Effect of fulvic acid and iron nano-chelate on improving growth characteristics and leaf elements content of gerbera (Gerbera jamesonii L. ‘Dune’)

Gerbera is one of the most beautiful and popular commercial cut flowers in the world and has taken the fourth place among this group of flowers. Considering the importance of flowers and ornamental plants, it seems necessary to improve the quantity and quality of these plants. A factorial experiment was conducted to investigate the effect of different concentrations of fulvic acid and iron nano-chelate on the morphological characteristics and the amount of leaf elements of Gerbera jamesonii ‘Dune’, based on a completely randomized design with two factors and three replications. The treatments included fulvic acid in 4 concentrations of 0, 50, 100 and 250 mg L-1 as drench and iron nano-chelate in 4 concentrations of 0, 1, 2 and 4 g L-1 as foliar application that applied in pot and in hydroponic conditions. The characteristics measured in this research were: the number of leaves, fresh and dry weight of leaves and roots, root volume, vase life and absorption rate of some nutrients. The results of the research showed that with the increase in the concentration of iron nano-chelate and fulvic acid, the number of leaves increased, so that the maximum number of leaves was obtained at the concentration of 250 mg L-1 of fulvic acid and 4 g L-1 of iron nano-chelate. Iron nano-chelate treatment alone caused an increase in leaf fresh weight, but this increase was significant only at a concentration of 4 g L-1 compared to the control. Root fresh weight was significantly increased in all fulvic acid and iron nano-chelate treatments. The root volume also increased with the application of different concentrations of fulvic acid, but its increase was significant only at the concentration of 100 mg L-1 of fulvic acid compared to the control. The amount of potassium absorption decreased with the increase in the concentration of iron nano-chelate and fulvic acid. Phosphorus absorption at a concentration of 250 mg L-1 of fulvic acid and iron and zinc absorption at a concentration of 2 g L-1 of iron nano-chelate with 50 and 250 mg L-1 of fulvic acid reached their maximum, respectively. The results of this research showed that fulvic acid and iron nano-chelate improve the growth characteristics of gerbera by affecting the optimal absorption of elements.