抄録
1. The authors has found from them studies that the form of the secondary growth tuber was influenced by the period of the drought that takes place during the growing. 2. Drought in the early period of growth resulted in the slow development of the 1st tuber and the rapid growth of the 2nd tuber, drought in the later period brought about contrary results. 3. It was recognized that the size of the lst tuber was in inverse proportion to the size of the secondary growth tuber according to the time during which the drought occurred.
