密度对不同品种水稻生育及产量构成因素的影响

水稻不同品种之间生长量差异较大，但不同密度间差异小．不同品种在稀植（３０×２６ｃｍ）处理下有效分蘖终止期同密植（３０×１３ｃｍ）相比，普遍向后延迟，且其叶龄指数分别为２０和６４，但最高分蘖期无明显差异，其叶龄指数分别为８０和７９；二次分蘖穗明显增多，提高了有效分蘖率；茎基部伸长节间短而粗，上部节间拉长，折损重大，抗倒能力增强，不同品种间都有同样的趋势．产量与结实率（ｘ１）、千粒重（ｘ２）、ｍ２穗数（ｘ３）、穗粒数（ｘ４）间回归方程为经产量方差分析结果表明不同品种、不同密度间和互作差异不显著．据各种农艺性状的终合分析，秋田３２是较适合烯植栽培的优良品种．

The Impact of Density on Rice Development and Yield Component of Different Varieties

The difference of increment is significant among different varieties, but it is insignificant among different densities.Thin planting delayed the end of active tillering compared to thick planting.when the highest tillering period came to an end, the leaf age indexes were 80 and 79,the secondary tillering ear increased,so the rate of effective tillering was improved.The elogative internode at the bottom of the stem was short and thick,the upper internode became long,lose was heavy,enhancing its capacity to the resistance to lodging,there are the same trends in different varieties.The regression equation of yields with a setting percentage (x1),thousand hemal weight(x2),strike number per unit area(x3),kernal number per ear(x4) was Y =-0. 163 0. 1843x1 0.0167x2 0.0005x3 0.0011X4.The result revealed by variance analysis was that:there were no significant differences among different varieties densities.According to the analysis of various agronomical characters:Qiutian-32 is.the superior variety for thin planting cultivation.