【作者】 喻晓坪；

【导师】 袁继超；

【作者基本信息】 四川农业大学 ， 作物耕作学与栽培学， 2006， 硕士

【摘要】 玉米群体结构调节与产量的形成是玉米基因和环境条件的共同作用下通过复杂的生理生化活动和生化代谢过程完成的。本试验以紧凑型玉米正红6号和半紧凑性玉米正红2号为材料，研究了不同密度和施氮量处理对玉米的群体结构调节、子粒产量和品质形成的影响。结果表明： 1．不同类型玉米均表现子粒产量与花后的干物质积累量和成熟期干物质积累量呈线性正相关，而与吐丝期的干物质积累量存在二次函数关系，表明玉米子粒产量高低取决于吐丝以后群体干物质积累量的高低。 2．叶面积系数(LAI)、光和势(LAD)和NAR与产量关系比较复杂，拔节期和吐丝期LAI与产量呈二次凸函数关系，存在最适LAI。拔节期正红6号的最适LAI为2.4左右，正红2号LAI为2.6左右；吐丝期正红6号的LAI为3.9-4.5，正红2号的LAI为4.9-5.2；成熟期正红6号LAI为2.2左右，正红2号的LAI为2.8-2.9；对于整个生育期的主攻方向，紧凑型玉米正红6号，花前主攻LAI，花后主攻NAR；对于半凑型品种正红2号，花前主攻LAI，花后应该注意二者的兼顾。 3．密肥对玉米群体结构的影响因不同品种和不同生育期表现有差异：正红6号，密度对于群体结构的影响在整个生育期都大于施氮量的影响，而正红2号，生育前期和生育后期，密度＞施氮量，中期施氮量＞密度。 4．不同品种，不同试验地点，密肥对于产量的影响程度和大小及高产优化方案不同；同一试验地点，正红6号，密度对产量的影响远大于施氮量的影响，而正红2号，密肥两者对产量的影响差异不大；同一品种(正红6号)，不同试验地点，土壤均为砂壤，土层较厚的一台土和草坝镇，密度对产量的影响远大于施氮量的影响；而土层薄的三台土，密肥对于产量具有同等影响。 5．不同品种，不同生态条件下，两因素对品质的影响程度和趋势不同，本试验范围内，盆中丘区，同一品种不同试验地点，密肥对品质的影响相当并存在交互作用；而在盆周山区，同一试验地点不同品种均表现密肥对品质的贡献率大小顺序为密度＞施氮量。 6．本试验结果表明：正红6号在盆中丘区一台土的高产种植密度为70719.11～84735.43株／hm~2，施氮量为171.9～387.2kg／hm~2；在盆中丘区三台土高产种植密度为61888.51～82111.49株／hm~2，施氮量347.46～500.04kg／hm~2；在盆周山区高产种植密度更多还原

【Abstract】 The population structure and the yield of corn arc controlled by both corn’s genes and environmental conditions through complicated physiological activities and the processes of biochemical metabolism. This experiment, with the material of Zhenghong 6 and Zhenghong 2, studies the population structure of the corn as well as corn’s yield and quality under the conditions of the different density and amount of nitrogen. The conclusions are as follows:1. The yield of corn’s grains goes directly along with the accumulation of dry matter after florescence and in mature stage, while it is in the quadratic relation to the accumulation of dry matter in spinning stage, which indicates that the high grain production of the corn depends on a large amount of the population-dry-matter accumulation so that to improve the production, corn colony should not only have high biological production but also be well fertilized and watered in the late stage to accumulate effective dry matter.2. The leave area index (LAI) is an important index to measure the population structure.And both LAI(LAD) and NAR is in complicated relations with the yield, the relation of both LAI and yield is the quadratic relation in the elongation stage and spinning stage, therefore, there are some the most favorable LAI. The experiment shows that in the elongation stage, the most favorable LAI of Zhenghong 6 is about 2.4 and that of Zhenghong 2 is around 2.6; in the silking stage, the former is between 3.9 and 4.5 and the latter between 4.9 and 5.2; in the mature stage, the former around 2.2 and the latter between 2.8 and 2.9. In the whole gestation stage of Zhenghong 6, it is most noticeable that the LAI should be held to a certain level before florescence and so should be the NAR after florescence, and in the same period Zhenghong 2 requires the same as Zhenghong 6 before florescence but after florescence both its LAI and NAR should be insisted.3. The density and nitrogen fertilizer play different effects on the population structure of different breeds of corn in different stages. The density produces a more effective effect on the population structure of Zhenghong 6 during the whole gestation stage than the amount of nitrogen fertilizer does. As to Zhenghong 2 it does so just in the early and late更多还原