Phenological growth stages of Cynara cardunculus: codification and description according to the BBCH scale

Cynara cardunculus is a herbaceous perennial crop known from ancient times. During the last three decades this thistle has intensively been researched and recently became a commercial crop for biofuel production. As there is an increasing need for more information on this crop, we present here the phenological growth stages based on the Biologische Bundesanstalt, Bundessortenamt, CHemische Industrie (BBCH) scale and its associated decimal code. Nine principal growth stages have been defined and each principal stage has been subdivided into secondary growth stages. Descriptive keys with illustrations are also provided. A practical use of the scale is proposed, with particular reference to harvest time and management treatments. This scale aims to support farmers and researchers to efficiently plan management practices and experimental treatments.