轮台白杏开心形树形冠内光分布特征

Light Distribution Patterns in the Crown of Open-vase Form of Armeniaca Vulgaris 'Luntaibaixing'

【目的】通过对轮台白杏开心形树形冠内光分布的解析,旨在深入了解盛果期轮台白杏生产园典型树体结构及其光能利用现状,为其整形修剪提供理论依据。【方法】采用等体积(50 cm×50 cm×50 cm)树冠立体分隔法,利用LAI-2000冠层分析仪和LI-191线状量子传感器测定每一树冠分隔体内叶面积指数、透光率和光合有效辐射的日变化及时节变化。【结果】盛果期轮台白杏生产园冠层消光系数(K)为0.808 5;冠内相对光合有效辐射强度上层>中层>下层,中部和内膛有交错,小于外围,在14:00达到高峰;冠内相对光合有效辐射强度随时节变化逐渐减小,叶幕稳定后冠内整体相对光合有效辐射强度在70%以下,无效光区占树冠体积的67.19%。【结论】轮台县盛果期轮台白杏生产园开心形树形主枝开张角度太小,冠层消光系数偏大,冠内光照分布不均匀,无效光区占树冠比例过高,不利于树冠对光能的有效利用。

【Objective】Through the analysis of light distribution in crown of open-vase form of Armeniaca vulgari＇Luntaibaixing＇,the research aimed at understanding typical tree structure and its light energy utilization status at A.vulgari＇Luntaibaixing＇ prosperous fruit stage,and to provide theoretical basis for its training and pruning.【Method】Adopted equal volume（50 cm×50 cm×50 cm） crown three-dimensional space method,and used LAI-2000 canopy analyzer and LI-191 linear quantum sensor to measure the diurnal variation and season changes each crown＇s disjunctive body leaf area index,light transmittancy and photosynthetically active radiation.【Result】The crown extinction coefficient（K） reaches 0.808 5 at A.vulgari＇Luntaibaixing＇ prosperous fruit stage;the relative photosynthetically active radiation intensity order inside the crown is the uppermiddlelower,the centre and chamber inside have crisscross,and the radiation intensity is less than periphery,it reaches peak at 14：00;The relative photosynthetically active radiation intensity inside the crown decreases with time changing,after the leaf screen is relatively stable,the crown photosynthetically active radiation intensity in under 70%,invalid light area accounts for 67.19% of the crown volume.【Conclusion】The primary scaffold opening angle of the open-vase form at A.vulgari＇Luntaibaixing＇ prosperous fruit stage in Luntai County is too small,tree crown extinction coefficient is too big,light distribution inside the crown is uneven invalid light area accounts for a high proportion of the crown,which is unfavorable to the effective use of light energy.