Researches On Relationship Between The Photosynthesis,Canopy, And Fruit Quality Of Different Shapes In Citrus

The relationship between canopy, photosynthesis and fruit quality of Citrus unshiu Marcow and Citrus reticulata Blanco were investigated in this paper. Main results were as follows:1. In Satsuma mandarin, the MLA of open-center shape was significantly larger than that of natural-round tree shape, the Light Extinction Coefficient of open-center shape was significantly lower than that of natural-round tree shape. For GuoqingNo.4, the LAI of open-center shape of during June to October was significantly lower than that of natural-round tree shape, and LAI of the two shapes both reached the highest value in August (open-center shape2.842, natural-round tree shape5.353); the TCDP and TCRP of open-center shape were significantly higher than that of natural-round tree shape, the maximums of TCDP of two shapes (0.279,0.142in respective) both occurred in June. For Guijing, the TCDP of natural-round shape in zenith angle6.5°was significantly smaller that of open-center shape.2. For Guoqing No.4, the Pn of open-center shape was significantly higher than natural-round shape during July to October; the Evap and Gs were both significantly higher than that of natural-round shape during June to October; during August to October, the Ci of open-center shape was significantly lower than that of natural-round shape. For Guijing:the Gs in inside crown and southeast of backbone of open-center shape were higher than that of natural-round shape; the Ci in low level of open-center shape were lower significantly than that of natural-round shape.3. The fruits of the two tree shapes of Guoqing No.4mainly distributed from0.5m to1.5m height of the canopy vertically, the yield of open-center shape and natural-round shape was respectively102.36kg and87.20kg per tree.4. For Guoqing NO.4:the Soluble solids content of inside crown and southeast crown of in open-center shape were significantly lower than that of natural-round shape; the titrable acidity content of fruits in low layer of open-center shape was significantly lower than that of natural-round shape; the Vitamine C content of fruits in low layer of open-center shape was significantly higher than that of natural-round shape. For Guijing: the Fruit index of low level in open-center shape was significantly higher than that of natural-round shape.5. In Satsuma mandarin, the LAI was negatively correlated with Evap; the MLA was positively correlated with Pn, the TCDP was positively correlated with the Evap and Gs; the Vitamin C content of fruits was positively correlated to Eva.6. The mean LAI of big canopy shape which was2.962was significantly lower than that of small canopy shape which was3.479, MLA of big canopy shape which was21.987°was significantly smaller than that of small canopy shape which was31.518°.7. The Evap of inside crown of big crown shape (average value0.48mmol·m-2·s-1) was significantly lower than that of small crown shape (average value0.85mmol·m-2·s-1); the Gs of inside crown and southeast crown of big crown shape were significantly lower than that of small crown shape; the Pn and Ci of inside crown of big crown shape was significantly lower than that of small crown shape.8. The soluble solids content of low layer in big crown shape was significantly higher than that of small crown shape; the Vitamine C content of southeast crown of big crown shape was significantly lower than that of small crown shape.9. The MLA in sparse Ponkan (40.003°) was significantly larger than that of dense Ponkan (38.636°), TCDP of sparse Ponkan (0.096) was significantly higher than that of dense Ponkan (0.042).10. The Evap in low layer of dense Ponkan (0.318mmol·m-2s-1) was significantly higher than that of sparse Ponkan (0.258mmol·m-2s-1).11. The fruit index of sparse Ponkan was significantly higher than that of dense Ponkan; the titratable acidity content of the fruits in low layer and southeast crown of sparse Ponkan was higher than that of dense Ponkan.It could be concluded from the above results that in Satsuma mandarin, transmission of light and photosynthetic capacity of the open-center shape were better than that of the natrual-round shape; the yield per tree of the open-center was higher than that of the natural-round shape. Therefore the open-center shape is suitable for Satsuma mandarin.