The Water of Life Grapevine: Reasons for Pruning, Summer Pruning Timing, and Branch Pruning Methods
Grapes are a relatively common fruit in autumn in our country. Because they are fleshy and sweet, and rich in various nutrients needed by the human body, they are deeply loved by people. They can not only be used to make wine, but also raisins, etc., so they have high economic value. And if you want high grape yields, in addition to simple planting techniques, you also need to prune and train them, so why do grapevines need pruning? When is the best time to prune in summer? How do you prune the branches?
1. Why do grapes need pruning?
1. Extend the growth lifespan: Grapes are perennial plants. Generally, they can bear fruit in the second year after planting, and the fruit tree can live for about 150 years and bear fruit for about 20 to 40 years. The purpose of pruning and training is to effectively extend the fruit tree's growth lifespan, allow the branches to renew and metabolize well, and delay aging.
2. Promote nutrient absorption: After a grapevine has grown for a certain period, the main branches will quickly take root and grow, absorbing a large amount of nutrients, causing the side branches to lack nutrition and be unable to grow normally. Therefore, pruning can effectively promote the physiological activity of the whole plant and branches, strengthen nutrient absorption in all parts, and enhance conduction, so as to promote continuous annual production of the tree.
3. Improve ventilation: After a grapevine has grown for a certain period, phenomena such as disordered growth, excessive growth, and rampant branch growth will appear, blocking the plant from absorbing light. Pruning and training can effectively improve ventilation, allow sunlight to reach every part, and enhance photosynthesis.
2. What benefits does grape pruning have?
1. Promote sufficient nutrients in branches: A pruned grapevine will reduce the number of flower buds, effectively improve the even distribution of nutrients, make the plant grow better, and at the same time improve ventilation and light exposure, so that the remaining branches have sufficient nutrients.
2. Regulate fruit load: The fruit load of a grapevine has a certain relationship with the number of buds. If there are many buds, the yield will be high, which will impose a certain load-bearing capacity on the tree body and affect grape fruiting. At the same time, it will also affect flower bud differentiation and branch maturity in the current year, which is not conducive to flowering and fruiting the following year.
3. Cultivate a reasonable tree structure: Pruning and training a grapevine can effectively improve its external shape, promote even nutrients among branches, effectively differentiate flower buds, and benefit fruiting the following year. At the same time, it can also make the tree grow better and delay aging.
3. How should grapes be pruned in summer?
1. What is the best time to prune grapevines in summer?
Generally, pruning around June is best.
2. What are the pruning standards for grapevines?
The pruning standards for grapevines are directly related to the grape variety, tree age, fruit load, and tree vigor, so when pruning, appropriate pruning methods can be adopted according to the specific conditions of the grapevine. Under normal circumstances, grapevine pruning methods include bud thinning pruning, long-cane pruning, short-cane pruning, double-cane pruning, and other methods. Below is a specific look at the various pruning standard methods:
(1) Thinning method: The thinning method is to cut away useless branches such as thin branches, residual branches, diseased branches, and weak branches.
(2) Short-cane pruning method: This means cutting off short canes at 2 to 3 buds. It is generally aimed at newly planted young trees and involves stumping pruning.
(3) Medium-cane pruning method: This method is generally used to prune areas where plants are missing, with the purpose of allowing branches to increase the amount of branches and leaves so that the entire space is even. Generally, pruning at 3 to 5 buds is sufficient.
(4) Long-cane pruning and ultra-long-cane pruning: This method is mainly used to extend the main vine. It can generally be used for home potted plants or small greenhouse plantings. Generally, pruning at 6 to 12 buds is sufficient.
(5) Double-cane renewal: This method is mainly to avoid dense trellis surfaces, which leads to nutrient deficiency. Generally, on the basis of last year's pruning, keep 1 to 2 buds on each of the two branches and prune accordingly.
(6) Single-cane renewal: This method is generally aimed at new shoots that have double canes. The specific method is to cut off one of the original double canes, and then shorten the retained branch.
(7) Major and minor renewal: Major renewal mainly involves cultivating a new mother cane, while minor renewal mainly involves removing weak and small branches so that the tree body has sufficient nutrition and the fruiting years are extended.
3. What summer pruning techniques are there for grapevines?
(1) Bud removal
During the period from when new shoots begin to grow until leaf expansion, late-developing buds, overly dense buds, poorly developed buds, or useless latent buds can be removed, so as to leave healthy and better flower buds to grow.
(2) Shoot positioning
After the grapevine produces inflorescences, shoot positioning can be carried out in places with few inflorescences, poor development, or overly dense inflorescences. Generally, it is best to prune at obvious positions with or without inflorescences, but when pruning, it should be done according to the seedling variety, fruit load, and tree vigor growth conditions. Usually, for single-espalier grapevines, leave 1 new shoot every 10 cm; for double-espalier grapevines, leave 1 new shoot every 10 to 15 cm; and for trellis cultivation, it is suitable to leave about 20 new shoots per sq m. If the differentiation rate of fruiting canes is low and the plant load is insufficient, in addition to retaining all fruiting canes, a certain number of vegetative canes should also be retained according to the density of the trellis surface.
(3) Pinching
When grapes have just grown flowers and are in full bloom, leave one inflorescence at around 6 to 8 leaves and remove the tender tips: pinch the main vine extension cane when it grows to 16 to 20 leaves, and pinch the reserve cane when it grows to 8 to 10 leaves.
(4) Leaf removal
After the grapevine has grown for a period, useless branches and leaves such as residual leaves and diseased leaves can be removed to reduce the occurrence of pests and diseases.
(5) Flower thinning
Two weeks before grapes bloom, excess or weak inflorescences can be removed. If the branch is weak, leave fewer inflorescences; if the branch is strong, then there is no need to thin the inflorescences.
(6) Remove secondary shoots
After a grapevine grows new shoots, each new shoot will grow some secondary shoots, so after the secondary shoots sprout, the secondary shoots of the entire plant should be removed to avoid absorbing nutrients, causing insufficient nutrients for the whole plant and affecting growth.
(7) Remove tendrils
During the growth period of a grapevine, some tendrils will grow, and tendrils, like branches, also absorb a large amount of nutrients. Therefore, while pruning branches, the tendrils can also be removed at the same time to ensure even nutrition for the whole plant.
(8) Tie new shoots
When the new shoots of a grapevine grow to 30 to 40 cm, a tripod can be set up below to support them, so as to help the plant maintain good ventilation and also prevent strong winds from breaking them. If there is a larger and sturdier support, that is best, as it can support the entire grapevine so that the whole grapevine can absorb light.
4. Pruning precautions
(1) When pruning, the cut must be smooth and flat, with no frayed edges, to avoid bacterial infection. At the same time, when pruning, it is best to cut 1 to 2 cm from the bud eye, so as to prevent the bud from being dried by wind, losing nutrients, withering, and dying.
(2) After pruning, the cuts must be promptly protected with wound protectant or similar, to avoid bacterial infection and plant death.
(3) When pruning branches, it is best to avoid opposing wounds, so as to prevent tree infection and spring bleeding, which can cause tree decline.