Field Performance and Medicinal Constituents of E. purpurea and E. angustifolia Varieties Grown in Eastern Washington: 2012–2013

A field experiment was initiated in 2012 at the Amway Corporation certified organic farm in eastern Washington state. Commercially available varieties (6 of each species) of Echinacea purpurea (Purple Coneflower) and Echinacea angustifolia (Narrow-Leaf Coneflower) were evaluated in a RCB, strip-split block field design, with 3 replications. Year of harvest [age of the plants at harvest] were the main blocks, with replications sub-blocked within each year, and varieties randomized within years. Individual experimental units consisted of 4 rows spaced 39 cm apart and 3 m long. For E. purpurea, the center two rows were harvested for aerial tops at an early bud stage, and roots near the end of the growing season. E. angustifolia roots were also harvested near the end of the growing season. Fresh and dry weights of aerial parts and/or roots from each experimental unit were recorded, and sub-samples collected for analytical chemistry and elemental analysis. The project will run for three years, and this report focuses on a combined analysis of the 2012 and 2013 results.