Effects of Fruit-bud Pruning on Mineral Content of Autumn Leaves During Flower-bud Differentiation, Growth of Fruit-bearing Branches, and Quality and Yield of Fruits of Longan

Effects of fruit-bud pruning on the mineral content of the autumn leaves during flower-bud differentiation stage, the growth of fruit-bearing branches, and the quality and yield of fruits of longan variety Lidongben were studied. The results showed that the N, P and K contents in the autumn leaves were higher when 1/3 of the fruit-buds was retained on a tree branch or no pruning (CK) was applied than if 1/2 of the buds was removed. The contents of Ca and Mg were in a decreasing order upon 1/2 pruning > 2/3 pruning > CK. There were no significant differences observed in 4 years on the length, diameter, and leaf count on the fruit-bearing branches on the trees that had 2/3 of the fruit-buds removed. Furthermore, these fruit-bearing branches tended to produce large individual fruits (above 13.0 g), big panicles (more than 800.0 g), excellent quality, and relatively consistent fruit-bearing performance (with 14.67% differentiation between the high and low production years). Furthermore, the average annual fruit yield increased 24.20% with an improved profitability of 44.68%, as compared to 1/2 pruning. Consequently, it was concluded that retention of 1/3 of the fruit-buds on a single fruit-bearing branch was recommended for longan pruning.