先玉335适宜栽培密度与性状指标研究

目的]寻求先玉335合理的种植密度，明确种植密度对玉米性状指标的影响。方法]以优质高产豫凑型玉米品种先玉335为试材，采用大垄双行种植方式，设4种种植密度（6．75万、7．50万、8．25万、9．00万株／hm^2），研究不同密度对产量及其相关性状指标的影响。结果]在大垄双行种植备件下，先玉335的产量随种植密度的加大呈降低趋势，在6．75万株／hm^2密度时，产量较高，玉米群体具有合理的株高和冠层结构，棒三叶叶绿素相对含量也较高。对株高、穗位高度以及LAI垂直分布的研究表明，该试验条件下，种植密度的增加会使玉米群体的抗倒伏能力降低，单株叶面积减少，群体LAI有所增加，LAI最大值出现的层次有所上升，玉米群体适宜高产的LAI在5．7左右。结论]在试验条件下，先玉335适宜的种植密度为6．75万株／hm^2；IAI最大值出现的层次随着密度的增加上移。

Preliminary Study on Proper Cultivation Density and Character Index of Xianyu 335

Objective] The study aimed at seeking rational planting density of Xianyu 335 and define the effect of planting density on maize character index.Method] With maize variety of Xianyu 335 with good quality, high yield and compact type as the tested material, the planting mode of double line at width ridge was adopted and 4 kinds of planting density were set up as 67 500, 75 000, 82 500 and 90 000 plants /hm2 and the effects of different density on yield and its relative character index were studied .Result] Under the conditions of double line planting at width ridge, the yield of Xianyu 335 showed a falling trend with the rising up of planting density, the yield was higher when the density was 67 500 plants/hm2, the maize population had rational plant height and canopy structure, the chlorophyll relative contents of three-ear-leaves was also higher.The research of LAI vertical distribution on the height of plant and ear indicated that under these test conditions, the increase of planting density would cause the decrease of the lodging resistance ability, reduction of leaf area per plant, slight rise of colony LAI, in creased level with the maximum LAI, in creased level with the maximum LAI and LAI fitting to high yield for maize population was about 5.7.Conclusion] Under these test conditions, the proper planting density of Xianyu 335 was 67 500 plants/hm2.The occurrence level with the maximum LAI moved up.