CN107593144B - Longan crown control and pruning method for balancing yield and tree vigor - Google Patents

Abstract

The invention discloses a longan crown control and yield and tree vigor balancing pruning method. The balanced pruning method is to prune the tree crown by retracting while carrying out flower thinning and/or fruit thinning on the longan tree; controlling the diameter of the retracted and trimmed branch to be below 3.5cm, the total length to be 0.6-1.5m and the total amount to be 25% -50%; carrying out fruit thinning treatment on the remaining fruiting branches; and after the longan tree is harvested, retracting and pruning branches of the longan tree, controlling the diameter of the pruned branches to be below 1.8cm and the length to be 0.3-1.2m so as to achieve the purposes of controlling the crown and balancing the yield and the tree vigor. The invention combines flower thinning and fruit thinning with crown control to carry out a balanced pruning method, thereby not only balancing the contradiction between plant growth and fruit thinning, but also balancing the relation between yield and quality, and simultaneously achieving the purposes of controlling the size of the crown, culturing strong summer shoots and obtaining high-quality autumn shoot bearing mother branches.

Description

Longan crown control and pruning method for balancing yield and tree vigor

Technical Field

The invention belongs to the technical field of fruit tree cultivation, and particularly relates to a longan crown control and yield and tree vigor balancing pruning method.

Background

Longan (Dimocarpus longan Long.) is a famous subtropical fruit in China, and the area and the yield are the first world-wide. In the high-quality and high-yield cultivation technology of longan, flower thinning, fruit thinning and crown management become conventional measures.

Flower thinning and fruit thinning means that a part of excessive flowers and young fruits are artificially removed to obtain high-quality fruits and continuously high yield. Most fruit trees bloom much more flowers than the last fruit. For example, in the years of flowering, the mature apple trees have 5% of flowers, and the peach trees have 15-20% of flowers, so that the fruits are mature, and the harvest can be achieved. Too much flowers and fruits are produced, nutrient supply is not required, normal development of fruits is influenced, a plurality of small fruits and secondary fruits are formed, tree vigor is weakened, the trees are prone to freezing damage and infection diseases, and production reduction in the next year is caused to result in a small year. Therefore, in addition to the self-regulation capability of the fruit trees, the flowers and young fruits which are dysplastic can naturally fall off, and the excess flowers and fruits also need to be manually removed to meet the production requirements. For longan, flower thinning and fruit thinning are important, because longan has the result characteristic of 'leaving young and leaving body intact', namely, the fruiting capacity is very strong, the number of flowers can be obtained in the productive year, the self-regulation energy is poor (natural fruit dropping is less), the fruit setting is very much, too many fruit setting causes small fruit result, poor quality and fruit bearing in the big and small years, and the condition of hanging dead trees (leaving body intact) often occurs. The flower thinning time of longan trees is generally about 3 middle days in Guangzhou just before blooming after the flower spikes are shaped. Thinning is generally performed after the young fruit is substantially stabilized, at which time the longan fruit is about the size of soybean, about 5 months in Guangzhou.

The proper amount of retained flowers and fruits does not affect the yield, the fruit quality can be obviously improved, the fruit weight and size are increased, and the commodity value is improved; excessive fruit bearing causes plant recession, slow fruit growth, small fruit, fruit cracking, low quality and the like, and the fruit dropping during maturation caused by the excessive fruit bearing also causes influence on yield.

