抄録
Using four varieties of different types, an investigation was made on the varietal differences in the influence of removal at heading of the whole panicles or half of the spikelets of each panicle. Main results were as follows: 1. The total nitrogen and chlorophyll contents on leaf area basis were maintained higher in the whole removal and half removal treatments than in the non-treated control, while photosynthetic activity not always followed the same trend. 2. The ripened grain percentage was improved by both the treatments to greater degrees in those varieties with larger sink, i.e., Tongil and Milyang 23, than in those wlth smaller sink, i. e., T-136 and Kochihibiki. 3. The total accumulation of dry matter aftel. heading was found to decrease by the removal of whole panicles in the three varieties other than T-136.
