in the solution led to accumulation of K in the leaves but decreased the Ca concentration of the leaves. Furthermore, K/Ca ratio of the leaves was affected by K/Ca ratio of the nutrient solution and highest ratio of K/Ca was recorded for the leaves of plants fed with nutrient solution of 10:2 K/Ca ratio and the lowest K/Ca ratio of leaves was observed for plants which supplied with the nutrient solutions of 4:4 and 6:4 K/Ca ratios. The highest chlorophyll index was recorded for Capitol cv. and K/Ca ratios of nutrient solution had significant different effects on chlorophyll fluorescence. It was noted that rising K/Ca ratio caused lower longevity of cut flowers in both cvs. The highest necrosis of petals was occurred at 10:2 ratio of K/Ca and Magic Red cv. was more sensitive with the highest percentage of necrosis. The appropriate K/Ca ratio was obtained in the 6:4 ratio in terms of nutritional balance, reduced antagonistic effects of K and Ca, postharvest quality and more longevity of cut flowers.