Phenological growth stages of underutilised crop yam bean (Pachyrhizus erosus L. Urban) according to the extended BBCH scale

Abstract

Yam bean (Pachyrhizus erosus (L.) Urban) is an underutilised tuberous legume crop which has great potential as a food crop. As a root crop, it produces high yields and as a legume, it can produce protein-rich food. The phenological growth stages of yam bean are first described here using BBCH (Biologische Bundesanstalt, Bundessortenamnt and Chemische Industrie) scale. We have developed a basic and extended numerical BBCH scale for the identification of different phenological growth stages of yam bean. All phenological stages, including germination (stage 0), leaf development (stage 1), formation of side shoots (stage 2), stem elongation (stage 3), tuber formation (stage 4), inflorescence emergence (stage 5), flowering (stage 6), development of pods (stage 7), ripening of pods (stage 8) and senescence (stage 9) are described using the BBCH scale. This BBCH phenological study in yam bean will be helpful for better crop management, crop improvement and characterisation of germplasm. This scale will also be useful for the yield enhancement of this crop as an emerging underutilised tuber crop.