Assessment of yield potentiality in crop plants

新品种生产力稳定，收获指数和结实率均高于老品种。一个值得注意的发现是它们的释放量减少了。结果表明，水稻成熟前期叶面积和穗轴重增大，后期根系呼吸速率增加，从而促进水稻成熟。通过对日本温暖地区栽培的春小麦品种与国外高产品种的比较，证实日本品种库容量差，并强调在库容量和源活性方面需要进一步改进。硬秆半矮秆春小麦品种在提高产量和收获指数的同时，对施氮量也有反应，在施氮量为12 kg时，籽粒产量可达550 g/m^2，抑制营养生长和提高收获指数是提高豆科作物产量的有效途径。大豆品种“日向”的矮秆突变株密植获得高产。指出了花生中帚状亚种的早熟性和少分支对高产的贡献。在蚕豆上，每保持100株高1 m的有效茎，可收获500 g/m^2左右的籽粒;在马铃薯、甘薯和芋头上，对光合能力和块茎生长性状不同的品种进行了比较。叶面积和叶活力的增加和维持与作物块茎的生长密切相关。通过对氮素吸收和利用率以及光能吸收和利用率的测定，对代表作物进行了正确的评价。这些结果和发现为了解作物的潜在产量提供了合理和有用的建议。

The newer cultivars or rice showed a stable productivity with higher harvest index and higher percentage of ripened grains than the older ones. A notable finding was a decrease their release. It was noticed that ripening of rice incereases by larger leaf area and rachis weight per grain during early ripening stage and by higher respiration rate of roots during later stage. As the results of comparison between the cultivars grown in warm areas of Japan and foreign highly productive ones, it was certified that the Japanese cultivars have poor sink capacity and stressed that further improvement is necessary in sink capacity and accompanying source activity.The semi-dwarf spring wheat strains with stiff straws increased yield and harvest index simultaneously responding to amounts of nitrogen, and grain yield attained 550g/m^2 under N 12kg level.Suppression of vegetative growth and increase of harvest index are effective commonly for increase of yield in grain legumes. Dense planting of dwarf mutantstrain of soybean cultivar, "Hyuga" produced high yield. contribution of earliness and few branch of sub-species fastigiata to higher yield was pointed out in peanut. In broad bean maintenance of 100 effective stems of 1 m high might giveabout 500g/m^2 of grains.In tuber crops(potato, sweet potato and taro), cultivars with distinct characters in photosynthetic ability and tuber growth were compared thoroughly. Increase and maintenance of leaf area and activity are closely related with tuber growth in each crop.Based on measurements of nitrogen uptake and rate of its utilization and absorption of solar energy and its utilization, representative crops were assessed correctly.These results and findings mentioned above present reasonable and usefull suggestions for understanding of potential crop yield.