不同行距配置方式对夏玉米冠层结构和群体抗性的影响

为探究行距配置方式对冠层微气象因子及群体抗逆性的影响,明确夏玉米适宜的行距配置方式,在方城和辉县设置大田试验,以3个不同株高类型的玉米杂交种为材料(中秆品种郑单958、高秆品种先玉335和矮秆品种512-4),设置2个种植密度(60 000株hm–2和75 000株hm–2),研究了5种行距配置方式(50 cm、60 cm、70 cm、80 cm等行距和80 cm+40 cm宽窄行)下冠层结构和群体抗逆性的变化。结果表明,不同株高类型杂交种在相同密度下,随行距扩大,株型变得松散,穗部叶片叶向值减小,并偏离种植行,向种植行垂直方向发展,冠层温湿度降低,群体抗逆性增强,但冠层光照截获率降低,产量也随之减少。对比发现,不同品种和密度下,60 cm等行距能够较好地协调冠层微气象因子与玉米产量的关系,叶片分布适宜,冠层温湿度和光能分布合理,显著提高了中下部的光能截获率,病虫害和倒伏的发生率较低,获得最高产量的频率最高,且适宜机械化田间作业,建议作为适宜黄淮海地区推广的种植方式。

Effects of Different Row Spaces on Canopy Structure and Resistance of Sum-mer Maize

In order to explore the effects of row spacing on canopy structure and stress resistance, and identify the appropriate row spacing suitable for the development of agricultural mechanization, field experiments were conducted at Fangcheng and Huixian, using three types of maize hybrids (Xianyu 335 is a high plant, Zhengdan 958 is a middle high plant, and 512-4 is a dwarf) with two plant population densities (60 000 and 75 000 plant ha^-1) and five row spaces (50 cm, 60 cm, 70 cm, 80 cm, and 80 cm+40 cm). The results showed that, for treatments with equal rows spacing under the same plant density, with the increasing of row spaces, different hybrids had a leave type and decreased leaf orientation value (LOV), their growth deviated from the plant rows, and trend to perpendicular to row; canopy temperature and humidity decreased, light interception and yield were reduced as well, while resistance to disease and insect was improved. The treatments with 60 cm row spacing can reasonably coordinate the relationship between the canopy microenvironment and yield, resulting in appropriate distribution of canopy leaves, suitable canopy temperature and humidity, maize light interception, especially, with the high light interception rate in the lower part of the canopy, and the significantly increased resistance to stresses, different hybrids with two densities got highest yield frequently in treatments with 60 cm of row spacing regardless of the varieties with different plant heights at planting densities, which so suitable for mechanical farming and field management. Therefore, we suggest that 60 cm is the optimal row spacing for summer corn in Huanghuaihai Region.