Blueberry Planting Considerations and Methods to Increase Yield

Blueberry is a shrub fruit with high nutritional value, pure taste and large market demand, so what are the considerations for blueberry planting? How to increase blueberry yield?

1. Considerations for blueberry planting

1. Site selection

For blueberry planting, it is advisable to choose the middle and lower parts of east-facing and south-facing slopes, with a slope of less than 30°; when the slope is steep, terraces should be built. As far as possible, choose a place with loose, fertile soil, good drainage, and moist but not waterlogged conditions to establish the orchard.

Blueberry growth requires strongly acidic soil conditions. The key to cultivating blueberries is soil improvement, adjusting the soil pH to around 5, and keeping the soil organic matter content no lower than 5%.

2. Variety selection

Middle and lower reaches of the Yangtze River region: For plots with strong soil stickiness, give priority to varieties with strong adaptability such as Southland, Brightwell rabbiteye, and Emerald.

Southern humid and cool microclimate areas: Some southern highbush varieties can be chosen for planting, such as Misty, O'Neal, Emerald, and Jewel.

Northern regions: Mainly northern highbush blueberries; in protected facilities, it is recommended to plant the early-maturing large-fruited northern highbush variety Duke, or early-maturing southern highbush varieties such as O'Neal and Misty.

Considering factors such as labor and management, the area of a contiguous orchard should not be too large (100-300 mu is recommended), and the number of varieties should not be too many (2-3 varieties), to facilitate management.

3. Soil improvement

In order to thoroughly improve the soil environment for blueberry growth, thorough soil improvement of the whole orchard is recommended.

In the autumn of the year before planting, first deep-plow the whole orchard to more than 40-60 cm, dig drainage ditches, level gentle slopes into mild gradients, and spread sulfur powder; the specific amount should be determined according to the measured soil pH. To ensure even distribution, it can be spread and rotary-tilled in two applications.

After rotary tilling and deep plowing in the orchard, before rotary tilling again, the material input per mu is: about 5 cubic meters of peat, about 3 tons of organic fertilizer, and sawdust or bark with a diameter of 3-5 cm as mulch at a thickness of 5-10 cm, 30-50 cubic meters per mu.

To avoid nitrogen deficiency caused by sawdust, 15 kg/mu of urea or other types of nitrogen fertilizer should also be added together with the sawdust. Ensure that all materials are mixed evenly with the orchard soil; after ridging, the improved soil basically all returns to the ridges.

4. Planting

Planting time: Blueberries can be planted in spring, autumn, or winter; in Northeast China, late spring planting is best.

Seedling selection: The seedling height should preferably be 35-50 cm, with 2-3 or more upright vigorous branches, healthy main branches that are not aged, few old and weak branches, and no old seedlings. The root system should be light yellow, well developed, not black, and without root circling.

Planting method: When planting, dig planting holes on the ridge, generally about 40×40×40 cm in size. Add 5 kg of organic fertilizer and 30-50 g of compound fertilizer at the bottom as base fertilizer, mix well with soil after adding, and leave it in the bottom layer. Cover with a layer of soil, then add some peat and insecticide on top, mix evenly with soil, and leave it in the upper layer of the planting hole, ready for planting.

Before planting, soak the nutrient-pot seedlings in water until thoroughly wet, take them out of the pots, shake the roots open slightly, dig another small hole of about 20 cm×20 cm in the already dug planting hole, plant the seedling in, press gently and firmly, and water thoroughly. Cover with pine needles, rice straw, sawdust, etc. to retain moisture and acidity, preferably covering 15-30 cm above the ground.

Post-planting management: After planting, water to settle the roots; after the water settles, the base of the plant should be level with the ridge surface, and it must not be planted too deep or too shallow. Cover with film before weeds grow to prevent weeds. After planting in autumn and winter, stumping should be done during the dormant period; for spring planting, stumping should be done as soon as possible.

5. Fertilization management

Base fertilizer: The most suitable application time is in autumn from leaf color change to before leaf fall; early application is more effective than late application. Generally, use decomposed sheep manure, cow manure, and rabbit manure as the main materials, applying fertilizer in trenches; for trees in full fruit period, 10-15 kg per tree, and for young trees, 5 kg per tree.

Topdressing: The topdressing period is during leaf bud germination and before and after flowering, mainly with quick-acting fertilizers; it is recommended to combine with root application of Sea Elf bio-stimulant root-application type at 300 times dilution. After fruit harvest, a small amount of phosphorus and potassium fertilizer can be applied to avoid excessive nitrogen causing excessive growth of young shoots, promote root growth, and make branches robust.

6. Water management

During the young fruit development period of blueberries, water supply must be sufficient and stable; sudden drying and sudden wetting should be avoided, otherwise it can easily cause red fruit and watery fruit. When drought is forecast to last more than 7 days, ensure a full watering within 5 days, and try to avoid watering during the high-temperature noon period.

Blueberries are more sensitive to waterlogging and must be drained in time; even half a day of waterlogging is not good for blueberries. When establishing the orchard, the irrigation and drainage facilities should be planned in combination with the local historical extreme flood weather, which is especially important for blueberry planting on flat land in the south.

7. Weed management

Herbicides are prohibited in blueberry orchards; all herbicides can cause phytotoxicity to blueberry plants or roots.

In production, to control weeds, straw, bark, wood chips, etc. are generally used for ground cover. This can not only control weeds, but after the covering plant material decays and leaches into the soil, it also has a good acidifying effect, helping to maintain soil pH at a slightly acidic level. It can also increase soil organic matter and fertility, reduce deficiency symptoms, promote blueberry growth and yield increase, and improve quality.

