A method for reducing the incidence rate of watermelons under high humidity and high temperature conditions

Abstract

The present invention discloses a method for reducing the incidence rate of watermelons under high humidity and high temperature conditions, belonging to the technical field of watermelon cultivation. Before planting watermelons, while applying basal fertilizer, a composite soil conditioner is used to improve the soil; before sowing watermelons, the seeds are first coated and then sown in the improved soil; the composite soil conditioner, by mass fraction, comprises the following components: 100 parts of calcined diatomite, 10-15 parts of perlite, 10-13 parts of bentonite, 8-10 parts of biomass charcoal, 5-8 parts of dried coconut coir, 20-30 parts of decomposed organic matter, and 5-8 parts of a composite microbial inoculum. The present invention effectively improves the adverse effects brought by high humidity and high temperature conditions during the growth process of watermelons and reduces the incidence rate by simultaneously coating watermelon seeds and applying a soil conditioner to the soil, thereby ensuring the yield of watermelons.

Description

Technical Field

[0001] The present invention belongs to the technical field of watermelon cultivation, and particularly relates to a method for reducing the incidence rate of watermelon under high temperature and humidity conditions. Background Art

[0002] Watermelon has a wide adaptability to soil, so it is widely planted in various regions of our country. China is a large consumer country of watermelon. The natural maturity period of watermelon is in summer. Since the southern region of the Yangtze River enters the plum rain season in summer, the soil humidity increases greatly. And watermelon is prone to an increase in the incidence rate under high temperature and humidity conditions. The main reasons are as follows: 1. The pathogens of diseases such as watermelon blight like high temperature and humidity environment, and the reproduction speed accelerates under high temperature and humidity conditions, and the number of bacteria increases rapidly; 2. The pathogens can be spread through rainwater, irrigation water and soil. Therefore, the humid and hot conditions provide favorable conditions for the growth and spread of pathogens. 3. The humid and hot environment will have a certain impact on the physiological functions of watermelon plants, such as weakened photosynthesis and enhanced respiration, resulting in a decrease in the stress resistance of watermelon and further increasing the risk of infection; 4. When the soil humidity is too high, the root respiration of the plants is inhibited, affecting the absorption and utilization of soil nutrients.

[0003] Therefore, how to reduce the incidence rate of watermelon under humid and hot conditions is an effective means to ensure the yield of watermelon. Summary of the Invention

[0004] To solve the above technical problems, the present invention proposes a method for reducing the incidence rate of watermelon under high temperature and humidity conditions. By simultaneously coating watermelon seeds and applying a soil conditioner to the soil, the adverse effects brought by high temperature and humidity conditions during the growth process of watermelon are effectively improved, the incidence rate is reduced, and thus the yield of watermelon is ensured.

[0005] The present invention adopts the following technical solutions to achieve the above object:

[0006] First, the present invention provides a method for reducing the incidence rate of watermelon under high temperature and humidity conditions. Before planting watermelon, while applying base fertilizer, a composite soil conditioner is used to improve the soil; before sowing watermelon, the seeds are first coated and then sown in the improved soil;

[0007] The composite soil conditioner includes the following components in parts by mass: 100 parts of calcined diatomite, 10 - 15 parts of perlite, 10 - 13 parts of bentonite, 8 - 10 parts of biochar, 5 - 8 parts of dried coconut coir, 20 - 30 parts of decomposed organic matter, and 5 - 8 parts of composite microbial inoculum.

[0008] The term "calcined diatomite" is prepared by calcining diatomite at high temperature. "Dried coconut coir" is prepared by drying coconut coir at high temperature. "Biochar" is obtained by pyrolyzing biomass materials at high temperature. Biomass materials include but are not limited to various plant straws, such as corn straws, wheat straws, rice husks, grass straws or leaves.

