Preharvest treatment method for improving quality of mango fruits

Abstract

The invention provides a pre-picking treatment method for improving mango fruit quality, which comprises the following steps: 25-35 days before picking, spraying a mixed agent A containing monopotassium phosphate, 24-epibrassinolide, paclobutrazol and Tween-80 on leaf surfaces; 15-25 days before picking, a mixed agent B containing monopotassium phosphate, 24-epibrassinolide, potassium cinnamate and Tween-80 is sprayed to the fruits twice in total, the interval is 7-10 days, and a mixed agent C containing monopotassium phosphate, compound sodium nitrophenolate, gamma-aminobutyric acid, methyl jasmonate and Tween-80 is sprayed at the same period. The pre-harvest treatment method can effectively promote the mango peel to turn red and improve the fruit quality. The pre-harvest treatment method is convenient to apply, easy to operate and friendly to the ecological environment, and has good economic benefits and social benefits.

Description

Technical Field

[0001] This invention relates to the field of fruit quality control technology, and in particular to a pre-harvest treatment method for improving the quality of mango fruits. Background Technology

[0002] mango( Mangiferaindica Mangoes, a tropical and subtropical fruit, are brightly colored, sweet, and rich in nutrients, making them a favorite among consumers. Mangoes are a vital pillar industry for agriculture in provinces such as Yunnan, Guangxi Zhuang Autonomous Region, Hainan, Sichuan, Guizhou, and Taiwan in my country. Mangoes are the largest fruit crop in Hainan Province, with a current planting area of ​​983,000 mu (approximately 65,533 hectares) and an annual total output of 943,000 tons, making it a crucial industry for rural revitalization.

[0003] The biggest advantage of Hainan mangoes is their early ripening, leading to higher economic returns from early market entry. Hainan employs a series of cultivation techniques, including regulating flowering and fruit preservation, to shift the mango ripening period from May-June of the following year to December-April. This off-season cultivation method has brought significant economic benefits to the Hainan mango industry. However, off-season cultivation has also brought many problems. One of the most significant is the improper use of plant growth regulators, which has resulted in a serious decline in mango quality. For example, the "Guifei" mango exhibits reduced sugar content at maturity, poor peel coloring, and severe post-harvest disease. This has become a bottleneck restricting the high-quality development of the Hainan mango industry. Therefore, developing application technologies to improve mango quality through pre-harvest quality control is of great practical significance.

[0004] Potassium dihydrogen phosphate (KH2PO4) is a highly efficient phosphorus-potassium compound fertilizer. Proper application can significantly improve the sugar content, color, flavor, and storage resistance of fruits. Potassium promotes the transport of photosynthetic products (sugars) to the fruit, while phosphorus participates in energy metabolism (ATP synthesis), jointly increasing the total soluble solids (TSS) content of the fruit. 24-Epibrassinolide (EBR) is a highly efficient, broad-spectrum plant growth regulator belonging to the brassinolide (BR) family. It promotes plant growth, enhances stress resistance, and improves fruit quality. Paclobutrazol (PBZ) is a plant growth retardant that regulates plant growth by inhibiting gibberellin synthesis. It improves quality by regulating hormone balance, optimizing nutrient distribution, and improving fruit physiological metabolism. Potassium cinnamate (PC) is a potassium salt of natural cinnamic acid with a mild cinnamon aroma. It effectively inhibits the activity of various bacteria and molds and can be used as a novel food additive. MeJA combined with PC treatment not only improves mango disease resistance but also enhances TSS content and other quality aspects.

