1, planting mode and density
Reasonable close planting is an important content of tea cultivation research. The so-called reasonable close planting of tea trees not only effectively utilizes the space and soil layer, but also gives full play to the individual and group structure of tea trees, thus achieving the goal of high yield, stable yield and high quality. It is suitable for mechanical tillage and mining, and it is also a condition to be considered for reasonable close planting.
To a certain extent, the tea yield increases with the increase of the number of tea trees per unit area; However, the output of Dan Cong showed the opposite trend, and decreased with the increase of tea trees. This is the result of the contradiction between tea group and individual. Reasonable close planting is to correctly handle this contradiction, ensure that tea trees can meet the needs of individual growth and development to the maximum extent under the premise of good population structure development, and make the output per unit area increased by the increase of close planting degree exceed the output reduced by individuals, so that tea trees can obtain high yield. According to the experimental results of different sowing methods in our hospital, if the growth of tea garden with 150× 150 (cm) (297 clumps per mu) is 100%, it will be 150×33 (cm) (per mu/kloc But if the yield of single clump is still 150× 150 (cm), 100%, 150×33 (cm), 150× 17 (cm). It can also be seen from this experiment that the number of clumps per mu in the latter two treatments increased by 3.5 times and 8 times, respectively, which greatly exceeded the decline of yield in Dan Cong, so the yield can still be increased.
Tea planting methods should consider two aspects, one is the row spacing of tea trees. That is, the arrangement mode, and the second is the number of seedlings per cluster. There are many ways to grow tea trees in China. There are also cluster tea gardens left over before liberation, which are gradually being eliminated because of low output and inconvenient management. Most of them are single-row strip tea gardens developed after liberation. The general planting specification is about the row spacing 150 cm and the cluster spacing is about 33 cm. 2-3 seedlings per cluster; The row spacing of big-leaf tea trees is about 165cm, and the cluster spacing is about 500m, and each cluster has 1-2 plants. Most high and stable yield farms in China are planted in this way. Some tea areas also use double-row strip planting tea garden, which is about 165 cm, and the row spacing and cluster spacing are about 33 cm. According to the report of Anhui Qimen Tea Research Institute, the output of single-row and double-row tea gardens is 19 1- 1968. In the first four years, the output of double-row tea garden was higher than that of single-row tea garden, increasing by 19.82%, and that of single-row tea garden was higher than that of double-row tea garden, increasing by 3.74%. In recent years, several rows of tea gardens have been tried in some areas. The tea garden planted in this way also has various specifications in row spacing, column spacing and cluster spacing. Moreover, after planting tea trees, farming is exempted, and other management measures are different from those of single-row and double-row tea gardens. It is reported that multi-row tea gardens have the advantages of early high yield, quick coverage of young tea trees and reduction of soil erosion. The emergence of this planting method, because of its short time, has an impact on the long-term growth and development of tea trees and the stable duration of high yield of tea trees, which needs further verification.
2. Sowing and transplanting techniques
Draw a line before sowing tea seeds or transplanting tea seedlings. The following principles should be considered when marking and aligning:
① The first line of Pingcha Garden should pass through the longest side of the plot, or be parallel to the main roads and canals. Draw the first line one meter away from the edge of the ground, and draw all the tea rows in turn according to the requirements of row spacing with this line as the baseline. The gentle slope tea garden requires contour strip planting, which should be marked from bottom to top, and marked line by line according to the requirements of promotion, so as to master the principle of contour but unequal width. For complex terrain, the line spacing range of high-speed range should be controlled between 1-2 meters. In a narrow horizontal tea garden, the tea line should be marked 3/5 away from the ridge; The first row should be drawn at a distance of 1 m from the ridge, and the last row should be kept at a distance of about one meter from the ditch, which is beneficial to the growth of tea trees and field management.
② The tea shop should be located in the sloping tea garden within the planning scope as far as possible to make full use of the land. Try to minimize wire insertion and avoid wire disconnection and wire closure. The turning angle of the tea shop and the intersection angle with the road should be suitable for the condition of machine farming.
