Effects of intercropping on growth, elemental composition and antioxidant activity of Artemisia scoparia and Raphanus sativus under lead supply

Artemisia species and radish demonstrate intensive allelopathic properties and high ability to hyperaccumulate heavy metals, but their interaction has not been studied up to date. In a pot experiment, the relationship between wormwood (A. scoparia L.) and radish grown individually or intercropped, without and with Pb(NO3)2 supply, was investigated. The intercropping had significant effects in both species, as a consequence of metal allelopathy. Radish showed decrease of root biomass (1.75- fold), Fe, Mn and Zn content (2-fold), Cu level (5.4-fold), and a 1.59-fold Pb increase in the leaves. In wormwood, a 1.75-fold increase of root biomass, as well as a 7.2- and 2.8-fold increase of root and leaf Fe content, respectively, were recorded. A. scoparia, the most Pb tolerant out of the 11 Artemisia species investigated, accumulated 6.6 and 9.9 times more Pb in leaves and roots respectively, compared to radish, under Pb supply which encouraged the growth of both plants. The intercropping under Pb supply induced a three-fold decrease of radish root biomass and 7.8-fold decrease of Pb content. Changes in plant antioxidant activity were recorded only under Pb supply and were not related to radish-wormwood interaction: the leaf phenolics content and antioxidant activity displayed 1.4- and 2- fold increases, respectively, in radish, and 1.4- and 1.6-fold decreases in wormwood. Synchronous changes in elemental composition of wormwood and radish in intercropping conditions, without or under Pb supply, suggest the significance of this phenomenon in plants interaction and arise high prospects of A. scoparia utilization to tackle weeds and soil Pb pollution.