合理的行距配置可以调节群体冠层结构的光合作用。山西太谷冬小麦产量徘徊不前, 为了研究晚熟冬麦区不同行距配置对不同穗型冬小麦光合性能与群体结构的影响, 在大田条件下选用两种不同穗型品种, 在播量一致的前提下, 分别采用10 cm和20 cm两种行距配置, 研究冬小麦群体结构、光能利用和产量结构的差异。研究结果表明: 全生育期总LAI值表现为B2 高于B1, 10 cm行距配置改变了叶片的垂直分布, 尤其对多穗型小麦品种冠层(60-80 cm)叶面积的提高最为明显。在小麦植株中、上部分45-90 cm处, 两种行距配置LI%均表现为B2 配置大于B1配置, 在株高60-75 cm处, 两种行距配置LI%差异最为明显, B2 配置较B1配置LI%提高达30%以上。花后旗叶PN和孕穗期至蜡熟期群体NPR均表现为10 cm行距配置高于20 cm行距配置。四个处理的总干物质重、绿叶、茎和穗的干物质重均表现为B2>B1行距配置。两个小麦品种的B2处理(10 cm行距配置)的产量和生物产量均极显著高于B1处理(20 cm行距配置); 但经济系数则呈现B2处理(10 cm行距配置)均小于相应小麦品种的B1处理。行距配置对不同小麦品种的影响不大。表明10 cm行距配置适用于北方晚熟冬麦区。

Reasonable row spacing can adjust crop canopy structure photosynthesis. Winter wheat (Triticum aestivum L.) yield of Taigu in Shanxi, northern China can not increase for a long period time because of late timing of seeding after the harvest of soybean, and large amount of water, fertilizer and seeds. To investigate the effects of row spacing on photosynthesis and population structure of winter wheat in Taigu, two wheat varieties, Shannong 9-1 (A1) and Shannong 9801(A2), with different spike shapes, were chosen in this field trial. With the same seeding rate, two row spacing, B1 (20 cm row spacing)) and B2 (10 cm row spacing)), measurements including population structure, photosynthetic characteristic and yield structure were investigated for 2 years in Taigu. The results showed that, in the whole growing period, the LAI of B2 was higher than that of B1, B2 row spacing altered the vertical distribution of leaves especially for multi-spike wheat variety (60-80 cm). The RLI% of B2 was higher than that of B1 at middle and upper plant layers (45-90 cm) and the maximal gap reached to 30% at the height of 60-75 cm. The PN of flag leaf (after flowering) and the PNPR (from booting stage to dough stage) with 10 cm row spacing were higher than that of 20 cm row spacing. The total dry substance weight, the dry substance weight of green leaves, stems and spikes of the four treatments were all demonstrated as B2>B1. The yield and biological yield of B2 in two wheat cultivars were both significantly higher than those of B1, but the economic coefficient of B2 are less than that B1 of the corresponding varieties of wheat. It indicated that row spacing has little effect on different wheat varieties, while it has more effect on grain number per spike than other yield components. It is more suitable for late maturing winter wheat region using 10 cm row spacing.