Establishing the phenological development stages of Sophora moorcroftiana using the BBCH scale

Sophora moorcroftiana (Benth.) Baker is a crucial shrub species for windbreak and soil conservation in Tibet (Xizang), playing an important role in plateau ecological protection and the biopharmaceutical industry. However, there have been no studies reporting on the phenological characteristics or effective accumulated temperature of this species. This research systematically describes the developmental processes of S. moorcroftiana across various phenological growth stages using the BBCH scale (Biologische Bundesanstalt, Bundessortenamt, and Chemische Industrie). Through long-term photography, tracking, and observation, eight main phenological stages were identified: bud development, leaf development, shoot development, inflorescence emergence, flowering, fruit development, seed maturation, and senescence and beginning of dormancy. Additionally, 41 secondary growth stages were detailed, accompanied by characteristic images, standardizing morphological features and phenological observation criteria for S. moorcroftiana. This study provides a scientific reference for research on the biological characteristics and breeding of superior varieties of S. moorcroftiana.