2000 Volume 69 Issue 2 Pages 182-188
The tillering ability and yield of sod-seeded rice are affected by the shading by manure crops during the intial stage. In this study, the effects of shading during the early stage of growth on the growth and yield components in rice Kibinohana were examined. Seedlings were grown in pots under 0, 50, 80, and 95% shading for 16 or 28 days after emergence in 1995, and for 25 or 34 days in 1996. The heavier the shading, the lower the plant age in leaf number during the first 2 to 3 weeks after the end of the treatment. In the shaded plants. the tillers started to emerge about 2 weeks after the shading. The tillers emerged 2 to 3 weeks after heavy shading were inferior in total number and culm diameter to those after light shading. After 95% shading, the number of tillers emerged 2 to 3 weeks after the shading, the survival rate and the spikelet number were lower than those after light shading. The spikelet number and the percentage of ripened grains were low, in the tillers emerged late. Consequently, the heavier the shading in the early growth stage, the later the tiller emergence and the lower the number of spikelets per head and the percentage of ripened grain pet plant. The heading time was also delayed by heavy shading.
