Exploiting Cynara cardunculus L. allelopathy for weed control

Allelopathy involves both the positive or detrimental, direct or indirect effects of one plant on target organisms through the release of secondary metabolites into the environment. This biological phenomenon can be manipulated by extracting the allelochemicals, most of which are water-soluble compounds, for the control of weeds. Recently, much attention has been given to the allelopathic effects of Cynara cardunculus L. extracts. From the recent research emerged that: 1) C. cardunculus allelopathy is variety and genotype dependent, with cultivated and wild cardoon showing greater allelopathic activity than the globe artichoke; 2) organic solvents are more effective than aqueous extracts in suppressing target weeds; 3) dried leaves and spring period (April) are the optimal plant material and harvest time, respectively, to enhance the allelopathic potential of C. cardunculus extracts; 4) sesquiterpene lactones and polyphenols are the primary chemical classes of allelochemicals in C. cardunculus; 5) in the field, cultivating C. cardunculus effectively reduces the soil weed seed bank and alters weed communities. Further efforts on C. cardunculus allelopathy are still required to identify the allelopathy-involved traits and transfer the genes into improved genotypes, as well as to maximize its allelopathic potential. This knowledge can play an important role for developing plant-based bioherbicides and promoting sustainable weed management in agroecosystems.