行距配置对春玉米群体冠层环境与光合特性的影响

以紧凑型玉米品种郑单958为试验材料,在密度75 000株·hm-2条件下,采用3种行距配置模式(110~0cm双株紧靠、82.5~27.5cm大垄双行和55~55cm等行距型),比较研究玉米群体冠层微环境、光合特性和产量的变化特征。结果表明,行距配置显著改变了群体冠层中光、CO2、温度和湿度等冠层微环境,合理行距配置(82.5~27.5cm)的植株上部叶片较为直立,下部叶片平展,群体内光分布较为合理,CO2分布更为均匀,花后叶绿素相对含量、LAI均高于其他2个处理,且高值持续期较长,生育后期下降缓慢,最大光合速率和表观量子效率较高,光能利用率和水分利用率亦优于其他2个处理。从产量和产量构成因素来看,大垄双行种植模式的平均产量最高,分别较双株紧靠和等行距种植模式高3.33%和2.08%,穗粒数和千粒质量的显著增加是产量较高的主要原因。

Effects of Different Row Spacing on Ecological Environment and Photosynthetic Characteristics of Spring Maize Populations

Recently, the study of row spacings on spring maize yields have become common in the pursuit of high yield. We studied the effects of row spacing on ecological environment, photosynthetic characteristics and grain yield under three row spaces in the same density of 75 000 plant·hm^-2, including double plants spacing 110 cm (double plants & wide rows), double lines spacing 82.5-27.5 cm on a wide ridge (wide-narrow rows), and equal lines spacing 55 cm (equal rows), and the maize cultivars Zhengdan 958 (ZD958) were served as material in the south of Liaoning. The results indicated as follows: population structure had a significant effect on the capture efficiency of PAR, distribution of CO₂, temperature and humidity in canopy. The treatment of wide-narrow rows had good performance on PAR penetration of canopy by modulating the angle and bending of bottom and top leaves, and the max chlorophyll content(SPAD) and LAI lasted for a long period and descended tardily at the late stage The photosynthesis, apparent quantum yield (AQY), radiation use efficiency (RUE) and water use efficiency (WUE) in the treatment of wide-narrow rows were higher than the other treatments. The yield of ZD958 was 12 740.9 kg/hm in the treatment of wide-narrow rows, 3.33% and 2.08% higher than the treatments of double plants & wide rows and equal rows, respectively. Yield gain in the treatment of wide-narrow rows was mainly due to the significant increase on spike grain number and 1 000-grain mass.