Simulation of Growth Process and Yield Formation of Angelica sinensis (Oliv.) Diels Based on the WOFOST Model

Angelica sinensis (Oliv.) Diels is an important medicinal plant widely cultivated in China. Under climate change, its growth dynamics and yield formation face considerable uncertainty, yet dynamic simulation studies remain limited and quantitative assessments still rely largely on empirical statistical methods. To address this gap, we developed a growth-process simulation model for A. sinensis using WOFOST-sugarbeet as the initial framework. Field observations were used to localize key parameters governing phenological development and dry-matter partitioning. Model performance was evaluated through within-season calibration, independent-year validation of growth processes, and interannual analysis of yield trends. Sensitivity analysis identified the thermal units required from greening to fleshy-root expansion (TSUM1) and the conversion efficiencies of assimilates into leaves (CVL), roots (CVR), and storage organs (CVO) as the key parameters affecting model outputs. After calibration with 2019 field data, the model satisfactorily simulated storage-organ total dry weight, aboveground total dry weight, and root length, with R2 values of 0.92, 0.98, and 0.88, respectively. Independent validation using 2020 data showed similarly strong agreement, with corresponding R2 values of 0.98, 0.97, and 0.92. The calibrated model also captured the interannual trend in A. sinensis yield from 2010 to 2024 (R2 = 0.79). Overall, the localized model provides technical support and a methodological reference for cultivation management optimization, accurate yield assessment, and climate-response mechanism analysis.