참당귀(Angelica gigas Nakai)의 재배에서 크게 문제가 되는 화성억제를 위해 온도, 일장 및 광도가 화아분화와 추대에 미치는 영향을 조사했으며, 관행재배와 화성을 추제시켜 재배생산된 근의 수량을 조사하여 연근별로 비교하였다. 본 시험에서 얻어진 결과를 요약하면 다음과 같다. 1. 자연온도처리(대조구)의 경우 11월 20일 처리구의 본엽 6~8매부터 화아분화 및 추대가 시작되어 처리기간이 길어질수록 추대율이 증가하다가 익년 1월 11일 이후부터는 변화가 없었으며 본엽 2~3매 는 어떤 구에서도 추대가 전혀 없었다. 2. 인공온도처리의 경우 처리온도가 높아질수록 주온감응한계엽령이 증가하였다. 즉, 1℃ , 5℃ , 9℃ 처리구 각각 3매, 5매, 6매가지는 전혀 추대가 없었으며 8주 8매구에서도 1℃ 에서 80%, 5℃ 에서 45%, 9℃ 에서 5%로 추대율이 저하하였다. 3. 참당귀의 추대율은 일장이 길어질수록 증가하였고, 광도시험에 있어서는 자연광구에서 가장 높았으나 광도가 감소할수록 점차 줄었으나 차광 50%까지 유의성이 인정되지 않았다. 4. 화도를 억제시켜 재배했을 때 10a당 건근중은 3년근이 가장 많았고 1ㆍ2년근에 비해 각각 3.6배, 2.4배 증수되었으며, 관행재배보다 2년근은 73.7%, 3년근은 159.6% 증수효과가 있었다.
Since the inhibition of floral induction was considered to be an important subject to get high yield of Angelica gigas, the effects of low temperature, daylengh and shading were investigated in this study. The yield of A. gigas root grown by inhibition of floral induction was compared with the yield obtained by traditional cultivation method. When the seedings were exposed to the natural low air temperature condition until late of November, the plants which had 6 to 8 leaves showed vernalizing effect, and when the low temperature treatment was prolonged until mid of January, 4 to 5 leaf plants showed vernalizing effect. But 2 to 3 leaf plants did not show vernalizing effect regardless of the length of chilling treatment. The effectiveness of exposure to low temperature was markedly dependent upon the age of plants. In the artificial low temperature treatment the range of temperature varied with plant age. Vernalizing effect at 1,5 and 9~circC of temperature did not show 3,5,6 leaf plants, respectively. The bolting percent in 8 leaf plant at 1,5 and 9~circC for 8 weeks decreased by 80,45 and 5%, respectively. As daylength became longer, the bolting percent of A. gigas was increased. plants which were grown in the full sunlight showed the highest value in bolting percent, and the bolting percent was not decreased significantly with changing from full sunlight to 50% shading. When A. gigas were grown by the inhibition of floral induction, dry root weight per l0a showed the greatest value in 3 year old plant which 3.6 and 2.4 times higher than that of 1 and 2 year old plant, respectively. The yield of root was increased by 73.7% in 2 year old plant and 159.6% in 3 year old plant compared with the yield obtained by traditional cultivation method.