Abstract
•Up to 3 harvests, the highest values of fresh & dry weight of leaves were obtained.•Up to 3 harvests, the highest values of carbohydrate and flavonoid were obtained.•Up to 3 harvests, the highest values of polyphenol & chlorogenic acid were obtained.•Up to 3 harvests, the highest values of caffeic acid and vanilic acid were obtained.•The minimum values obtained from plants which were harvested once in the season.
Cardoon (Cynara cardunculus) is a highly promising medicinal plant that has been used to treat several diseases, but there remains a great need for research into both the agriculture and chemical composition of the plant. For this study, cardoon was cultivated for two successive seasons (2009/2010 and 2010/2011) at the experimental farm of the Faculty of Agriculture, Cairo University. Specifically, the study investigated the effect of numerous harvests of leaves (one, two, three and four harvests/cuts) on both the growth and the active constituents of C. cardunculus plants. Both the fresh and the dry weight of the harvested leaves were measured and the active constituents, such as carbohydrate, flavonoid, polyphenol and chlorogenic acid content, were measured. It was found that as the number of harvests increased (up to three harvests) the values of these parameters also increased in both seasons.