2011 Volume 10 Issue 3 Pages 359-366
Characteristics of dry matter production and assimilate partitioning in conventionally cultivated trees, trees that were sheet mulched from Aug.7 (78 days after full bloom) to Dec.18 (harvest time) and trees that underwent trunk girdling on Aug.23 (94 days after full bloom) were determined in 43-year-old satsuma mandarin (Citrus unshiu Marcow.). In the conventionally cultivated trees, the land area occupied by the tree canopy was about 7.4 m2 and the leaf area index was about 4. The yield per tree was about 67 kg, that per unit land area occupied by the tree canopy was 9.1 kg·m−2, and that per unit leaf area was about 2.3 kg·m−2. There were no significant differences in the land areas occupied by tree canopy, leaf area indices and fruit productivities of sheet-mulched trees and trunk-girdled trees, compared to those of conventionally cultivated trees. Total soluble solids content was highest in sheet-mulched trees, followed by that in trunk-girdled trees, and was smallest in conventionally cultivated trees. In conventionally cultivated trees, annual dry matter gains per tree were about 16.5 kg. The annual dry matter gains of fruit, new leaf, new root, old wood, old root and new shoot were about 10.6, 2.7, 1.3, 0.8, 0.7 and 0.4 kg, respectively. The dry matter gains per unit leaf dry weight and per unit leaf area were about 3.75 g·g−1 and about 560 g·m−2, respectively. The percentages of assimilates partitioned into fruit, new leaf, new root, old wood, old root and new shoot were about 64, 16, 8, 5, 4 and 3%, respectively. There were no significant differences in the sheet-mulched trees and trunk-girdled trees in the annual dry matter gains per tree and the percentages of assimilates partitioned into each organ, compared with those in the conventionally cultivated trees, except for the percentages of assimilates partitioned into new root, which were significantly smaller. There were no significant differences in the dry matter gains per unit leaf dry weight or per unit leaf area in the sheet-mulched trees and trunk-girdled trees, compared with those of the conventionally cultivated trees.