[0005] γ-aminobutyric acid (GABA) gamma-aminobutyric acidGamma-aminobutyric acid (GABA) is a natural non-protein amino acid, which is widely present in plants and has the effects of regulating plant growth, enhancing stress resistance and improving fruit quality. Previous studies have shown that preharvest or postharvest treatment of GABA can improve the resistance of postharvest mangoes to anthracnose and maintain fruit quality. Methyl jasmonate (MeJA) is an important plant elicitor, which has been widely studied in the induction of disease resistance and quality maintenance of fruits and vegetables. Studies have shown that MeJA can activate the phenylpropanoid metabolic pathway, increase the content of secondary metabolites such as total phenols and flavonoids in crops, promote the accumulation of anthocyanins in fruits, and improve fruit color and quality. Sodium complex nitrophenol (CSN) is composed of 5-nitrosodium guaiacol, o-nitrosodium phenol and p-nitrosodium phenol. After contacting with crops, it can rapidly penetrate into the plant body, promote the protoplasmic flow of cells, and improve the cell vitality. At the same time, it can promote growth and development, prevent flower and fruit drop, improve product quality, increase yield and stress resistance of crops. Previous studies have shown that preharvest spraying of sodium complex nitrophenol can promote the red coloration of mango fruit peel and the yellow coloration of fruit peel at the mature stage, and improve the disease resistance of fruits. compound sodium nitrophenolate Therefore, it is necessary to develop comprehensive control measures using multiple substances and at different stages for production. SUMMARY

[0006] Therefore, the present application provides a preharvest treatment method for improving the quality of mango fruits, which solves the above problems.

[0007] The technical scheme of the present application is as follows: a preharvest treatment method for improving the quality of mango fruits, comprising the following steps: (1) 25-35 days before the mature stage of mango picking, a mixed agent A is used for foliar spraying treatment of mangoes; (2) 15-25 days before the mature stage of mango picking, a mixed agent B is used for first spraying treatment of mango fruits; (3) 7-10 days after the first spraying treatment of step (2), the mixed agent B is used for second spraying treatment of mango fruits; (4) simultaneously or alternately with step (2) or step (3), and within 15-25 days before the mature stage of mango picking, a mixed agent C is used for spraying treatment of mango fruits; The mixed agent A comprises potassium dihydrogen phosphate, 24-epibrassinolide, paclobutrazol and Tween-80; The mixed agent B comprises potassium dihydrogen phosphate, 24-epibrassinolide, potassium cinnamate and Tween-80; The mixed agent C comprises potassium dihydrogen phosphate, sodium complex nitrophenol, gamma-aminobutyric acid, methyl jasmonate and Tween-80.

[0008] Further, the concentrations of the components in the mixed agent A are as follows: potassium dihydrogen phosphate 2000-4000 mg / L, 24-epibrassilolide 2-10 mg / L, paclobutrazol 200-400 mg / L, and the volume percentage concentration of Tween-80 is 0.02-0.3%.

[0009] Further, the concentrations of the components in the mixed agent B are as follows: potassium dihydrogen phosphate 2000-4000 mg / L, 24-epibrassilolide 2-10 mg / L, potassium cinnamate 2-10 g / L, and the volume percentage concentration of Tween-80 is 0.02-0.3%.

[0010] Further, the concentrations of the components in the mixed agent C are as follows: potassium dihydrogen phosphate 1000-3000 mg / L, sodium complexing nitrophenol 500-2000 mg / L, gamma-aminobutyric acid 200-1000 mg / L, methyl jasmonate 10-100 μmol / L, and the volume percentage concentration of Tween-80 is 0.02-0.3%.

[0011] Further, the concentrations of the components in the mixed agent A are as follows: potassium dihydrogen phosphate 3000 mg / L, 24-epibrassilolide 5 mg / L, paclobutrazol 300 mg / L, and the volume percentage concentration of Tween-80 is 0.1%.

[0012] Further, the concentrations of the components in the mixed agent B are as follows: potassium dihydrogen phosphate 3000 mg / L, 24-epibrassilolide 5 mg / L, potassium cinnamate 5000 mg / L, and the volume percentage concentration of Tween-80 is 0.1%.

[0013] Further, the concentrations of the components in the mixed agent C are as follows: potassium dihydrogen phosphate 2000 mg / L, sodium complexing nitrophenol 1000 mg / L, gamma-aminobutyric acid 500 mg / L, methyl jasmonate 50 μmol / L, and the volume percentage concentration of Tween-80 is 0.1%.

