不同密度下不同行距对玉米光合及产量的影响

Effects of Planting Density under Different Row-Spacings on Photosynthesis and Yield of Maize

试验以重庆及西南地区的最适玉米品种类型—半紧凑型品种为材料,采用4种密度(主处理)和3种行距(副处理)的两因素裂区设计,研究了重庆地区不同密度下不同行距对玉米光合速率、产量及产量性状的影响,为选育出最适合重庆及西南地区的玉米种植密度及种植方式提供理论和实践依据.试验结果表明,密度对产量有极显著影响,密度为3 500株/667m2时产量最高.密度对穗长、穗粗、行粒数有极显著影响,对百粒质量有显著影响,对穗行数和秃尖长没有显著影响;随着密度的增大,株高、穗位高增大,茎粗减少;光合速率降低,穗位叶叶面积先增大后减少.行距配置对产量有显著影响,行距配置为0.9m时产量最高.行距配置对穗部性状没有显著影响,随着行距配置的增大,株高、穗位高、光合速率、穗位叶叶面积呈先上升后下降的趋势,茎粗呈下降趋势.密度和行距配置对产量的互作效应不显著.种植密度和行距配置对产量、产量相关性状、植株性状、光合速率、叶面积有调节作用.种植密度为3 500株/667m2,且行距配置为0.9m时,有效协调了群体与个体的矛盾,产量最高,这可作为重庆及西南地区玉米种植参考.

A semi-compact maize cuhivar, which is best adaptable to the environment of Chongqing and Southwest China, was grown in a field experiment of two factor split-plot design with four planting densi- ties （main plots） and three row-spacings （sub-plots） to study the influence of planting density and row- spacing on yield and agronomic characters of maize so as to provide a theoretical and practical basis for maize cultivation in Chongqing and Southwest China. The result showed that maize yield was highly signif- icantly influenced by planting sensity, being the highest when the planting density was 3 500 plants/mu （667 m2）. Planting density had highly significant effects on ear length, ear width and kernels per row, a significant effect on 100-kernel weight and no significant effect on rows per ear and bald length. With in- creasing planting density, plant height and ear height increased, stem diameter declined, photosynthetic rate dropped and the leaf area of the ear leaf first increased and then decreased. Maize yield was significant- ly influenced by row spacing, being the highest with a spacing of 0.9 m. Row spacing had no significant effect on ear characters. With increasing row spacing, plant height, ear height, photosynthetic rate and ear leaf first increased and then decreased and stem diameter showed a downward trend. Interaction be- tween planting density and row spacing had no significant effect on yield. In conclusion, planting density and row spacing had a regulation effect on yield, yield-related traits and agronomic characters, and the combination of 3500 plants/ha and a row spacing of 0.9 m is recommended for maize cultivation in Chongqing.