2. Illumination: Litchi requires high illumination. Even if it is cultivated as a potted plant, it usually needs to be placed in a sunny place. Due to sufficient light, plants can effectively promote photosynthesis, thus ensuring that plants grow more healthily. Moreover, if sufficient light is provided in the flowering and fruiting period, it can promote flowering and fruiting, promote the development of fruits, and then improve the quality of fruits. However, if the light is too strong, the water evaporation is also large, and it is difficult to bloom and pollinate. However, sufficient light is needed to improve the color and quality of fruit during the fruit hanging period.
3. Temperature: The normal growth of litchi is greatly affected by temperature, especially in the flower and fruit period, which is often more sensitive to temperature. Litchi roots often grow fastest in the temperature environment of 23℃-26℃, and new shoots can germinate smoothly when the space temperature reaches above 65438 06℃. Generally, plants grow fastest in the environment of 24℃-29℃. When the temperature reaches 13℃, litchi will blossom gradually, and it will bloom most when the temperature reaches 20℃-24℃, but in order to ensure the normal differentiation of flower buds, the flowering temperature is generally required not to exceed 27℃. It can be seen that litchi, a fruit tree, prefers warmth.
4. Watering: The growth of litchi needs sufficient water, especially in order to promote the germination of new shoots, it is generally watered once a week, otherwise the germination of plants will be affected to some extent in the case of water shortage. When the water is sufficient, it often grows luxuriantly, which is also beneficial to grow into mature fruiting branches. However, watering should be appropriately increased after heading to promote the growth of fruit ears, and the amount needed during fruit expansion is often more, which can promote the growth and development of fruits. However, if excessive watering leads to water accumulation in the basin, it is often easy to cause fruit drop and may also lead to downy mildew of the fruit.
5. Fertilization: Because the growth of potted litchi saplings is often weak, mainly due to poor root distribution, limited flowerpot size and soil volume, dilute and decomposed chicken manure water, bean cake water or compound fertilizer water and fertilizer are generally applied two years before planting in the upper pot, mainly chemical fertilizer. Proper topdressing can accelerate the rapid formation of litchi crown and lay a good foundation for flowering and fruiting.
6. Pruning: Pruning of potted litchi can generally be carried out in four seasons, but mainly in spring, summer and winter. Spring cutting is generally carried out in March-May every year; Summer pruning is mostly carried out in July-August in midsummer; Winter shearing generally starts from 65438+February and is carried out during February of the following year. However, pruning is generally based on cutting off pests and diseases, overgrown branches and old and weak branches. Proper pruning can not only promote the germination of new branches, but also maintain good plant type.
7. Shaping: Generally, the shaping of litchi is completed within 2-3 years after planting in the upper basin. Usually, plants with short stems and even and compact main branches are cut into semi-circular crowns. Keep 3-5 main branches in different directions of potted plants, and cultivate 2-3 auxiliary main branches for each main branch to finally form the trunk of potted litchi. When the bifurcation angle of the main branch and the auxiliary branch is relatively small, it can be adjusted by pulling, supporting and jacking until the required angle, thus making the potted plant more beautiful.
8. Pests and diseases: Litchi trees are more vulnerable to pests and diseases such as anthracnose, midges, inchworm and leaf gall midge, so it is necessary to provide a good growth atmosphere for plants during the maintenance and management period to avoid being infected with pests and diseases. And once you suffer from these pests and diseases, you should spray them in time to kill them. The drugs that can be used are thiophanate-methyl, fresh amine, Baitai, abamectin, dichlorvos, pyrethroids and so on. Dilute with water in an appropriate proportion, and then spray.
9. Planting method of open-air litchi. Grafting propagation of seedlings: Litchi is mostly planted in hills and slopes. These soils usually contain less organic matter, and the soil layer is shallow, so the ability of water and fertilizer conservation is poor. If soil management is not paid attention to, the growth and development of litchi will be seriously affected. Lichee mycorrhiza is aerobic, and loose soil ventilation is beneficial to root growth and development. Young orchards generally loosen soil and weed 5-6 times a year. Weeds with high temperature and high humidity grow rapidly in summer and autumn, and the frequency of weeding by loosening soil is more. The surface temperature is low in spring and the dry rainfall on the surface is less in winter. Weeds grow more slowly and are cultivated less often. The main contents of soil improvement in litchi orchard include deep ploughing, ripening and thickening soil layer to increase organic matter. Its purpose is to improve soil physical and chemical properties, improve fertility and create good conditions for root growth. The soil improvement method is to open an annular ditch or two flat fertilization ditches around the original planting hole.
10. Soil management under the crown: the root system of young litchi trees grows weakly and has mycorrhiza with some fungi. The growth of mycorrhiza needs a relatively ventilated soil environment. Therefore, the soil around the trunk under litchi canopy must be fertile and loose, rich in organic matter, which is conducive to the formation of mycorrhiza and the rapid development of roots. Therefore, the soil under the canopy should be loosened in time and covered with organic fertilizer to prevent hardening.
1 1. Soil management outside the tree tray: In order to increase economic income, short-term crops such as vegetables and leguminous green manure were intercropped in the young litchi orchard, and fertilization, irrigation and loosening were carried out for many times, and the straw and green manure in intercropping crops were turned into the soil to increase organic matter and improve the soil. In the second and third years after planting, the soil around the tree tray must be improved in a planned way. In autumn and winter, dig a ditch 50 cm deep and 40-50 cm wide outside the original planting hole. Each plant is pressed with about 100 kg of weeds, leaves or green manure and 1.5 kg of calcium superphosphate every year, and then covered with soil. Digging and pressing the green fertilization ditch should be done on the east and west sides of the seedlings first, then on the north and south sides of the seedlings or around the crown.
