Carambola is not cold-tolerant. The annual average temperature is above 265438 0℃, which can be planted in areas without frost and snow in winter, and is widely planted in Hezhou, Wuzhou, Guiping, Yulin, Liuzhou, Nanning and other cities. It is not suitable for open cultivation in counties, cities and regions with snowy winter or long frost period in northern and western Guangxi.
1. Excellent varieties
1. 1 Malaysia B 10 Sweet carambola is also called "honey carambola". The plant is tall and fast-growing, the fruit is yellow when it is ripe, the weight of a single fruit is 150-300g, the flesh is light yellow, juicy, sweet, slag-melting, the core is small, there are few or no seeds, and the soluble solids are 7%- 10%.
1.2 Malaysia B 17 Sweet carambola is also called crystal honey carambola and red carambola. The plant is of medium height and growth potential, and the weight of a single fruit is 200-400g. When the fruit is immature, it has crystal-like fruit spots. When it is mature, it is golden yellow, crisp, juicy and fragrant, with soluble solids 1 1%- 13%.
1.3 The average single fruit weight of honey-shredded sweet carambola is 168g. The flesh is white and yellow, tender, juicy, sweet and of good quality.
Cultivate seedlings
2. 1 sow the seeds immediately after taking them out, wash them with clear water, or store them for a short time, and store them in wet sand after drying in the shade (the humidity should be controlled by hand, and the water should be sewn by hand without dripping).
2.2 March-April and 9-65438+ 10 are suitable sowing dates and sowing methods. The seedbed should be carefully arranged and the seeds should be evenly scattered on the seedbed. Cover with a layer of 1-2cm of scorched soil or fine soil, drench thoroughly with water, cover with grass to keep warm, drench thoroughly with water every 2-3 days until germination, and pay attention to prevent rats in the seedbed from eating seeds.
2.3 After transplanting and sowing, it began to germinate about 15d, and the seedling height was 10- 12cm. The plant spacing is (15-20) cm× (20-25) cm. Sprinkle water 1 time every day within 10 days after transplanting, and pay attention to shading. After transplanting the seedlings for one month, apply decomposed rare human and animal manure once a month. The stem thickness of grafted seedlings is about 0.6 cm.
2.4 Selection and treatment of scions The scions should be selected from excellent mother plants, and the branches that grow outside the crown 1-2 years in the sun are the most suitable, while the branches with weak shade or just bearing fruit are not suitable. After the scion is picked, leave a petiole 0.3-0.5 cm long and cut off the leaves to reduce water evaporation. It is best to pick while picking, or wrap it with a wet towel to keep the scion fresh. After the scion is harvested, if it can't be grafted in time, the easiest way is to bury it in the wet sand layer in the shade for preservation. Generally speaking, the storage of scions for 3-5 days does not affect the grafting survival rate.
2.5 Grafting period and method: Grafting can be carried out from late February to 65438+early February, and from mid-March to early May and from 9-65438+ 10 in Guangxi. The grafting method adopts single bud cutting, the grafting position is selected to be 10- 15cm above the ground, and the rootstock stem is more than 0.6cm thick and smooth. When grafting, the incision should be aligned with the cambium, smooth, with a length of 1- 1.2cm and a scion length of about 1.5-2cm. There are buds on the upper part of the incision, and the incision and scion are completely wrapped with film. In addition, bud grafting and branch-belly grafting can also be used. Among them, cutting has the highest survival rate, the simplest method, the best seedling rate and seedling quality.
2.6 After the grafted seedlings survive, after 15-20 days, when the new buds on the scion generally grow 3-5 leaves, dilute liquid fertilizer or manure can be applied once a month. Keep a strong new scion tip and erase the rest; In addition, wipe off new shoots from the roots at any time. When every other batch of new buds begins to germinate, they can be untied to facilitate the healing and growth of grafted parts, and pay attention to watering and moisturizing. When the cork length of the new shoot stem of the scion is about 65438±05cm, the seedlings can leave the nursery.
3. Key points of cultivation techniques
3. 1 planting
3. 1 1 garden carambola likes high temperature, humidity, still wind and cool environment, and avoids direct sunlight, water stains and strong winds, and is not cold-resistant or frost-resistant. Therefore, we should choose an environment with high humidity and low wind for planting. Hills and mountainous areas should choose areas with low slopes, south leeward, deep and loose soil layers, rich organic matter, strong water retention and easy drainage to build gardens.
3. 12 planting time and density March-April in spring is the most suitable planting period of carambola. South China is warmer in winter, and autumn planting can also be carried out. Planting density can be determined according to soil fertility and management level. Gardens with fertile soil should be properly sparsely planted, and those with high management level can be properly densely planted. Generally, the plant spacing is 3m×4m, and 255 plants are planted every 667 square meters.
