How does pomegranate crack fruit return a responsibility? What shall I do? How to prevent it?

Pomegranate fruit is rich in nutrition, and its vitamin C content is one or two times higher than that of apples and pears. Fruit cracking often occurs in the process of planting, which brings economic losses to fruit growers, so what is the matter of pomegranate fruit cracking? What shall I do? How to prevent it?

Why does pomegranate crack fruit

1. Varieties: pomegranate varieties under different cultivation conditions have the phenomenon of fruit cracking. The general maturity period is in the rainy season, the fruit is large, the pericarp is thin and smooth, the pericarp is red and white, and other varieties are easy to crack fruit. Such as Yicheng red pomegranate, Shaanxi Lintong Tianhong egg and pink sweet pomegranate.

two。 Soil fertilizer: clay soil, black soil, acid and white soil, low-lying clay, more water retention, poor air permeability, not only poor fruit quality, but also easy to crack fruit. Application of nitrogen fertilizer or inorganic fertilizer over water, lack of trace elements such as Ca, K, B, serious soil erosion, soil consolidation, easy to cause fruit cracking.

3. Moisture: during the mature period, the soil moisture is too large or the humidity changes too much, such as high temperature, drought, sudden rainstorm or continuous rainy days, the fruit absorbs too much water and is easy to crack. Excessive humidity in the air can also cause fruit cracking.

4. Temperature: there is a certain correlation between the change of temperature and humidity, the fruit expands rapidly in the environment of high temperature and high humidity, and the fruit is easy to crack when the temperature drops suddenly.

5. Lighting: improper pruning in the growing season, partial exposure to the fruit, large temperature difference between day and night or easy to crack after rain, the crack is often sunny.

6. Growth period: fruit cracking generally occurs in the post-expansion period and maturity period (color conversion period), and the fruit cracking is more serious in case of overcast or rain or cooling.

7. Harvest: harvest when the temperature is low in the morning or after rain, excessive harvest when ripe, collision during harvest and transportation, all of which are easy to cause fruit cracking. The cracking of pomegranate fruit is often caused by a variety of comprehensive factors, especially in the middle and later stages of pomegranate expansion, material accumulation and transformation are taking place, rapid grain expansion, large vacuole of grain plasma cells, loose structure, strong water absorption and high expansion rate. the pericarp becomes thinner gradually and the pericarp cells are small and dense. The expansion rate is small, and the fibrosis is not enough at this time, and the texture is brittle and tender. If there is a sudden rainstorm, continuous rain or cooling in the high temperature and dry season, it will cause fruit cracking. Variety is a genetic factor, which is the decisive factor of pomegranate fruit cracking, the mature pomegranate is very easy to crack, and the more cracked pomegranate grain is, the more delicious the pomegranate grain is, all kinds of birds compete to peck at each other so that the offspring of pomegranate can spread everywhere, which is also the result of natural selection.

Prevention and control of cracked pomegranate fruit

1. Variety selection:

Early-maturing or late-maturing varieties are not easy to crack, such as medium fruit type, thick green peel, copper shell, thick pericarp, rough rust color and so on. Such as Zaozhuang Yancheng Daqing skin, green skin rough and so on. In addition, Dahongpao is not easy to crack because of its thick pericarp. Other green-skinned pomegranates such as Huaiyuan in Anhui Province are also excellent varieties with less split fruit.

two。 Soil:

Yecheng pomegranate is best planted in the yellow loam, which is high in topography, middle and downhill on the sunny side, and the upper layer is deep and slightly sticky. This kind of soil has good water permeability, rich mineral content, high fruit quality and is not easy to crack. The more suitable soil is oil sandy soil, calcareous loam and so on.

3. Fertilizer:

Increase the application of organic fertilizer, such as farm manure, pig manure, chicken and duck manure, green manure, etc., inorganic fertilizer with formula fertilization, little or no nitrogen fertilizer. Regular spraying of 2000ppmCaCL2 solution and appropriate amount of P, K and B elements during fruit expansion are beneficial to improve fruit quality and prevent fruit cracking.