[0009] Diatomite is a porous siliceous biogenic sedimentary rock formed by the remains of diatomaceous earth. After calcination treatment, the pores formed inside it increase and expand, and the specific surface area is greatly improved, which can greatly improve the air permeability of the soil; bentonite has a porous structure and can expand after absorbing water, making the soil structure loose, improving the soil permeability, and at the same time having a high cation exchange capacity, which can absorb and retain nutrients in the soil and reduce nutrient loss; perlite has tiny pores inside, and the particle shape of perlite makes the pores between it and soil particles also increase accordingly. These pores and voids can quickly drain the water in the soil and reduce water retention. When the three components of calcined diatomite, perlite and bentonite are combined in a specific proportion, it can greatly improve the air permeability of the soil, which is beneficial to improving the adverse effects of high-humidity soil on the roots of watermelon. Biochar and dried coconut coir can increase the organic matter content of the soil. The increase in the organic matter content and the porosity of biochar and coconut coir also further improve the texture of the soil. The combination of the three can further optimize the soil environment. The compound microbial inoculant can be adsorbed inside the porous components and inhibit the growth and reproduction of pathogenic bacteria by means of competition, antagonism and induced resistance, thereby improving the disease resistance of watermelon.

[0010] The method for coating the seeds is as follows: Mix nano-white zeolite and trace elements and dissolve them in an aqueous solution of sodium alginate, chitosan and ethylene glycol. Add watermelon seeds, mix well, then fish them out and air-dry. The mass ratio of the nano-white zeolite to the trace elements is 10∶(3 - 5).

[0011] The large porosity structure of nano-white zeolite can adsorb trace elements, so that the trace elements can provide sufficient nutrients for watermelon seeds in the early stage. Sodium alginate and chitosan are mixed with ethylene glycol as the coating agent for watermelon seeds after being mixed in specific components. Ammonium alginate and chitosan are natural polymer materials with good biocompatibility and biodegradability, which can provide a suitable environment for seed germination. The addition of ethylene glycol can also adjust the permeability and moisture retention, promote seed germination, and at the same time, the mixture of the three components has good antibacterial properties, effectively avoiding the ability of watermelon seeds to resist pathogenic bacteria.

[0012] Preferably, the high-humidity soil in the southern region is usually acidic, which is not conducive to the growth of watermelon. Therefore, the compound soil conditioner of the present invention also includes a pH regulator, and the pH regulator is limestone powder. The addition amount of the pH regulator is to adjust the soil pH value to 6.0 - 7.

[0013] Preferably, the mass concentrations of sodium alginate, chitosan and ethylene glycol in the aqueous solution are 1-2%, 1-2% and 5-6% respectively.

[0014] Preferably, the total addition amount of the nano - clinoptilolite and trace elements in the aqueous solution is 8-10 wt.%.

[0015] Preferably, the preparation method of the calcined diatomite is to calcine diatomite at 500-600 °C for 1-2 h.

[0016] Preferably, the base fertilizer is decomposed organic matter; the decomposed organic matter is prepared by mixing animal manure and plant straw in a mass ratio of (2-3):10, decomposing for 1-2 weeks, and then drying and pulverizing to 10-20 mesh.

[0017] Preferably, the trace elements are copper, iron, manganese, zinc, boron and molybdenum. The ratio of trace elements can be formulated according to the conventional ratio of trace elements required by watermelon.

[0018] Preferably, the compound microbial inoculum includes Bacillus subtilis, Trichoderma viride, actinomycetes and Trichoderma harzianum; the content of each kind of bacteria is ≥ 1 billion / g.

[0019] Preferably, the mass ratio of the base fertilizer to the compound soil conditioner is 100:(4-6).

[0020] Bacillus subtilis directly destroys the hyphal structure of pathogenic bacteria by producing antibacterial substances such as lipopeptide antibiotics, thereby inhibiting the growth and reproduction of pathogenic bacteria. For watermelon fusarium wilt, Bacillus subtilis can significantly reduce the number of pathogenic bacteria such as Fusarium oxysporum around the watermelon roots and reduce the occurrence probability of fusarium wilt. Trichoderma viride can produce a variety of antibacterial substances, which have a significant inhibitory effect on pathogenic bacteria such as watermelon fusarium wilt. Trichoderma viride can invade the pathogenic bacteria colony and inhibit its growth and reproduction. Through this mechanism, the number of pathogenic bacteria around the watermelon roots is effectively reduced, thereby reducing the occurrence probability of diseases. Actinomycetes can produce a variety of antibacterial substances, which have a significant inhibitory effect on pathogenic bacteria such as watermelon fusarium wilt. By producing antibacterial active substances such as antibiotics and cell wall degrading enzymes, actinomycetes can destroy the cell wall and cell membrane of pathogenic bacteria, inhibit their growth and reproduction, and thus reduce the occurrence of watermelon diseases. Trichoderma harzianum can induce systemic resistance in watermelon plants, and this resistance mechanism can comprehensively activate the defense system of watermelon itself. When the watermelon plant is invaded by pathogenic bacteria, the systemic resistance can respond quickly and produce a series of defense - related proteins and enzymes, such as chitinase, β-1,3 - glucanase, etc., which can decompose the cell wall of pathogenic bacteria and thus effectively inhibit the growth and reproduction of pathogenic bacteria.

