Influence of Additional Micronutrient Supply on Growth, Nutritional Status and Flower Quality of Three Rose Cultivars in a Soilless Culture

Abstract

ABSTRACT The effect of additional supply of iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) on three rose cultivars was investigated. Five fertilizer treatments were utilized: 0 (control), 150 μ mol Fe L− 1, 150 μ mol Fe + 10 μ mol Mn L− 1, 150 μ mol Fe + 10 μ mol Mn + 12 μ mol Zn L− 1, 150 μ mol Fe + 10 μ mol Mn + 12 μ mol Zn + 5 μ mol Cu L− 1. The results demonstrated significant variation among rose cultivars in developing Zn, Fe, and Mn deficiency symptoms and response to micronutrient supplies. For ‘Modern Girl’ and ‘Orange Juice’, all micronutrient treatments resulted in higher stem length and thickness as compared to the control. No significant increase in stem length was observed in ‘Aqua Fresh’. All cultivars had the greatest flower vase life in the added Zn treatments. All fertilizer treatments significantly increased Fe concentration in the leaves of ‘Modern Girl’ and ‘Aqua Fresh’ as compared to the control. The Fe-Mn-Zn-Cu treatment significantly increased leaf concentration of Mn, Zn, and Cu in all cultivars. Leaf sodium (Na) concentration was lower in the micronutrient treatments that included Zn addition as compared to the treatments that did not include added Zn. No visible mildew symptom was observed in the treatments with Zn addition. The results showed that genotypic variation and sufficient micronutrient supply are two key factors in success production of rose in the soilless culture. Furthermore, the results indicated the importance of Zn in enhancing the quality of the rose flower.