Comparison of Yields and Fruit Quality between 'Matsumotowase-Fuyu' Japanese Persimmon Trees Trained to a Horizontal Trellis and Open Center Free-Standing Ones

Abstract

To reduce labor costs in the cultivation of Japanese persimmon which is prone to be too vigorous, a horizontal trellis training system was attempted as a practical method for lowering the tree height. The frameworks of an open center, 3.6 m high 'Matsumotowase-Fuyu' Japanese persimmon trees were altered to a horizontal frame at 1.8 m height on February 1992 by cutting back secondary scaffold branches at 1.5. to 1.6 m above ground level. The tree growth, yields and fruit quality of the altered trees were compared with the open-center free-standing trees control. One year after altering the framework, the canopy area on horizontally trellised trees expanded vigorously, compared with the control group. After pruning, the trees with altered the framework were left with twenty percent more lateral branches than the open center free-standing trees. Two years after altering, the number of shoots per canopy area was greater in the treated trees than in the control, but the number of shoots per lateral branches and mean shoot length did not significantly differ from the control group. Annual fruit yield was 300 kg/a higher in the horizontal trellis system than that of the unaltered free standing system group, and the number of fruits per canopy area exceeded 10 fruits/m². Over 4-year period, the horizontally trellised trees produced more flowers per lateral branch than did the open center free-standing ones. Physiological fruit drop rates were lower in horizontally trellised trees than in those of the control. Fruit on the former was significantly heavier than that on the letter. The percentage of fruit weighing more than 260 g accounted for 61.2% of the total yield in horizontally trellised trees. During the period of 80 days after blossoming to harvest, fruit diameter increased significantly faster on horizontally trellised trees than that on the free standing trees. Similarly, the commencement of fruit skin coloring and harvest time was advanced in the treated trees compared with those of the control. In conclusion, by lowering tree height the horizontal trellis training system achieves the following: decreased harvest and pruning costs, increased yield and fruit weight, improved fruit quality, and advanced maturation. These advantages indicate that this system has a strong potential as a training system that will be used extensively in the near future.