【摘要】 研究认为在结角层中的上层角果经济性状最好,下层渐差,各层单位面积角果皮的生产力自上而下随累计角果皮面积指数的增加而降低,两者呈二次方程关系。角果的籽粒重量不仅与开花先后有关,更主要的与光照条件有关。各一次枝果序的生产力与它在结角层中位置的高低和果序的长度有关。理想的结角层一次枝序的结角起点与主序基本相平,并均有较长的果序和较高的生产力。更多还原

【Abstract】 Mature rape pods were sampled layer by layer at intervals of 10 cm in the crop canopy from 76 fields of 3 sites in north Jiangsu in 1979-82, and their economic characters examined. It was found that the pods in the middle and upper layers had the best economic characters.The lower the pods were located, the poorer they were in economic characters. The productivity of pods in the podding layers was affected not only by the order of anthesis, but to a greater extent by the illumination condition in different positions. The productivity per unit pericarp area (PPA) of pods in the upper and middle layers was higher than that in the lower layers. PPA decreased with the increase in accumulative pericarp area indexes (PAI), which may be described by a quadratic equation. The upper limit to PAI was 5 in Yangzhou city and 6 in Suniing County. The productivity of the pods on primary branches was related to the position and length of infructescences. The podding layers are preferably to consist mainly of the main stem and primary branches which have fairly long infructescences and start podding nearly at the same height, thus forming a thick and productive podding sectiton in the crop canopy.更多还原