In the northern regions of Japan, the lateral buds on the main stem of a transplanted rice plant develop normally into tillers so far as they are below the lO th node or so. Those on the upper several nodes, do not elongate and remain dormant until harvest. Such upper buds, however, elongate and give ripe kernels under conditions where abandont storage of starch is favoured together with rich accumulation of nitrogen compounds in the culm and leaf sheath: They elongate readily when the tillers on the lower nodes are cut off one by one as soon as they appear and only the main stern is left or when the panicles are cut off soon after heading, or when the plant grown under some unfavourable conditions in the earlier growth such as low light intensity, lack of nutrients, is suddenly recovered after heading.