Blueberry Planting Techniques

Blueberry is a fruit with high nutritional value. Its market price is relatively high compared to many common fruits. At present, there are many places in China that cultivate blueberries on a large scale. If you want to join in blueberry planting , you must first master the planting techniques .

1. Soil

Ideal soil conditions for blueberry cultivation: pH value between 4.5 and 5.5; organic matter content of 8% to 12%; low salt content, conductivity not exceeding 1000μS/cm, preferably less than 200μS/cm; loose soil with good drainage, preferably sandy loam or sandy soil, not sticky, no water accumulation, and good irrigation conditions.

If the soil condition is poor, it needs to be improved. When the soil texture is poor, river sand or weathered rocks can be added; when the pH value is too high, sulfur can be added to adjust it; when there is insufficient organic matter, peat can be added to improve it.

2. Temperature and humidity

Lowbush blueberries require more than 1,000 hours of cold temperature accumulation time of ≤7.2℃ during their winter dormancy period; southern highbush blueberries and rabbiteye blueberries also require 400-600 hours of cold temperature accumulation time to ensure complete differentiation of flower buds. Insufficient cold accumulated temperature will result in the failure of flower buds and leaf buds to germinate.

The heating process needs to be gradual to avoid overheating. During the budding period, the daytime temperature is maintained at 23~25℃, and the nighttime temperature is not lower than 8℃; during the flowering period, the daytime temperature is maintained at 20~22℃, and the nighttime temperature is 8~13℃; during the fruit expansion period, the daytime temperature is maintained at 22~25℃, and the nighttime temperature is 10~15℃.

Blueberries have certain requirements for air humidity. A humidity of 60% to 70% is conducive to their growth. A humidity exceeding 90% or below 20% may lead to slow growth or even death.

3. Lighting

Long days are beneficial to the nutritional growth of blueberries, while short days are beneficial to flower bud differentiation. The most suitable short-day treatment time is 50-65 days. Full-sun light intensity helps to form a large number of flower buds and improve fruit quality. The influence of light is mainly reflected in the photoperiod and light intensity.

The photoperiod refers to the period of alternation between light and darkness. More than 12 hours of light is conducive to the vegetative growth of blueberries. More than 16 hours of light is only conducive to vegetative growth and no flower buds can be formed. Flower bud development is best when the light time is 8 hours.

When the photosynthetic rate is significantly reduced, increasing the light intensity can significantly increase the number of flower buds. Low light will cause a significant decrease in the percentage of fruit during the fruit maturity period, and the fruit maturity rate and fruit sugar content will also decrease.

4. Moisture

Blueberries are sensitive to water and have different water requirements at different growth stages. The soil needs to be kept moist but not waterlogged (the soil should clump together when held in the hand but no water can be squeezed out).

① During the vegetative growth period, maintaining proper water conditions helps the plant grow strong;

②During the fruit development period and before maturity, reduce water supply appropriately to prevent excessive vegetative growth from competing with the fruit for nutrients;

③ After the fruit is harvested, restore water supply to promote plant nutritional growth;

④ From Mid-Autumn Festival to late autumn, in order to encourage the plants to enter dormancy in time, the water supply should be reduced.

5. Fertilizer and water

Blueberries have strict requirements on water quality. The conductivity of irrigation water needs to be lower than 1000μS/cm, and that of greenhouse cultivation needs to be lower than 300μS/cm. The lower the better. The pH should be below 6.5. Note that among the water source improvement methods, only reverse osmosis desalination is effective, and lowering the pH by adding sulfuric acid, acetic acid or acidic liquid fertilizers is not advisable.

Blueberry is a typical calcium-averse, chlorine-averse, and oligotrophic plant, so excessive fertilization should be avoided. Nitrogen fertilizers should be ammonium nitrogen and nitrate nitrogen in a molar ratio of 3:1. Ammonium sulfate is preferred, 15 to 20 g per plant per year. Avoid using potassium chloride as potassium fertilizer. Potassium sulfate is preferred, 5 to 8 g per plant per year. Potassium dihydrogen phosphate is preferred as phosphorus fertilizer, 4 to 6 g per plant per year. Inorganic fertilizers need to be completely dissolved and evenly poured under the tree crown. The concentration should be less than 0.2%, once every 2 to 3 weeks.

6. Pruning

Pruning is crucial to ensuring the growth and fruiting of blueberries. It can solve the problems of ventilation and light transmission, enhance tree vigor, improve quality, increase fruit size, increase commercial fruit rate, and extend the fruiting period and tree life. Blueberry pruning needs to be carried out throughout the entire growth process to achieve "pruning according to the tree and pruning according to the situation" to achieve the best "branch-to-fruit ratio", "leaf-to-fruit ratio", optimal yield and best quality.

Young tree pruning: 1 to 2 years after planting, remove weak branches, drooping branches (from the base), crossed branches, and old branches, select 2 to 3 strong one-year-old basal branches, and remove all flower buds by pruning or pulling out the flower buds.

In the 3rd to 4th year after transplanting, thin out weak branches, drooping branches (from the base), crossed branches, diseased branches and withered branches. Branches over three years old should be cut back to a position with strong branches so that they can bear fruit in moderation.

Adult pruning: When thinning branches, remove weak branches and keep strong branches. For upright varieties, remove the central trunk, open a skylight, and keep moderate branches. For branches over three years old, follow the 6-thinning 1 principle and thin out from the base. The best fruiting age for large fruiting branches is 5 to 6 years. After this age, they need to be cut back and renewed. Weak branches can be pruned by removing flower buds to make them stronger.

The above is a complete introduction to blueberry cultivation techniques. Blueberries have high requirements for light and soil conditions, so only the best environment can grow high-quality blueberries.