Management of fruit tree crowns involves developing and maintaining tree shapes that correlate with the maximum productivity and fruit quality of the fruit tree. The basic principle of crown management of the perennial fruit trees is to utilize land and climate factors of three-dimensional space to the maximum extent to improve productivity. Tree vigor, light and temperature and humidity are important factors influencing the yield of fruit trees and the quality of fruits. The difficulty of crown management is how to best control tree vigor, effectively utilize sunlight and temperature, and improve fruit yield and quality, thereby reducing the influence of adverse weather factors to the minimum. Some basic principles of crown management are as follows: the method utilizes light to the maximum extent, avoids forming local microclimate suitable for pest and disease damage, is convenient for farm operation, obtains the maximum productivity and the best quality, and obtains the cost economy of ideal crown modeling. The management of the longan tree crown mainly comprises the steps of pruning a tree body through measures such as branch thinning, retraction, branch pulling and the like, for example, thinning or cutting large branches which affect the structure of the tree body such as spindly branches, excessively high branches, excessively dense large branches and the like, and promoting the fruiting and the growth of the longan tree crown by adjusting the longan tree crown. Longan belongs to evergreen fruit trees, the vegetative growth is vigorous, the crown is high, and the branch tips and the fruit growth have a certain competitive relationship during fruiting, so in the traditional management method, the pruning of the bearing tree of longan in spring and summer mainly carries out pruning and trimming on poor and thin branches such as old, weak, sick, withered and shaded branches, and is rarely combined with the shaping of the tree body. Crown management work requiring a large amount of pruning work is usually carried out after fruit harvesting, wherein the work comprises pruning big branches, retracting pruning and pruning the dense joints (commonly called tap joints) at the base parts of the bearing branches, so that the phenomenon that a pile of young shoots are taken out from one branch to affect the quality of the young shoots is avoided. The traditional longan fruit-picking retraction pruning method mostly adopts light retraction, and only retracts to the positions of the dragon head section or a plurality of buds below, so that the crown can be increased year by year. If re-retraction pruning is adopted after fruit picking (the diameter of the retracted branch is more than 3 cm), the overgrowth of the branch which is extracted after retraction pruning is strong (the thicker the retracted branch is, the stronger the overgrowth of the branch is), the flower formation and fruit bearing in the next year are influenced, and the phenomenon of the fruit bearing in the big year and the small year of longan is formed.

Flower thinning and fruit thinning and crown management are the most time-consuming and labor-consuming links in longan cultivation management except fruit picking, mechanical alternatives are not available at present, all manual operations are adopted, statistics shows that the labor cost per mu in Yuexi longan production areas exceeds 1000 yuan, and the labor cost per mu in some finely managed standard orchards reaches 1000 yuan.

However, the labor force is lacked and the labor cost is high nowadays, the traditional fine work type management mode and the cultivation mode of a tall tree crown are not suitable, and the simple and efficient management mode and the dwarfing cultivation mode are advocated vigorously.

The fruit tree balance pruning method mentioned in article "fruit tree balance pruning method" of wujiamin et al (wujiamin, tianjun. fruit tree balance pruning method [ J ]. tobacco terrace fruit tree, 2006(3):51-52.) only relates to the structure of the tree body, proposes a pruning improvement method for the tree body with strong top and weak bottom or strong bottom and weak top, does not have the content of controlling the size of the crown and the like, and does not relate to the specific tree species. Because of different fruit tree species, the difference is larger. For example, the Feizixiao litchi tree has early mature period, is resistant to pruning, has long time for long tip after pruning and has complete time for culturing good fruiting mother branches, so the whole tree is often pruned by retraction after fruit picking (flat head pruning), and leaves are basically pruned; however, because the mature period of the longan tree is late, the fruit is generally not re-shrunk and trimmed after fruit picking, and the crown is reduced and dredged by adopting 'skylight opening' (1-2 big branches in the crown are dredged) and the like.

The invention patent with the application number of 2015107305753, namely 'a longan tree retraction transformation method', the invention patent with the application number of 2015102389470 ', a longan re-retraction pruning tree flower promoting method', and a Master thesis in Chengke, namely 'discussion of the reason why longan re-retraction pruning trees are not easy to flower and research on technology for promoting out-of-season flower formation' (Chengke, discussion of the reason why longan re-retraction pruning trees are not easy to flower and research on technology for promoting out-of-season flower formation [ D ]. Guangxi university, 2006.) both adopt full-tree retraction pruning 'plain type're-pruning on longans in spring, and the pruning method has an effect on the current annual output of longans.

The invention patent with application number 2013106976272 discloses a management method for overcoming the year-to-year phenomenon of Shixia longan, which only relates to trimming of longan after fruit picking and does not relate to trimming of flower and fruit period.

