【摘要】 在良好栽培条件下,玉米品种的产量水平在公顷4.5万株稀植时,主要是由配合力决定的,而在公顷6.0万株密植时耐密性又成为主要影响因素.耐密性是一个综合性状.耐密性强(或耐密型)玉米,是以较高配合力为前提的,不仅株型紧凑、而且还具有秆强、根系发达、结实性好、易抓苗、植株整齐度高等特点.耐密型玉米适于密植的根本原因是耐密性强.公顷11000～12000kg 高产群体,由于品种的繁茂程度、光合效率以及经济系数有差异,其主要数量指标为总光合势316.4～439.2万m~2·日/ha,最大叶面积系数4.25～5.53,净同化率5.76～7.55g/m~2·日,经济系数0.496～0.549.籽粒灌浆初期穗位处由间透光率22.8%～25.6%,近地面处8%～10%.更多还原

【Abstract】 Under good cultural situation,maize yield levels are mainly determined by the combining ability at the planting density for 45,000 plants per hectare and affected by density tolerance at the planting density for 60,000 plants per hectare. The density tolerance is a synthetic character. Better combining ability is a prerequisite for the maize with better density tolerance (or tolerant to density type). It has not only upright leaf plants but also stronger stalk, more developed roots, better kernels, better emergence seedlings and evener plants et al. The principal reason that tolerant to density maize is good for close planting is that it has better density tolerance. Because of the defferences of the luxuriant level,photosynthetic efficiency and economic coefficient of variety,the main quantity indexes of high-yielding population for 11, ,000-12,000kg per hectare are total photosynthetic leaf-area and duration(3,164,000-4,392,000m2·d·?ha-1),maximum index of leaf-area(4. 25-5. 53), net assimilating rate(5. 76-7. 55g·m-1·d-1),economic coefficient (0. 496-0. 549)and percentage of radiation (22. 8-25. 6% at ear and 8-10% near ground)at early grainfilling.更多还原