(3) After marking, ditching can be done. The width and depth of planting ditch depend on the type and quantity of fertilizer and whether tea seeds are used for direct seeding or transplanting tea seedlings. In tea gardens where compost, manure and transplanted tea seedlings are planted, the planting ditch should be wider; In tea gardens where rapeseed cakes and tea seeds are used for direct seeding, the planting ditch is shallower. Generally, the width is about 20 cm and the depth is about 30 cm. The amount of base fertilizer is 30-40 tons per mu, or 200-300 kg of rapeseed cake, and a certain amount of phosphorus and potassium fertilizer is applied. After the base fertilizer is applied, cover it with soil for 3-5 cm to prevent the tea roots from directly contacting the fertilizer and avoid burning the roots. After fertilization, you can sow tea seeds or transplant tea seedlings.
(1) It is relatively simple and easy to develop new tea gardens by direct seeding of tea seeds, and the early management is not as strict as that of tea gardens with transplanted tea seedlings. Therefore, units with large development areas often use direct seeding of tea seeds, and the following links should be mastered when sowing:
(1) Tea seeds suitable for sowing date should be harvested before and after the first frost. The sowing period of tea seeds is long, from 1 1 month to March of the following year, and all seeds can be sown except the freezing period. Winter sowing is often used in production, which can save the storage of tea seeds. The seedling stage in the second year is about half a month earlier than that in spring sowing. Some units can also use the spring sowing period in February and March because of the large planting area or the inability to keep up with the land leveling work for a while. Practice has proved that spring sowing in most tea areas in China should not exceed the end of March, otherwise it will greatly affect the emergence rate and the growth potential of tea seedlings. At the same time, it is difficult for tea seeds sown after April to survive the summer safely even if they emerge. The reason is that tea seeds emerge late and are easy to burn at high temperature in summer, which increases the mortality rate of tea seedlings. Spring sowing tea seeds should be soaked to accelerate germination, so as to improve the emergence rate of tea seeds and enhance the growth potential of tea seedlings. Due to the low temperature and long freezing period in winter, tea in northern China used to be planted in spring, but in recent years, some of them have been successfully planted in winter. For example, in Jinqiao Tea Farm of Dengdeng Commune in Fengyang County, Anhui Province, tea seeds are sown in winter and covered with soil, and then the soil 5- 10 cm higher than the surface is piled up on the sowing line to make a soil ridge. After thawing in the following spring, the soil ridges were removed, and the tea seedlings were unearthed early and neatly. This is a good experience.
(2) Sowing quality The sowing depth is the main item to check the sowing quality. Too deep and too shallow can't meet the quality requirements. The suitable sowing depth of tea seeds is 3-5 cm. According to the experimental data in Hunan, different sowing depths are closely related to the emergence, seedling height and seedling rate of tea seeds. If the sowing depth is 4.5 cm, the initial seedling stage is on May 22, and the peak seedling stage is on June 24, when the seedling height is 30. 1cm, the seedling rate is 75.3%. However, at the depth of 9 cm, the initial seedling stage was June 12, and the peak seedling stage was August 20, when the seedling height was 22.2 cm and the seedling rate was 63.4%. It can be seen that there is a big difference between the two.
In some areas with special climatic conditions, in order to improve the sowing quality and ensure that all seedlings are strong in the year of emergence, some agricultural technical measures adapted to this area have been taken accordingly, and good results have been achieved. For example, in Shandong province, the sowing date of tea seeds (early April) is in the spring drought period. In addition to soaking seeds to accelerate germination, water is poured on the sowing line first, then tea seeds are sown, and the soil is immediately covered, and a steamed bun-shaped mound about 15cm higher than the ground is made on the covered sowing hole. The local name is "piling soil to preserve moisture". The purpose is to increase soil moisture content and reduce evaporation, which is a great victory. When using this technical measure, we should pay attention to timely bulldozing. The experience is that it is ideal to choose the time to push the soil when the tea seedlings are about to break through the ground and have not yet reached the surface. The early stage will affect the effect, and the later stage will infer the bud tip. It is best to cooperate with cuttings for shade when pushing the soil.
