Blueberry is a low perennial shrub belonging to the genus Vaccinium of the azalea family. It is native to North America and East Asia, distributed in North Korea, Japan, Mongolia, Russia, Europe, North America, and China's Heilongjiang, Inner Mongolia, Jilin Changbai Mountain, and other countries and regions. It grows at an altitude of 900-2300 m.
Blueberry fruits are rich in nutrients, especially rich in anthocyanins. It not only has good nutrition and health effects, but also has the functions of preventing brain aging, strengthening the heart, anti-cancer, softening blood vessels, and enhancing human immunity. The earliest country for blueberry cultivation is the United States, but it has not reached a century of cultivation history. Because of its high health value, it is popular all over the world. It is one of the five healthy fruits recommended by the World Food and Agriculture Organization.
Blueberry morphological characteristics
The size and color of blueberry fruits vary by species. The fruits of most varieties are dark blue or violet when they are ripe, such as rabbit-eye blueberries, highbush blueberries, and lowbush blueberries. A few varieties are red. Blueberry fruits are spherical, oval, oblate, or pear-shaped.
The flowers of blueberries are racemes. The inflorescence is mostly lateral, sometimes terminal. Usually composed of 7 to 10 flowers, the flowers are bisexual, solitary or twin in the leaf axils, radially symmetrical or bilaterally symmetrical. The flower buds of blueberries generally grow on top of the branches. In spring, flower buds germinate first for 3 to 4 weeks before reaching full bloom. When the flower buds germinate, the leaf buds begin to grow, and when the flower buds are in full bloom, the leaf buds germinate and grow to their proper length.
Blueberries have evergreen and deciduous leaves. The leaves of blueberries are single leaves alternate, sparsely opposite or whorled, and the whole or serrated. High, semi-high, and low-bush blueberries shed their leaves before winter. Rabbit eyes are evergreen, and the leaves can remain on the tree for 2 to 3 years. The most common leaf shape is oval without stipules. The size of the leaves varies depending on the species. The leaf length of tall bush blueberries can reach 8 cm, while that of low bush blueberries is generally less than 1 cm. The leaf length of rabbiteye blueberries is between high bush blueberries and low bush blueberries.
Blueberry growth habit and growing environment and distribution
Blueberries can grow multiple times in a growing season, and secondary growth is more common. In the third year after planting, seedlings grow significantly faster, new shoots germinate and grow vigorously, and the annual growth can reach more than 1 meter. Flower buds are mostly formed at the top of the shoots that year, and the flower buds differentiate from the top down. The number of flower buds that can be differentiated per branch is related to the variety and the thickness of the branch. Highbush blueberries generally have 4~7, rabbit-eye blueberries have 3~6, and the flower buds are mainly solitary at the nodes. Different types of blueberries have different flower bud differentiation periods. Shortbus blueberries and highbush blueberries start to differentiate from July to August, and rabbit-eye blueberries start from mid-June. By the end of September to early October, the differentiation of blueberries has been completed. From the morphological point of view, blueberry flower buds are plump, elliptical, or nearly spherical. Below the flower buds are some narrow-tipped vegetative buds and resting buds.
It exists in the world, mainly distributed in areas with cool and sunny climates, such as North Korea, Japan, Mongolia, Russia, Europe, North America, and the Heilongjiang, Inner Mongolia, and Changbai Mountain regions of mainland China. It grows in areas between 900 meters and 2300 meters above sea level. It is more common in coniferous forests, peat swamps, mountain tundra, and pastures, and is also an important part of heather shrubs.
The quality of blueberries in North America is world-renowned. Half-highbush blueberries are suitable for planting in cold temperate regions, northern highbush blueberries and some semi-highbush blueberries are suitable for planting in warm temperate regions, and rabbit-eye blueberries and southern highbush blueberries are suitable for planting in subtropical regions.
Blueberry efficacy and role
Blueberry fruit has the functions of improving eyesight, enhancing self-immunity, anti-cancer, enhancing memory, anti-oxidation, and slowing down aging.
The anthocyanins in blueberries can promote the regeneration of rhodopsin in retinal cells, prevent severe myopia and retinal detachment, and improve vision. At the same time, anthocyanins can accelerate the regeneration of rhodopsin, and rhodopsin is an indispensable ingredient to ensure good vision.
Blueberry berries can enhance the body's resistance to infectious diseases. Blueberry berries are a high-fiber food that can be a good source of fiber in the daily diet. Blueberries contain a lot of potassium. Potassium can help maintain fluid balance in the body, normal blood pressure, and heart function. Blueberries have the effect of resisting free radicals.
Blueberry berries are also a low-calorie food. The nutrients contained in blueberries have an inhibitory effect on cancers in the middle and early stages. The anthocyanins in blueberry fruits are very powerful antioxidants, which can help prevent the formation of plaque in the arteries and various cancers, reducing the possibility of cancer.
Anti-oxidant and slow down the aging
Natural blueberry anthocyanins are the most effective antioxidants. USDA research shows that among more than 40 kinds of fruits and vegetables that people often eat, blueberries have the strongest antioxidant capacity.
Blueberries can only grow healthily in an acidic medium. The pH value of the cultivation soil is between 4 and 5, which is most suitable for blueberry growth. This problem has plagued many blueberry lovers because the pH value of pastoral soil is generally between 6 and 7. Even the acidic soil sold in the flower and bird market has the lowest pH value between 5.5 and 6.
After the blueberry seedlings are planted in pots, they are not exposed to the sun indoors and kept in a ventilated place for a week. This process is called slow seedlings. It can be moved outside the balcony for normal maintenance after a week. Blueberries like wetness, especially in summer, they need enough water every day. In the absence of sufficient sunlight, the growth of blueberries is stagnant, and even if they bloom, they will not bear fruit. Blueberries do not have high requirements for fertilizer, but big fat will hurt it. There is a certain amount of leaf soil in the medium, which can meet the growth needs of blueberries. Usually, an appropriate amount of top dressing is required to ensure the normal growth and quality of the fruit.