Effects of plant density and different organic and chemical fertilizers on some phytochemical characteristics of Iranian ox-tongue (Echium amoenum Fisch. & Mey.)

This research was aimed to investigate the effects of plant density and organic and chemical fertilizers on some phytochemical characteristics of Iranian ox-tongue (Echium amoenum Fisch. & Mey.). The study was conducted as a split plot experiment based on RCBD design with three replications, conducted in 2011-2014, in Ferdowsi University of Mashhad, Iran. The main and sub plots included three plant densities (10, 5 and 3 plants per m2) and three types of organic fertilizers and one type of chemical fertilizer (compost, vermicompost, cow manure, nitrogen chemical fertilizer and control), respectively. The results showed that the highest antioxidant activity was obtained in a density of 10 plants per m2 (79 mg/ml) and the highest total phenols was observed in a density of 5 plants per m2 (51 mg GAE/g flower DW). Compost, vermicompost, cow manure and chemical fertilizer increased total phenols to 51, 35, 40 and 63%, respectively compared to control. Application of vermicompost and cow manure in a density of 3 plants per m2 increased total flavonoid up to 39 and 38%, respectively compared to control. The highest total anthocyanin was obtained in a density of 5 plants per m2. Vermicompost and cow manure increased the seed oil (10 and 13%), and seed protein content (34 and 13%), respectively compared to control. In general, according to the findings of this research, it seems that the use of eco-friendly inputs and determining the optimal density of Iranian ox-tongue could result in improving the quality and health of product and minimizing the damage caused by chemical inputs.