3. 13 planting method: Carambola seedlings should be planted with improved varieties and strong seedlings. The depth and width of the planting hole are 0.8- 1m respectively, and the hole is filled with sufficient base fertilizer. Organic fertilizers such as green manure, burnt soil and decomposed pig cow dung can be applied in layers, which can be divided into 30-50 kg and 1-2 kg of calcium magnesium phosphate fertilizer. The lower soil is backfilled on the top floor and piled into a mound 20-30cm above the ground. After that, mash the soil in the planting hole, put the seedlings into the depth of 10-20cm (that is, the depth is the same as that of the nursery), let the roots evacuate, then cover the soil and gently lift the seedlings and compact them. After planting, make a tree tray around the sapling, cover it with hay and drench it with water. Sprinkle water once a day for a week after planting, and then keep the tree tray wet.
3.2 Soil, fertilizer and water management
3.2. 1 intertillage weeding and soil improvement in young orchards, 4-5 times a year, from spring to autumn; Or weeding with herbicide, adding glyphosate 1.5kg into water every 667 square meters, and spraying weed stems and leaves 2-3 times a year. After young trees are planted for 2-3 years, the roots are full of planting holes. Therefore, reaming should be carried out in winter to facilitate root growth, and the reaming of the whole garden should be completed within 2-4 years after planting. Every year, after the fruits of adult trees are picked in late winter and early spring, the soil should be deeply ploughed by 40-50cm, and organic fertilizer should be applied to improve the soil aggregate structure and soil fertility.
3.2.2 Fertilization shall be started after young trees survive 1 month, with the principle of frequent application and light application, with nitrogen fertilizer as the main fertilizer. Twice a month, apply 5 kg or 20-50 g compound fertilizer to each decomposed and diluted human and animal manure. After 1 1 month, the application of quick-acting fertilizer was stopped, and winter fertilizer was applied in winter, and the soil mixed with phosphorus fertilizer was applied to each plant 10kg. Fertilization for adult trees: after harvesting the last batch of fruits in March every year, deep ploughing and soil improvement are carried out, and organic fertilizer 10-20kg and appropriate nitrogen fertilizer are applied to the plants to restore tree vigor; Apply 20-30 kilograms of organic fertilizer in autumn. After each batch of fruits is harvested and before germination, nitrogen fertilizer should be applied as appropriate, generally not before each bud is planted and bloomed. Apply less nitrogen fertilizer in the young fruit stage to avoid fruit drop caused by vigorous growth of branches, and apply more phosphorus and potassium fertilizer in the middle fruit stage. Four-year-old trees are applied with 50kg of decomposed human excrement, compound fertilizer 1.5kg and magnesium fertilizer every year to promote fruit coloring. If the weather is hot and dry in flowering period, flowers and fruits can be protected by spraying water or fruit protectants, such as spraying gibberellin 2.5g+ Wang Lu 85g plus 50kg water or gibberellin 2.5g+ urea 0. 1kg+ potassium dihydrogen phosphate 0. 15kg+ boric acid 0.05kg plus 50kg water.
3.2.3 Carambola irrigation and drainage needs more water, so it is afraid of waterlogging. Drainage should be done in flat orchards, deep furrows and high ridges should be cultivated in places with high groundwater level, and irrigation should be done during long drought, especially during fruit development. Lack of water can easily lead to small or large fruit drop. In mountain orchards, contour terraces and sewage ditches should be built to conserve water.
3.3 Plastic dressing
3.3. 1 Young trees prune the poplars mainly in the shape of natural round heads. Generally, the top is cut when the seedling is 50-60cm high. After germination, select 3-5 buds to grow into main branches. When the first branch is about 50cm long, the core is removed to promote the germination of the branch, and 3-4 lateral buds are left on each branch, and then the branch naturally branches to form a natural round-headed crown.
3.3.2 Pruning of adult trees Adult trees are mainly pruned twice a year. For the first time, after picking the last batch of fruits in March, long branches, dense branches, weak branches, decaying branches and dead branches were mainly cut off to facilitate the emergence of new buds and the germination of buds. This trim is heavier. The second time was carried out in June, mainly cutting off weak branches, dense branches and long branches, and keeping evenly distributed drooping whip branches as fruiting branches. Pruning can make the branches stout and improve the big fruit rate.
3.4 Poplar with thin fruit has a large amount of peach blossoms and high fruit setting rate, which is easy to bear too many fruits, affecting tree vigor, fruit quality and the next flowering. Therefore, reasonable fruit thinning must be carried out to adjust the contradiction between growth and fruiting, so as to increase the shape and quality of fruit and achieve the purpose of high yield and high quality cultivation. Generally, deformed fruit, diseased fruit and small fruit are thinned twice from fruit setting to bagging (when the fruit grows to 5cm), and 1-2 fruits are left per ear.
4. Pest control
4. 1 Main diseases and their prevention and treatment
4. 1. 1 carambola anthracnose, which mainly harms fruits, leaves can also get sick and have wounds.