Study on the Optimal Harvesting Age of Astragalus Mongholicus Under Wild-Simulated Cultivation in Inner Mongolia

The harvesting age is a critical factor influencing the quality of medicinal crops, as it significantly affects the content of active compounds and clinical efficacy, which vary across different cultivation years. This study aims to clarify the growth and development patterns of wild-simulated and cultivated Astragalus mongholicus at different ages and provide theoretical and practical guidance for determining its optimal harvesting age. The morphological indicators, photosynthetic performance, stress resistance enzyme activities, medicinal compounds, and yields of Astragalus mongholicus cultivated and wild-simulated for one, two, three, and four years were analyzed. Results showed that the harvesting age influenced the various measurement indicators of wild-simulated Astragalus mongholicus. The underground growth of the two-year-old plants was the most vigorous, with a stronger photosynthetic capacity and the highest content of calycosin-7-O-glucoside. Both two-year-old and three-year-old plants exhibited higher superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) enzyme activities. The three-year-old plants had the highest astragaloside IV content and the greatest economic benefit. Considering both the quality of the medicinal material and the economic returns, this study suggests that the optimal harvesting age for wild-simulated cultivated Astragalus mongholicus in Inner Mongolia is three years, though harvesting at two years may also be feasible under practical conditions.