Effect of Combination of Nitrigen, Humic Acid and Vita Free on Seed Yield, Yield Components and Quality Traits of Two Sunflower Cultivars

Combining organic and chemical fertilizers is one of the most important ways to achieve sustainable agriculture. In order to investigate the effect of organic fertilizers with chemical fertilizers on yield, yield components, and quality traits of sunflower, a factorial experiment was conducted in a randomized complete block design with three replications in spring 2018 at Gonbad Kavous University farm research. Cultivar factor included Haysan 25 and Oscar and combination of fertilizer factor included no fertilizer application, 100 kg N/ha, 50 kg N/ha, 50 kg N/ha + 1.5 kg humic acid/ha, 50 kg N/ha + 0.5 kg Vita free/ha, and 50 kg N/ha + 1.5 kg humic acid+ 0.5 kg Vita free/ha. The results showed that the effect of cultivar and fertilizer on most of the measured traits was significant. Oscar cultivar produced higher grain yield, biological yield and oil percent and oil yield than Haysan 25 cultivar. Grain yield, oil yield, biological yield and plant height in 100 kg N/ha treatment was higher than other fertilizer treatments though not significantly different from 50 kg N/ha + 1.5 kg humic acid/ha + 0.5 kg Vita free/ha treatment. Based on the results, in order to achieve the maximum seed and oil yield of sunflower and to prevent excessive use of chemical fertilizers, the combined use of Nitrogen fertilizer, humic acid and vita free is necessary.