(3) Sowing grain in each hole is a summary of the long-term production practice of working people in China. It is one of the things that should be paid attention to in sowing work to adopt the appropriate sowing quantity. Too many seeds are sown in each hole. It seems that the tea seedlings unearthed in the past are not bad, but it will have adverse consequences because of the crowded tea seedlings in the future. If the number of seeds sown is too small, it will affect the seedling stage and emergence rate, and it is easy to cause cluster failure. Generally, after picking tea seeds, especially after soaking and accelerating germination, it is enough to sow four or five seeds per hole. If you don't pick tea seeds, you should increase the number of seeds according to the quality of tea seeds. When sowing, we should strictly control the row spacing and cluster spacing, and at the same time put the tea seeds evenly in the holes, not next to each other.
After the tea seeds are sown and covered with soil, some chaff or stick marks are sprinkled on the sowing line, which is beneficial to the smooth weeding work before emergence and does not hurt the seedlings.
(2) Transplanting tea seedlings has been mentioned above. Direct seeding of tea seeds has many advantages, but it also has disadvantages. The most prominent thing is that the offspring of seedlings are chaotic, and the characteristics of tea trees vary greatly among individuals. This is the main reason why the common sexually propagated tea trees have different leaf shapes, different germination dates and different growth strengths. With the continuous popularization of excellent varieties, the short cutting propagation of tea seedlings has been regarded as an important way to provide excellent seedlings. When developing new tea gardens in the future, the proportion of transplanted tea seedlings will increase year by year. Pay attention to the following points when transplanting tea seedlings:
① It is more suitable to select two-year-old seedlings for transplanting middle-aged lobular tea trees. One-year-old seedlings with good growth can also be transplanted if their height is above 25 cm. Due to the long cultivation time of tea trees in southern China, most of the cultivated tea trees are large-leaved trees or small trees, and the annual seedlings are about 50 cm. At that time, transplanting from nursery has been widely used in production, achieving the effect of rapid gardening.
② Transplanting tea seedlings in dormant period on the ground is easy to survive, so late autumn and early spring are suitable for transplanting. In areas with good soil moisture, the survival rate after transplanting the first frost is relatively high. At this time, the aboveground part gradually stopped growing, and the root system still had a growth peak. After transplanting, the root system recovered well in that year, and the tea seedlings germinated and grew earlier in the next year than in spring. Some areas are often dry in late autumn, and transplanting in early spring is more suitable. The period should be from the shock pad period to the vernal equinox, not too late, otherwise it will affect the survival rate. Tea seedlings transplanted in early spring are not as early as those planted in autumn, and often germinate and grow before the root system is fully recovered, so management should be strengthened, otherwise there will be stiff seedlings and dead seedlings. The tea planting area in China is vast, and the climatic conditions vary from place to place. In some areas, late autumn and early spring are dry seasons. Under such climatic conditions, if there are no irrigation measures, the growth of tea seedlings after transplanting is very unsatisfactory, so it is better to transplant tea seedlings in other periods. For example, in Yunnan Province, the suitable transplanting period is from awning to summer. It is difficult to survive if it rains too early, and the growth period is short after the end of the year. The roots often cannot be well restored when they enter the dry season, and the seedlings are easy to die. Some provinces (autonomous regions) have similar situations. Therefore, the determination of transplanting date should also consider the local precipitation at that time, otherwise it will get twice the result with half the effort and it is not easy to achieve the ideal effect.