[0014] Further, in step (1), the spraying amount of the mixed agent A is 500-800 ml per square meter of mango tree crown.

[0015] Further, the spraying treatment of step (1) focuses on the leaves of the mango plants; the spraying treatments of steps (2), (3) and (4) all focus on the surfaces of the mango fruits.

[0016] Further, the environmental temperature during spraying is 20-30℃, and the relative humidity is 60-80%.

[0017] Compared with the prior art, the present application has the following advantages: The present application combines the sugar-increasing treatment and the color-promoting treatment of mangoes to achieve the purpose of increasing sugar and promoting color of the fruit, thereby improving the quality of the fruit. After the pre-harvest method is used to treat the mangoes, the a value of the peel color of the mangoes reaches 10.55-11.49 when the mangoes reach the physiological maturity period, which is 2.63-3.57 higher than that of the control fruit (7.92), and the increase range is 33.21-45.08%; the TSS content of the mango pulp is 15.61-16.54%, which is 1.28-2.21 percentage points higher than that of the control fruit (14.33), and the increase range is 8.93-15.42%; meanwhile, the quality such as the content of vitamin C, citric acid and sucrose is maintained. The pre-harvest treatment method can effectively promote the peel of the mangoes to turn red and improve the quality of the fruit. The pre-harvest treatment method is convenient to apply, simple to operate, friendly to the ecological environment, and has good economic and social benefits. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The mature period mangoes (0 d after harvest) are picked; Figure 2 The physiological maturity period mangoes (10 d after harvest) are picked. DETAILED DESCRIPTION

[0019] In order to better understand the technical content of the present application, the following specific examples are provided to further illustrate the present application.

[0020] The experimental methods used in the embodiments of the present application are conventional methods unless otherwise specified.

[0021] The materials, reagents and the like used in the embodiments of the present application can be obtained from commercial channels unless otherwise specified.

[0022] Embodiment 1 (1) 30 d before the mature period mangoes are picked, the mangoes are treated with mixed agent A for foliar spraying once; the mixed agent A includes 2000 mg / L potassium dihydrogen phosphate, 2 mg / L 24-epibrassinolide, 200 mg / L paclobutrazol and 0.1% w / v emulsifier Tween-80.

[0023] (2) 20 d before the mature period mangoes are picked, the fruit is treated with mixed agent B for spraying twice with an interval of 10 d; the mixed agent B includes 2000 mg / L potassium dihydrogen phosphate, 2 mg / L 24-epibrassinolide, 2000 mg / L potassium cinnamate and 0.1% w / v emulsifier Tween-80.

[0024] (3) 20 d before the harvest of mangoes, the fruits were sprayed with mixed agent C; mixed agent C included 1000 mg / L potassium dihydrogen phosphate, 500 mg / L sodium complex nitrophenol, 200 mg / L γ-aminobutyric acid, 10 μmol / L methyl jasmonate, and 0.1% w / v emulsifier Tween-80.

[0025] Example 2 (1) 30 d before the harvest of mangoes, the mangoes were sprayed with mixed agent A once; mixed agent A included 3000 mg / L potassium dihydrogen phosphate, 5 mg / L 24-epibrassinolide, 300 mg / L paclobutrazol, and 0.1% emulsifier Tween-80 by volume percentage.

[0026] (2) 20 d before the harvest of mangoes, the fruits were sprayed with mixed agent B twice with an interval of 10 d; mixed agent B included 3000 mg / L potassium dihydrogen phosphate, 5 mg / L 24-epibrassinolide, 5000 mg / L potassium cinnamate, and 0.1% emulsifier Tween-80 by volume percentage.

[0027] (3) 20 d before the harvest of mangoes, the fruits were sprayed with mixed agent C; mixed agent C included 2000 mg / L potassium dihydrogen phosphate, 1000 mg / L sodium complex nitrophenol, 500 mg / L γ-aminobutyric acid, 50 μmol / L methyl jasmonate, and 0.1% emulsifier Tween-80 by volume percentage.

