行距配置对‘兰考矮早八’小麦后期群体冠层结构及其微环境的影响

EFFECTS OF ROW SPACING IN WINTER WHEAT ON CANOPY STRUCTURE AND MICROCLIMATE IN LATER GROWTH STAGE

在大田试验条件下,研究了在同一密度(375×104株.hm-2)下,行距配置对大穗型冬小麦(Triticum aestivum)品种‘兰考矮早八’后期群体冠层结构、冠层微环境及产量构成的影响。结果表明,冠层叶面积指数随着行距的增大而减小;而冠层开度随着行距的增大而增加。行距配置还可改变小麦冠层微环境,冠层不同层次的光截获及消光系数均随着行距的增大而减小;随着行距增加,冠层不同层次的温度升高,而湿度下降;随着行距缩小,冠层不同层次的CO2分布更趋均匀,有利于群体光合作用。通过缩小行距,能够使植株分布均匀,竞争减弱,使产量构成因素实现最佳配置,从而获得较高的产量。从该研究看,15cm行距的产量最高,可作为该类品种的较佳行距配置。

Aims Row spacing is a cultivation technique used for many field crops, but not wheat, for which traditional row spacing of 20 cm is used regardless of spike-type wheat cultivar. Our objective was to examine the effects of row spacing on canopy structure, its microclimate and yield in heavy-ear winter wheat, Triticum aestivum . Methods We conducted a field experiment on the farm of National Engineering Research Center for Wheat, Zhengzhou, China, using heavy-ear winter wheat cultivar ‘Lankao Aizao 8＇. Three row spacing treatments （15, 20 and 30 cm） were used in a randomized complete block arrangement with three replications. Important findings Leaf area index decreased and canopy openness increased with increased row spacing. Moreover, light interception at different layers, extinction coefficient, and relative humidity decreased, canopy temperature at each layer increased, and the spread of carbon dioxide was unchanged. Yield could be increased by reducing row spacing to have an even plant-to-plant distribution that could weaken competition. Our finding that 15 cm row spacing was beneficial to canopy structure and yield indicated that heavy-ear winter wheat cultivar ‘Lankao Aizao 8＇ should not be planted in conventional 20 cm row spacing.