密度对大豆群体叶面积指数及干物质积累分配的影响

Effect of Density on Leaf Area Index,Dry Matter Accumulation and Distribution in Soybean Population

在大田条件下,以垦农4号为材料,研究了大豆在5种密度条件下的叶面积指数及干物质积累分配规律。结果表明:叶面积指数在一定密度范围内随密度增加呈增加趋势,R5期叶面积指数主要集中在冠层中上部;干物质阶段积累量、日积累量以及阶段积累量占总积累量的比例,均呈单峰曲线变化。干物质阶段积累量随密度的增加而增加,单株干物质日积累量随密度的增加而降低;单位面积株重、茎重、叶重、叶柄重及荚重均随着密度增加呈增加的趋势,R5期干物重主要集中在冠层中下部,并随着密度的增加干物重的重心有上移的趋势;随种植密度增加,群体内单株的荚数、粒数和粒重逐渐减少。种植密度对叶面指数、干物质积累分配及产量影响显著。种植密度为36万株.hm-2时,群体产量最大。

Five planting density of Kennong 4 were set,plants were sampled at V4,R1,R3,R5,R6 stage and the change law of leaf area index（LAI） and dry matter（DM） accumulation and distribution in five soybean populations were determined.LAI increased with the increase of planting density at a certain range.LAI at R5 stage concentrated in the upper and middle canopy.DM phase accumulation,daily accumulation and of total accumulation showed a single peak curve.DM phase accumulation increased with increase of planting density and daily accumulation decreased with increase of planting density.Whole plant,stem,leaf,petiole and pod weight of unit area increased with the increase of planting density.Dry weight at R5 stage concentrated in the bottom and middle canopy,and the center of dry weight increased with the increase of planting density.The pods number,seeds number and seed weight of single plant increased as the the density decreased.The planting density had significant effects on leaf area index and dry matter accumulation and distribution and yield.The yield was the highest at the planting density of 3.6×1055 plants·ha-1.