In the article of forest wisdom (forest wisdom, old longan tree retraction trimming and management technology [ J ] Fujian hot work technology, 2006,31(3): 26-27), it is mentioned that spring retraction trimming is carried out for fruitless or young fruit trees after blossom, and is not combined with flower thinning and fruit thinning of longan, and in addition, the crown management of old longan trees is aimed at, and the young and strong longan trees are not involved. The management of the old trees mainly comprises updating and rejuvenating, promoting the growth of new shoots by re-shrinking and pruning and replacing old branches. The key point is to rejuvenate the tree body, and no requirements are made on the fruiting in the current year and the next year. The crown management of the young and strong trees must be combined with the result of the next year, so that the young and strong trees have certain difference.

Disclosure of Invention

The invention aims to provide a longan crown balancing pruning method.

The technical scheme adopted by the invention is as follows:

a longan crown balancing pruning method comprises the following steps:

the method comprises the following steps of 1, performing retraction pruning on a crown while flower thinning and/or fruit thinning are performed on a longan tree; controlling the diameter of the branch subjected to retraction pruning to be below 3.5cm, controlling the total length of the retraction pruning to be 0.6-1.5m and controlling the total amount of the retraction pruning to be 25% -50%;

carrying out fruit thinning treatment on the remaining fruiting branches;

and (3) after the longan tree is harvested, retracting and pruning branches of the longan tree, controlling the diameter of the pruned branches to be below 1.8cm, and controlling the length of the retracting and pruning to be 0.3-1.2m so as to achieve the purposes of controlling the crown of the longan tree and balancing the yield and the tree vigor.

The invention combines flower thinning and fruit thinning with crown control to carry out a balanced pruning method. By combining the retraction of a part of branches during flower thinning or fruit thinning in spring, the crown is reduced, and simultaneously, the 3-4 times of new shoots of the retracted branches become high-quality bearing mother branches in the next year, thereby achieving the purposes of controlling the crown and realizing high yield in successive years.

Preferably, the time for thinning is determined just before flowering after the ear is set, or according to common knowledge. Guangzhou is about 3 middle and last ten months.

Preferably, the fruit thinning time is that after young fruits are basically stable in fruit setting, the longan fruits are about the size of soybeans; or determined according to common general knowledge. Guangzhou is about ten days of month 5.

Generally, the balanced pruning method of the present technology is started while thinning flowers. When the flowers are thinned, balanced pruning is carried out, the pruned branches have enough time to grow into high-quality fruiting mother branches in the next year, and the quality of the branches is better. The balanced pruning can also reduce the nutrition waste to the tree body when thinning flowers. If balanced pruning can be basically carried out in place while flower thinning is carried out, the remaining fruiting branches are subjected to conventional fruit thinning treatment.

However, balanced pruning is sometimes not possible in one step. In some years, uncertain factors exist from flowering to fruit setting, so balanced trimming is required to be performed during flower thinning, for example, branches with the total quantity of 40% are required to be retracted, 30% is retracted during flower thinning, and 10% is left to be performed during fruit thinning. It is sufficient to control the total number and length of the two balanced trimmings within the above range.

Or just doing balanced pruning during thinning. At the moment, the balanced pruning can be accurately seen, and if the number of branches, the number of branches and the number of fruits are required to be thinned, the accurate judgment can be carried out. For example, the shoots retract 25% -50%, and 60 fruits are left per spike, etc. However, balanced pruning is only performed during fruit thinning, so that the nutrition of some trees is slightly wasted (part of the nutrients of the trees are consumed from flowers to small fruits) compared with balanced pruning during flower thinning, and the time for the growth of new shoots is slightly shorter than that during flower thinning.

Preferably, the retraction pruning is performed by selecting branches without flowers and fruits, and then branches with sparse flowers, branches with large spica, or branches with sparse fruits. If all branches are flowering or fruit branches in the harvest year, the branches which normally bloom and fruit are selected for retraction pruning according to common knowledge.

Sparse means that there is little or no sporadic flowering or fruiting. A large panicle generally refers to a panicle that is more than 40cm in length. In general, the longan fruit is preferably medium panicle, which is 20-30cm in length.

Preferably, the retraction pruning of the crown is carried out while thinning flowers or fruits, the diameter of the branch subjected to retraction pruning is controlled to be less than 3cm, the total length of the retraction pruning is 0.8-1.2m, and the total amount of the retraction pruning is 30% -50%.

