Root chicory (Cichorium intybus L. var. sativus) is potential alternative medicinal and sugar crop which accumulates a high amount of linear polyfructan, inulin in its roots. A problem in root production is that over-wintered stock plants often flower. Once the plant becomes reproductive, stem elongation and root growth slows and floral buds arise from every node, rendering the plants useless for propagation. The objectives of this research was to examine the effectiveness of manipulating environmental factors containing photoperiod, temperature and number of leaf states. The experiment was performed in growth chamber to create two photoperiods (8 h, and 16 h) with three temperature regimes (5℃/3℃, 10℃/8℃ and 15℃/13℃ day/night temperature) for a total of six treatments on three type of true-leaf stage of plant. Data of bolting rate, shoot and root length, shoot and fresh weight was invetigated in each treatments. This is the first report on changes in bolting rate and shoots and roots production during a whole growing season and differences in the effect of cold and photoperiod treatment depending on the true-leaf stage of plant.

참당귀(當歸) 재배(栽培)에 있어서 추태율(抽苔率)과 수양(收量)과의 관계(關係)를 알아보기 위하여 1992년(年)부터 1994년(年)까지 3년(年)동안 121개(個) 시험구(試驗區)에서 조사(調査)된 자료(資料)를 분석(分析)하였다. 1. 참당귀(當歸)의 추태율(抽苔率)은 초기생육(初期生育)이 좋을수록 높아지는 경향이었다. 2. 수양(收量)은 전혀 추태(抽苔)되지 않은 포장(圃場)보다 11%정도 추태(抽苔)된 포장(圃場)에서 가장 많았다. 11%이상(以上)으로 추태율(抽苔率)이 높아지면 수양(收量)이 낮아지는 경향이었으며, 30%이상(以上)으로 추태율(抽苔率)이 높을 때에 수양(收量)이 급격하게 낮아졌다. 3. 묘(苗)크기 에 따라 중묘(中苗), 소묘(小苗)에서는 추태율(抽苔率) 10~15%범위(範圍)에서 수양(收量)이 높고 대묘(大苗)에서는 추태율(抽苔率) 5~10%범위(範圍)에서 수양(收量)이 높게 나타났다.