[0028] Example 3 (1) 30 d before the harvest of mangoes, the mangoes were sprayed with mixed agent A once; mixed agent A included 3000 mg / L potassium dihydrogen phosphate, 5 mg / L 24-epibrassinolide, 300 mg / L paclobutrazol, and 0.1% emulsifier Tween-80 by volume percentage.

[0029] (2) 20 d before the harvest of mangoes, the fruits were sprayed with mixed agent B twice with an interval of 10 d; mixed agent B included 3000 mg / L potassium dihydrogen phosphate, 5 mg / L 24-epibrassinolide, 5000 mg / L potassium cinnamate, and 0.1% emulsifier Tween-80 by volume percentage.

[0030] (3) 20 d before the harvest of mangoes, the fruits were sprayed with mixed agent C; mixed agent C included 2000 mg / L potassium dihydrogen phosphate, 1000 mg / L sodium complex nitrophenol, 1000 mg / L γ-aminobutyric acid, 50 μmol / L methyl jasmonate, and 0.1% emulsifier Tween-80 by volume percentage.

[0031] Example 4 (1) 30 d before the mature stage of mango picking, the mango was treated with mixed agent A for foliar spraying once; mixed agent A included 3000 mg / L potassium dihydrogen phosphate, 5 mg / L 24-epibrassinolid, 300 mg / L paclobutrazol and 0.1% emulsifier Tween-80 by volume percentage.

[0032] (2) 20 d before the mature stage of mango picking, the fruit was treated with mixed agent B for spraying twice with an interval of 10 d; mixed agent B included 3000 mg / L potassium dihydrogen phosphate, 5 mg / L 24-epibrassinolid, 5000 mg / L potassium cinnamate and 0.1% emulsifier Tween-80 by volume percentage.

[0033] (3) 20 d before the mature stage of mango picking, the fruit was treated with mixed agent C for spraying; mixed agent C included 3000 mg / L potassium dihydrogen phosphate, 2000 mg / L sodium nitrophenol, 1000 mg / L gamma-aminobutyric acid, 100 μmol / L jasmonic acid methyl ester and 0.1% emulsifier Tween-80 by volume percentage.

[0034] Comparative Example 1 (1) 30 d before the mature stage of mango picking, the mango was treated with a water solution containing 0.1% emulsifier Tween-80 for foliar spraying once.

[0035] (2) 20 d before the mature stage of mango picking, the fruit was treated with a water solution containing 0.1% emulsifier Tween-80 for spraying twice with an interval of 10 d.

[0036] (3) 20 d before the mature stage of mango picking, the fruit was treated with a water solution containing 0.1% emulsifier Tween-80 for spraying once.

[0037] Comparative Example 2 (1) 30 d before the mature stage of mango picking, the mango was treated with mixed agent A for foliar spraying twice with an interval of 10 d; mixed agent A included 3000 mg / L potassium dihydrogen phosphate, 5 mg / L 24-epibrassinolid, 300 mg / L paclobutrazol and 0.1% emulsifier Tween-80 by volume percentage.

[0038] (2) 20 d before the mature stage of mango picking, the fruit was treated with mixed agent B for spraying twice with an interval of 10 d; mixed agent B included 3000 mg / L potassium dihydrogen phosphate, 5 mg / L 24-epibrassinolid, 5000 mg / L potassium cinnamate and 0.1% emulsifier Tween-80 by volume percentage.

[0039] (3) 20 d before the mature stage of mango picking, the fruit was sprayed once with a water solution containing 0.1% emulsifier Tween-80.

