Seed germination, vegetative growth and concentration of some elements in French marigold (Tageta patula) as influenced by salinity and ammonium nitrate

Marigold has special importance and application in landscape designing. Nowadays, various species and cultivars of this plant are grown in many climates, where different environmental stresses such as freezing, salinity and drought can lead to vegetative disorders. This study was carried out to investigate the interactions between salinity and ammonium nitrate on seed germination, vegetative growth and sodium and potassium concentrations in French marigold flowers (Tegeta patula). The experiment was conducted as a factorial arrangement based on a completely randomized design with two factors: salinity (0, 2, 4, 6 and 8 mmos cm-1) and ammonium nitrate (0, 15 and 30 g l-1) with four replications. Based on the obtained results, different salinity concentrations were negatively influenced all studied parameters except germination rate. The application of ammonium nitrate recovered the studied parameters to the same level as the control plants. Plant height was decreased by increasing salinity concentrations. The tallest plant was observed in the control treatments. Salinity levels negatively influenced shoot fresh weight. Different levels of ammonium nitrate had significant effects on root dry weight and potassium and sodium contents. Ammonium nitrate led to reductions in root dry weight and potassium content, and an enhancement in sodium content in the shoot. Sodium and potassium levels were increased and root dry weight was decreased by increasing salinity. Enhancement of potassium ions in the marigold following salinity stress can improve its tolerance to salinity stress.