③ It is very important to transplant with soil, take as few damaged roots as possible, and take more soil when planting in time. Shortening the time from seedling raising to planting is also an important factor to improve the survival rate of tea seedlings. When raising seedlings in the nursery after a long sunny day, it is best to fill enough water the day before, which will help to hurt the roots less and cultivate the soil more. When transporting tea seedlings in other places, we should take some corresponding protective measures, such as dipping the roots with yellow mud, wrapping the roots with wet straw for each bundle of tea seedlings, sprinkling water around the carriage or spreading wet straw bags, and covering the top to improve the humidity to prevent the tea seedlings from passing by me due to water loss. If the journey takes a long time, it is necessary to prevent the tea seedlings from being heated. On the way, it is best to turn the tea seedlings over or sprinkle water several times to facilitate heat dissipation and moisture retention. After the tea seedlings are transported to the destination, they should be planted in time. If there are too many tea seedlings to plant, it is necessary to transplant rice seedlings and then complete the planting work in the shortest time. When transplanting and planting, use 2-3 seedlings per hole. Don't lean together and pay attention to stretching. The taproot is too long, you can cut off a part. Adding soil layer by layer during transplanting is one of the keys to improve the survival rate. When the soil is buried more than half, water is poured enough for planting. After the water seeps down, continue to add soil until it is flush with the mud door. Too deep or too shallow is not advisable. When transplanting Su Miao, you should look back and forth in the same row, and control the row spacing to make it neat and beautiful. Cutting in time after transplanting and keeping the height about 15-20 cm is an effective measure to improve the survival rate.
(4) Transplanting and seedling raising in nutrient pots have been reported at home and abroad. Its advantages are high survival rate; After transplanting, there is no phenomenon that squatting seedlings stop growing; Without changing the restriction of transplanting period, the management after planting is more convenient, the garden is quickly completed and the yield is high. Conditional units can make full use of it.
Practice tells us that the survival rate and growth of tea seedlings are closely related to the above management links, and the water management after planting is of special significance.
3, young tea tree care
The nursing care of young tea trees includes drought resistance and antifreeze, thinning seedlings, weeding, rational fertilization, pruning, topping and lighting, pest control and so on. Here, only the drought resistance, frost resistance and thinning seedlings of the first and second instars are described, and other technical measures are described in relevant chapters.
(1) Drought and freezing At present, most of agricultural production is still "open-air factories". Unfavorable climatic conditions, such as drought and flood, severe cold and heat, will directly affect the growth of crops and may even cause crop death. The harm of disastrous weather to tea production is drought and freezing. In the Yangtze River basin, the former often appears in summer and the latter in winter. Young tea trees have weak resistance to adverse climatic conditions, and the degree of damage is higher than that of adult tea trees, so they need special care.
① Drought resistance It is obvious to distinguish the climatic conditions of major tea-producing provinces (regions) in China. Take temperature and precipitation as examples. In Lingtou, Hainan Island in the south of China, the annual average temperature is 23. 1℃, and the precipitation is 24 14.6 mm; In the middle of Hangzhou, the annual average temperature 16. 1℃ and precipitation1400.7 mm; Penglai, Shandong Province in the north, the annual average temperature is 1 1.8℃, and the precipitation is 623.6 mm ... However, there are * * * similarities in different climates. For example, the distribution of annual precipitation is uneven, and there are obvious differences between rainy season and dry season. The dry season in Hainan Island usually occurs from February to April, in Hangzhou from July to August, and in Shandong from 1 1 month to May. All these have a certain impact on tea production, even in years with little precipitation. For example, the middle and lower reaches of the Yangtze River are controlled by the subtropical ridge from July to August, and the high temperature and drought can last for dozens of days. During this period, the seasonal yield of tea is also the lowest in the whole year, which has a great impact on young tea trees, especially the seedlings and transplanted seedlings in the same year. If corresponding measures are not taken in management, seedlings will often be burned to death, which is what people call drought.
