University of Tehran perss Journal of Crops Improvement 2008-8337 19 1 2017 03 21 The Effect of Limited irrigation Stress and Humic Acid on the Some Morphological and Root Phytochemical Characteristics of Purple coneflower The Effect of Limited irrigation Stress and Humic Acid on the Some Morphological and Root Phytochemical Characteristics of Purple coneflower 1 14 60403 10.22059/jci.2017.60403 FA Abbas Alizade Ahmad Abadi1 M.Sc. Student, Dept. of Horticulture, faculty of plant product, Gorgan University of Agricultural Sciences and Natural Resources-Iran Sarah Khorasaninejad Assistant Prof., Dept. of Horticulture, plant product faculty, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. 0000-0002-2786-4015 Khodayar Hemmati Associate Prof., Dept. of Horticulture, plant product faculty, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. Journal Article 2016 03 07 In order to study the effects of Humic acid levels and irrigation regimes on the some morphological and biochemical characteristics of Echinacea purpurea L., a pot experiment was conducted as factorial based on randomized complete block design with three replications and four experimental units at research farm of Gorgan University of Agricultural Sciences and Natural Resources, during growing season of 2014- 15. Treatments were four levels of irrigation regimes (40, 60, 80 and 100 percent field capacity) and humic acid including four levels: (0, 250, 500 and 1000 mg/kg). The results showed that irrigation regimes had significant effect on all measured properties except root length. Humic acid increased all of the growth caractristics and morphological traits in 5% level statistically, while had significant effect on total flavonoid and increased it. Interaction effect of humic acid and irrigation regimes was significant for wet and dry weight of root and shoot, total phenol and flavonoid. Therfore, the limited irrigation had negative effect on growth and plants increased their phenol and antioxidant components to stress coping. Humic acid increased growth and yield in plants that were faced with stress. In order to study the effects of Humic acid levels and irrigation regimes on the some morphological and biochemical characteristics of Echinacea purpurea L., a pot experiment was conducted as factorial based on randomized complete block design with three replications and four experimental units at research farm of Gorgan University of Agricultural Sciences and Natural Resources, during growing season of 2014- 15. Treatments were four levels of irrigation regimes (40, 60, 80 and 100 percent field capacity) and humic acid including four levels: (0, 250, 500 and 1000 mg/kg). The results showed that irrigation regimes had significant effect on all measured properties except root length. Humic acid increased all of the growth caractristics and morphological traits in 5% level statistically, while had significant effect on total flavonoid and increased it. Interaction effect of humic acid and irrigation regimes was significant for wet and dry weight of root and shoot, total phenol and flavonoid. Therfore, the limited irrigation had negative effect on growth and plants increased their phenol and antioxidant components to stress coping. Humic acid increased growth and yield in plants that were faced with stress. https://jci.ut.ac.ir/article_60403_35309ec8898385cea2e85454a678c50e.pdf