Effect of seedling age and chilling on the growth and flowering characteristics of Primula sieboldi.

摘要

P. sieboldi is native to Korea, and has attractive plant characteristics when potted and used as bedding plants. An experiment was conducted to study the relationship between the seedling age and chilling requirement for flowering of P. sieboldi. The growth of plant after potting was not affected by seedling ages, but growth was better when seedlings were transplanted early. Plants with 13 true leaves transplanted before 18 August [year not given] flowered 100%, regardless of the seedling ages. However, flowering was low in plants transplanted after 1 September. When plants were transferred to a greenhouse and kept at dayight temperature of 25鳦/15鳦 after 1 December, they flowered normally. However, when the plants were transferred earlier than1 December, the flowering percentage was low and the quality of potted plants became poor. The number of days to reach budding stage after forcing was 28-39 days. The estimated chilling hour required for flowering was 318 h (2541 h in nature) based on the accumulated low temperature below 5鳦 outdoor in Suwon. The time of flowering could be controlled from 3 January to 22 February depending on the time of forcing. The duration of flowering period was 23-29 days.