[0021] Second aspect, the present invention also provides a method for cultivating watermelons in a high humidity and high temperature climate. In the early stage, the method for reducing the incidence rate of watermelons under high humidity and high temperature conditions is used to reduce the incidence rate of watermelons, and in the later stage, conventional water and fertilizer management is carried out. In high humidity and high temperature areas, the rainfall is large, and the irrigation frequency can be reduced according to the soil conditions. Since the soil conditioner includes organic fertilizers and the improved soil reduces nutrient loss, the application amount of inorganic fertilizers is reduced by 20% - 40% according to the conventional dosage.

[0022] The present invention has the following technical effects:

[0023] The present invention coats watermelon seeds with a seed coating agent, which not only provides nutrients in the early stage but also improves the antibacterial performance, greatly improving the germination rate of watermelon seeds. At the same time, by improving the soil before sowing, while increasing the soil organic matter content, the soil structure is effectively improved. The addition of the compound microbial inoculant directly improves the disease resistance ability during the growth process of watermelons. The present invention uses multiple methods simultaneously and synergistically, and ensures the yield of watermelons by reducing the incidence rate of watermelons under high temperature and high humidity soil.

[0024] The method of the present invention is aimed at cultivating watermelons under high humidity and high temperature conditions. Using the method of the present invention can reduce the fertilizer application amount of watermelons, save costs greatly while ensuring the yield. Detailed implementation manners

[0025] The various exemplary implementation manners of the present invention are now described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0026] It should be understood that the terms described in the present invention are only for describing specific implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0027] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0028] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0029] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0030] The embodiment of the present invention discloses a method for reducing the incidence of watermelon under high humidity and heat conditions. Before planting watermelon, base fertilizer is applied and a composite soil conditioner is used to improve the soil; before sowing watermelon, the seeds are coated and then sown in the improved soil;

[0031] The composite soil conditioner comprises the following components by weight: 100 parts of calcined diatomaceous earth, 10-15 parts of perlite, 10-13 parts of bentonite, 8-10 parts of biochar, 5-8 parts of dried coconut bran and 5-8 parts of composite microbial agent.

[0032] The method for coating the seeds is as follows: mixing nano white zeolite and trace elements and dissolving them in an aqueous solution of sodium alginate, chitosan and ethylene glycol, adding watermelon seeds, mixing well, taking them out and air-drying them; the mass ratio of the nano white zeolite to the trace elements is 10:(3-5).

[0033] The preparation method of the composite soil conditioner may be simple physical blending in some embodiments. In other embodiments, the calcined diatomaceous earth, perlite and bentonite may be blended and then granulated, and then blended with other components. The granulation method is not limited and conventional technical means may be used.

[0034] The high humidity soil in the southern region is usually acidic, which is not conducive to the growth of watermelon. Therefore, in some preferred embodiments of the present invention, the composite soil conditioner also includes a pH regulator, which is limestone powder, and the amount of the pH regulator added is such that the soil pH value is adjusted to 6.0 to 7. If it is a coastal area, the soil is alkaline, and humic acid can also be used to adjust the pH value to 6.0 to 7.

[0035] Preferably, the mass concentrations of the sodium alginate, chitosan and ethylene glycol in the aqueous solution are 1-2%, 1-2% and 5-6%, respectively.

[0036] Preferably, the total amount of the nano white zeolite and trace elements added to the aqueous solution is 8-10 wt.%.

[0037] Preferably, the calcined diatomite is prepared by calcining diatomite at 500 - 600 °C for 1 - 2 h.

