One: Blueberry planting technology
1. 1 Garden selection
According to the ecological adaptability of blueberry, the suitable planting area (that is, the climate suitable area) is determined first, and then the planting plot is selected. When choosing planting plots, we should first know or measure the pH value of the soil, which should be between 4.2 and 5.5. Secondly, we should try to choose places with loose soil, rich organic matter and good irrigation and drainage conditions. If it is mountainous, try to choose the middle and lower part of the south slope, and the slope should not exceed 15. When it is greater than 15, a terrace with a width of 2m should be built; The best site types are barren hills and low-yield pine forests, and sloping fields can also be converted into farmland. However, the survival rate of returning farmland is not as high as that of pine forest transformation, and there are more pests and weeds than pine forest transformation, which increases the management cost. In the hilly and mountainous areas in the south, combining with the construction of commercial forest bases, popularizing blueberry planting can not only improve the ecological environment, but also adjust the forest species structure and increase the economic income of people in mountainous areas.
1.2 Planting density and soil preparation
Planting density:1.0-1.5m× 2.0-3.0m, which is suitable for high cluster blueberry; Rabbit eye blueberry often chooses1.5m× 2-2.5m; Select 0.6 ~ 1.2× 2m for semi-high cluster blueberry. In foreign countries, the actual planting density often depends on the degree of mechanization. In the north and south of China, we can choose the appropriate density according to the actual business objectives.
Soil preparation: digging planting holes before planting is called soil preparation, and the specification of soil preparation (planting holes) is 1.0m (length) × 1.0m (width )× ×0.5m (depth). When planting semi-high-bush blueberry and short-bush blueberry, the specifications of soil preparation can be appropriately reduced, and when planting rabbit-eye blueberry, the specifications of soil preparation can be appropriately increased. After digging the planting hole, the soil taken out should be mixed with broken pine bark and humus soil under peat or pine forest, and then filled into the hole. Backfill soil should be 20-30cm higher than the ground, and appropriate amount of sulfur powder can be added when the soil acidity is insufficient.
1.3 Variety configuration and planting time
Cross pollination is one of the important factors to improve blueberry yield and fruit size. The self-pollination rate of high-bush blueberry is high, while the self-pollination rate of low-bush blueberry and rabbit-eye blueberry is low or not. Cross-pollination can increase the fruit setting rate of Vaccinium highbush from 67% to 82%, and that of rabbit eye berries from 18% to 47%. Therefore, in blueberry orchard, at least two varieties should be configured to pollinate each other to improve yield and quality. Generally, the allocation ratio of pollination trees is 2-3: 1, that is, 2-3 rows of main varieties and 1 row of pollinated varieties.
Planting time: in the south where winter is not very dry, it is best to plant it from autumn to early spring before germination. The planting depth of annual seedlings is 15-20cm, and the soil should be compacted to achieve "three supports, two steps and one seedling". Dry areas in autumn and winter are suitable for planting in rainy season; Where there are irrigation conditions, it can be planted all year round. Planting in Majiang, Guizhou in summer, the survival rate can reach more than 95%.
Two: management technology
2. 1 fertilization
Blueberries have a low demand for fertilizer. When the soil acidity is satisfied, only a small amount of nitrogen fertilizer is generally needed, and other fertilizers can also be applied according to leaf analysis or element deficiency. However, we should pay special attention to the fact that blueberry is a plant that hates calcium and has the ability to quickly absorb and accumulate calcium. When planted in calcareous soil, it will lose iron, lose green or die because of absorbing too much calcium. From the whole tree nutrition analysis, blueberry is an oligotrophic plant. Compared with other fruit trees, the content of nitrogen, phosphorus, potassium, magnesium and calcium in this tree is very low. Therefore, excessive fertilization often leads to excessive fertilizer, which damages trees and affects yield. Blueberry is a tree species that likes ammonium nitrogen, and it is forbidden to use nitrate nitrogen when applying nitrogen, because nitrate nitrogen is harmful to blueberry, especially nano 3；; Ammonium nitrogen has a better effect. When the pH is lower than 5.0, urea is better. In strong acidic environment, urea can be successfully converted into ammonium nitrogen, and when the pH is above 5.0, (NH4)2SO4 is better. In practical application, it depends on the pH value of soil. When applying potassium fertilizer, KCl should not be applied, because Cl is harmful to blueberries, so K2SO4 can be used. Organic manure and farmyard manure, such as pigs and cow dung, should be used as much as possible in production. You can also sow green manure, such as white clover.
Fertilization methods can be applied in the whole garden or in furrows. Ditching is generally appropriate in southern mountainous areas, which can effectively reduce the loss of fertilizer and water. When applying chemical fertilizer, the ditch width is 20-30cm and the ditch depth is10-15cm; When applying farmyard manure in autumn and winter, the width of the ditch is 30-35 cm and the depth of the ditch is 35-40 cm. Green manure is buried in the soil by digging and pressing green manure.
