Phenological growth stages of edible asparagus (Asparagus officinalis): codification and description according to the BBCH scale
BBCH [Biologische Bundesanstalt (Julius Kühn-Institut), Bundessortenamt, CHemische Industrie] scales are used in applied natural sciences for the description of phenological growth stages of plants and are available for many crops today. Currently, a specific BBCH scale for Asparagus officinalis, a perennial vegetable plant of worldwide interest, does not exist. In this study, an extended BBCH scale was developed, describing precisely the growth stages of A. officinalis. Nine principal growth stages were defined and subdivided into several secondary growth stages resulting in a two-digit decimal code. Detailed descriptions of the particular stages and illustrations were included to clarify the application of the code system. The scale is proposed to specify and harmonise research activities as well as to enhance comparability of crop management practices for growers of asparagus.