Blueberries have a low demand for fertilizer. When the soil acidity is satisfied, only a small amount of nitrogen fertilizer is usually applied. Excessive fertilization often leads to excessive fertilizer, which damages trees and affects yield.

Nitrate nitrogen is forbidden, and urea is better. When applying potassium fertilizer, KCL should not be applied, but 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.

Generally, furrow fertilization is appropriate, which can effectively reduce the loss of fertilizer and water. When applying chemical fertilizer, the ditch width is 20~25cm and the ditch depth is 10~ 15cm. When applying farmyard manure or pressing green in autumn and winter, the ditch width is 30~35cm and the ditch depth is 35 ~ 40cm. The green manure is buried in the soil by digging and pressing green. Fertilization time is generally divided into germination, fruit ripening and post-harvest three times.

irrigate

Blueberries have shallow roots and like to be wet, so they need to be irrigated in time. Pay attention to water source and water quality when irrigation. Deep well water generally has high pH value and high sodium and calcium content, which will affect the growth and yield of blueberries for a long time. During irrigation, the pH value can be adjusted to about 465,438+05 with sulfuric acid before irrigation, but the acid water can be irrigated for 65,438+0 times every three times.

3. Temperature control

The key to promote cultivation is to break the flower bud differentiation period and dormancy period of blueberry. The suitable temperature for blueberry growth in greenhouse is 20~25e, with the highest temperature not exceeding 30e and the lowest temperature not lower than 12e. The chilling requirement of high clump blueberry should be in the low temperature state of 0~7 12e, and the accumulated temperature time should be 800 ~1200 h. If the chilling requirement is insufficient, it will lead to poor germination and insufficient flowering, which will affect the fruit yield and quality. The key to realize the off-season production of blueberry is to adjust the dormancy time of blueberry in time. It is worth noting that the temperature control must be slow, whether it is entering the low temperature state in advance or entering the growth period after dormancy is completed, so as not to affect the growth and development of blueberries in a short time.

Step 4: plastic trimming

Pruning of small trees. In this period, flower buds are mainly removed, with the purpose of expanding the crown, increasing the number of branches and promoting the development of roots. In the second and third years after planting, the weak branches are drained in the spring, and the crown is still enlarged in the third and fourth years, but the fruit is medium. Generally, the plant yield should be controlled below 1kg in the third year, with strong branches as the main ones.

Pruning of adult trees. At this time, pruning is mainly to control the height of the tree and improve the lighting conditions, mainly to thin branches, and to thin out branches that are too dense, too thin, branches that are damaged by diseases and insect pests and roots. The root activity is stronger than that of open varieties when thinning branches; Vertical varieties go to the center to dry, open the skylight and leave the middle branches. The best fruiting age of big branches is 5~6 years old, so they should be retracted and updated in time. Weak branches erase flower buds and make them stronger. Adult trees have a lot of flowers, so some buds need to be cut off. Generally, each strong branch leaves 4~6 flower buds.