Cultivation mode for improving quality and refreshing time of pitaya

Abstract

The invention belongs to the technical field of pitaya planting, and particularly relates to a cultivation mode for improving the quality of pitaya and prolonging the fresh-keeping period of pitaya. The cultivation mode for improving the quality of the pitaya and prolonging the fresh-keeping period of the pitaya comprises the following steps that selenium fertilizer is applied in the flower and fruit development period of the pitaya, and the application amount of the selenium fertilizer is 1300-1600 kg / mu; the selenium fertilizer is a selenium-rich high-calcium bio-organic fertilizer. According to the method, the selenium-rich high-calcium bio-organic fertilizer is applied in the flower and fruit development period of the pitaya, so that the selenium content of the pitaya fruits can be remarkably increased and is higher than the selenium content standard of fresh fruits in the local standard DB45 / T1061-2014 of Guangxi province; in addition, the amino acid chelated selenium fertilizer and nano calcium carbonate are sprayed in the young fruit stage, the oxidase content of the dragon fruits can be remarkably increased, and the preservation period of the dragon fruits can be prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of pitaya planting, and particularly relates to a cultivation mode for improving the quality and shelf life of pitaya. Background Art

[0002] Pitaya is a tropical and subtropical fruit with simple cultivation technology. It is rich in nutrition and unique in function. It contains plant albumin and anthocyanin which are rare in general plants, as well as rich vitamins and water-soluble dietary fiber, and is deeply loved by people. In addition to being eaten raw, the flowers and fruits of pitaya can be processed into various nutritional and health foods, such as pitaya juice, sauce, preserved fruit and canned beverages. In addition, the flowers and stems can be used as medicine, which is very effective in treating hypertension and diabetes. Secondly, the flowers and fruits of pitaya are very bright in color and can be directly used as bonsai and garden cultivation for viewing.

[0003] Selenium is an essential trace element in the human body. It participates in the synthesis of various selenoenzymes and selenoproteins in the human body, can enhance human immunity, promote the proliferation of lymphocytes and the synthesis of antibodies and immunoglobulins, and has a significant inhibitory and protective effect on various cancer diseases such as colon cancer, skin cancer, liver cancer and breast cancer. Its intermediate metabolites in the body have strong anti-cancer activity. Therefore, selenium is considered by scientists to be the "king of cancer prevention" among human trace elements.

[0004] In the process of pitaya planting, the selenium content of pitaya fruit can be increased by applying an appropriate amount of exogenous selenium, which improves the fruit quality of pitaya and helps to improve the economic value of pitaya. At present, there are many reports on how to increase the yield of pitaya and how to improve the total sugar, vitamin C, soluble sugar and total acid in pitaya fruit. However, there are fewer reports on how to increase the selenium content of pitaya. In the process of pitaya planting, the inventor applied the selenium-rich high-calcium biological organic fertilizer (selenium content 115mg / kg) of Beihai Lidi Fertilizer Co., Ltd., and found that the selenium fertilizer can effectively increase the selenium content in pitaya, which is of great significance to realizing selenium-rich pitaya, improving pitaya quality and promoting the development of pitaya industry. Spraying amino acid chelated selenium fertilizer in pitaya young fruit stage can increase the antioxidant enzyme content of pitaya edible part, which is conducive to extending the storage fresh-keeping period in the later stage, and spraying nano calcium carbonate mixedly can increase the thickness of the peel, which is also conducive to extending the fresh-keeping period after harvesting.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] The purpose of the present invention is to provide a cultivation mode for improving the quality and shelf life of pitaya, which can effectively increase the selenium content in pitaya, and is of great significance for achieving selenium-enriched pitaya, improving the quality of pitaya and promoting the development of the pitaya industry.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A cultivation mode for improving the quality and shelf life of pitaya, comprising the following steps:

[0009] Selenium fertilizer is applied during the flower and fruit development period of pitaya, and the application amount of the selenium fertilizer is 1300-1600kg / mu; the selenium fertilizer is a selenium-rich and high-calcium biological organic fertilizer.

[0010] Amino acid chelated selenium fertilizer and nano calcium carbonate are sprayed during the young fruit stage of pitaya. The application amount of the selenium fertilizer is 2L / mu, which is diluted 200 times; the application amount of the nano calcium carbonate is 20kg / mu, which is diluted 20 times and then mixed with the amino acid chelated selenium fertilizer for spraying.

