Effect of bio-fertilizers and nitrogen on quantitative and qualitative characteristics of tepals in saffron (Crocus sativus L.)

In order to investigate the effect of different nitrogen sources on some quantitative and biochemical characteristics of Saffron Petals, an experiment was conducted based on randomized complete block design with three replications on the Research Farm of University of Zanjan. The treatments were Azotobarvar-1 bio-fertilizer (containing free-living nitrogen-fixing bacteria Azotobacter vinelandii) with two levels (0.1 and 0.2 percent), Nitrokara (containing symbiotic and free-living nitrogen-fixing bacteria Azorhizobium caulinodan) with two levels (1 and 2 percent) and combinations of both of them with four treatments (1percent Nitrokara 0.1 percent Azotobarvar-1, 1 percent Nitrokara 0.2 percent Azotobarvar-1, 2 percent Nitrokara 0.1 percent Azotobarvar-1, 2 percent Nitrokara 0.2 percent Azotobarvar-1) compared to control and one nitrogen level (40 kg/ha). The results showed that the highest yield of petals and stigma were obtained in 0.2 percent Azotobacter while the highest average dry flower weight resulted in 2 percent Azorhizobium treatment. The highest leaf nitrogen content and total chlorophyll were obtained in 0.2 percent Azotobacter and 40 kg/ha of nitrogen treatments. Also 40 Kg/ha nitrogen resulted in the highest leaf area. The highest antioxidant, total phenol and anthocyanin of tepal were achieved in 0.1 percent Azotobacter while the highest amount of flavonoid was observed in 1 percent Azorhizobium. The results showed that the application of all treatments increased yield of saffron petals. The 0.2 percent Azotobacter was the best treatment in terms of quantity of petal yield and 0.1 percent Azotobacter resulted in highest antioxidant content and therefore it can be recommended