Phenological growth stages of highbush blueberries (Vaccinium spp.): codification and description according to the BBCH scale

Highbush blueberries (<i>Vaccinium</i> spp.) are cultivated crop plants worldwide and they are still gaining importance. But a common uniform description of the phenological development was missing so far. In this work, a specific code is presented, based on the decimal BBCH scale. The BBCH scale comprises the macrostages 0-9, with macrostage 4 being omitted here, because it has no relevance for blueberry crops grown in the field. Each macrostage is subdivided in several microstages, each describing a notable developmental stage. The BBCH code takes special reference to the fruit development, fruit ripening and several fruit pickings, which are typical for blueberries. For each macrostage the main development as well as cultivation characteristics are explained in more detail. The new BBCH code is compared with other descriptions of phenotypical development of highbush blueberries and transformations are suggested. The BBCH code is developed for cultivated highbush blueberries and is therefore applicable to northern, southern, and rabbiteye blueberries as well.