Causes and control measures of fruit cracking of Shatang orange

Sweet orange, also known as: October orange. Origin Huaiji, Guangning, Sihui area. Originally produced in Shatang Village, Huangtian Town, Sihui City, it was named Shatang Orange. The main producing areas are: Lipu (Xiuren Town), Huaiji, Guangning, Sihui. Satangju fruit oblate, the top has tumor-shaped projections, pedicle navel depression, orange color, thin fruit wall, easy to peel. Sand Tangju is especially delicious and extremely sweet produced in Huangtian Town of Sihui. It has no residue and delicate taste. It is really a good product. It contains rich vitamin C, calcium, fiber, a small amount of protein, fat and rich glucose, fructose, sucrose, malic acid, citric acid, carotene, thiamine, riboflavin, nicotinic acid, ascorbic acid, calcium, phosphorus, magnesium, sodium and other essential elements of the human body. It has the effects of regulating qi and resolving phlegm, moistening lung and clearing intestines, enriching blood and invigorating spleen, etc.

Reasons for sugar orange cracking:

1, fertilization is unreasonable, tree nutrition imbalance. For example, partial application of phosphorus fertilizer, insufficient nitrogen and potassium will make the pericarp thin to a certain extent; lack of trace elements such as calcium, potassium, boron, zinc and molybdenum will make the toughness, elasticity and buffering of the pericarp worse; no or less application of organic fertilizer, soil hardening, insufficient permeability, poor ability to retain water and fertilizer are more likely to occur fruit cracking.

2. The endogenous hormones in the tree body are unbalanced, and the development of pericarp and pulp is not synchronous. Carbohydrate and sugar accumulated more and grew faster in flesh after fruit growth to expansion stage, but at this time, the epidermal cells of fruit divided less and grew slowly, resulting in inconsistent growth speed inside and outside fruit. Some growers see more flowering and fruit setting in the early stage, and the concentration of gibberellin is lower and the frequency is less, which directly affects the thickness of pericarp in the later stage, resulting in more fruit cracking.

3. Weather influence: long-term drought, sudden rainstorm, excessive water supply from roots to fruits, rapid expansion of pulp gizzards due to water absorption; after rain, due to the structural characteristics of pericarp tissue, relatively little water absorption, slow cell division and growth of pericarp, poor toughness, easy to produce sudden burst.

4, canker disease, anthracnose, red spider, fruit fly and other diseases and insect pests are not well controlled, resulting in local growth of fruit peel blocked, or even destroyed. This situation causes a considerable proportion of fruit cracking.

5. Fruit cracking is also related to the condition of fruit trees themselves. Under the same conditions, the cracking rate of fruit trees in full fruit stage was higher than that of fruit trees in young fruit stage; the cracking rate of fruit trees in high yield stage was higher than that of fruit trees in moderate fruit bearing stage; the cracking rate of fruit trees in crown top and periphery was higher than that of fruit trees in middle and upper parts and inner bore branches; and the cracking rate of fruit trees with acid rootstock was higher than that of fruit trees with bitter orange rootstock.

Measures to prevent fruit cracking of orange:

It is a comprehensive technical measure to control fruit cracking of Satangju. According to the causes of fruit cracking, early prevention and early preparation, earnestly grasp each production link, can really effectively reduce fruit cracking, obtain high and stable yield.

1. Organic fertilizer should be used as the main fertilizer, and phosphate fertilizer should not be applied. Yanshen biological organic fertilizer or Yala biological organic fertilizer is selected as base fertilizer or topdressing fertilizer; compound fertilizer with medium nitrogen, low phosphorus and high potassium and containing various medium and trace elements and compound synergist is selected as fruit strengthening fertilizer, such as Yalamei double 18-5-22 synergistic compound fertilizer, Entaike 12-11-18 stable long-term compound fertilizer, etc., which can moderately increase the thickness and toughness of pericarp and reduce fruit cracking. In previous years, it is best to apply Yala high-end medium and trace element water-soluble fertilizer 10kg/mu/time to fruit trees with serious fruit drop, respectively in spring and autumn. After fertilizer is applied, cover it with soil.

2. For orchards with large soil acidity (PH value below 5.5), lime shall be applied to the ground in April and May after flowering to regulate soil pH value. Calcium can enhance the strength and toughness of pericarp and reduce fruit cracking. 1 jin/plant for crown diameter less than 2 meters, 2 jin/plant for crown diameter of 3~4 meters. Lime application amount should be applied according to soil pH and soil quality. Excessive lime application will cause iron deficiency, zinc deficiency and other element deficiency phenomena in fruit trees, resulting in soil hardening.

3. When hanging fruit trees enter the fruit expansion period, high-quality foliar fertilizer should be sprayed frequently, especially in arid areas and seasons. in combination with that prevention and control of disease and insect pest, foliar fertilizer containing calcium and zinc, such as yalaphos potassium nutrient solution or yalitol calcium and zinc solution, are sprayed on foliar surface every 10-15 days to regulate nutrient balance of tree bodies. Spraying foliar fertilizer is simple and economical, which can effectively reduce fruit cracking and promote fruit expansion.

4. Strengthen water management. Tree cover grass maintains soil moisture, balances tree cover soil moisture supply, and avoids sudden drying and wetting. Proper grass between rows of fruit trees can reduce water evaporation and strong sunlight radiation, and can effectively prevent abnormal fruit cracking. Expansion period of more than 15 days without rain caused by drought, should be watered in time. Combined with watering and spraying with aramex solution, the effect is better. Drench topsoil at the beginning of drenching, and then irrigate deep soil after two or three days.

5. Fruit cracking occurred mostly at the top and periphery of canopy. Therefore, it is necessary to combine pruning, reasonable fruit thinning and fertilization measures, and apply a strong fruit color conversion fertilizer before flower bud differentiation. This not only can prevent the big and small years from bearing fruit, but also can reduce the leafless flowers and fruits and bear fruit at the top of the mother branch. Promote uniform fruiting of middle and lower branches of crown and inner bore, reduce top peripheral fruit.

6. Spraying "920" reasonably to protect flowers and fruits can promote the division and expansion of pericarp cells and reduce fruit cracking. Spraying after flowering and before the peak of fruit drop, concentration 20-30PPM, spraying 2 times in total, try not to exceed 3 times, make the peel thickness in a reasonable range of 1.4-2.0 mm, not only the fruit quality is better, but also rarely split fruit and thick skin fruit. If the fruit peel development stagnates without rain for a long time in the expansion period, it can also be considered to spray "920" or triacontanol plus 0.3% urea plus Yala phosphorus potassium nutrient solution, especially before heavy rain, the key parts of the fruit are easy to crack, and the crack prevention effect is quite obvious. However, spraying too much "920" after September will affect flower bud differentiation, less flowers in the coming year, rough and loose pericarp, delay coloring, affect fruit quality and timely listing, generally not recommended to use.

7, timely control of various diseases and insect pests, to avoid damage caused by diseases and insect pests, fruit cracking caused by damage to the peel. The fruit that has been split should be removed in time. In order to avoid fruit rot infection and continue to consume nutrients, water.