2006 Volume 5 Issue 3 Pages 277-282
Seasonal changes in the starch contents of leaves, shoots and roots, and the photosynthetic rate of the alternate-bearing ‘Aoshima Unshu’ Satsuma mandarin were investigated from fall to spring. Off-year trees showed higher starch levels in the leaves, shoots and roots from fall to spring than on-year trees. Accumulations of starch were observed earlier in roots than in other organs. The starch contents in the roots of off-year trees increased from November and the starch contents of on-year trees increased from January in Shizuoka. The organs showing the strongest concentrations of starch were the roots, and the months were November to February.
Photosynthetic activity of Satsuma mandarin was observed in winter, indicating that photosynthesis by the leaves plays a role in starch accumulation in the roots during winter.
Relationships of the negative correlation were found between the starch content of the roots in December and the numbers of flowers (number of leaves/number of flowers) the following spring. These results show that the numbers of flowers can be forecast from the content of roots that were collected in the winter of the same season.
