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以江苏春玉米品种苏玉30、苏玉20和农大108为试验材料,在6.0、7.5和9.0万株·hm-2 3个密度条件下,研究高产条件下种植密度对春玉米品种产量、干物质积累、籽粒灌浆及光合速率的影响。结果表明:3个玉米品种的群体干物质积累量随密度的增加而增加,而单株产量、收获指数均随密度的增加而降低,群体产量随密度的增加呈先增加后降低的趋势。3个品种在7.5万株·hm-2密度下群体产量均达到最大值,苏玉30和苏玉20在各密度下的产量均高于农大108。与农大108相比,苏玉30、苏玉20在高密度下具有较高叶面积指数(LAI)、光合速率(Pn)、叶绿素含量(SPAD)、理论粒重(A)、最大灌浆速率(Gmax)、灌浆活跃期(P),为其干物质的积累和高产的形成奠定了基础,具有耐密植的特点。适当提高种植密度和选用耐密品种有利于江苏春玉米产量潜力的挖掘。
Jiangsu spring maize varieties Suyu 30, Suyu 20 and Nongda 108 were used to study the effects of planting density on the yield and dryness of spring maize varieties under the conditions of 6.0, 7.5 and 9.0 million hm-2 density. Effects of Material Accumulation, Grain Filling and Photosynthetic Rate. The results showed that the dry matter accumulation of three maize varieties increased with the increase of density, while the yield per plant and harvest index decreased with the increase of density. The population yield increased first and then decreased with the increase of density. The yield of three cultivars reached the maximum under the density of 75,000 hm-2. The yield of Suyu 30 and Suyu 20 was higher than that of Nongda 108 at all densities. Compared with Nongda 108, Suyu 30 and Suyu 20 had higher leaf area index (LAI), photosynthetic rate (Pn), chlorophyll content (SPAD), theoretical grain weight (A) and maximum filling rate Gmax) and active period of grain filling (P), which laid the foundation for the accumulation of dry matter and the high yield formation. Appropriate to increase the planting density and selection of resistant varieties is conducive to the production of spring maize potential of mining.