抄録
The present paper reports the effects of light, temperature, sugar and fertilizers on the thiamin activity for the earlier growth of sweetpotatoes when sprayed on the leaves.
The results obtained were as follows:
1. Thiamin application was more effective for the growth in the dark than in the light.
2. Under temperatures unfavorable for the growth, thiamin was more effective than under favorable.
3. Combined application of thiamin with sugar was more effective for the growth of root than single application of thiamin or sugar, whereas the growth of top was retarded by the single spray of sugar.
4. When applied in optimum quantity by soil application, phosphorus was the most effective of the three manurial elements for the thiamin activity, but when applied surplusly, nitrogen which was otherwise the most unfavorable for the growth was the most effective.
