growth and yield of saffron (crocus sativus l.) affected by different levels of fulvic acid and cow manure in the second growing season

Purpose: the experiment was conducted to evaluate the optimal amounts of cow manure and fulvic acid and the interaction effects of inputs on the yield of saffron in the second growing season. research methods: in this research, a factorial experiment based on randomized complete block design (rcbd) with three replications was conducted in 2015-2016 and 2016-2017 growing seasons, in the university of birjand, iran. experimental factors included cow manure in four levels (0, 10, 20, and 30 t.ha^-1) and fulvic acid plus some micronutrients in three levels (0, 5, and 10 kg.ha^-1). findings: the results in the second year showed that the effect of cow manure was significant on flower number per m2 and total fresh flower yield and dry stigma yield so that the highest total fresh flower yield (32.081 g.m^2) and dry stigma yield (0.325 g.m^2) obtained in the treatment of 20 t.ha^-1 cow manure and the lowest amount of these traits observed in the control (no- fertilization). the application of 10 kg.ha^-1 fulvic acid led to the highest mean flower weight (0.512 g) and stigma yield (0.035 g.plant-1). the results of interaction effects showed that simultaneous application of cow manure and fulvic acid had a significant effect on fresh flower yield and the highest amount of these traits (33.613 g.m^2) obtained in the combined application of 20 t.ha^-1 cow manure and 10 kg.ha^-1 fulvic acid. in general, it seems that separate and simultaneous application of optimal amounts of cow manure and fulvic acid, while improving the reproductive characteristics and yield of saffron, can guarantee the healthy and sustainable production of this valuable medicinal. research limitations: there was no significant limitation to the research. originality/value: this research evaluates the simultaneous application of eco-friendly inputs of cow manure and fulvic acid on reproductive characteristics and yield of saffron which has been less studied.