The diameter of the retracted and trimmed branch is controlled to be below 3cm, the new shoot growing after retraction can basically eliminate the overgrowth of the branch after growth in summer and autumn, and the flower formation in the next year is not influenced. If the branches are too thick, the excessive growth of the branches cannot be eliminated after the branches are retracted in summer and autumn, and the flower formation in the next year can be influenced.

The invention controls the quantity of the retraction pruning to be 30-50%, and can balance the relationship between the yield and the tree vigor in the current year. Because the retracted branches are too few, the purpose of controlling the crown can not be achieved; too much shoot retraction can affect current year yield.

Preferably, the retraction pruning of the crown is carried out while thinning flowers or fruits, and when the young shoots are extracted from the pruned big branches, 2-3 young shoots are reserved on each big branch. Generally, after about 20-40 days of retraction pruning, the large branches will sprout multiple shoots. Too many shoots can result in each shoot being weak, affecting the growth of the next shoot. In order to avoid that a pile of young shoots are taken out from one branch and the quality of the young shoots is influenced, the quantity control is needed. The invention limits the preservation of 2-3 shoots on each big branch, and has the advantages of enabling the shoots to be strong and laying a better foundation for the next shoot regeneration.

Preferably, the fruit thinning treatment is carried out on the remaining fruit branches according to the conventional management. For example, the Shixia variety has 50-60 fruits per ear.

Preferably, after the longan tree is harvested, the fruit branches are retracted and trimmed, the diameter of the trimmed branches is controlled to be less than 1.5cm, the length of the retracted and trimmed branches is 0.3-1m, and the purpose of controlling the tree crown is achieved. The overgrowth property of the branch after retraction is mainly considered, because the branch which is too thick can be generally extracted for 2 times after fruit picking, the overgrowth property of the extracted branch in autumn cannot be eliminated, and the flower formation in the next year is influenced. If the retracted branches are too thin, the purpose of reducing the crown cannot be achieved.

According to the technology, through a balanced pruning method, one big branch is pruned at a time, and sometimes 10-20 panicles or fruits exist on one big branch, so that the effects of flower thinning and fruit thinning are achieved while the crown is controlled. After the retraction pruning according to the technology, the flowers and the fruits of the branches which are blossoming and have dense fruits are thinned according to the conventional method, so that the time can be saved, and the efficiency is improved.

The balance pruning method is suitable for conventional longan trees which grow naturally and have round-head crowns. The method of the invention is suitable for young and strong longan trees or old longan trees with no great requirement on the tree age. And dense cultivation of longan trees is advocated in the early years in Guangdong and the like, so that the whole orchard is closed, part of longan trees do not have enough growth space, and the crowns of the longan trees are in umbrella-shaped structures. The umbrella-shaped crown needs to be treated by the method of the invention after being treated by some conventional methods to restore the round head shape.

The balance pruning method is suitable for the conventional longan trees with the crown height of about 2.5-4.5 m. The crown is not dense or large enough, that is, the longan tree with too small age is not in the application range of the technology.

Note by the term of expertise:

growing bare branches: on the branches of developing trees, the growing branches with excessively vigorous growth potential in the current year are called spindly branches. The branch is a developed branch which is over-grown and not fully developed, shows upright, long internodes, large and thin leaves, and is not full of buds on the branch and stops growing late, and most of the branches are formed by stimulating and germinating hidden buds.

The part of the tree above the trunk, along with the part of the collected branches and leaves, is like a crown, so it is called a crown.

Retraction, also known as pinch-shear. Refers to cutting off a part of a 2-year-old branch or a multi-year-old branch.

And (4) fruiting mother branches: refers to the base branch of the bearing branch. The longan spica is mostly branches directly extracted from terminal buds or lateral buds of autumn shoots at the end of the last year and is the fruiting mother branch of the second year (the spica is directly extracted from a big branch at a few parts). Thus, autumn shoots are the main fruiting mother branch of longan in the second year.