2.2 Weed control and soil management
Weeding with herbicides is an economical and effective measure, but soil management needs other requirements besides weeding. It is a good management method to cover the ground with organic residues of plants, and the garden can be covered with crushed pine bark, pine needles, moss and litter. Where there are many pine trees, dead pine needles are good ground cover. Ground mulching has many advantages: firstly, it is beneficial to maintain soil moisture, buffer the sudden change of soil temperature and humidity, and protect roots; Secondly, it is beneficial to keep the soil pH at a low level; Third, it can increase soil organic matter and fertility, reduce element deficiency, promote growth and increase yield; Fourth, the effect of weed control is good. In addition, covering also made the blueberry cultivated successfully in arid and high-slope mineral soil. Some people covered the ground with polypropylene plastic film, which also achieved a good effect of soil moisture conservation and weed prevention. But it is not as effective as plant residues in other aspects. Seasonal intercropping of low crops between rows also has a good effect, which can not only increase the content of soil organic matter, but also have a good effect on weed control between rows, especially in cohesive soil. When planting blueberries in a large area, it is difficult to cover them with plant residues; The most effective measure is to use herbicides to kill weeds before planting. After planting, green manure, such as white clover, red clover and other leguminous plants, can completely cover the garden and increase soil fertility after three years. Good results have been achieved in planting white clover in Majiang blueberry orchard in Guizhou.
In addition, in soil management, water irrigation is also one of the important factors to increase production, especially in the arid and water-deficient areas in the north. The rainfall conditions in the south can completely ensure the normal high yield of blueberries, but the drought during the fruit expansion period will greatly reduce the yield, so it is necessary to establish irrigation facilities.
2.3 plastic finishing
Pruning fruit trees is to adjust the contradiction between reproductive growth and vegetative growth, solve the problem of ventilation and light transmission, and reduce pests and diseases, so as to achieve high yield, high quality and high efficiency. Blueberries are perennial shrubs, and pruning is different from large fruit trees. Moreover, the pruning methods of high bush blueberry and rabbit eye blueberry are different, so they should be treated differently.
The main task of pruning tall blueberries is to adjust the fruit potential of the current year and the following year. The pruning of young trees is mainly to keep the balance between the above-ground and underground parts and promote the formation of crown as soon as possible. Generally, in 1-2 years after planting, flower buds are mainly removed in order to promote root growth, expand crown and increase branches; Pruning in the third year mainly removes weak branches, pests and diseases at the base, keeps the crown upright, and makes the fruit leave the ground after fruiting. In the third year, the plant yield is controlled at about 1kg. Generally, the pruning amount is not large before the third year to the fourth year of planting. For mature trees, we should pay attention to the quality and quantity of harvest. For erect varieties, the branches in the center of the crown are thinned to make the crown open; For open varieties, the lower radial branches should be cut off and the weak branches should be cut off again to promote the formation of strong branches and produce more leaves; Sparse weak branches, keep strong branches, and cut short long fruit branches. According to the strength of branches, keep 3-5 flower buds, and each branch should have enough leaves to meet the nutrition needed for fruit growth and ensure fruit quality. When the number of flowers is large, it is necessary to sparse flowers and fruits, even the whole inflorescence. When the tree body is further aged, if the variety is not updated after 20 years, a large number of trees will be retracted and rejuvenated.
Pruning of rabbit's eye blueberries depends on the growth of the trees. Rabbit-eye blueberries can produce high yield. Therefore, for young trees, it is mainly to remove the weak branches at the lower part and the overcrowded branches in the middle of the crown. For mature trees, it is mainly to prevent the crown from being too high and the holes from being too dense. Dense branches, twigs, cross branches and pest branches are thinned out. Results The main branch is more than 5-6 years old, so it should be recovered and updated. Because the large-scale cultivation of blueberry in China has just started, its cultivation and management techniques are still being explored and tested.
2.4 Pest control
Diseases of blueberry are rare in new planting areas, and there are many kinds of pests, but there are no reports of great harm in China. However, with the expansion of cultivation scale and the extension of cultivation time, its pest control will become an important content in blueberry production management.
The common diseases of blueberry mainly include powdery mildew, downy mildew, stiff fruit disease and stem rot. Sometimes growers often mistake the lack of elements (trace elements such as iron, potassium and magnesium) in blueberry trees for diseases. Different species and varieties of blueberries have obviously different resistance to diseases. The resistance of high bush blueberry was obviously lower than that of rabbit eye blueberry. For example, Daruo in high-bush blueberries is prone to root rot and stem canker. All kinds of diseases of blueberry can be prevented and controlled by sulfur agents or other fungicides in the production and operation season. It is reported that stem canker is difficult to control with fungicides. Therefore, the disease has become a devastating disease of blueberry in northern North Carolina, USA, and there is no report of the disease in China.
The common pests in blueberry orchard mainly include aphids, mites, fruit flies, poisonous moths, spiny moths, silkworm moths, longicorn beetles, bedbugs, branch-tip fruit eaters and other harmful leaves, fruits and branches. Insecticides can be used to control leaf pests, such as aphids, mites, poisonous moths, thorn moths and wild silkworms. For branch pests such as longicorn beetles and fruit eaters, after understanding their life history, pesticides can be sprayed on larvae; For fruit pests such as Drosophila melanogaster and some longicorn beetles, sweet and sour solution can be used to trap and kill adults, especially the 1-2 generation adults in early May, which is the key control measure to reduce the harm in fruit maturity from July to August, and the effect is very good.