[0011] More specifically, the pitaya variety is Jindu No. 1.

[0012] More specifically, the selenium-rich high-calcium biological organic fertilizer was purchased from Beihai Lidi Fertilizer Co., Ltd., and its selenium content was 115 mg / kg. The amino acid chelated selenium fertilizer was homemade in the laboratory, and its selenium content was 0.2 mg / kg; the nano calcium carbonate was provided by Guilin University of Technology, and the particle size of calcium carbonate was between 100-300 nm.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention applies selenium-rich and high-calcium biological organic fertilizer during the pitaya flower and fruit development period, which can significantly increase the selenium content of the pitaya fruit, and is higher than the standard of the selenium content standard of fresh fruit in Guangxi local standard DB45 / T1061-2014; in addition, amino acid chelated selenium fertilizer and nano calcium carbonate are sprayed during the young fruit stage, which can significantly increase the oxidase content thereof, and is helpful to prolong the shelf life of the pitaya. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the gradual extraction of selenium content in different forms and valence states in soil;

[0016] Figure 2 The effect of different exogenous selenium concentrations on selenium absorption and accumulation in different parts of pitaya;

[0017] Figure 3 It is the migration and transformation of different exogenous selenium in soil after being added into soil; Figure 4 The picture shows that ripe dragon fruits with different treatments were placed under refrigerated conditions for 30 days. DETAILED DESCRIPTION

[0018] The technical solution of the present invention is clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0019] 1. Materials and Methods

[0020] 1.1 Materials

[0021] Test location: Pitaya test demonstration base of Minhang Ecological Science and Technology Agriculture Co., Ltd., Guiping City, Guigang City, Guangxi Province. Soil selenium content and basic agrochemical properties are shown in Table 1.

[0022] Experimental pitaya variety: Jindu No. 1.

[0023] Experimental fertilizer: selenium-rich and high-calcium biological organic fertilizer (Beihai Lidi Fertilizer Co., Ltd., selenium content 115 mg / kg).

[0024] Table 1 Basic physical and chemical properties and selenium content of soil at test points

[0025]

[0026] 1.2 Methods

[0027] 1.2.1 Experimental design

[0028] Four selenium supply gradients were set: 0 (CK), 1000 kg / mu (A), 1300 kg / mu (B) and 1600 kg / mu (C).

[0029] Selenium fertilizer used was selenium-rich high-calcium bio-organic fertilizer (selenium content 115 mg / kg). A 15 cm deep trench was dug on both sides of the pitaya root, and selenium fertilizer was applied during the fruit development period in August 2020. The row length of the plot was 10 m, the row spacing was 2.5 m, and each plot contained 4 rows of pitaya. Each treatment was repeated 3 times in random blocks.

[0030] 1.2.2 Sample collection and measurement methods

[0031] Pitaya samples were collected during the fruiting period in September 2020 (about 30 days after fertilization). Since pitaya is a fruit that matures in batches, mature pitaya, immature pitaya and pitaya stems were picked at the same time. Soil was collected from the roots of pitaya, brought back to the laboratory, air-dried, ground, and sieved through 10 mesh, 20 mesh, 60 mesh and 100 mesh according to the test indicators, and kept for later use.

[0032] The plants were divided into mature flesh, mature peel, immature flesh, immature peel and stem. The selenium content was determined after the fresh samples were squeezed into juice. The selenium content was determined according to GB / T 21729-2008.

[0033] The analysis and determination of basic physical and chemical properties of soil refer to the methods of "Soil Agrochemical Analysis": the determination of organic matter adopts the potassium dichromate volumetric method (external heating method); the determination of soil total nitrogen adopts the semi-micro Kjeldahl method; the determination of effective nitrogen adopts the alkaline diffusion method; the determination of effective phosphorus adopts the 0.5 mol·L -1 NaHCO3 (pH 8.5) extraction, molybdenum blue colorimetry; available potassium was determined using cold 2 mol·L -1 HNO3 solution extraction-flame photometry.

[0034] The total selenium content in soil samples was digested using a 3+2 (V+V) HNO3+HClO4 (V+V) mixed acid at 170°C using an electric heating plate according to NY / T1104-2006.

