Effects of planting date and planting density on yield performance of maize | 播期和种植密度对玉米产量性能的影响

chinois. 摘　　要：以先玉335、郑单958和登海661为材料,设置3个播期和4个种植密度处理,研究播期和密度对玉米产量性能构成指标的影响。结果表明,播期推迟,其产量、生育期天数、平均叶面积指数、收获指数、穗粒数、千粒重均降低,平均净同化率依次增加,穗数无显著性差异。随密度增加,其产量、平均叶面积指数、穗数均增加,平均净同化率、生育期天数、收获指数、穗粒数、千粒重依次降低。对产量性能构成指标与播期和密度进行回归分析,表明密度对产量性能等指标的影响程度都大于播期。产量性能构成指标对产量的直接通径效应均为正效应,平均叶面积指数通过生育天数、穗数对产量有正向的间接效应,且穗数的正效应较大;平均叶面积指数通过平均净同化率、穗粒数、千粒重对产量有负向的间接效应,且平均净同化率的负效应较大。平衡协调产量性能构成指标的关系,适当提前播种和增加种植密度可增加玉米平均叶面积指数、生育期天数及穗数,有利于产量的提高。试验表明,平均叶面积指数为4.18、平均净同化率为5 g（/m2.d）、生育期天数为120 d、收获指数为0.50、有效穗数为89 000穗/hm2、单穗粒数为480粒、千粒重为290g,玉米可以实现12000kg/hm2以上产量水平。

anglais. Three varieties（Xianyu 335,Zhengdan 958 and Denghai 661）were carried,set up three planting date and four different density,the leaf area,yield and yield components were measured.The results showed that yield,growth period of days,average leaf area index,harvest index and grains per spike were decreased with planting date delayed.The average net assimilation rate was followed an increasing trend,but no significant difference between ears.yield,average leaf area index and ears were followed by an increasing trend respectively with the density increasing,average net assimilation rate,growth period of days,harvest index and grains per spike were followed by decreasing trend with the density.Regressions modeling between planting date and density on seven indicators of yield performance respectively,densities had a more effect than planting date on seven indicators of yield performance.The several indexes of yield performance had a positive effects on yield,average leaf area index had a indirect effect on yield through growing days and ears,in which ears had a lager positive effect.Average leaf area index through the average net assimilation rate,panicle,1 000-grain weight,and the average net assimilation rate,had a lager negative effects on yield.Balanced the relationship between yield performance indexes and yield,increase early-sowing and increase density properly could increase the leaf area index,growth period of days and spikelets.This study showed that yield reached to 12 000 kg/ha,average leaf area index was 4.18,average net assimilation rate was 5 g/（m2・d）,growth period of days was 120 days,harvest index was 0.50,ears was 89 000 plants/ha,grains per spike was 480,1000-grain weight was 290 g.