The effects of nitrogen on rose-scented pelargonium as a potted ornamental plant; growth and development, quality and biochemical characteristics

This study presents a novel approach to the production dynamics of rose-scented pelargonium for pot cultivation as an ornamental plant. It investigates how nitrogen supply affects plant growth, development, quality attributes, and biochemical properties to provide insights for enhanced commercial viability. Nitrogen concentrations (0, 50, 100, 200, and 400 mg l-1) were applied weekly for 3 months. Results show that increased nitrogen levels raised nitrogen concentrations in shoots (1.32%-2.57%) and roots (0.39%-1.27%). Periodic morphological evaluations indicated that the effects of nitrogen doses on growth started to appear after the second month of the experiment. By the end of the experiment (90th day), it was determined that increased nitrogen application resulted in reduced plant height, stem length, internode length, total phenolic compound (TPC) antioxidant capacity (DPPH) and malondialdehyde (MDA). In contrast, increases were observed in the number and length of lateral branches, stem thickness, leaf count, shoot biomass, chlorophyll (Clfs) levels and total carotenoid. MDA, TPC, and Clfs can be considered important biochemical indicators of nitrogen deficiency stress, defense mechanism, and plant quality in rose-scented pelargonium, respectively. It was determined that a minimum nitrogen concentration of 100 mg l-1 is required to obtain healthy, high-quality plants with strong visual appeal for the presentation of rose-scented pelargonium as potted ornamental plants. Higher concentrations may offer an advantage for more compact plant formation. To enhance the market value of rose-scented pelargonium as potted ornamental plants, future studies could include different pot sizes and pinching practices alongside nitrogen fertilization.