Allelopathic effects of Cynara cardunculus L leaf aqueous extractson seed germination of some Mediterranean weed species

摘要

It is known that the presence of weeds causes serious losses tothe agricultural production, both in quantitative and qualitativeterms. The major problem in modem agriculture is the environmental impact of synthetic herbicides and the increase in herbicide-resistant weed species. Allelopathic compounds can be usedto develop a sustainable weed management system based on natural products. The objective of this study was to evaluate the allelopathic potential of leaf aqueous extracts (40 and 80%) obtainedfrom Cynara cardunculus L. plant species on seed germinationand mean germination time of six common weeds inMediterranean agroecosystems: Amaranthus retroflexus L.，Diplotaxis erucoides (L.) DC., Portulaca oleracea L., Lavateraarborea L., Brassica campestris L. and Solarium nigrum L.Effects varied with the weed species and the concentrations of theextracts. On average, the aqueous leaf extracts significantlyreduced the final percentage of seed germination compared to thecontrol for A. retroflexus (-58.1%), D. erucoides (-43.9%) and P.oleracea (-42.5%). The rate of germination decreased withincreasing extract concentration. In C. cardunculus L. var.sylvestris the autoallelopathic activity also was demonstrated.These results are very promising in order to produce a bioherbicide based on C. cardunculus allelochemicals.