Blueberry Planting Precautions and Methods to Increase Yield

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

I. Precautions 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, and the site should be chosen as far as possible where the soil is loose, fertile, well-drained, and moist but not waterlogged.

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

2. Variety selection

Middle and lower reaches of the Yangtze River: For plots with strong soil stickiness, prioritize varieties with strong adaptability such as Nanjin, Rabbiteye Brightwell, 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: Northern highbush blueberries are mainly used. In protected facilities, it is recommended to plant the northern highbush early-maturing large-fruit variety Duke, or southern highbush early-maturing 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, it is recommended to improve the soil thoroughly, amending the entire orchard.

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

For rotary tilling and deep plowing of 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 also needs to be added together with the sawdust. Ensure that all materials are mixed evenly with the orchard soil. After ridging, the improved soil basically returns to the ridges.

4. Planting

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

Seedling selection: The height of the seedlings should preferably be 35-50 cm, with 2-3 or more upright and robust branches. The main branches should be healthy and not aged, with 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 ridges, 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 nursery pot seedlings in water until thoroughly soaked, take them out of the pots, shake the roots slightly to loosen them, 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, with a coverage height of 15-30 cm above the ground.

Post-planting management: After planting, water with settling water. After watering and settling, the base of the plant should be level with the ridge surface; it must not be planted too deep or too shallow. Before weeds grow, cover with film to prevent weeds. For autumn and winter planting, perform stumping during the dormant period; for spring planting, perform stumping 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, and early application is better than late application. Generally, decomposed sheep manure, cow manure, and rabbit manure are mainly used, applied by trenching. For trees in full fruit period, 10-15 kg per plant; for young trees, 5 kg per plant.

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

6. Water management

During the young fruit development period, the water supply for blueberries must be sufficient and stable, and sudden drying and sudden wetting should be avoided, otherwise it is very easy to cause red fruit and fruit cracking. 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. Blueberries cannot tolerate even half a day of waterlogging. 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 in flatland blueberry planting in the south.

7. Weed management

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

In production, in order to control weeds, straw, bark, wood chips, etc. are generally used for ground mulching. This can not only control weed damage, but after the mulching plant material rots and leaches into the soil, it also has a good acid-lowering effect, helping to maintain soil pH at a relatively acidic level. It can also increase soil organic matter and fertility, reduce deficiency symptoms, promote blueberry growth and yield, and improve quality.

8. Pruning and shaping

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

In a year, summer pruning and winter pruning are the main practices. Winter pruning: rejuvenate weak trees and control yield of strong trees; summer pruning: remove density from strong trees and promote vigor.

Young tree stage: After stumping and pruning the planted seedlings, new branches increase. In summer, attention should be paid to timely pinching, and in the following year, flower buds should be thinned in time to cultivate tree vigor early.

Initial fruiting stage: For normally growing trees in the initial fruiting stage, generally retain 20-30 fruiting branches in the fruiting year to 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 reasonable load, generally retaining 70-100 fruiting branches, so as to achieve high and stable yield, good quality, and prolong the years of full fruiting.

9. Flower and fruit management

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

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

Dry hot winds during the flowering period in northern regions: In northern regions, in cold sheds and open fields in mid-April during the flowering period, there is drought and little rain. Once high-temperature weather occurs, air humidity is often below 20%, and blueberry corollas often shrivel and turn yellow, greatly affecting the vitality of blueberry stamen pollen and pistil stigmas, 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, prioritizing physical and biological control, and using chemical control when necessary, but using low-toxicity, safe, or biological-source pesticides, and paying attention to the safe pre-harvest interval.

II. How to increase blueberry yield?

1. Select superior 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. Secondly, 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, and they cannot be planted arbitrarily. The most common planting time we choose is from the end of August to September in autumn. Planting at this time will result in 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 can also keep up with the rhythm when the flowering and fruiting season arrives.

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. The fertilizer and water management for blueberries differs to some extent at each growth stage, and management also differs for each variety. Under normal circumstances, seedlings need two fertilizations during the seedling stage. Taller blueberry plants need trenching for topdressing, while shorter plants only need broadcasting. Each time, farmyard manure or organic fertilizer is mainly used. After blueberries bear fruit, on the basis of these two fertilizations, apply one more topdressing, mainly foliar fertilizer, to promote fruit growth. From then on, 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

For field management, we must first talk about pollination pairing in blueberry planting. Each plant must be planted in a 4:1 pattern, which can increase the chance of pollination and thus increase the fruit set rate. Secondly, it is necessary to thin branches of blueberry seedlings in the field and remove relatively weak branches and leaves; new branches will grow again. 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 against the cold, otherwise the blueberry seedlings will be frostbitten. In addition, 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. Weeds, debris, fallen leaves, dead branches, etc. need to be cleaned up and burned 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 prefer to pair pollinator trees well. Under relatively stable weather, 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 introducing bee colonies into the orchard for bee pollination, or collecting pollen for pollination. Finally, it is also possible to 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 of great help in increasing blueberry yield.