Abstract
The experiment was undertaken to determine the effect of phosphorus deficiency on the development of tillering bud in rice seedling by water culture method. Design of experiment, composition of nutrient solution, materials and methods of experiment etc. were the same as the previous report. The nutrient solution lacking in phosphorus used for this study omitted the P2O5-ion from the standard nutrient solution shown in table 2 in the previous report. The results are summarized as follows; In the rice seedling which has been grown under phosphorus deficient condition since the seedling of rice plant: 1. In case the plant was supplied with phosphorus since the early stage of the 4 h foliage leaf, the 2nd tailoring bud grew fairly well. 2. In case the plant was supplied with phosphorus since the late stage of the 5th foliage leaf, the development of the 2nd tailoring bud was remarkably inhibited but the 3 rd tailoring bud grew well. 3. In case the plant was supplied with phosphorus since the middle stage of the 6 h foliage leaf, not only the development of the 2 d tillering bud but also that of the 3 rd one were remarkably inhibited, but the 4th tillering bud and the following 5th, 6th, 7th etc., showed remarkable growth. 4. In case the plant was grown under phosphorus deficient condition throughout the whole growing periods of the plant, all the tillering buds in the plant were rested to grow. From these results, the effects of phosphorus deficiency on the development of tillering bud in rice seedling were nearly the same as those obtained in the case of nitrogen deficiency, but the degree of the effects in the case of phosphorus deficiency was not so remarkable as those in the case of nitrogen deficiency.
