Seed viability, germination, and seedling growth of Kigelia africana (Lam.) Benth. to provenance and storage duration

Variations of climate conditions challenge germination of Kigelia africana seeds and growth across its distribution range. This study assessed the influence of provenances (with varied climate conditions) and seed storage duration on seed germination and seedling growth across three climatic zones in Benin. A three-way randomized complete block design was established, including seed provenances, storage duration (freshly collected, one-year and two-year storage), and seed soaking duration (0, 24 and 48 h). Nine treatments were applied to seeds from three provenances, each repeated three times. The number of seeds germinated per treatment was recorded daily, as were the time to first germination and the average germination duration. Seedlings were transplanted and growth parameters such as height, stem diameter, and number of leaves were measured weekly for 12 weeks. The results showed that no seed stored for two years germinated. The mean germination rates of freshly collected seeds and seeds stored for one year were 65.22% and 57.22%, respectively. Freshly collected seeds, whether soaked for 24 h or not, significantly affected positively seedling height (estimate = 0.12, p < 0.001) and stem diameter (estimate = 0.06, p < 0.001). These results provide important insights for the conservation of Kigelia africana through climate-zone-specific approaches.