Abstract
The authors made a histological observation, using the “Nijisseiki” pear, that a quantity of stored nourishment in a tree bore upon flesh cell-division, i.e., the number of cells.
With a view to regulate stored nourishment, the defoliation periods were divided into the following:
(1) Sept. 15, (2) Sept. 30, (3) Oct. 15, (4) Oct. 30, (5) the continual plucking period from the flowering-time to the beginning of June, and (6) the standard. The comparison of stored nourishment was made by a iodine reaction. The summary of the effects were as follows.
1. The ceasing period of flesh cell division was rather determined by the number of days after a flowering-time (25_??_30 days after full bloom) than by size of fruits. The size of flesh cell at this stage was 40_??_50μ.
2. The fruits on a tree which had less stored nourishment by a plucking last autumn became small by a small number of cells.
3. Concerning the fruits on a tree which lea-ves were plucked in spring, they were small for thesake of the bpoord growth of each cell rather than the small number of cells.
4. Therefore it came to the conclusion that the number of cells was chiefly controlled by the nourishment in a tree during the period from last autumn to the middle of May, and that the size of each cell was chiefly controlled by the nourish-ment in a tree during the period from May to the harvesting time.
