抄録
In order to obtain the relationship between the root thickening and some characters of sweet potatoes, 30 varieties and lines were grown and harvested at early and late time. Some results of this experiment were given in figure 1, 2, 3 and 4. By the figure 1, We can say that the higher the ratio of the early and late harvesting potato yields, the better tuber thickening we can have. As the result of the above relationship, positive correlation between early tuber thickening and marketable tuber number, and negative correlation between early tuber thickening and T/R ratio are seen in figure 2 and 3. Then also negative correlation is seen between early tuber thickening and degrees of dry-matter accumulation in Fig. 4.
