The effects of chemical and organomineral sources nitrogen doses on yield and quality properties of sunflower

In this study, it was aimed to determine the effects of chemical and organomineral nitrogen doses on yield and quality characteristics of oil sunflower. The research was carried out in the production period of 2023, using Roseta oil sunflower variety, according to the split-plots experimental design in randomized blocks with three replications. Chemical and organomineral fertilizers were applied to the main plots and nitrogen doses were applied to the sub-plots. Organomineral and chemical fertilizer doses were applied in 7 doses as 0 (control), 3, 6, 9, 12, 15, 18 kg/da pure nitrogen. In the experiment, findings related to on germination, flowering and maturity time, plant height, stem diameter, number of leaves per plant, table diameter, number of seeds in the table, seed yield per table, thousand seed weight, seed yield per decare, oil ratio and oil yield were analyzed. According to the results obtained; varied between plant height 158.9-178.4 cm, stem diameter 18.3-22.9 mm, table diameter 19.1-22.3 cm, thousand seed weight 60.4-74.9 g, seed yield 353.5-474.9 kg/da, oil content 40.8-45.8%, oil yield 162.0-203.5 kg/da. While there was no difference between chemical and organomineral fertilizer sources in terms of oil ratios in seeds, oil ratios decreased as nitrogen doses increased. Application of chemical fertilizers among nitrogen sources had a positive effect on seed and oil yield per decare. The application of 15 kg/da nitrogen dose was found to be more suitable than the other doses in seed and oil yield per decare. Similarly, satisfactory results were obtained from organomineral fertilizer applications in terms of seed yield per decare. Considering the positive contributions of these organic fertilizers to the ecosystem, it was concluded that it would be appropriate to use these fertilizers in sunflower cultivation. Keywords: Nitrogen, Helianthus annuus L., Chemical fertilizer, Organomineral fertilizer, Oil ratio