4. Reasonable pruning:

Reasonable pruning during the growing period, ensuring ventilation and light transmission, strong tree potential, light spot area under the crown generally accounts for 10% of the crown projection area, 15%, and uniform light transmission.

When cutting in winter, it is necessary to sparse or retract some of the larger crossed branches and overlapping branches, adjust the subordinate relationship of all levels of backbone branches, and retract the peripheral dense fruiting branches and weak drooping branches. Summer pruning is mainly sprouting, coring and pruning. The useless and dense squeezed shoots should be wiped out as soon as possible, and the useless overgrown branches can be removed in time, and the branches with space can be transformed into fruiting branches by coring and twisting.

5. Hormone treatment:

Spraying gibberellin (GA3) 50mg/L 2-3 times every 10-15 days during pomegranate color changing could reduce the fruit cracking rate.

6. Irrigation and drainage:

Irrigation of pomegranate should be prohibited during maturity, and drainage should be timely in rainy days to prevent soil moisture from being too high.

Because of the high heat capacity of water, it plays a certain role in regulating fruit temperature, preventing sunburn and sudden cooling. Therefore, in the fruit growth and development season, we should seize the opportunity to water reasonably, keep the soil moist and the temperature suitable. Especially before the fruit is about to ripen, as long as the soil moisture is moderate, generally do not need watering. Such as the technical climate is really dry, but also the use of small water carefully irrigated, do not flood irrigation, so as not to cause excess water and excessive soil moisture. The whole pomegranate garden should be covered with grass after the rainy season, with a thickness of 15-20 cm, which can also control temperature and moisture, and grass decay can also increase the content of soil organic matter and improve soil fertility.

7. Overlay:

The ground cover has the function of drought prevention and heat preservation. It can prevent excessive change of soil temperature, reduce temperature difference, prevent soil erosion, reduce the loss of trace elements, maintain microbial activity, increase organic matter, and make fruit cells grow evenly so as to prevent fruit cracking. The mulch has grass grass, wheat straw, green manure and so on.

8. Bagging:

Bagging is one of the most effective methods to prevent fruit cracking. Bagging can prevent the changes of sun and rain and sudden cold and heat of the fruit, cushion the temperature and humidity, protect the fruit and prevent fruit cracking; bagging can also improve the quality of the fruit, make the pulp delicate and well colored, and prevent the infection of diseases and insect pests. Bagging is generally carried out in the young fruit stage, and the materials used can be waste newspapers, Kraft paper or sulfuric acid paper bags, or special fruit bags can be purchased directly. In addition, we should also pay attention to the control of fruit borer, such as peach borer, spray 2-3 times 20% permethrin EC 2000 times during flowering and fruit stage or use cotton ball dipped in 80% dichlorvos EC into pomegranate calyx oyster.

9. Timely control of fruit pests:

The main fruit borer pests are peach borer and peach heart borer. The control measures are as follows: first, we should focus on the three key periods of stinging of overwintering larvae, emergence of adults, egg and larva hatching. To control the overwintering generation of larvae, phoxim granules can be applied underground before the larvae are stung; during the occurrence of adults, 1000 times of 90% trichlorfon, or 1000 times of 50% phoxim, or 2000-3000 times of pyrethroids are sprayed for control; during the incubation period of eggs and larvae, spraying 50% fenitrothion or 1000 times of 90% trichlorfon has a good effect. Pick up and remove the damaged fruit in time to deal with it so as to reduce the source of insects. Second, before the larvae eat fruit, use 50% phoxim or 90% trichlorfon 0.5 kg plus 10 kg water to control. Third, fruit bagging. Bagging before spawning can not only prevent larvae from eating fruit, but also treat a variety of diseases and improve fruit quality.