Abstract
In the present paper are described the behavior of reserve carbohydrate contents, together with the variations of moisture content, amylase activities, pH value of the pressed juice and the respiration rate of seed sweet potatoes during their hot-nursery period, using the variety "Gokoku" as material. The experimental results obtained may be summarized as follow: 1. At the sprouting stage of the root tubers, the respiration rate and moisture content showed remarkable increase, while the starch and non-reducing sugar contents decreased as compared with those at the time of bedding. 2. When the number of sbrouts reached maximum the reduction rate of starch became less, while the abundant moisture content and the respiration rate were similar as in the preceding sprouting stage. 3. Upon attaining a later stage in the hot-nursery, the seed tuber give rise some local swelling or crack on the tuber surface due to the vigorous growth of new young shoots. At this stage the reducing and non-reducing sugar contents were low, which in turn resulted in decrease of respiration rate and moisture content. Starch content at this stage, however, increased a little according to the supply of photosynthetic products from the young shoots.
