不同树形柑橘冠层春梢、叶片营养及果实的空间分布

Spatial distribution of spring shoot,leaf nutrition and fruit in citrus canopy with different tree shapes

【目的】研究不同柑橘树形春梢、叶片营养及果实的空间分布,以期筛选出适宜重庆三峡库区奥林达夏橙的最优树形。【方法】以自然圆头形、开心形、篱壁形和主干形4种不同树形的奥林达夏橙植株为试材,调查分析冠层春梢数量、叶片矿质营养及果实空间分布变化。【结果】抽生春梢总量以开心形最多,为1249枝。较其他3种树形,圆头形枝梢多分布在树冠上层和外部,占总枝梢的58.39%和79.32%,呈蛋壳状。各树形叶片N、Ca、S、Fe、Cu含量均呈从上至下、从外向内降低的趋势,不同树形间,叶片平均N、P、Ca、S、Fe、Cu含量均以圆头形最低。各树形果实多集中于树冠中上层及外部,果实品质以上部和外部的较好。各树形间,单株产量、果面色泽综合指标(CCI值)、可溶性固形物(TSS)、固酸比、维生素C(VC)含量以开心形最高,较圆头形分别高出58.07%、11.68%、5.93%、6.51%和8.35%,且达显著水平。【结论】在重庆三峡库区奥林达夏橙栽培中,开心形树形可以通过改善光照、增强光合、扩大结果面积、改良枝组结构、优化矿质营养供应,从而提高果实品质,是该地区最理想的树形。

【Objective】The spatial distribution of spring shoots,leaf nutrition and fruit of different citrus tree shapes was studied in order to screen the best tree shape suitable for Olinda Valencia orange in the Three Gorges Reservoir Area of Chongqing.【Method】The number of spring shoots in canopy,mineral nu-trition in the leaves and spatial distribution of fruits of Olinda Valencia orange plants with four different tree shapes,namely,natural round head,open center,hedge wall and trunk,were studied and analyzed.【Result】The total number of sprouting spring shoots was 1249,with the most open shape in the middle.Compared with the other three tree shapes,the round headed branches are mostly distributed in the upper and outer parts of the crown,accounting for 58.39%and 79.32%of the total branches,respectively.The contents of N,Ca,S,Fe and Cu in leaves of different tree shapes decreased from top to bottom and from outside to in-side.Among the different tree shapes,the average contents of N,P,Ca,S,Fe and Cu in leaves were the low-est in the round head shape.The fruits of different tree shapes are mostly concentrated in the upper middle layer and outside of the canopy,and the fruit quality is better in the upper part and outside.Among the tree shapes,the yield per plant,comprehensive index of fruit surface color(CCI),total soluble solids(TSS),solid acid ratio,and vitamin C content(VC)of the open center shape were the highest,58.07%,11.68%,5.93%,6.51%and 8.35%higher than those of the round head shape,respectively,and reached a signifi-cant level.【Conclusion】In the cultivation of Olinda Valencia orange in the Three Gorges Reservoir Area of Chongqing,the open center tree shape can improve the fruit quality by improving the light,enhancing photo-synthesis,expanding the fruit area,improving the branch group structure,and optimizing the mineral nutri-tion supply,which is the most ideal tree shape in this area.