The invention has the beneficial effects that:

the invention combines flower thinning and fruit thinning with crown control to obtain a balanced pruning method. The balanced pruning method of the invention not only can balance the contradiction between plant growth and fruiting, but also can balance the relation between yield and quality, and simultaneously can achieve the purposes of controlling the size of the tree crown, culturing strong summer shoots and obtaining high-quality autumn shoot fruiting mother branches. Years of practice prove that the method provided by the invention is matched with scientific fertilization to obtain a relatively ideal effect.

In the prior art, flower thinning and fruit thinning are performed one ear by one ear, and the technology cuts one big branch at a time by a balanced pruning method, and sometimes 10-20 ear flowers or fruits exist on one big branch, so that the flower thinning and fruit thinning function is realized while the crown is controlled. After the retraction pruning according to the technology, the flowers and the fruits of the branches which are blossoming and have dense fruits are thinned according to the conventional method, so that the time can be saved, and the efficiency is improved.

The big branch retraction of the invention effectively reduces the crown, completes a one-time balance pruning method, reduces the crown by about 1m, and can basically control the crown of the Shixia longan to be maintained in a certain size range every year. By controlling the tree crowns, the cost of flower thinning and fruit thinning is correspondingly reduced, and the efficiency of flower thinning and fruit thinning is improved. After the tree crowns are reduced, workers can flower and fruit thinning by standing on the ground without climbing trees, efficiency is greatly improved, and cost is correspondingly reduced.

The branches with big branches retracted by the balanced pruning method can be used for cultivating summer shoots once and autumn shoots 2-3 times, and the excessive growth of the branches is basically eliminated, so that the aim of cultivating strong autumn shoot bearing mother branches is fulfilled, and a solid foundation is laid for the next year of high yield.

The young shoots which are extracted after the pruning and the retraction in the flowering period or the young fruit period of the invention do not influence the fruit setting rate of the existing longan.

Drawings

FIG. 1 is a diagram illustrating the effect of longan crown trimming;

FIG. 2 is a diagram illustrating the effect of longan crown trimming;

FIG. 3 is a diagram illustrating the effect of longan crown trimming;

FIG. 4 is a diagram illustrating the effect of longan crown trimming;

FIG. 5 is a diagram illustrating the effect of longan crown trimming;

FIG. 6 shows shoot to fruit ratio and fruit drop rate of an adult tree;

FIG. 7 shows the shoot-to-fruit ratio and the fruit drop rate of young trees.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

Example 1

The method is carried out in an Shixia longan orchard in the Wuchuan forest field, the area is 30 mu, and the Shixia longan crown balance trimming is carried out while flower thinning or fruit thinning is carried out in 2012 years continuously.

In 2010, in the middle and last 3 months, before blooming after the flower spikes are shaped, crown balancing pruning is carried out. Retracting branches without flowers, wherein the retraction length is 0.8-1.2 m. The thickness of the retracted branches is controlled below 3cm (the retraction position of the flowering phase in figure 1), the number of the retracted branches is controlled between 30 and 45 percent, and the pruning effect is shown in figure 1. Shoots are extracted from the pruned big branches (fig. 2), and 2-3 shoots are reserved on each big branch (fig. 3). And performing conventional fruit thinning treatment on the remaining fruiting branches. In the last 7 th month, after the longan tree is harvested, retracting and pruning branches of the longan tree, and controlling the diameter of the pruned branches to be below 1.5cm (the retracted position after the longan tree is harvested in the picture 1 and the length of the retracted pruning to be 0.3-1.0m, thereby achieving the purpose of controlling the crown of the longan tree.

In 2011, in the last ten days of 5 months, the young fruits are basically stable in fruit setting, and the longan fruits are about the size of soybeans. And (4) performing retraction pruning on the longan tree, wherein during the retraction pruning, a branch without fruits is selected preferentially, then a branch with sparse fruits is selected, and a branch with fruits is selected again. The thickness of the retracted branches is controlled below 3cm (the retracted position in the small fruit stage in figure 4), the retracted length is 0.8-1.2m, and the number of the retracted branches is controlled at 30-45%. If the fruit setting is still too much in the later period, the remaining fruit branches are subjected to conventional fruit thinning treatment, and about 60 fruits are left in each ear. And at the end of 6 months, retracting and pruning branches of the longan trees after the longan trees are harvested, controlling the diameter of the pruned branches to be below 1.5cm (the retracting position after the longan trees are harvested in the picture 4), and controlling the length of the retracting and pruning to be 0.3-1.0m so as to achieve the purpose of controlling the tree crowns. The trimming effect is shown in fig. 4.