The reasons why tea trees suffer from drought are as follows: First, tea trees originated in southwest China, and formed the characteristics of shade tolerance and water demand in the process of system development. Although this characteristic of tea tree has changed in the process of gradually moving northward, it has higher shade tolerance and water demand than some crops. Second, young tea seedlings, especially those unearthed that year, are vulnerable because of their delicate stems and leaves and deep underground roots. Thirdly, from the perspective of environmental factors, drought and gale in the north and scorching sun and high temperature in the south are common drought-like weather. Under such climatic conditions, the transpiration of tea trees is significantly enhanced. At this time, if the soil is short of water, there will be an imbalance between supply and demand. If this situation develops to a certain extent, it will grow in the shade, the leaves will suffer and the whole plant will die.
In the long-term production practice, people have created many experiences in drought resistance, which can be summarized as follows:
Selecting drought-resistant varieties can reduce the degree of damage to a certain extent.
Irrigation to increase soil water content is the fundamental way to solve drought disaster. Therefore, water conservancy conditions should be considered when developing new tea gardens for dry season irrigation.
Cover the ground to reduce evaporation, use weeds and crop straws on the spot, and cover the ground before the dry season comes. First, it can reduce evaporation, reduce ground temperature and keep moisture; Secondly, it can increase soil organic matter and improve soil. When closing the garden to cover the grass, you should prevent "covering your head", otherwise the high temperature will make the tea seedlings wilt, which is not conducive to the growth of tea seedlings. The amount of grass covered is 30-40 loads per mu.
Cutting to protect seedlings from shading has an ideal effect on the seedlings unearthed that year, and at the same time, it uses less grass than the ground, and it is more labor-saving to spend flowers. Before the dry season comes, straw, pine branches, branches and other shading materials can be planted in the southwest of tea trees, which is about 15 cm away from tea seedlings, so that it can play a role in shading and protecting seedlings during the high temperature period from 10 am to 3 pm. When doing this work, be careful not to cover the tea seedlings in the shade, so that the tea seedlings can be wetted by dew. During the sunshade period, we should do a good job in nursing the sunshade. If we find that the shade has fallen and covered the seedlings, we should sometimes straighten it. When straw is used as shade, it is not suitable to insert the whole bundle directly, which is easy to cover the seedlings. In the specific operation, the middle part of the wheat straw can be folded in half and staggered, and the base part can be tied into a fan shape, so that the base part can be buried in the southwest of the tea seedlings, thus playing the role of shading and protecting the seedlings.
Strengthen management and improve the drought resistance of tea trees. During the period from sowing tea seeds to emergence, the unearthed seedlings can meet the requirements of early, strong and neat, which will greatly improve the drought resistance of seedlings. In the investigation of drought disaster at seedling stage, it can be found that tea seedlings that are seriously damaged are often seedlings that are unearthed late or grow in dry season, and are most likely to be burned to death. Therefore, sowing in autumn or soaking seeds in spring to accelerate germination is a successful experience in practice and worth popularizing. Through the investigation of drought disaster, it can be seen that before the arrival of high temperature and drought period, if the seedling height is above 5 cm, the drought resistance of several tea seedlings with real leaves will be significantly improved. Shallow tillage and weeding are also helpful to improve the drought resistance of tea seedlings. Dry season is an effective way to reduce the competition between weeds and tea seedlings for water. However, shallow tillage and weeding should be done early, otherwise it will be self-defeating and aggravate the drought. Introducing exotic soil and applying thin water and fertilizer frequently in dry season can not only replenish water but also increase nutrients, thus improving the drought resistance of tea seedlings.
② Frost damage of frost-resistant tea trees includes snow freezing, wind freezing and frost. Snow freezing and frost are common in Jiangnan, but these three kinds of freezing injuries have occurred in other tea areas. After freezing, tea trees have two manifestations: red withered and green withered, and the southern tea area is dominated by red withered, while the northern tea area has both. Frost and wind fallow are immediate injuries after freezing, while snow freezing is a gradual freezing injury in the process of snow melting, which has a certain protective effect on tea trees during the snow-covered period.
