Effect of some chemical fertilizer and biofertilizer on quantitative and qualitative characteristics of Saffron

In this research، effects of chemical and biological fertilizers on qualitative and quantitative traits of saffron، were evaluated in a field experiment as randomized complete block design with three replications at Saffron Research Farm of Shahed University during growing season of 2012-2013. Experimental factors were chemical nitrogen fertilizer (0، 25 and 50 kg. ha-1) and plant growth promoting rhizobacteria including Pseudomonas and Bacillus as biofertilizer (inoculation and uninoculation). The results indicated that complete application of chemical fertilizer with biofertilizer enhanced yield of saffron، up to 217%، compared to control. The highest yield obtained in application of biofertilizer and 50 kg. ha-1 chemical fertilizer. It is worth noting that control (no inoculation) resulted in highest percentage of ingredients of stigma. Application of 50 kg. ha-1 of fertilizer was caused severe loss of quality traits in stigma، as safranal and crocin contents decreased by 5. 13% and 10. 9%، respectively. Integrated application of 25 kg. ha-1 nitrogen fertilizer and bio-fertilizer increased the picrocrocin up to 11. 9% compared to control. Application of 50 kg. ha-1 nitrogen fertilizer along with biofertilizer was the efficient treatment in increment of stigma yield and qualitative characteristics of saffron leaves. The concentration of phosphorus، zinc and copper increased up to 83. 05، 69. 36 and 86. 6%، respectively compared to control. Totally، Pseudomonas and Bacillus inoculation increased most of the qualitative and quantitative traits of saffron through nutrients uptake.