不同果袋对‘大久保’桃果实品质的影响

以晚熟桃品种‘大久保’为试验材料，研究不同纸质类型果袋（白色单层、黄色单层、外黄内白双层和外黄内黑双层）对桃成熟果实外观和内在品质的影响，以不套袋为对照，测定并比较分析不同处理的果实纵横径、果重、果实硬度、表面着色、可溶性固形物、可溶性糖、可滴定酸、维生素 C 等含量。结果表明：与对照相比，套袋处理使桃果成熟期推迟，显著降低桃果病虫果率和果锈指数，增加好果率，并显著增加了果皮亮度和果实硬度。4种套袋处理中，双层纸袋处理的病虫果率显著低于单层处理，而黄色单层纸袋平均单果重显著高于其他3个处理；双层纸袋处理的果实黄蓝色差和色调角均显著高于其他纸袋处理；而2个单层纸袋处理的红绿色差与黄蓝色差比值显著大于其他处理和对照；套袋后各处理桃果可溶性固形物、可滴定酸含量差异不显著，但使桃果的维生素 C 和可溶性糖的含量降低，综合分析，套袋可增加桃果的外观品质和商品性，提高经济效益，其中用黄色单层纸袋对福建地区晚熟桃效果最好。

Effect of Pouches on Fruit Quality of Dajiubao Peaches

Four different kinds of paper pouches （i.e.,white single-layer,yellow single-layer,yellow-outside-white-inside double-layer,and yellow-outside-black-inside double-layer）were used to study their effects on the fruit appearance and quality of late-ripening peach,Dajiubao,in a bagging cultivation.The latitudinal and longitudinal diameters,weight,firmness,surface coloration,and contents of soluble solids,soluble sugars,titratable acids and vitamin C of the bagged and bare （control）fruits were determined.The results showed that,with the bagging,the disease and pest infection rates and fruit rust index were significantly reduced,while color saturation and flesh firmness increased.Damages due to diseases and pests were lower on fruits bagged with double-layer pouches than either single-layer or control.The average single fruit weight was significantly higher than the others when the yellow single-layer pouches were used.The blue-yellow chromatic aberration and color saturation of the peaches bagged with the double-layer pouches were higher than other treatments.The red-green chromatic aberration and chromatic aberration ratio on the fruits bagged with the single-layer pouches were higher than other treatments and control.On the other hand,the differences on the soluble solids and titratable acids contents were not significant between the treatments or control.However,the soluble sugars and vitamin C contents of the bagged peaches were lower than control.Therefore,the bagging appeared to improve the apparent quality of the fruits rendering a desirable consumer perception and commercial value of the commodity.For the purpose,the yellow single-layer pouches seemed particularly applicable for the late-ripening peaches in Fujian.