Tea has a certain ability to resist low temperature, but the cold resistance of different organs is different. According to relevant data, the cold resistance of tea leaves, stems and roots decreased in turn. In the investigation of freezing injury, it can be found that the roots of tea trees are often not easily damaged by freezing because of soil protection. Therefore, in production practice, the degree of frost damage evolution of tea trees is to damage leaves first and then extend to stems. Only when the temperature is extremely cold will the roots freeze.
The cause of frostbite is related to temperature. From the climate analysis, there are nothing more than three factors, namely, low temperature, drought and strong wind. These three factors often occur in children, and low temperature is the dominant factor. Drought and strong winds will deepen the degree of freezing damage. According to the relationship between the overwintering of tea trees in Rizhao1971-kloc-0/977 in Shandong province and meteorological factors, it is pointed out that the longest continuous days when the total negative accumulated temperature exceeds-100℃, the extreme minimum temperature is lower than-10℃ and the daily average temperature is lower than/kloc. In addition, the temperature drops sharply in winter, and the frozen soil is deep and lasts for a long time. At this time, strong wind and drought have also become an important reason for the deepening of freezing damage. Second, it is related to varieties. Different varieties have different cold resistance, some varieties are cold resistant, and some varieties are cold resistant. Judging from the introduction results of Shandong Province, tea seeds from Anhui, Zhejiang, Jiangsu, Hunan, Shaanxi and other provinces were introduced in the early stage of trial planting. After years of observation and comparison, it is proved that the social species near Huangshan Mountain in Anhui Province have strong cold resistance in the local area. There are also strong local tea seeds in Shandong. Growth and cold resistance are stronger. Third, it is related to geography. There is obvious correlation between freezing injury and latitude and altitude, and different slope directions of tea gardens are also related factors of different freezing injuries. Usually, tea plants in tea gardens at high latitudes, high altitudes and northern slopes are prone to freezing, and tea gardens in valleys and corridors where cold air is deposited are also prone to freezing. Fourth, it is related to the management of * * * gardens. Poor management and improper measures in tea gardens will also cause freezing injury to tea trees.
Methods to prevent or reduce freezing injury;
Selecting varieties with strong cold resistance is the fundamental way to solve the freezing injury of tea trees, and the cold resistance of each variety is determined by the genetic characteristics of tea trees themselves. Therefore, when opening new tea gardens in areas where freezing damage often occurs, we should pay attention to the cold resistance of various varieties, choose varieties with strong cold resistance as the introduction targets in the future, and pay special attention to selecting and retaining local tea seeds with strong cold resistance, so as to expand new tea gardens and fundamentally solve the cold resistance problem of tea trees.
Physical methods prevent freezing injury from occurring in winter and early spring with frequent cold currents. With the help of favorable terrain and wind deflector, the effect of cold protection and warmth can be achieved. When developing new tea gardens in the southern and northern mountainous areas with higher latitudes, we should first choose the favorable terrain to avoid the wind and the sun, so that we can rely on the barrier function of the peaks to play the role of cold and antifreeze; Secondly, when opening up a new tea garden, we should consciously keep some of the original trees, pay attention to the greening work on both sides of the road, and add shelter belts. These are permanent protection measures, which are worth popularizing. In addition, covering soil for one or two-year-old tea seedlings in winter (pay attention to uncovering the top and digging in stages in early spring), adding wind barriers and spreading grass on the ground are also effective anti-freezing measures.
Chemical protection is to use chemical agents to keep warm, reduce transpiration, or promote the senescence of branches and leaves, improve the degree of lignification, and thus increase the cold resistance of tea trees. According to relevant data, spraying steam inhibitor and heat preservation agent on the surface of tea and soil during the wintering period has certain anti-freezing effect. According to other data, spraying 2-4 drops in late April and165438+1early October is helpful for tea trees to overwinter. Using chemicals to protect tea trees from overwintering is a new way to solve the problem of safe overwintering of tea trees. There is little research in this field, which needs further discussion.
