The Role of Mulching with Residues of two Medicinal Plants on Weed Diversity in Maize

In the present study, there were studied the effects of mulch with the residues of two aromatic and medicinal plants (Sideritis scardica Griseb and Echinacea purpurea) on weed flora and first growth of a maize crop. A field and a pot experiment were conducted at Agricultural University of Athens. In particular, the field experiment was conducted under organic conditions, while in the pot experiment special attention was paid to the first growth of maize plants under the effect of plant residues. Our results showed that there was a significant effect of plant residues on weed flora. The incorporation of Sideritis sp. residues resulted to a lower number of different weed species (low richness) and an intense effect on most weed species. During the early growth stages of maize there was a satisfactory control of the broadleaf weeds after the incorporation of S. scardica, resulting to a significantly lower biomass. However, this effect progressively disappeared, with E. purpurea mulch progressively showing a higher phytotoxic activity. The pot experiment revealed that there was not any negative effect of mulching on maize seed germination, emergence and early growth.