The effects of different nitrogen concentrations on plant growth, quality and physiological parameters of pelargonium (Pelargonium sp.)

In this study, the effects of different nitrogen concentrations on the growth, development, quality and physiological properties of the Pelargonium (Pelargonium graveolens L. Herit.) plant were investigated. To obtain uniform seedlings, cuttings from rootstock plants were transplanted into pots after rooting. Five different nitrogen concentrations (0, 50, 100, 200 and 400 mg l-1 N) were applied during three months in the experiment. Morphological and physiological parameters were evaluated in the study. At the end of the experiment, with the increase of nitrogen level, a decrease in plant height and internode length, and an increase in other vegetative parameters were observed. Decrease in total phenolic compound content, antioxidant capacity and malondialdehyde level while an increase in shoot and root moisture contents, total carotenoid and chlorophyll (a, b and total) contents were determined. In addition, moderate and high nitrogen treatments levels (≥100 mg l-1 N) increased the nitrogen contents of plant tissues. As a result, 100 mg l-1 N is the limit value to be applied for pelargonium, while lower application doses are insufficient. However, nitrogen treatments levels above 100 mg l-1 N promoted stunting and compactness in plants. Therefore, 200 or 400 mg l-1 N treatments can be recommended for the growing pelargonium in pots.