[0040] Performance test The selection of the pharmaceutical formula and the treatment method adopted by the present application are made on the basis of the following theories and experimental results: (1) Selection of mixed pharmaceutical A As can be seen from Table 1, the treatment effect of KH2PO4 (3000 mg / L) + EBR (5 mg / L) + PBZ (300 mg / L) in mixed pharmaceutical A is better than that of KH2PO4 (3000 mg / L) + EBR (5 mg / L) combination and PBZ (300 mg / L) alone, and compared with the control, the fruit peel color a value and the pulp TSS content are significantly improved, indicating that mixed pharmaceutical A has obvious effect in increasing sugar and promoting red turning.

[0041] Table 1 Effect of pre-harvest mixed pharmaceutical A treatment on mango fruit peel color a value and pulp TSS content (Guifei mango)

[0042] Note: The above treatment is sprayed on the leaf surface once 30 d before picking, and the data is measured at the mature stage (10 d after picking).

[0043] (2) Selection of mixed pharmaceutical B As can be seen from Table 2, the treatment effect of KH2PO4 (3000 mg / L) + EBR (5 mg / L) + PC (1000 mg / L) in mixed pharmaceutical A is better than that of KH2PO4 (3000 mg / L) + EBR (5 mg / L) combination and PC (5000 mg / L) alone, and compared with the control, the fruit peel color a value and the pulp TSS content are significantly improved, indicating that mixed pharmaceutical B has obvious effect in increasing sugar and promoting red turning.

[0044] Table 2 Effect of pre-harvest mixed pharmaceutical B treatment on mango fruit peel color (a value) and pulp TSS content (Guifei mango)

[0045] Note: The above treatment is sprayed on the leaf surface once 30 d before picking, and the data is measured at the mature stage (10 d after picking).

[0046] (3) Selection of mixed pharmaceutical C 1) Screening of pre-harvest GABA concentration: As shown in Table 3, pre-harvest GABA treatment at different concentrations improved the quality indicators of mangoes such as TSS, vitamin C and citric acid content to varying degrees. In terms of overall effect, pre-harvest treatment with 500 mg / L GABA was the best.

[0047] 2) Synergistic effect of GABA and MeJA As shown in Table 4, pre-harvest GABA, MeJA and their combination significantly improved the peel color a value and pulp TSS, vitamin C and citric acid content of mangoes. Pre-harvest GABA+MeJA combination treatment was the best, significantly better than GABA and MeJA alone. This indicates that GABA and MeJA combination treatment has obvious synergistic effect.

[0048] Table 3 Effect of pre-harvest GABA treatment at different concentrations on the quality of mango pulp (Guifei mango)

[0049] Note: Spray treatment on the fruit surface once 20 days before harvest. The above data were measured at the ripe stage (10 days after harvest).

[0050] Table 4 Effect of pre-harvest GABA and MeJA combination treatment on the peel color a value and pulp quality of mangoes (Guifei mango)

[0051] Note: Spray treatment on the fruit surface once 20 days before harvest. The above data were measured at the ripe stage (10 days after harvest).

[0052] 3) Synergistic effect of mixed formula C pesticide As can be seen from Table 5, the KH2PO4 (3000 mg / L) + CSN (1000 mg / L) treatment, the GABA (500 mg / L) + MeJA (50 μmol / L) treatment and the mixed agent C, i.e. KH2PO4 (3000 mg / L) + CSN (1000 mg / L) + GABA (500 mg / L) + MeJA (50 μmol / L) combined treatment, can effectively promote the increase of the color a value, and the mixed agent C treatment is superior to the KH2PO4 (3000 mg / L) + CSN (1000 mg / L) treatment and the GABA (500 mg / L) + MeJA (50 μmol / L) treatment, and the effect of promoting the fruit peel to turn red is more obvious; in terms of improving the TSS content, the mixed agent C treatment is superior to the KH2PO4 (3000 mg / L) + CSN (1000 mg / L) treatment and the GABA (500 mg / L) + MeJA (50 μmol / L) treatment, and the TSS content of the fruit pulp is significantly increased compared with the control.