Strengthening management and improving the cold resistance of tea trees The content of tea cultivation management is very extensive. In recent years, from the results of planting tea trees in the north, it can be seen that the safety of tea trees crossing the east is closely related to three aspects: soil tillage before planting, tea picking and fertilizer and water management in tea gardens. Shandong province pays special attention to the quality of tea garden reclamation. Generally, terraced tea gardens are located on sloping fields, and the soil is 80- 100 cm deep, which is regarded as the content of technical regulations. Numerous examples have proved that tea gardens that meet the above reclamation standards are lightly frozen. During the light harvesting of young tea trees, early closure of the garden is also closely related to the safety and freezing injury of tea trees. In Rizhao county, Shandong province, the freezing injury index of tea trees can be reduced by stopping picking before and after Bailu and picking tender buds before and after the autumn equinox. In the management of fertilizer and water in tea gardens, it is necessary to irrigate overwintering water, apply base fertilizer early and control topdressing in stages, which is also different from the fertilization principle in southern tea areas. At present, the application period of base fertilizer in most tea areas in China is arranged in late autumn or early winter after autumn tea, but the practice results in many northern tea areas show that the application period of base fertilizer before and after Bailu is more suitable. At this time, the application of base fertilizer can make the root system heal quickly, grow quickly and have a good effect of safe overwintering, which is determined by the climatic conditions in the north. In late autumn and early winter in the north, the temperature and ground temperature drop rapidly, and early application of base fertilizer can achieve positive results. Topdressing by stages is one of the important principles of rational fertilization, but the annual change of temperature in northern China is slow in early spring and rapid in late autumn. According to this feature, the topdressing method of promoting before and controlling after is adopted, which is also different from other tea areas. The specific method is to apply nitrogen fertilizer in time when tea buds germinate in spring and summer to promote the growth of tea buds; Topdressing in autumn should not be too late, otherwise the phenomenon of "falling in love with autumn" will appear in the new shoots, which will aggravate the freezing injury of tea trees. Therefore, the last topdressing will not pass in August. Increasing the application amount of phosphorus and potassium fertilizer is helpful to improve the cold resistance of tea trees. In addition, spreading grass on the ground and covering grass on the canopy in winter may not be effective in raising the ground temperature, reducing the thickness of frozen soil and reducing the temperature difference between day and night on the canopy.
(2) Interplanting gap At present, most new tea gardens are developed by direct seeding of tea seeds. As mentioned earlier, the offspring of sexual reproduction are chaotic and vary greatly among individuals; At the same time, when sowing tea seeds, considering that the final number of seedlings per cluster is 2-3, the sowing amount per hole is also appropriately increased. For these reasons, it is necessary to interplant seedlings to make the characteristics of tea trees relatively consistent, and lay the foundation for rapid garden building, mechanized tea picking and high-yield, stable-yield and high-quality tea. The principle of thinning seedlings should be excavated, the superior and the inferior should be eliminated, and the strong and weak should be retained. At the time of tea seedling and second instar, after the annual growth, the thinning work is carried out. There are 2-3 seedlings in each cluster of medium-lobulated tea trees, and 1-2 seedlings in each cluster of large-leaved tea trees. Tea trees after thinning should stabilize the soil with loose roots in time to facilitate the growth of tea seedlings. Tea seedlings with excellent properties are separated due to too many seedlings in the process of thinning, which can be used to replant missing clumps, which not only solves part of the seedling source, but also is suitable for transplanting with soil and planting in time, so the survival rate of tea seedlings after replanting is also high.
In production, due to various reasons, the phenomenon of missing blocks often occurs. Replanting tea seedlings in time after missing clumps to ensure the survival rate of replanted tea seedlings is a link that can't be ignored to improve the yield of tea gardens, otherwise it will lead to missing clumps and broken rows, which will be unsightly and affect the yield of tea gardens. If replanting is not done at the first or second age, it will be difficult and the survival rate will be greatly reduced with the increase of tree age in the future. This is the experience of * * *. In the work of replanting seedlings in Xinyuan Garden, seedlings of the same age should be selected for replanting. Points for attention in transplanting.
Tea cultivation techniques