The formation of grape summer buds is closely related to management techniques, especially coring and twisting. Under natural conditions, the inflorescence formed by summer buds is less and smaller, but after artificial coring, the inflorescence differentiation is enhanced and the inflorescence is relatively large. However, due to the short incubation time of flower bud differentiation, the inflorescence differentiation of summer buds is generally weak, especially for longan, milk and other varieties in the oriental variety group, and the inflorescence differentiation ability of summer buds is obviously lower than that of European and American hybrid varieties.
Extrabud formation of grape flower buds is a phenomenon that flower buds differentiate beyond nodes, which is the most remarkable feature of cultivated grape varieties. On the branches of common fruit trees, with the different node positions of the buds on the branches, the buds have obvious heterogeneity, thus forming the regularity of the formation and distribution of flower buds on the branches, that is, the inflorescence only differentiates into buds born at a certain node, while the differentiation of grape flower buds has obvious "festival differentiation" phenomenon. That is, from the third node at the base of the branch to the thirtieth node at the top of the branch or even above, as long as there are corresponding environmental conditions, flower buds can be differentiated. In recent years, the method of "arch tip" has been used to differentiate the "foot bud" at the base of grape branches into normal inflorescences, which is also very rare in other fruit trees.
The early maturity of grape buds and the supernode differentiation of flower buds laid a good foundation for grape to bear fruit many times a year.
(2) The scope of application of secondary fruiting of grapes is in tropical areas. It is a normal management method for grapes to bear fruit many times a year after artificial treatment, while in temperate areas, grapes are only harvested once a year, but in some special circumstances, the technology of bearing fruit many times a year can also be adopted.
1. When natural disasters seriously affect the current year's yield, especially in early spring in Northeast China, North China, Northwest China and other areas, grape eyes are frozen, new shoots are damaged by late frost after germination, or inflorescences are damaged by natural disasters such as hail after flowering and fruit setting, secondary fruit-bearing technology is often used to make up for the loss of grape yield in that year.
2. When the vineyard encounters special climate influence, such as abnormal flowering, pollination and fertilization of grapes due to rain or continuous drought and high temperature, or the fruit is in a continuous rainy season when it is ripe, or the yield is seriously affected by other natural disasters, the secondary fruiting technology can be adopted to adjust the flowering or maturity of grapes to a suitable period to ensure the normal harvest of grapes.
3. In some areas with long growing season, abundant sunshine and accumulated temperature in Central China and South China, the technique of grape multiple fruiting can be used to improve the yield per unit area and economic benefits, especially in hilly slopes with high accumulated temperature in Central China and South China, the local light and heat resources should be fully utilized to study and popularize the technique of grape multiple fruiting once a year.
4. In protected cultivation, the secondary fruiting technology of grape can be implemented according to local conditions, especially in protected cultivation. In order to delay the ripening of grapes as much as possible, we should make full use of the characteristics of facility coverage to prolong the post-harvest period and promote the secondary fruit of grapes, so as to enrich the delayed cultivation content and improve the benefit.
(III) Multiple fruiting techniques of grapes in one year The multiple fruiting techniques of grapes in one year can be divided into two methods: secondary fruiting by using winter buds and secondary fruiting by using summer buds:
1. Use the secondary fruiting technology of winter buds on the branches of the current year to promote secondary fruiting. Because the flower buds of winter buds are well differentiated, the yield and quality of secondary fruiting can be guaranteed, and the secondary fruiting of winter buds is often used in production. When winter buds bear fruit for the second time, the key technology is to force and accelerate the flower bud differentiation and formation of winter buds on branches in that year. Second, the secondary branches of winter buds should germinate in a timely and orderly manner to ensure that the fruits can fully mature in that year. The main measures are as follows:
(1) Core-taking of the main shoot Because the inflorescence differentiation in the winter buds on the branches of the current year has started from before flowering to the initial flowering stage, when the winter buds are used for secondary fruiting, the core-taking of the main shoot is generally carried out when there are 4-6 leaves spread flat above the inflorescence. The main purpose of this core-picking is to promote the concentration of tree nutrition to winter buds, thus promoting the differentiation of flower buds more fully.