[0053] Table 5 Effects of the mixed agent C treatment before harvesting on the color a value of the mango fruit peel and the TSS content of the fruit pulp (Guifei mango)

[0054] Note: The above treatments are sprayed on the fruit surface once at 20 d before harvesting; the data are measured at the ripe stage (10 d after harvesting).

[0055] (4) Synergistic effect of the mixed agent A+B and C combined treatment As can be seen from Table 6, Figure 1 and Figure 2 the color a value of the fruit peel at the time of harvesting is significantly higher than that of the control (CK), and the TSS content at the physiological mature stage is significantly higher than that of CK; at 20 d before harvesting, the mango is treated with the mixed agent C, and the color a value of the fruit peel at the time of harvesting is significantly higher than that of CK, and the color a value and the TSS content at the physiological mature stage are significantly higher than those of CK; the mango is treated with A+B+C combined treatment, and the color a value of the fruit peel at the time of harvesting is the largest and significantly higher than that of CK and A+B treatment; and the color a value and the TSS content at the physiological mature stage are significantly higher than those of CK, A+B and C treatments. It is shown that the A+B+C combined treatment can effectively promote the fruit peel to turn red and improve the TSS content at the physiological mature stage, and the effect of the A+B+C combined treatment is obviously superior to that of the A+B and C single treatments, and the good sugar increasing and red turning promoting effects are achieved.

[0056] Table 6 Effects of the treatment before harvesting on the color a value of the mango fruit peel and the TSS content of the fruit pulp (Guifei mango)

[0057] Note: Mixed agent A treatment: including KH2PO4, EBR and PBZ, the concentration is 3000 mg / L, 5 mg / L and 1000 mg / L respectively, spraying treatment once on the leaves 20 days before picking; Mixed agent B treatment: including KH2PO4, EBR and PC, the concentration is 3000 mg / L, 5 mg / L and 5000 mg / L respectively, spraying treatment every 10 days, a total of 2 times; Mixed agent C treatment: including KH2PO4, CSN, GABA and MeJA, the concentration is 2000 mg / L, 1000 mg / L, 500 mg / L and 50 μmol / L respectively, spraying treatment once on the fruit 20 days before picking; A+B+C treatment: combination of A, B and C treatment. The same column data in the table after different lowercase English letters represent significant difference at 5% level.

[0058] The determination and calculation method of the soluble solids content (TSS), vitamin C, citric acid, sucrose content and peel red index (a value) of mango pulp involved in the following examples of the present application are as follows: The TSS content (%) is determined by a handheld refractometer; the vitamin C, citric acid and sucrose content are determined by a high performance liquid chromatograph; the peel red index (a value) is determined by a Konica-Minolta CR-410 color difference instrument, the color a value from negative to positive represents the change of mango fruit (Gui Fei) from green to red, and the greater the positive value represents the redder fruit.

[0059] Table 7 Influence of each treatment of the examples and comparative examples on the peel color a value and TSS content of mango (physiological maturity period)

[0060] Note: Different lowercase English letters after the same column data represent significant difference (P<0.05).

[0061] The results show that: by using the method of the examples, the peel color a value of mango is 10.55~11.49, which is increased by 2.63~3.57 compared with the control fruit (7.92), and the increase range is 33.21~45.08%; the TSS content of mango pulp is 15.61~16.54%, which is increased by 1.28~2.21 percentage points compared with the control fruit (14.33%), and the increase range is 8.93~15.42%; at the same time, compared with comparative examples 1 and 2, the method also maintains a high content of vitamin C, citric acid and sucrose. It shows that the treatment methods of examples 1~4 can promote the peel turning red of mango fruit, increase the TSS and sucrose content of pulp, maintain a high content of vitamin C and citric acid, so as to achieve the effect of increasing sugar and promoting color of fruit, improving the quality of fruit.

