식물생장에 미치는 Inula lactone의 억제효과를 조사하였다. 1. lactone은 생장중인 Phaseolus volgaris의 줄기와 잎의 생장을 크게 억제하였으나 그 효과는 처리부위에만 국한되었다. 2. lactone을 뿌리부위에 처리하면 식물 전체의 생장이 억제되었다. 3. lactone과 접촉된 줄기의 표피는 검게 변색되었고, 피층의 발달은 중단되며, 형성층과 사관부는 band상의 구조물로 변질되었다. 4. GA는 lactone에 의한 생장억제를 경우에 따라 일부 회복시킬 수 있었다. 5. lactone은 체내 이동이 대단히 어렵고, 생활력이 활발한 세포에 대해서 더욱 큰 작용성을 나타내었다.

The inhibitory effect of Inula sesquiterpene lactones on the growth of Phaseolus vulgaris was tested and the abnormality of the stem organization caused by the lactones was also examined. The longitudinal growth of the young stem and the expansion of the young leaf were stopped by the application of the lactones. However, this inhibitory effect was appeared and strictly restricted within the treated area. So the young shoot was observed for possible bending as a result of the unilateral application of the lactones. When the application of the lactones into the medium, the growth of the plant was entirely repressed. However, the growth of shoot and re-initiation of root were started after the plant was transfered to the lactone free medium. And partial reversal of inhibition of the stem growth was achieved by the additions of gibberelline and the lactones.