[0035] Method for determining soil selenium forms and valence states: Referring to the graded treatment method of Qu Jianguo et al., selenium in the soil is divided into five binding forms through graded leaching. Accurately weigh the air-dried soil that has passed the test, place it in a clean polyethylene centrifuge tube, and add the leaching solution step by step according to the soil-liquid ratio for continuous leaching. For details, see Figure 1 .

[0036] 2. Results and Analysis

[0037] 2.1 Effects of different exogenous selenium on selenium content and quality of pitaya

[0038] The results are shown in Table 2.

[0039] Table 2 Effects of different exogenous selenium on selenium content and quality of pitaya

[0040]

[0041] As shown in Table 2, after the application of different concentrations of exogenous selenium, the selenium content in the pulp was significantly higher than that of the control CK. According to the selenium content standard of fresh fruit in Guangxi local standard DB45 / T1061-2014 (0.01-0.10 mg / kg), the AC treatments all reached the selenium-rich standard. And the selenium content of the fruit in treatments B and C was significantly higher than that in treatment A. In addition, the application of selenium had a significant effect on vitamin C, soluble sugar and total acid in the fruit. It can be seen that the application of different concentrations of exogenous selenium can improve the quality of pitaya.

[0042] 2.2 Effects of different exogenous selenium concentrations on selenium absorption and accumulation in different parts of pitaya

[0043] Results Figure 2 .

[0044] Since pitaya takes a long time to harvest, we chose to pick the test fruits 20 days after fertilization. Figure 2It can be seen that compared with the control CK, exogenous selenium significantly increased the selenium content in different parts. Among them, the selenium content in immature flesh is higher than that in other parts, and when 1600kg / mu is applied, the selenium content in immature flesh increases significantly. According to the standard of selenium content in fresh fruits (0.01-0.10mg / kg) in Guangxi local standard DB45 / T1061-2014, the selenium content in mature flesh at 1300kg / mu and 1600kg / mu reaches the selenium-rich standard, but considering the cost and selenium content in immature flesh, 1300kg / mu is a more ideal application amount. At the same time, it can be seen from the test results that selenium is more likely to accumulate in the flesh, and the selenium content in immature flesh is higher than that in mature flesh. Therefore, the order of selenium content is: immature flesh > mature flesh > immature peel > mature peel > stem.

[0045] 2.3 Effects of different exogenous selenium concentrations on total and available selenium in soil

[0046] The results are shown in Table 3.

[0047] Table 3 Effects of different exogenous selenium concentrations on total selenium and available selenium in soil

[0048]

[0049] When exogenous selenium is applied to the soil, the increase in the selenium content of pitaya mainly comes from the absorption of selenium applied to the soil. As shown in Table 3, the total selenium in the cultivated layer soil increased significantly, but there was no significant difference between different treatments. The selenium in the soil that can be absorbed by plants is effective selenium, and water-soluble selenium and exchangeable selenium are usually considered to be effective selenium. Compared with the control CK, the water-soluble selenium and exchangeable selenium are significantly higher than the control. Among them, the water-soluble selenium content is the highest in treatment B (1300kg / mu) and treatment C (1600kg / mu), while the exchangeable state varies significantly among different treatments, with treatment B having the highest content. The law of the effective state is consistent with that of the water-soluble state, and this law is consistent with the law of selenium content in the pulp, indicating that the effective selenium content in the soil directly determines the selenium content in the fruit.

[0050] 2.4 Migration and transformation of exogenous selenium in soil after application

[0051] Results Figure 3 and Table 4.

[0052] Table 4 Effects of migration and transformation of exogenous selenium in soil after application

[0053]

[0054] After exogenous selenium is applied to the soil, a portion of it will be absorbed by plants, and the rest will remain in the soil. Figure 3As shown in Table 4, after applying 1000kg / mu (A), the total selenium content in the soil at different depths increased (from shallow to deep) by 32.77%, 15.18% and 108.96% relative to the control CK at the same depth; after applying 1300kg / mu (B), the total selenium content in the soil at different depths increased by 70.90%, 34.83% and 151.22%; after applying 1600kg / mu (C), the total selenium content in the soil at different depths increased by 95.29%, 69.79% and 210.96%. After the application of exogenous selenium to the soil, as the concentration of exogenous selenium increased, the selenium content at different depths of the soil increased significantly. And it mainly accumulated in the soil at a depth of 40-60cm, with the least accumulation in the soil at a depth of 20-40cm. This shows that after selenium is applied to the soil, a large amount of selenium will migrate vertically to deeper soil layers, and part of it will also accumulate in the plow layer.