In 2012, in the last ten days of 5 months, the young fruits are basically stable, and the longan fruits are about the size of soybeans. And (4) performing retraction pruning on the longan tree, wherein during the retraction pruning, a branch without fruits is selected preferentially, then a branch with sparse fruits is selected, and a branch with fruits is selected again. The thickness of the retracted branches is controlled to be less than 3cm, the retracted length is 0.8-1.2m, and the number of the retracted branches is controlled to be 30-45%. And performing conventional fruit thinning treatment on the remaining fruiting branches. In the last 7 th month, after the longan tree is harvested, retracting and pruning branches of the longan tree, controlling the diameter of the pruned branches to be below 1.5cm, and controlling the length of the retracting and pruning to be 0.3-1.0m so as to achieve the purpose of controlling the crown (figure 5).

The retracted branches can grow for 3-4 times after nearly one year to become fruiting mother branches in the next year (figure 5), and better yield can be obtained in the next year through tip control and flower promotion or flower forcing treatment. Specific data are shown in table 1.

TABLE 1 Total shoot Length and terminal shoot thickness and yield regenerated after retraction at different times for each year

As can be seen from table 1, the balanced trimming can substantially maintain the carpopodium longan crown within a certain range, and three consecutive years of high yield can sufficiently prove that the balanced trimming is feasible on the carpopodium longan.

Example 2

Carrying out an Shixia longan balance pruning test in fruit tree research institute of agricultural academy of sciences in Guangdong province 5, 9 days in 2012, selecting Shixia longan 6 plants with crown sizes close to each other and moderate fruiting amount, and carrying out three treatments, wherein each treatment group comprises 2 trees, and the treatment group comprises 1: balanced pruning (5 months and 9 days), the retraction of the branch is about 30-50% in the young fruit period (fruit thinning period), the diameter of the retracted pruned branch is below 3cm, and the total length of the retracted pruned branch is 0.8-1.0 m; slightly retracting the rest branches after picking fruits, controlling the diameter of the trimmed branches to be below 1.5cm, and controlling the length of the retracted trimmed branches to be 0.3-0.8 m; treatment group 2: the flower and fruit period is not retracted, and the fruits are picked and trimmed according to a conventional management method (refer to plum blossom King, longan high-benefit cultivation technology 200 th edition, China agricultural Press, 2009) (7 months and 26 days); treatment group 3: big branches (crown depression) were retracted after picking (26 days in 7 months), and the size of the crown, growth of new shoots after retraction, yield in the current year (table 2), quality of the last autumn shoot, and flowering rate and yield in the next year (table 3) were investigated and recorded.

TABLE 2 crown size and annual yield at different periods

TABLE 3 last autumn shoot quality and yield and flower formation rate in 2013

The results in tables 2 and 3 show that: the treatment group 1 adopts a balanced pruning method, which has certain influence on the yield of the current year, but can control the size of the crown in a balanced way, and can keep the yield of the next year to achieve high yield of the next year. The quality of the last autumn tip growing on the branch after 5 months of retraction is obviously better than that of the autumn tip after fruit picking, the autumn tips have more length, thickness and multiple leaves, the flower forming rate is higher (90.4%) in the next year, and the yield is more stable. Flower thinning and fruit thinning costs much less than conventionally managed plants. The treatment group 2 adopts plants which are pruned conventionally, the yield in 2013 is also guaranteed, but the tree crowns grow up year by year, the orchard is sealed and closed after the tree crowns grow up to a certain degree, the yield is influenced finally, and the cost for flower and fruit thinning of longan is increased when the tree crowns are high. Big branches retract and are pruned after the fruits are picked in the treatment group 3, although the crowns can be pressed down, the bare-grown branches are strong (the internodes are 2.78cm long), and the flowers and fruits are poor in the next year, so that the big branches retract and are pruned after the fruits are picked is not recommended in general production.

