种植密度对玉米生理特性和产量构成的影响

Effects of Planting Density on Physiological Characteristics and Yield Components of Maize

[目的]研究玉米种植密度对玉米生理特性和产量构成的影响。[方法]以迪卡638为试验材料,设置a(5.25万株/hm^2)、b(6.00万/株hm^2)和c(6.75万株/hm^2)3个种植密度,分别对不同生育时期的叶绿素相对含量、叶N含量、光合有效辐射、穗层透光率和产量构成因素及产量进行分析比较。[结果]叶绿素相对含量随生育期的推移呈先上升后下降的趋势,迪卡638在3种密度处理下变化趋势是一致的,叶绿素含量最大值出现在c处理的抽雄期,叶N含量与叶绿素相对含量呈正相关。不同种植密度下的光合有效辐射和穗层透光率均随着生育期的推进,呈现出逐渐下降的趋势。产量构成因素结果表明,随着种植密度增加,迪卡638穗长、穗粗、行粒数、千粒重下降,穗行数、出籽率和产量上升,在c处理密度(6.75万株/hm^2)处理下产量达到最大值8 044.6kg/hm^2。[结论]该研究可为玉米的大面积推广种植提供理论基础。

[Objective]The effects of planting density on physiological characteristics and yield components of maize were studied.[Method]Dika 638 was used as the experimental material. The chlorophyll relative content, leaf N content, photosynthetic active radiation, spike layer transmittance yield components and yield were analyzed and compared at different growth stages with three planting densities of a (52.5 thousand plants/hm^2), b (60.0 thousand plants/hm^2) and c (67.5 thousand plants/hm^2).[Result] The chlorophyll relative content increased first and then decreased with the growth period. The variation trend of Dika 638 under three kinds of density treatments was consistent. The maximum chlorophyll content appeared in the heading stage of c treatment, and the leaf N content was positively correlated with the relative chlorophyll content.Photosynthetic active radiation and spike layer transmittance at different densities showed a decreasing trend with the development of growth period. The results of yield components showed that with the increase of planting density, the ear length, ear diameter, kernels per row and 1 000-grain weight of Dika 638 decreased, the ear row number, shelling percentage and yield increased, and the maximum yield reached 8 044.6 kg/hm^2 under C treatment density (67.5 thousand plants/hm^2).[Conclusion]This research can provide a theoretical basis for large-scale cultivation of corn.