2017 ASHS Annual Conference

Echinacea purpurea, or purple coneflower, is a traditional herbal medicinal for American Indian and now used to stimulate immune system. However, there are different report on its response to nitrogen fertilizer. In 2015, a nitrogen benchmarking study was conducted to investigate the growth, phytonutrient levels in Echinacea purpurea shoots and roots in response to nitrogen rates. Nitrogen feathermeal (13-0-0) was applied to Echinacea purpurea in April at the rate of 0, 100, 150, 200, or 250 pounds nitrogen/acre (lbs. N/Ac). Shoots were harvested at early July and end of the October, respectively. Roots were harvested at the end of October. In the July harvest, organic nitrogen fertilizer increased Echinacea shoot biomass with the highest production at 150 lbs. N/Ac. In the October harvest, organic fertilizer increased the biomass of both shoots and roots with the highest production at 200 lbs. N/Ac. 100 to 200 lbs./Ac Nitrogen fertilizer also increased nitrogen levels in shoots in July harvest and shoots and roots in October harvest. In July harvest, nitrogen fertilizer decreased the content of cafaric acid, cichoric acid, and total polyphenols in Echinacea purpurea shoots, in a dose response manner. In October harvest, nitrogen fertilizer did not significantly affect shoot cafaric acid content. However, high dose nitrogen fertilizer (200 and 250 lbs. N/Ac) increased shoot cichoric acid and total polyphenols content. Furthermore, nitrogen fertilizer decreased the contents of total alkamides, caftaric acid, cichoric acid and total polyphenols in the roots of Echinacea purpurea. In conclusion, a low dose of nitrogen fertilizer (100 – 200 lbs. N/Ac) can be applied to maintain the balance of growth and quality to Echinacea purpurea

Key words: Echinacea purpurea, organic nitrogen fertilizer, biomass, caftaric acid, cichoric acid and total polyphenols