Abstract: Sowing date is a critical factor affecting the growth and yield of millet, and its optimal management is essential for maximizing productivity. In this study, the effects of sowing date on the growth and yield of foxtail millet were investigated through field experiments combined with APSIM-Millet model simulations. Using historical meteorological data (1984—2023), we further explored strategies for optimizing sowing date management. The APSIM-Millet model accurately simulated the growth process of foxtail millet across different sowing dates and varieties. Historical simulation revealed that the optimal sowing date for millet in Shanxi Province was gradually delayed from north to south, with additional variations due to irrigation conditions. For the late-maturing variety Jingu 21, the best rain-fed sowing window ranged from March 30 to April 19 in northern Datong City, shifting southward to May 21 to June 10 in the southernmost Yuncheng City. Under irrigation conditions, the optimal sowing date was 20～30 days later than under rain-fed conditions. In contrast, the early-maturing millet variety Tonggu 30 exhibited a later optimum sowing date than Jingu 21, with a 70-day north-south span. Irrigation further aggravated regional differences. These findings highlight the close relationship between sowing date responsiveness and regional water/heat resource distribution. In cold northern regions, early sowing helps avoid later-season drought, while the warm and humid southern areas benefit from delaying sowing to optimize light and temperature utilization. Integrating field experiment results, the rain-fed early sowing mode was preferred in arid northern Shanxi, and gradient sowing being adjusted to irrigation availability in the warmer southern Shanxi, and climate-resource efficiency was realized through varietal adaptations, e.g. , limited southward extension the late maturing variety Jingu 21 and enhanced north-south sowing differentiation for the early maturing variety Tonggu 30. This study provides a theoretical foundation for optimizing regional sowing dates in Shanxi’s millet production systems.
Key words: millet; variety; sowing date; APSIM-Millet model; yield
（Acta Laser Biology Sinica, 2026, 35(1): 062-071）