Abstract:

To explore the effect of different soil water content on citrus fruit quality， the 10-year-old ‘Yichang mandarin orange’ was as the object in 2018—2020， and 3 treatments （T1： 23%~26%； T2： 20%~23%； T3： 17%~20%） of soil water content were set in the young fruit period， fruit expansion period， and color change and sugar-increasing period. The quality of citrus was analyzed by measuring total fruit weight， total pulp weight， juice weight， edible rate， juice yield， fruit shape index， soluble solids， total sugar， titratable acid and Vc content. The results showed that the soil water content in the young fruit period was extremely significantly positive correlated with the fruit shape index， the soil water content in the fruit expansion period was significantly negatively correlated with the total sugar content， and the soil water content in the color change and sugar-increasing period was significantly positive correlated with the fruit shape index， and was significantly negatively correlated with the total sugar content. With the decreasing of soil moisture content， the weights of whole fruit， fruit weight and juice all showed downward trend， the total sugar content showed upward trend， and the content of soluble solids increased firstly and then decreased. The higher the soil moisture content in the young fruit stage and the color-changing sugar-increasing period， the higher the fruit type index； the lower the soil moisture content in the fruit swelling period and the color-changing sugar-increasing period， the higher the fruit sugar content. When the soil water content was 23%~26%， the shape quality was best and flavor quality was medium. When the soil water content was 20%~23%， the flavor quality was best and the shape quality was medium. When the soil water content was 17%~20%， the flavor and shape quality were worst. So it was recommended that the soil water content should be adjusted to 20%~23% during actual citrus planting.

Key words: citrus, soil moisture content, fruit quality, membership function, significance analysis

摘要：

为探究不同土壤含水量对柑橘果实品质的影响，以10年生‘宜昌蜜柑’为研究对象，于2018—2020年在柑橘幼果期、果实膨大期和转色增糖期设置3个土壤含水率处理（T1：23%~26%；T2：20%~23%；T3：17%~20%），对不同处理下柑橘的全果重、全果肉重、果汁重、可食率、果汁率、果形指数、可溶固形物、总糖、可滴定酸、Vc含量等指标进行分析。结果表明，在幼果期，土壤含水率与果形指数呈极显著正相关；在果实膨大期，土壤含水率与总糖含量呈显著负相关；在转色增糖期，土壤含水率与果形指数呈现显著正相关，与总糖含量呈显著负相关。随着土壤含水率的降低，柑橘全果重、全果肉重和果汁重均呈现下降趋势，总糖含量呈上升趋势，可溶固形物含量先上升后下降。综上所述，幼果期和果实转色增糖期的土壤含水率越高，果型指数越高；果实膨大期和转色增糖期土壤含水率越低则果实含糖量越高。土壤含水率为23%~26%时，柑橘果实外形品质最佳，风味品质中等；土壤含水率为20%~23%时，果实风味品质最佳，外形品质中等；土壤含水率为17%~20%时，果实外形及风味品质均较差。因此，综合考虑建议在实际柑橘生产中，土壤含水率以20%~23%为宜。

关键词: 柑橘, 土壤含水率, 果实品质, 隶属函数, 显著性分析