Evaluation of fulvic acid and cow manure on vegetative characteristics and flower yield of saffron (Crocus sativus L.) in the first year

The nutrient management is one of the most important factors in relation to quantitative and qualitative characteristics of saffron (Crocus sativus L.). In order to investigate the effects of different of cow manure and fulvic acid levels on yield and vegetative characteristics of saffron, an experiment was conducted as factorial based on a randomized complete block design with three replications at the Agricultural Research Station, University of Birjand during growing season of 2015. Treatments were four levels of cow manure (0, 10, 20 and 30 t.ha-1) and three fulvic acid (0, 5 and 10 kg.ha-1). . Results showed that cow manure improved the saffron flower characteristics (flower number and fresh total yield and stigma yield). The highest flower fresh total (6.289 g.m-2) and stigma fresh (0.299 g.m-2) yield were obtained in plants treated with 10 t.ha-1 cow manure, while the lowest values were recorded in control (5.18 and 0.235 g.m-2). Leaf photosynthetic pigments (chl a and total) were influenced by cow manure. Results also showed that fulvic acid has a positive effect flower number and fresh total yield, stigma yield and average weight and SPAD. The highest of flower number (17.29 per.m-2) and SPAD (14.39) were observed in 10 kg.ha-1 fulvic acid. Application of different levels of cow manure and fulvic acid had a positive effect on the flower fresh total yield, stigma, total chl and SPAD. The highest of stigma dry yield (0.085 g.m-2) were obtained in plants treated with 10 t.ha-1 cow manure and 5 kg.ha-1 fulvic acid. Thus, results showed that cow manure and fulvic acid have significant impact on flower yield and photosynthetic pigments of saffron.