[0062] The above merely provides the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A preharvest treatment method for improving the quality of mango fruits, characterized in that, It comprises the following steps: (1) 25-35 days before the mature period of mango picking, mixed agent A is used for foliar spraying treatment of mango; (2) 15-25 days before the mature period of mango picking, mixed agent B is used for the first spraying treatment of mango fruit; (3) 7-10 days after the first spraying treatment of step (2), mixed agent B is used for the second spraying treatment of mango fruit; (4) mixed agent C is used for spraying treatment of mango fruit at the same time or staggered with step (2) or step (3) and within 15-25 days before the mature period of mango picking; The mixed agent A comprises potassium dihydrogen phosphate, 24-epibrassinolide, paclobutrazol and Tween-80; The mixed agent B comprises potassium dihydrogen phosphate, 24-epibrassinolide, potassium cinnamate and Tween-80; The mixed agent C comprises potassium dihydrogen phosphate, sodium complexing nitrophenol, gamma-aminobutyric acid, methyl jasmonate and Tween-80.

2. A preharvest treatment method for improving the quality of mango fruits as claimed in claim 1, wherein, The concentrations of the components in the mixed agent A are respectively: potassium dihydrogen phosphate 2000-4000 mg / L, 24-epibrassinolide 2-10 mg / L, paclobutrazol 200-400 mg / L, and the volume percentage concentration of Tween-80 is 0.02-0.3%.

3. A preharvest treatment method for improving the quality of mango fruits as claimed in claim 1, wherein, The concentrations of the components in the mixed agent B are respectively: potassium dihydrogen phosphate 2000-4000 mg / L, 24-epibrassinolide 2-10 mg / L, potassium cinnamate 2-10 g / L, and the volume percentage concentration of Tween-80 is 0.02-0.3%.

4. A preharvest treatment method for improving the quality of mango fruits as claimed in claim 1, wherein, The concentrations of the components in the mixed agent C are respectively: potassium dihydrogen phosphate 1000-3000 mg / L, sodium complexing nitrophenol 500-2000 mg / L, gamma-aminobutyric acid 200-1000 mg / L, methyl jasmonate 10-100 μmol / L, and the volume percentage concentration of Tween-80 is 0.02-0.3%.

5. A preharvest treatment method for improving the quality of mango fruits as claimed in claim 2, wherein the said treatment is carried out at the stage of fruit development of 3-4 months after flowering. The concentrations of the components in the mixed agent A are respectively: potassium dihydrogen phosphate 3000 mg / L, 24-epibrassinolide 5 mg / L, paclobutrazol 300 mg / L, and the volume percentage concentration of Tween-80 is 0.1%.

6. A preharvest treatment method for improving the quality of mango fruits as claimed in claim 3, wherein the said treatment is carried out at the stage of fruit development of 3-4 months after flowering. The concentrations of the components in the mixed agent B are respectively: potassium dihydrogen phosphate 3000 mg / L, 24-epibrassinolide 5 mg / L, potassium cinnamate 5000 mg / L, and the volume percentage concentration of Tween-80 is 0.1%.

7. A preharvest treatment method for improving the quality of mango fruits as claimed in claim 4, wherein the said treatment is carried out at the stage of fruit development of 3-4 months after flowering. The concentrations of the components in the mixed agent C are respectively: potassium dihydrogen phosphate 2000 mg / L, sodium complexing nitrophenol 1000 mg / L, gamma-aminobutyric acid 500 mg / L, methyl jasmonate 50 μmol / L, and the volume percentage concentration of Tween-80 is 0.1%.

8. A preharvest treatment method for improving the quality of mango fruits as claimed in claim 1, wherein, In step (1), the spraying amount of mixed agent A is 500-800 ml per square meter of mango tree crown.

9. A preharvest treatment method for improving the quality of mango fruits as claimed in claim 1, wherein, The spraying treatment of step (1) focuses on the leaves of mango plants; the spraying treatments of steps (2), (3) and (4) all focus on the surface of mango fruit.

10. A preharvest treatment method for improving the quality of mango fruits as claimed in claim 1, wherein, The environmental temperature during spraying is 20-30℃, and the relative humidity is 60-80%.

Images