① Plastic surgery
Persimmon modeling should be combined with variety characteristics. Varieties with weak apical dominance, many branches and open crown, such as pomegranate persimmon, can be shaped into straight branches or inclined stems; For varieties with strong dryness, sparse distribution and strong top advantage, such as mopan persimmon, it is advisable to adopt straight-dried sparse layer shape or round head shape. In production practice, we should make the best use of the situation and vary from tree to tree according to the growth and fruiting characteristics of varieties. Straight stems and inclined stems are easy to shape, while straight branches are difficult to shape only by twisting branches because persimmon branches are brittle. Usually, the reverse polarity grafting method is adopted (that is, the direction of abdominal grafting is changed, the incision is upward and the bud tip is downward). This method can effectively control the tree potential with strong polarity, and is the first choice of persimmon vertical branch modeling technology.
② Pruning
Growth pruning has the following measures:
Wipe the bud
According to the needs of the tree, the dense, misplaced and overgrown branches and buds are erased, so as to cultivate strong branches, form flower buds and bear fruit early.
Pick a heart
Leave 20 cm for the strong branches to pick the core, promote the secondary branches, and cultivate the fruiting mother branches.
ring
For strong trees that don't bear fruit, they can be girdled at the end of blooming to make them bear fruit earlier.
blossom and fruit thinning
Flowers are sparse when budding, and fruits are sparse after flowering. The amount of fruit left varies with varieties, with large fruit type per branch 1 fruit, medium fruit type with 2 fruits per branch and small fruit type with 3 fruits per branch. Sparse front fruit, dense fruit and base fruit. Most of them leave the fruit in the middle.
When pruning in winter, attention should be paid to the skeleton cultivation of potted persimmon trees in their young stage. For the robust branches of the year, pruning is used to promote branching, thus cultivating a more compact tree type.
After potted trees enter the fruiting stage, it is still necessary to restrain the excessive growth of developing branches and promote the growth of excellent fruiting mother branches. For trees with weak growth potential, when pruning, it is necessary to maintain strength and weaken, and cultivate strong branches and fruits.
As a result, when there are too many mother branches, the weak are removed and the strong are retained. When there are too many buds, you can selectively cut them off as preparatory branches to prepare for the next year's results.
When pruning fruiting branches, it should depend on the shape and branching situation. When the growth position is too long or the growth potential is weak, the former fruiting branches can be removed, leaving the developing branches behind and re-cultivating the fruiting mother branches. The fruiting branch with suitable position can still be retained as the new fruiting mother branch.
When the length of developing branches is 20 ~ 40 cm, it is easiest to form fruiting mother branches. When the developing branches of young trees are too long, they should be cut short. Weakly developed branches are not easy to form fruiting mother branches, so short stumps can be left at the lower full buds or at the base to promote strong new branches.
(2) promoting flowers and fruits
Persimmon is a tree species with strong branches and high fruit setting rate. When potted, only by maintaining a strong tree can it blossom and bear fruit.
Measures to promote flowers and protect fruits usually include the following methods:
① girdling or girdling
Girdling flowering potted trees can effectively inhibit vegetative growth and promote flower bud differentiation. If you circumcise your foreskin 5 ~ 7 days before flowering, it will help to prevent falling flowers; Girdling 5 ~ 7 days after flowering can effectively prevent fruit dropping. Girdling the main branch, trunk or fruiting mother branch at full flowering stage can reduce physiological fruit drop and improve fruit setting rate.
(2) strengthen the management of growth period.
Adequate fertilizer and water supply can enhance photosynthetic efficiency, promote nutrient accumulation of trees, enrich the growth and development of branches and flower buds, and lay a foundation for improving fruit setting rate.
③ Drought treatment
Persimmon promotes flower bud formation at the initial stage of flower bud differentiation.
4 thinning flowers and fruits.
Picking flowers and smearing buds: 2 ~ 3 fruiting branches can be left on each fruiting mother branch, and more flowers can be picked or even thinned. Only 2 ~ 3 flowers are left on each fruiting branch, and 4 ~ 6 leaves are left above the last flower for coring. In summer and autumn, leave two leaves to pick the core, reduce nutrient consumption, concentrate on reproduction and growth, and promote fruit development. During fruit thinning, generally 1 ~ 2 fruits are left in each fruiting branch, and the correct and robust fruit in the middle is reserved, and the rest are thinned.
⑤ Topdressing outside roots
Potassium, phosphorus, zinc and boron are mainly topdressing before the first physiological fruit drop. After that, nitrogen fertilizer should be added, which is insufficient and the secondary physiological fruit drop is serious.
⑥ chemical reagent
Use 150 mg/L gibberellin 1 time in full bloom, and use 180 ~ 200 mg/L gibberellin 1 time in young fruits after flowering. Spraying 250-350 times of 15% paclobutrazol on 2-4-year-old young trees from defoliation to spring shoot germination.