南疆间作模式下扁桃树形差异对间作区域光环境及冬小麦相关产量指标的影响

Effect of Tree Form on Intercrop Area Light Environment and Grain Yield Related Indexes of Wheat in Almond-Winter Wheat Intercropping Systems in Southern Xinjiang

【目的】南疆地区间作种植模式下,研究成龄扁桃4种不同树形树体结构、枝叶分布差异;树形对间作区光合有效辐射(灌浆期)分布、日变化规律及小麦产量构成指标差异,为南疆扁桃-冬小麦间作模式选择适宜高光效树形提供一定的理论依据。【方法】以11年生扁桃(晚丰)-冬小麦(新冬20号)间作模式为研究对象,设主干分层形、高干开心形、开心形和小冠半圆形四个树形结构处理,对其树冠结构指标、枝条及产量分布范围进行调查;对间作区域光合有效辐射分布及日变化规律、小麦产量构成指标进行分区测定。【结果】不同树形处理树冠体积、枝量、单位体积枝量、不同区域枝条分布比例、单株负载量之间均存在一定差异;树形对不同间作区域PAR强度和日变化规律存在影响较大,影响程度由高至低依次为开心形、主干分层形、高干开心形和小冠半圆形;树形对不同间作区域小麦产量构成指标存在较大影响,部分差异达到极显著水平,不同区域小麦千粒重、单穗粒重与PAR日均值呈极显著正相关关系。【结论】树冠对光能的拦截受树冠体积、枝条量、枝条分布的共同影响,树冠截光造成的遮阴胁迫是盛果期扁桃-小麦间作系统中小麦籽粒减产的主要原因之一。小冠半圆形和高干开心形树形间作区光环境优于其它2个树形处理,对间作小麦产量影响小。

【Objective】This projects aims to study the crown structure,shoots distribution between various tree forms,and the photosynthetically active radiation（ PAR） distribution and change regularity and winter wheat grain yield difference in various intercrop area caused by almond tree crown structure in Southern Xinjiang. 【Method】Use 11 a old almond（ Wanfeng）- winter wheat（ Xindong 20） intercropping system as materials,set 4 treatments as trunk- delaminating shape,high trunk open centre shape,open and little crown semicircle shape. Investigate the tree structure,shoots and almond nuts distribution; determinate the PAR intensity change regularity and wheat grain yield components index in various intercrop area. 【Result】There were various canopy volumes,quantity of branches,number of branches in unit volume,the proportion of different regional branches distribution and tree lode between tree froms. The daily average value and daily variation trend of PAR in various intercropping areas were largely influenced by tree forms,and the influence degrees from high to low in order were open center shape,trunk- delaminating shape,high trunk open center shape and little crown semicircle shape. There were large differences in wheat indicators of yield components between tree form treatments,some difference reached a significant level. There was significant positive correlation between wheat kilo grain weight and PAR daily average value（ grain- filling stage）. 【Conclusion】Light interception of tree crown is influenced by crown volume,number of brunches and brunch distribution.High trunk open centre and little crown shape tree from intercropping area light environment is better than the other two forms. In adult almond- winter wheat intercropping system light competition is one of the main reasons of wheat production reduction.