12. Fertilization: Fertilization can be started one month after planting. In two or three years, it is mainly to increase roots, promote shoots and strengthen shoots. Master "two fertilizers on one branch" or "three fertilizers on one branch", that is, when the top buds of branches germinate, apply the quick-acting fertilizer mainly containing high nitrogen fertilizer and containing a large number of elements in order to promote the rapid growth and long leaves of new shoots. When the growth of new shoots basically stops and the leaf color changes from red to green, apply the second fertilizer to promote the new shoots to turn green quickly and the branches to thicken. After the new buds turn green, apply fertilizer for the third time to accelerate the aging of the new buds. Young roots have weak ability to absorb fertilizer, so they can be sprayed with Guoli international litchi foliar fertilizer every year. Fertilizer and water management of 1-2-year-old young trees after planting can promote the total leaf area of root groups and branches. After the young litchi survives, the root system is few and weak, and the absorption is weak, so it is not suitable to increase the water content. Fertilization is based on high quality, nitrogen combined with a small amount of phosphorus and potassium fertilizer, less but more precise, and the principle of diligent application and thin application. Young trees planted in that year can be applied with thin fertilizer and water 1-2 times a month. In the second and third years, it is mainly to increase the amount of roots to promote buds and strengthen buds. Quick-acting fertilizer, mainly nitrogen fertilizer, is applied once every time the top buds of branches germinate to promote the rapid growth of new shoots. When the leaves turn from red to green, apply the second fertilizer to promote the branches to turn green quickly, improve photosynthetic efficiency and accumulate nutrients. Fertilization can also be applied after the new shoots turn green, so as to accelerate the senescence of the new shoots and shorten the bamboo shoot development period. Fertilization method 1. It is best to use Guoli international litchi irrigation fertilizer for young trees. After the second year, it can be applied to the shallow ditch on the soil around the crown, and then the soil should be irrigated in time when it is dry. The leaves can absorb fertilizer quickly, and the absorption rate is high. Fertilization can be applied outside the roots after the new shoots turn green. Spraying potassium dihydrogen propolis on the leaves can promote the rapid maturity of the new shoots. But pay special attention to the concentration, too high concentration will burn the leaves. The concentration should be reduced appropriately in case of high temperature and drought. Young litchi has weak root distribution and is easily affected by the change of topsoil moisture. Under the condition of high temperature and drought, if the soil moisture is too little, it will inhibit the germination and growth of branches and even lead to plant death. Therefore, attention should be paid to irrigation and moisturizing in dry season. Attention should be paid to eliminating stagnant water in rainy season.
13. Watering: Irrigation and drainage are important components of litchi trees. Litchi young roots are few and shallow, which is greatly influenced by the change of topsoil moisture. Under the condition of dry soil and dry atmosphere, attention should be paid to watering and moisturizing. In rainy season, the planting position should be raised appropriately to prevent plants from sinking due to water accumulation in planting holes, so as to facilitate normal growth.
14. Weeding: Weeding and loosening soil can help loosen soil and promote root system development. Young trees can be combined with management in intercropping crops to weed and loosen soil. Weeds grow fast in summer and autumn when it is hot and rainy, and the soil is easy to harden. Weed and loosen the soil more frequently. The temperature is low in winter and spring, and weeds grow slowly. Young roots are shallow, according to the range, the loose soil should be 8- 10 cm shallow, and it can be as deep as 15 cm outside the rhizosphere range.
15. Pruning: Pruning young litchi trees requires that young litchi trees can cultivate trunks 30-40 cm high. 3-4 evenly distributed main branches make the incident angle suitable, so the pruning objects are cross branches, over-dense branches, weak branches and panicles that are not allowed to bear fruit. Pruning can be done by pruning, coring, pulling, hanging and spreading. Branches that can be cut or not can be temporarily retained in order to effectively use nutrients to expand the crown. In the past, young litchi trees were rarely pruned, with messy crowns, too many branches, too many pests and diseases, and serious weakness. Prune once a year in winter, and cut off too dense shade branches, cross branches, overlapping branches, pest branches, weak branches and dead branches, so as to effectively use nutrients, expand the crown, make the crown ventilated and transparent, and reduce pests and diseases. After each new branch matures, but before the next new branch germinates, leave 20-30 cm long branches and upright branches for short cutting. When pruning young trees, pay attention to the balance of crown, and don't vary in height or width. If the strength of the backbone branches is quite different, it can suppress the strong and help the weak.
16. Bagging: Conditional orchards can start to turn red at the base around the fifth ripe stage of litchi fruit. Bagging fruit ears can not only prevent insects and diseases, but also prevent bats, moisturize, cool down, prevent sunlight, damage the fruit, reduce evaporation, increase the temperature in the bag and promote fruit ripening. You can use authoritarian fruit bags or transparent plastic film bags or translucent sulfuric acid paper bags. The cylinder is about 30-40 cm long and 20-25 cm wide, depending on the length and size of the ear. Punch some holes with a diameter of 0.5 cm on it, tie the upper part of the ear and open the lower part slightly. Spraying insect and disease prevention pesticides before bagging. When picking fruits, the ears and bags are picked together. Note that litchi trees like high temperature, high humidity and sunshine, and its heredity requires relatively low temperature during flower bud differentiation, but the lowest temperature is -2 to -4℃, which will suffer from freezing injury. Sunny and warm weather is the most favorable during flowering, while low humidity, continuous rain, dry heat or strong north wind are not conducive to flowering and pollination. Unfavorable disaster weather in the flower and fruit period will cause loss of flowers and even harvest.