The purpose of pruning in winter is to cut off diseases and pests, twigs, young branches, too dense branches and too many buds, adjust the appropriate load, stabilize the yield, improve the quality and restore vitality. According to different populations and varieties, the pruning of long, medium and short branches is determined. The purpose of summer pruning is to control the excessive growth of new shoots during the growing period, concentrate nutrition on the supply of fruit ears, control the growth of secondary shoots, improve the light conditions on the shelf surface, improve the quality of berries, increase the yield, make the branches and vines develop fully and healthily, and lay a good foundation for high quality and high yield next year.
(1) Bud-wiping and fixed-branch bud-wiping are to further adjust the tree load on the basis of pruning and leaving buds in winter to ensure the yield and quality of that year.
Bud smearing time is usually carried out after winter bud germination until the inflorescence is exposed. First, thin and pointed elbow buds and hidden buds are erased from the trunk and roots; Only 1 strong buds are selected for double buds or triple buds, and all others are erased. When the new shoot grows to 10 ~ 15 cm, the shoot can be fixed. Because of the different germination time of the bud eye, it needs to be smeared three times from bud smearing to bud fixing.
The number and degree of fixed branches should be determined according to varieties, tree age, tree potential, cultivation and management conditions and the number of buds left during pruning in winter. If there are many branches left when pruning long branches in winter, they will be sparse. If 8 ~ 12 branches are pruned in winter, they can be kept for 2 ~ 3 years. Pruning in winter uses short tips, because it leaves fewer buds, so it should also leave less; Leave more strong branches and less weak branches; Varieties with high germination rate and strong fruiting force, such as Rose Fragrant, should be sparse and less retained, while varieties with low germination rate and weak branching force, such as longan and milk, should be sparse and less retained.
(2) Core removal and secondary tip removal is to remove the tender tip of the new tip by 3 ~ 5 cm. Picking is carried out before flowering until the new buds stop growing. Picking the core of new shoots before flowering can inhibit the prolonged growth of new shoots, make the nutrients made by leaves turn to inflorescences, make good fertilization and improve the fruit setting rate; Picking new shoots in the later stage can improve the light conditions on the shelf surface, promote flower bud differentiation, increase yield, enrich branches and vines, and lay a good foundation for increasing production next year. Picking the core of new shoots can also promote the growth of branches, advance the formation of young trees and early yield, balance the growth of new shoots and reduce the amount of pruning in winter.
Picking before flowering is the most effective in 3 ~ 7 days before flowering or at the early flowering stage. Premature coring and short branches will inhibit the extension of new shoots and affect the robust growth of trees; If the topping is too late, the flowering period has passed, and the inflorescence is not fully nourished, the effect is not obvious.
It is advisable to leave 5 ~ 7 leaves above the inflorescence. It is suitable to leave 10 ~ 15 leaves for vegetative branches; Generally, 12 ~ 20 leaves can be left for coring; For fruiting branches with few leaves and weak growth, topping can be temporarily omitted.
After the core of the main shoot is removed, the summer buds in the axils of leaves will germinate. When there are too many auxiliary buds, it will not only consume nutrients, but also affect ventilation and light transmission, so it should be removed as soon as possible. For example, if there are weak auxiliary branches between the axils under the ear, they should be erased from the base. The stronger secondary branch above the inflorescence can leave 4 ~ 5 leaves, and the weaker secondary branch can leave 1 ~ 2 leaves. If the secondary branches are erased from the leafless base, it is easy to promote the shading of winter buds and affect the annual output in the future. During the whole growth period, secondary branches will be picked repeatedly, twice, three times or even more, so they should be picked repeatedly in time until they are no longer picked.
The effect of pinching new shoots varies with varieties, tree age, tree potential and cultivation management technology level: for varieties with serious flower and fruit loss, the effect of pinching new shoots is remarkable; In the same variety, the effect of strong branch enucleation is more significant than that of weak branch enucleation.
Different shaping, pruning and scaffolding have different requirements for coring: hedges, sheds, small sheds and so on. The area of scaffolding is small. If the coring is not timely, the vines will be easily closed, so the coring should be timely and many times. The large scaffold has a large surface area, so the coring times can be appropriately reduced.