不同密度对关中灌区穴播冬小麦光合特性及产量影响

为探究不同密度处理对穴播冬小麦光合特性及产量的影响,试验对比分析不同生育期不同密度处理条件下冬小麦净光合速率、气孔导度、蒸腾速率和产量等生理指标的动态变化过程。试验采用裂区设计,以行距18cm(R1)、22cm(R2)为主区,穴距12cm(H1)、16cm(H2)、20cm(H3)、24cm(H4)为副主区,每穴粒数12粒(S1)、10粒(S2)、8粒(S3)为副区,研究田间高产栽培条件下不同行距、穴距及穴粒数配置对穴播冬小麦光合特性和产量的影响。结果表明:相同密度处理条件下,各生理指标在拔节期受影响最显著:其中拔节期叶片净光合速率、蒸腾速率、气孔导度和成熟期田间有效穗数均在H3S3水平下达到最高;小麦单株分蘖在不同密度水平下变化规律与成熟期小麦穗数表现一致;小麦叶片净光合速率、蒸腾速率和叶片气孔导度在不同密度水平下变化规律与成熟期穗粒数表现一致;小麦叶片光合指标在各生育期变化趋势呈现"M"型变化,即分别在返青期、抽穗期和灌浆期各光合指标降低,在拔节期和开花期各光合指标达到最高。行距和穴距对小麦光合特性和产量的影响具有交互性,通过选取适宜行距、穴距密度组合能够有效地调控小麦植株间微环境区域内光、热、水、肥的平衡,利于植株充分提高光合效率,增加有机物积累。因此,行距和穴距是关中地区穴播冬小麦实现稳产、增产的主要因素之一。同时,拔节期为关中地区穴播冬小麦田间管理的关键时期,生产中需加强该生长阶段的田间水肥管理以确保高产。

Effects of Different Densities on Photosynthetic Characteristics and Yields of Winter Wheat under Bunch Planting in Guanzhong Irrigation Areas

To investigate the effects of different treatments of densitiesy on the photosynthetic characteristics and yields of winter wheat under bunch planting, the dynamic changes of several eco-physical characteristics of wheat growth were measured and compared, including height, tiller,photosynthetic characteristic and yield.Three treatments were arranged in a split-split plot design.The whole-plot treatment factor was the row spacing of 22 cm or 18 cm.The subplot treatment factor was the hole spacing, including 12 cm, 16 cm, 20 cm and 24 cm.The sub-subplot treatment factor was the point grains, including 12, 10 and 8.At the same density treatment, the physiological indexes were influenced greatest at the jointing stage.And the wheat tillers, photosynthetic rate, transpiration rate, stomata conductance and effective panicles were the highest in 20 cm hole spacing and 8 point grains, while the effects of density treatments on the tillers of wheat at jointing stage were consistent with the effective panicles at mature stage.The height of wheat is mainly affected by row spacing and the height was highest in 16 cm hole spacing under the same row spacing and point grains.Clear interaction between the effects of row spacing and hole spacing, the jointing stage was the critical periods for field management in winter wheat under bunch planting.Reasonable irrigation and fertilizer managements are needed at the growth stages,so as to guarantee higher yield of winter wheat in arid region.