(2) After the main branches of the secondary branches are removed, all the secondary branches are removed, so that the nutrients are completely concentrated and transported to the top 1-2 winter buds to promote the early germination of winter buds. If there is no inflorescence on the first sprouting winter bud branch, the secondary branch of the winter bud can be cut off together with the tip of the main branch to stimulate the germination of the winter bud with inflorescence under the branch. Due to the long development time of winter buds, the inflorescence differentiation degree on the secondary branches of winter buds is high.
In order to improve the quality of the secondary bud inflorescence of winter buds, the secondary buds are usually smeared twice. Erase the middle and lower secondary branches for the first time and temporarily keep the upper 1-2 secondary branches. Core the L-2 secondary branches with 2-3 leaves until about 10- 15 days after the first secondary branch erasure, and then erase the L-2 secondary branches. In this way, the newly sprouted secondary branches of winter buds are not only neat and consistent, but also the inflorescences in winter buds are large and stout, and the seed setting rate is also high.
The germination time of winter buds can be controlled by controlling the time of cutting off the top secondary branches. Although delaying the germination time of winter buds can improve the inflorescence strength, the late development of secondary branches of winter buds will directly affect the growth and maturity of fruits. Therefore, it must be noted that the emergence time of winter buds should not be too late. In North China, the suitable time for cutting off the top secondary branches to force winter buds is from the end of May to the beginning of June, and other regions can flexibly decide according to local specific climatic conditions.
2. Using the secondary fruiting technology of summer buds, summer buds germinate immediately after dormancy, and secondary summer buds are easy to produce after primary summer bud germination, which is easy to cause nutrient dispersion, and flower buds are difficult to form or the quality of flower buds formed is not high. Therefore, when using the secondary fruits of summer buds, it is necessary to ensure the good inflorescence formation in summer buds first, which is the technical key to using the secondary fruits of summer buds. Because of this, the time requirement for removing the core and erasing the secondary fruits of summer buds is very strict.
(1) When the main shoot is cored, when the secondary fruit is used, it is necessary to pick the core in time before the summer bud germinates to promote the formation of flower buds, so the coring time should not be too late. Because the summer buds in the axillary nodes above the main inflorescence of common Eurasian varieties are easy to form flower buds, the coring time of main shoots for promoting secondary fruits is about 1 week earlier than that of common varieties. At the same time, it should be determined by combining the specific environment of a region and the flower bud formation of varieties. The key is to do it when there are 1-2 summer buds below the coring position, so be sure to pay attention.
(2) Erase all the sub-buds of summer buds. All the secondary branches of the sprouted summer buds on the main branches are erased at the same time, so that all the nutrients in the tree are concentrated on the sprouted summer buds at the top 1-2, which promotes the differentiation and formation of flower buds. Generally, after the core is removed from the main shoot, the top summer bud can germinate in about 5 days, and a good summer bud sub-shoot inflorescence can be formed by strengthening management.
(3) For the secondary branches with inflorescences, the tips should be picked at 2-3 leaves above the secondary branches to promote the normal growth of inflorescences.
(4) If no inflorescence is formed in the induced secondary buds of summer buds, it should be picked again when the buds spread 4-5 leaves to promote the secondary buds, but it should be noted that there must be 65,438+0-2 buds below the buds.
(4) Problems that should be paid attention to when using secondary branches and secondary fruits. It is a new technology to improve the economic benefit of grape cultivation by using secondary branches to produce more fruits. Under good management conditions, the yield can generally be increased by about 10%-20%, and the supply period of fresh fruit can be prolonged. In the past, it was thought that the secondary fruit had small ears, small fruit grains and poor quality, but practice showed that the quality was poor as long as strict management measures were followed and the load was controlled. The quality of the secondary fruit is not worse than that of the primary fruit, and can even exceed the quality of the primary fruit. There are many reports about this at home and abroad. In recent years, the secondary fruit technology can also improve the quality of wine grapes and wine.
However, the multi-year fruit competition is a technique to artificially adjust the growth results. If it is not carried out in accordance with scientific laws, it will certainly form various adverse effects. Therefore, the following problems should be paid attention to when using the technology with more than one year's achievements in production.
