Effects of Some Cultural Conditions on the Development in Later Growth Stage of Rice Plant in the Ill-drained Paddy Field

[摘要] To clarify the rice plant growth cultured in the ill-drained paddy field in the Hokuriku district, the authors investigated the relation between yield and several conditions differing in spacings, methods of nitrogen fertilizer dressing, and water managements, with special reference to the growth analysis during the ripening stage. The results obtained may be summarized as follows. 1. Such cultural conditions as thick planting, double row planting, split application of nitrogen fertilizer, midsummer-drainage were effective in increasing yield. 2. Number of both panicles and spikelets, leaf area and top dry weight per unit field area at heading time, had not close relation with yield. 3. Three curves were drawn through the levels of light extinction coefficent in the figure illustrating the relation between NAR and nitrogen content in the leaf-blade during the ripening stage. 4. Such properties as optimum leaf area, high nitrogen content and good arrangement of leaves during the ripening stage increased both NAR and RGR, and resulted in increasing yield.

[学科分类] 农业科学（综合）