Example 3

In 2014 3-4, a balanced pruning test is developed in test bases such as Guangzhou, Zhongshan, Enping, Bingping and the like, and the purpose of thinning flowers is achieved by retracting branches in the flowering period. Mainly aiming at branches which are positioned at the middle upper part of a crown and have the diameter of less than 3cm, the length of retraction pruning is 0.8-1.2m, and the number of retraction pruning is controlled to be 30-40%. The method mainly aims at large plants in large orchards, 10 trees are selected in each orchard, 5 branches are thinned according to the balanced pruning method, 5 traditional thinning flowers are adopted, the using time of each thinning flower is recorded, the sizes of crowns before and after pruning are measured, plant yield is counted during fruit picking, and the results are shown in table 4.

TABLE 4 comparison of Balanced pruning with traditional thinning

It can be seen from table 4 that the big branch thinning by balanced pruning has a slight influence on the yield, but can greatly reduce the thinning time, improve the thinning efficiency, improve the working efficiency, reduce the thinning difficulty, and simultaneously can achieve the effect of reducing the tree crown.

In addition, if the aim of flower thinning is not completely achieved after balanced pruning, flower thinning treatment is carried out according to a conventional method.

Example 4

Extreme experiments were used to verify the relationship of the balanced pruning to the ratio of shoots to fruit drop of the present invention.

In 2014, the method is developed in fruit orchards of fruit bearing institute of agricultural academy of sciences of Guangdong province, 13 Shixia adult plants and 8 Shixia young plants are selected, balanced pruning is carried out on 25 days in 3 months, 40-50% of flower ears are removed from the adult trees, 80-90% of flower ears are removed from the young trees, only one ear of flower is left in 7 th and 8 th young trees, other plants are subjected to plate-counting and fruit-counting on 28 days in 4 months, 10-12 ears are removed from each plant, the ratio of long-tip branches and fruiting branches is counted when the fruits are basically mature (14 days in 7 months), the fruits are counted, the fruit drop rate is calculated, and the counted results are shown in figures 6 and 7.

As shown in fig. 6 and 7, the ratio of the shoots to the fruits is not proportional to the fruit drop rate, which shows that the growth of the new shoots after the longan is subjected to the balanced pruning has no influence on the fruit drop of the longan, and the growth of the new shoots in the flower and fruit period has little influence on the fruit setting of the longan, which is very beneficial for the development of the balanced pruning of the longan, and is one of the bases for the inventor to carry out the balanced pruning of the longan.

Claims (6)

1. A longan crown balancing pruning method is characterized by comprising the following steps:

the method comprises the following steps of 1, performing retraction pruning on a crown while flower thinning and/or fruit thinning are performed on a longan tree; controlling the diameter of the branch subjected to retraction pruning to be below 3cm, controlling the total length of the retraction pruning to be 0.8-1.2m and controlling the total amount of the retraction pruning to be 30% -50%;

carrying out fruit thinning treatment on the remaining fruiting branches;

after the longan tree is harvested, retracting and pruning branches of the longan tree, controlling the diameter of the pruned branches to be below 1.8cm, and controlling the length of the retracting and pruning to be 0.3-1.2m so as to achieve the purposes of controlling the crown of the longan tree and balancing the yield and the tree vigor;

when the pruned big branches are taken out and young shoots are generated, 2-3 young shoots are reserved on each big branch.

2. The balanced pruning method of claim 1, wherein: the time of flower thinning is just before blooming after the flower spikes are shaped.

3. The balanced pruning method of claim 1, wherein: the fruit thinning time is after the young fruit is basically stable.

4. The balanced pruning method of claim 1, wherein: during retraction pruning, the branches without flowers and fruits are preferably selected, and then the branches with sparse flowers, big spica or sparse fruits are selected, and the branches with sparse fruits are again the normal flowers and fruit branches.

5. The balanced pruning method of claim 1, wherein: and carrying out fruit thinning treatment on the remaining fruit branches according to conventional management.

6. The balanced pruning method of claim 1, wherein: and after the longan tree is harvested, retracting and pruning branches of the longan tree, controlling the diameter of the pruned branches to be below 1.5cm, and controlling the length of the retracting and pruning to be 0.3-1 m.

Images