Abstract: [Objective] The growth of one-and two-year-old Castanopsis hystrix seedlings raised with different media and different sizes of containers were compared, and their out-planted performances were also evaluated, aiming to determine the optimum container size and medium, as well as to provide guidance to selection of suitable seedling age for planting.[Method] C. hystrix seedlings were raised in containers of two sizes with eleven media. Growth dynamics and early field performance were investigated, respectively. Variance analysis with Duncan's multiple comparison was conducted to test differences in seedling growth and the early field performance among treatments, and correlation analysis was used to determine the relationship between seedling growth and early filed performance.[Result] Container size and growing medium significantly influenced height, root collar diameter, root and total biomass of one-and two-year-old seedlings. Moreover, their interaction significantly affected height, root collar diameter and root biomass of one-and two-year-old seedlings as well as total biomass of two-year-old seedlings. For one-year-old seedlings, there was significant difference in height but not in survival rate among media in the first year after out-planting. A significant difference was found in root collar diameter but not in height and survival rate in the second year after out-planting. For two-year-old seedlings, there were profound effects of container size and medium on height and root collar diameter in the first year after out-planting. Moreover, the interaction of container size and medium influenced obviously the height of two-year-old seedlings in the first year after planting. The height in the first year, and height and root collar diameter in the second year after planting showed positive relationships with the height, root collar diameter and total biomass of one-year-old seedlings in the nursery, respectively. However, the height in the first and second year after planting were negatively correlated with the root and shoot ratio in the nursery, respectively. As for two-year-old seedlings, with container size one, their height and root collar diameter at the first year after planting were positively correlated with the height and total biomass in the nursery separately, while with container size two, their height in the first year after planting had a positive relationship with their height, root collar diameter, root and total biomass in the nursery, while the root collar diameter in the first year after planting was positively correlated with total biomass in the nursery, suggesting that seedling quality significantly influenced the field growth performance of C. hystrix seedlings within first two years after planting.[Conclusion] The interaction of container size and medium had a profound effect on the seedling growth of one-year and two-year-old C. hystrix seedlings, therefore the optimum medium should be selected according to different seedling ages and container sizes. Container size one (8 cm×12 cm, diameter×height) and medium ten (50% composted bark, 25% yellow soil and 25% surface soil) were recommended to raise one-year-old C. hystrix seedlings, while container size two (12 cm×15 cm, diameter×height) and medium seven (50% composted bark and 50% surface soil) were suggested to raise two-year-old ones according to the seedling growth performance in nursery and after planting. It could be preliminarily concluded that under weed-controlled site, the field performance of one-year-old C. hystrix seedlings with container size one in the second year after out-planting was better than those of two-year-old seedlings with container size two in the first year after planting.

Key words: Castanopsis hystrix, seedling age, seedling quality, growth dynamics, field performance