1. Variety selection The flower bud formation characteristics of different varieties are different, and the ability to bear fruit many times a year varies greatly among varieties. Generally speaking, Eurasian varieties, Black Sea varieties and European-American hybrid varieties in Central and Western Europe have strong multiple seed-setting ability, while oriental varieties have obviously poor multiple seed-setting ability, but even in the same variety group, different varieties will have different multiple seed-setting ability under different cultivation conditions, so it is necessary to observe, study and select them.
We should pay attention to the local environmental conditions. Using the secondary fruiting technology, the plant growth period will be relatively prolonged. Therefore, we must pay attention to the local climatic conditions, especially the effective accumulated temperature in the growing period, frost-free period and sunshine ≥ 10℃. Some northern areas with short frost-free period and low effective accumulated temperature, especially those with early cooling in late autumn, do not necessarily need to bear fruit for more than one year (except for delayed cultivation in facilities). In central and southern China, autumn is not only suitable for temperature, but also has less rainfall and plenty of sunshine.
3. Strengthening the management of technical plants many times a year has obviously increased the nutrient consumption of trees, so the corresponding management techniques must keep up, such as water and fertilizer management, soil management, pest control and so on. In fertilizer management, we should pay attention to balanced fertilization throughout the year, appropriately increase the number of topdressing, pay attention to drainage and flood prevention in summer and autumn rainy season, and pay attention to drought prevention in the later period. At the same time, we should attach great importance to pest control, ensure the healthy growth of functional leaves, and pay special attention to reasonable load and timely harvest in cultivation management. In the case of more than one year of fruit, overload not only affects the quality and maturity of fruit, but also has a great influence on the growth, yield and quality of trees in the next year. Therefore, it is necessary to emphasize the reasonable load. How to determine the proportion of main fruit and secondary fruit in an area can be determined according to the growth of trees, cultivation purposes and management conditions. For example, in order to delay maturity, you can leave more secondary fruits. If the fruit ripening is delayed to prevent rain, the primary fruit can be thinned and only the secondary fruit can be kept.
Pay attention to timely harvesting when using the technology of more than one year, and harvesting must be carried out after the characteristics of grape varieties are fully displayed, and it is not advisable to harvest them too early.
In order to promote the stability and high quality of secondary fruits year after year, a series of supporting techniques such as pruning and shaping, chemical regulation and improving photosynthetic efficiency of leaves should be paid attention to. Generally, ccc of 1000-2000 mg/kg is sprayed after the first pit removal to promote flower bud differentiation, and at the same time, 20 mg/kg or 25 mg/kg CPPU GA3 is used to increase the fruit grains of secondary fruits after fruit setting. At the same time, spraying 450-500mg/L ethephon on the ear at the beginning of the second fruit ripening can also promote the ripening.
4. Through research, the standardized cultivation technique with multiple fruits in one year has become a set of standardized cultivation techniques in foreign countries and Taiwan Province Province of China. At present, although it has been applied in some parts of China, there is no systematic research and no standardized technology, which leads to inconsistent management technology and even unsatisfactory results. Therefore, the current secondary fruit-setting techniques of grapes, especially in protected cultivation areas in Central China, South China and North China, should be thoroughly studied, and feasible local multi-year fruit-setting techniques should be put forward, so that the multi-year fruit-setting techniques of grapes can become standardized cultivation techniques.
5. Don't blindly pursue the second result, so as to prevent adverse effects on the growth and results of grapes in the coming year. At present, harvesting once a year is the main cultivation mode in most grape growing areas in northwest, north and northeast China, which has been formed for a long time to adapt to local ecological conditions. In these areas, unless there are special climatic conditions (such as late frost and hail causing serious losses to the first fruit), it is generally unnecessary to blindly bear fruit many times a year. In order to avoid the adverse effects of excessive nutrient consumption on the growth of trees, and even lead to poor maturity of branches and imperfect inflorescence differentiation, which seriously affects the yield and income in the coming year, whether a place adopts the technology of bearing fruit more than once a year must be based on the local specific climate, cultivation and variety conditions, and it is not possible to blindly pursue bearing fruit more than once a year.