Incorporation of Residues of the Medicinal Plant Echinacea purpurea for Weed Management in an Organic Sunflower

Summary

Eastern purple coneflower [Echinacea purpurea (L.) Moench.] is globally recognized as one of the most popular medicinal herbs. In the present study, the effects of incorporation of the plant residues of this medicinal plant on weed flora and early growth of a sunflower crop were investigated. A field and a pot experiment were conducted at the Agricultural University of Athens. The field experiment was conducted under organic conditions, while in the pot experiment the focus was on the early growth of sunflower plants under the effect of plant residues. The results showed that there was a significant effect of plant residues on weed flora and the producted biomass, especially during the first crucial growth stages of sunflower. Particularly, the incorporation of E. purpurea residues resulted to a lower number of different weed species (low richness) and an intense effect on most weed species. The pot experiment revealed that sunflower seed germination was not affected by the incorporation of E. purpurea residues. However, the activity of eastern purple coneflower residues was inadequately selective (and needs to be further evaluated), since there was a negative effect on sunflower growth.