Effects of temperature, light, nutrients and smoke-water on seed germination and seedling growth of Astragalus membranaceus, Panax notoginseng and Magnolia officinalis — Highly traded Chinese medicinal plants

Astragalus membranceus, Magnolia officinalis and Panax notoginseng, are fundamental herbs in traditional Chinese medicines and are in great demand. Optimum conditions for seed germination and seedling growth were investigated to increase baseline knowledge of these three valuable species. The optimum temperature for seed germination of A. membranaceus and P. notoginseng was 10 °C. The highest germination of M. officinalis seeds occurred between 15 and 25 °C. Seeds of all three species showed better germination under light conditions than in the dark. Seedlings of A. membranaceus and P. notoginseng showed the best growth at higher levels of nutrient [25% and 50% Hoagland's nutrient solution (HS)]. In contrast, M. officinalis seedlings showed the best growth response at a low nutrient level (10% HS). This study indicated that supplementary nitrogen to A. membranaceus seedlings and potassium to M. officinalis and P. notoginseng seedlings can improve seedling quality/growth. Smoke-water markedly improved both seed germination and seedling growth of A. membranceus at normal growth conditions. Smoke-water can be a useful tool in Good Agriculture Practice of some important Chinese medicinal plants.

► Germination and seedling growth requirements of important Chinese medicinal plants.
► Light and low temperatures essential for optimum germination.
► Magnolia officinalis and Panax notoginseng potassium requiring species.
► Smoke-water enhance germination and seedling development of Astragalus membranaceus.