Abstract

R. Romero, R.M. Barros Camba, A. Rigueiro and J.L. Fernández Lorenzo

Echinacea purpurea (L.) Moench. is a perennial plant used for the treatment and prevention of the common cold and flu because of its immunomodulatory and anti-inflammatory effects. At present, it is one of the most widely used medicinal herbs in the world. This study evaluated several weeding methods during three years of E. purpurea cultivation: mulching with black polyethylene film, corn gluten meal treatment, white clover living mulch, flame weeding, and metribuzin application. The adventitious flora was periodically inventoried, recording the coverage (%) and density (individuals/m2 ). Furthermore, yields of biomass were determined and concentrations of alkamides and caffeic acid derivatives were analyzed. Plastic mulching and metribuzin controlled weeds efficiently, allowing profitable biomass production. The highest yield of aerial and underground parts was afforded by plots mulched with black polyethylene film (5800 kg DM/ha and 1032.5 kg DM/ha at year 3). The highest concentrations of alkamides were found in plants from plots treated with metribuzin. Caffeic acid derivatives concentration in plants from plots treated with metribuzin was similar to that from plots treated with plastic mulching.