1. Pruning period
It can be divided into winter pruning (dormant pruning) and summer pruning (growth pruning). After defoliation in autumn and winter every year, winter pruning is carried out before sap flows out in early spring of the following year. If pruning is too late, the cut will not heal easily, causing bleeding, affecting germination and even dying branches and vines. Summer pruning is pruning in the growing season, including pruning from leaf spreading in spring to defoliation in autumn.
Winter pruning
The main contents include three aspects: the selection of fruiting mother branch and cutting length, the renewal of branches and vines and the treatment of over-branches.
Except for the long branches sprouting at the base of the trunk and the main lateral branches, almost all the new shoots of kiwifruit at fruiting age can form flower buds and become the fruiting mother branches in the next year. Ordinary vegetative branches and medium-long fruit branches have moderate growth potential, full branches and full buds, and should be reserved as fruiting mother branches; Too strong or too weak branches and short fruit branches should not be reserved as fruiting mother branches. When pruning, the length of branches is as follows: for Chinese kiwifruit varieties, 6- 10 full buds are reserved for vegetative branches, 4-6 buds are reserved for long fruit branches, and 2-4 full buds are reserved for middle fruit branches, so as to keep the spacing between mother branches at about 30 cm; Delicious kiwifruit varieties, the vegetative branches leave 10- 15 buds, the long fruit branches leave 6- 10 buds, and the middle fruit branches leave 4-6 buds. The spacing between mother branches should be about 40 cm.
There are three treatment schemes for long branches: first, in most cases, useless branches begin to taper from the base; The second is to cut off 4-8 buds to produce 3-5 fully developed vegetative branches (as fruiting mother branches); Third, cut off 2-3 buds, so as to produce 1-2 strong seedlings (for regeneration of lateral branches) in the second year.
The regeneration of vines can be divided into fruiting mother branches and perennial vines. When the fruiting mother branch that has been aging or has been fruiting for 2-3 years continuously is updated, if there are many fruiting and robust fruiting branches or vegetative branches at the base of the fruiting mother branch, the fruiting mother branch can be retracted to the robust part to prevent the fruiting part from moving out; If the fruiting mother branch is too weak or the branches on it are too high, it should be deleted from the latent bud at the base to promote the germination of the latent bud, and then the fruiting mother branch should be cultured. The regeneration method of perennial vines is to remove the aging vines from the base and re-cultivate the fruiting vines with new buds germinated by latent buds. The regeneration should be carried out year by year, and the amount of lateral branch regeneration should be controlled at 4%-5% every year. When the hedge frame is reshaped, the branches and vines are frequently updated, so it is advisable to adopt the double branch regeneration method.
When cutting in winter, we should also cut off dead branches, pests and slender branches and sort out the entangled branches. Also, you should pay attention, because the flesh of kiwifruit is hollow, the cut mouth is easy to dry. In order not to affect the germination of the cut bud, the cut should be about 2 cm away from the cut bud.
summer pruning
Pruning kiwifruit in summer is very important to adjust the contradiction between vegetative growth and reproductive growth and improve yield and quality. The main measures of summer pruning are:
Removing sprouting and wiping buds: it is carried out in spring and summer when the buds germinate, and the sprouting tillers at the roots, the sprouting tillers under the trunk, the main vines and the big shears are removed. As a result, only one second or third bud is left on the mother branch, and the buds with overgrown branches are removed.
Tapping: remove the top of vigorous new shoots (fruiting branches and developing branches) to promote the growth and enrichment of new shoots below. Strong fruiting branches are glued with adhesive tape from 7-8 leaves above the fruiting position, while weak fruiting branches are not glued with adhesive tape. If the overgrown branches are used as preparatory branches or regenerated branches, 4-6 leaves need to be tied, while the developing branches need to be tied with about 12 leaves, and only 65,438 leaves remain after coring.
Short cutting and thinning: thinning over-developed branches, too thin fruiting branches and diseases and pests. The principle of thinning branches is to leave a new shoot on the mother branch of 10- 15 cm, and leave 10- 15 evenly distributed strong branches per square meter. Cut short the new shoots, horizontal branches and curved branches that are too prosperous and not picked in time.
Tie vines: Tie vines many times in time during the growing season to guide new shoots to a reasonable place.
4. Male pruning
The shaping of male plants and female plants is basically the same Male plants are pruned after flowering in May-June, with 3-4 branches per plant and 4-6 buds per branch. When the new branch length is 1 m, pick the tip. Pruning in winter is generally light, which can ensure a large number of flowers for male plants and provide a large number of pollen for female plants. Only thin dead branches, twisted branches, crossed branches and sprouted branches are thinned in winter pruning, and all branches that are full of growth are reserved, and they are cut short when necessary. Retract or thin old perennial branches. After flowering, cut the branches that are too long and thin the branches that are too dense.