Conservation and sustainable development of Stephania brachyandra Diels: Cultivation, management and preliminary processing techniques

Stephania brachyandra Diels is a valuable medicinal plant containing rotundin, an alkaloid known for its sedative and analgesic properties. However, overexploitation has posed significant threats to its natural populations. This study aims to develop sustainable techniques for cultivation, care, and post-harvest preservation. Four experiments were conducted to evaluate the effects of planting density, fertilization, pest management, and storage methods on tuber growth and yield. Results showed that low planting density (28,000–42,000 plants/ha) significantly improved tuber development in the long term, while medium density was advantageous during early growth stages. The application of nitrogen (N), phosphorus (P), and potassium (K) fertilizers, especially when combined with organic amendments, enhanced both tuber size and soil fertility. Caterpillars were the only pests observed, and their impact on overall yield was minimal. Moreover, storing tubers in sand or mesh bags at controlled temperature and humidity reduced post-harvest weight loss and extended storage life. This study offers a scientific basis for the conservation and sustainable development of S. brachyandra Diels, contributing to the long-term availability of this important medicinal resource.