京白梨郁闭园树体结构改造对冠层光照分布、枝类组成与果实品质的影响

Effect of Tree Form Improvment on Light Penetration,Branch Composition and Fruit Quality in Canopy Overcrowd‘Jingbai’Pear Orchard

为解决京白梨园由于树冠郁闭造成的内膛光照不足,树体结果部位外移,果实产量低、品质差等问题,以农民传统修剪方法为对照,研究郁闭京白梨园经提干、疏除主枝、回缩等树体结构改造对冠层光照分布、枝类组成及果实品质和产量等指标的影响。结果表明,京白梨郁闭园进行树体结构改造后,树冠内部由上而下、由内及外光照条件显著改善,树冠无效光区体积较改造前降低23.0%,而适宜光区提高16.0%。改造后的京白梨树枝梢比例与结构组成变化明显,其中短枝比例较改造前提高32.7%,长枝比例则降低29.2%;同时,由于树冠内部光照条件改善,促进了树冠下层与内膛形成更多短枝。改造后果实可溶性固形物、总糖含量分别比改造前提高0.5%、3.8%,糖酸比提高了3.7。果实硬度比郁闭树果实降低1.4 kg/cm2,可滴定酸含量也降低0.07%,显著提高了果实品质。因此,京白梨郁闭园进行提干、疏枝、回缩等树体结构改造措施,可显著改善树体光照条件、促进中短枝形成、提升果实品质。

In‘Jingbai’pear orchards,overcrowd canopy can cause insufficient sunlight distribution and outward movement of fruiting parts,and it results in low yield and poor quality.Compared to many farmers‘traditional pruning methods(TPM),we studied the effect of the improved pruning method(IPM)on the canopy light distribution,branch composition,fruit quality and yield,the IPM included increasing trunk height,removing main branches and retracting branches.The results showed that compared to TPM,IPM significantly enhanced sunlight distribution in bottom and inside canopy,while the volume of ineffective sunlight area in the canopy reduced by 23.0%,and the suitable sunlight area increased by 16.0%.Meanwhile,the IPM also showed significant effect on the ratio of branch to shoot and the branch composition.The ratio of spur shoots increased by 32.7%and ratio of long shoots decreased by 29.2%.Moreover,due to the improvement of light penetration,IPM increased spur shoots in the lower and inner parts of the canopy.The investigation on fruit quality showed soluble solids content,total sugar and the ratio of sugar to acid were 0.5%,3.8%and 3.7 respectively higher in IPM compared to TPM,however,the fruit firmness and titratable acid were 1.4 kg/cm2 and 0.07%lower,respectively.In conclusion,this study suggests that improved tree pruning methods,consisting of increasing trunk height,removing main branches and retracting branches,can significantly improve light penetration inside the canopy,promote the development of spur and medium shoots,and increase the fruit quality in canopy overcrowd‘Jingbai’pear orchard.