[0055] In summary, the present invention applies selenium-rich high-calcium biological organic fertilizer during the pitaya flower and fruit development period, which can significantly improve the selenium content of pitaya fruit, and is higher than the standard of the selenium content standard of fresh fruit in Guangxi local standard DB45 / T1061-2014. In addition, the cultivation mode has a significant impact on fruit vitamin C, soluble sugar and total acid, which helps to achieve selenium-rich pitaya, improve the quality of pitaya and promote the development of pitaya industry. In addition, water-soluble selenium and exchangeable selenium in the soil can be significantly increased, which is conducive to the selenium-rich planting of pitaya.

[0056] 2. Effects of amino acid chelated selenium fertilizer and nano calcium carbonate on the shelf life of pitaya

[0057] 2.1 Test location

[0058] Shilong Town, Guiping City

[0059] 2.2 Dragon fruit varieties

[0060] Jindu No.1

[0061] 2.3 Test materials

[0062] Sodium selenite, amino acid chelated selenium fertilizer (selenium content 0.2 mg / kg, homemade), nano calcium carbonate (provided by Guilin University of Technology, particle size 100-300 nm).

[0063] 2.4 Experimental treatment

[0064] Table 5 Experimental treatment

[0065]

[0066] Note: G and H treated sodium selenite is directly dissolved in calcium carbonate solution.

[0067] Dig about 15cm deep trenches on both sides of the pitaya root, apply selenium fertilizer during the pitaya flower and fruit development period, the application rate of the selenium fertilizer is 600kg / mu, and the selenium fertilizer is a selenium-rich and high-calcium biological organic fertilizer; spray the treatment in Table 5 during the young fruit stage (10-15 days before harvest). The row length of the plot is 10m, the row spacing is 2.5m, each plot contains 4 rows of pitaya, each treatment is repeated 3 times, and the random block arrangement is arranged.

[0068] 2.5 Sample collection

[0069] After the ripe dragon fruits were picked and placed under refrigerated conditions for 30 days, the antioxidant enzymes of the treatment were observed and measured. Ten ripe dragon fruits were harvested from each plot for testing, and three replicates were used for each treatment. Figure 4 and Table 6.

[0070] Table 6 Antioxidant enzyme content in different treatments

[0071]

[0072] Depend on Figure 4 It can be seen that the brown spots on the surface of pitaya treated with E, F, G, and H are significantly less than those in other treatments. Under the same storage time and temperature conditions, the mixture of amino acid chelated selenium fertilizer and nano-calcium carbonate can extend the shelf life of pitaya.

[0073] As shown in Table 6, spraying a mixture of amino acid chelated selenium and nano-calcium carbonate, as well as a mixture of sodium selenite and nano-calcium carbonate during the young fruit stage can significantly increase the oxidase content. The increase in antioxidant enzymes significantly extends the shelf life of pitaya.

Claims

1. A cultivation mode for improving the quality and shelf life of pitaya, characterized in that: The following steps are involved: Selenium fertilizer is applied during the pitaya flower and fruit development period, and the application amount of the selenium fertilizer is 1300-1600 kg / mu; the selenium fertilizer is a selenium-rich and high-calcium biological organic fertilizer; Amino acid chelated selenium fertilizer and nano calcium carbonate are sprayed during the young fruit stage. The application amount of the amino acid chelated selenium fertilizer is 2L / mu, which is diluted 200 times; the application amount of the nano calcium carbonate is 20kg / mu, which is diluted 20 times and then mixed with the amino acid chelated selenium fertilizer for spraying.

2. The cultivation mode for improving dragon fruit quality and shelf life according to claim 1, characterized in that, The pitaya variety is Jindu No.

1.

3. The cultivation mode for improving dragon fruit quality and shelf life according to claim 1, characterized in that, The selenium-rich and high-calcium biological organic fertilizer was purchased from Beihai Lidi Fertilizer Co., Ltd., and its selenium content was 115 mg / kg; Amino acid chelated selenium fertilizer was homemade in the laboratory, and its selenium content was 0.2 mg / kg; nano calcium carbonate was provided by Guilin University of Technology.

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