8. Pruning and shaping

Blueberry is a perennial clustered small shrub, and its shaping and pruning differ from major fruits. The main method is to properly regulate the relationship between vegetative growth and fruiting, and regularly thin out weak branches, fruiting branches, and aged branches.

Within a year, summer pruning and winter pruning are the main practices. Winter pruning: rejuvenate weak trees and control yield of strong trees; summer pruning: thin out dense growth of strong trees and promote vigor.

Young tree stage: After stumping and pruning of planted seedlings, new branches increase; attention should be paid to timely pinching in summer, timely thinning of flower buds the following year, and early cultivation of tree vigor.

Early fruiting stage: For normally growing trees in the early fruiting stage, generally retain 20-30 fruiting branches in the fruiting year, which can obtain a yield of 0.5-1 kg; for those with weaker growth, most fruiting branches can be cut back.

Full fruiting stage: The pruning task in this period is to maintain robust tree vigor and a reasonable load, generally retaining 70-100 fruiting branches, so as to achieve high and stable yield, good quality, and extend the number of years of the full fruiting stage.

9. Flower and fruit management

Pollination: Begin placing bees at the early flowering stage; use bumblebees in protected facilities, and in open fields place one box of honeybees per about 5 mu (each box has 10,000-20,000 bees).

Rain sheltering during flowering and fruiting in southern regions: In rainy southern regions, there is often cloudy and rainy weather during the flowering and fruiting periods, which can seriously affect fruit set rate and affect fruit picking and quality. Rain-shelter cultivation can be used, covering with film in the middle of flowering and removing the film at the late fruit stage.

Dry hot wind during flowering in northern regions: In northern regions, during the flowering period in mid-April in cold sheds and open fields, there is drought and little rain. Once high-temperature weather occurs, air humidity is often below 20%, and blueberry corollas often shrink and turn yellow, greatly affecting the vitality of blueberry stamens and pollen and the pistil stigma, causing poor pollination. Attention should be paid to watering to supplement humidity.

10. Disease and pest control

Blueberries have few diseases and pests. Common ones include powdery mildew and downy mildew; pests include aphids, mites, fruit flies, longhorn beetles, and scarab beetles.

Attention should be paid to prevention first and integrated control, protecting and utilizing various natural enemies, maintaining ecological balance in the blueberry orchard, giving priority to physical and biological control, and using chemical control when necessary, but using low-toxicity, safe, or biological-source pesticides, and paying attention to the pre-harvest interval.

2. How to increase blueberry yield?

1. Choose good varieties

There are many blueberry varieties, including lowbush blueberries and highbush blueberries, some suitable for cool regions and some suitable for warm regions. At present, there are as many as more than 20 existing blueberry varieties, so the types are diverse. Among them, rabbiteye blueberry is the easiest to keep alive, and O'Neal is also a very good variety, especially suitable for planting in southern China. There are also some blueberries suitable for planting in the north, which the editor will not list one by one here. Choosing suitable varieties is the most basic method to increase blueberry yield. Second, it is recommended to plant multiple varieties when planting, so that yield and quality will be better.

2. Sow at the right time

There is a suitable time for planting blueberries; they cannot be planted casually. The most common planting time is from the end of August to September in autumn. Planting at this time will have a much higher survival rate and is also suitable for blueberry growth and development. Of course, they can also be planted in spring, but it is best in early spring, so that blueberries can take root and sprout in this season, and when the flowering and fruiting season comes, they can also keep up with the pace.

3. Fertilizer and water management

After blueberry planting, we need to carry out reasonable fertilizer and water management according to the nature of the planting soil. Fertilizer and water management for blueberries differs to some extent at each growth stage, and management also differs for each variety. Under normal circumstances, two fertilizations are needed during the seedling stage. Taller blueberry plants need topdressing by digging trenches, while shorter plants only need broadcasting. Each time, farmyard manure or organic fertilizer is the main material. After blueberries bear fruit, on the basis of these two fertilizations, apply one more topdressing, mainly foliar fertilizer, to promote fruit growth. Thereafter, foliar fertilizer needs to be sprayed about once every two to three months each year, which can make blueberry seedlings grow better and avoid premature aging and yield reduction.

4. Field management

Field management first requires discussing the pollination arrangement for blueberry planting. Each plant must be planted according to a 4:1 pattern, which can increase the chance of pollination and thereby improve the fruit set rate. Second, the blueberry seedlings in the field should be thinned of branches, removing relatively weak branches and leaves; they will then grow new branches. After a certain number of years, all old branches need to be cut off to let new branches emerge, meaning renewal. Then, every winter, the seedlings need to be protected for warmth, otherwise the blueberry seedlings will be frostbitten. Also, during the flowering period, flower control is needed, and after flowering, fruit control is needed. The methods of flower and fruit control are both based on the principle of retaining good and large ones. Finally, there is field cleanup, which requires cleaning up weeds, debris, fallen leaves, dead branches, etc., and burning them to ashes to avoid virus infection.

5. Artificial pollination

Artificial pollination is also a way to increase yield, but under normal circumstances it is not used. We tend to prefer arranging pollinizer trees well; when the weather is relatively stable, the pollination success rate is very high. Of course, other situations cannot be ruled out, so we need to use artificial pollination methods. One is to use external forces, such as placing bee colonies in the orchard for bee pollination, or collecting pollen for pollination. Finally, one can also directly pick male flowers and then apply the pollen of the male flowers to the female flowers, then cover the female flowers with the male flowers for pollination. These are all methods of artificial assisted pollination, which can also be used when necessary and are very helpful for increasing blueberry yield.