[0038] Preferably, the base fertilizer is decomposed organic matter; the decomposed organic matter is prepared by mixing animal manure and plant straw in a mass ratio of (2 - 3):10, composting for 1 - 2 weeks, and then drying and pulverizing to 10 - 20 mesh.

[0039] Preferably, the trace elements are copper, iron, manganese, zinc, boron, and molybdenum. The ratio of trace elements can be prepared according to the conventional ratio required by watermelon. It can be prepared by oneself or directly purchase products of compound trace elements.

[0040] Preferably, the compound microbial inoculum includes Bacillus subtilis, Trichoderma viride, actinomycetes, and Trichoderma harzianum; the content of each bacterium is ≥ 100 million / g of mold.

[0041] In some preferred embodiments, the mass ratio of the base fertilizer to the compound soil conditioner is 100:(4 - 86).

[0042] The embodiment of the present invention also discloses a method for planting watermelon in a high - humidity and high - temperature climate. In the early stage, the method for reducing the incidence rate of watermelon under high - humidity and high - temperature conditions is used to reduce the incidence rate of watermelon, and in the later stage, conventional water and fertilizer management is carried out. In high - humidity and high - temperature areas, the rainfall is large, and the irrigation frequency can be reduced according to the soil conditions. Since the soil conditioner includes organic fertilizers and the improved soil reduces nutrient loss, the application amount of inorganic fertilizers is reduced by 20% - 40% with reference to the conventional dosage.

[0043] In the embodiments of the present invention, "parts" are "parts by mass" unless otherwise specified.

[0044] In the following examples, the biochar is corn straw biochar; the decomposed organic matter is prepared by mixing chicken manure, cow manure, rice bran, and corn straw in equal mass, composting for 2 weeks, and then drying and pulverizing.

[0045] In the compound microorganisms, Bacillus subtilis is purchased from Jinan Jinyuan Biotechnology Co., Ltd., 100 billion / g;

[0046] Trichoderma viride is purchased from Shandong Nuojie Biotechnology Co., Ltd., 10 billion / g;

[0047] Actinomycetes are purchased from Shandong Zhongkangyuan Biotechnology Co., Ltd., 10 billion / g;

[0048] Trichoderma harzianum is purchased from Shandong Dehe Mingxing Biotechnology Co., Ltd., ≥ 100 million / g of mold.

[0049] The compound microbial inoculum is prepared by mixing the above four microbial inoculants in equal mass.

[0050] Trace elements include copper, iron, manganese, zinc, boron and molybdenum, which are compound trace elements purchased from Zhengzhou Zhengyan Biotechnology Co., Ltd.

[0051] Preparation method of calcined diatomite: The diatomite is calcined at 600 °C for 1.5 h, cooled and then crushed through a 50-mesh sieve.

[0052] In the following examples, the planting area is selected from a suburb of Shanghai. The soil is slightly acidic with a pH value of 5.5. First, sprinkle limestone powder on the planting area, and after deep plowing later, mix it with the soil. The application amount of limestone powder is such that the soil pH reaches 6 - 7.

[0053] Example 1

[0054] A method for reducing the incidence of watermelon under high humidity and heat conditions, comprising the following steps:

[0055] S1. Dissolve sodium alginate, chitosan and ethylene glycol in water, and their concentrations in the aqueous solution (mass concentration, the same below) are 2%, 1.5% and 5.5% respectively;

[0056] S2. Weigh nano - white zeolite and trace elements according to a mass ratio of 10∶3, mix them and dissolve them in the above - mentioned aqueous solution. The total addition amount of nano - white zeolite and trace elements in the aqueous solution is 10 wt.%. Add watermelon seeds, soak for 30 min and then take them out and air - dry for later use;

[0057] S3. Prepare a composite soil conditioner according to the following weight parts: 100 parts of calcined diatomite, 10 parts of perlite, 10 parts of bentonite, 8 parts of biomass charcoal, 8 parts of dry coconut coir and 5 parts of composite microbial inoculant.

[0058] S4. Deep - plow the soil (more than 30 cm), and apply the decomposed organic matter and the composite soil conditioner together to the soil by broadcasting. The application amount of the decomposed organic matter is 1500 kg / mu, and the application amount of the composite soil conditioner is 75 kg / mu;

[0059] S5. Plant watermelon seeds;

[0060] S6. Top - dress: When the watermelon seedlings grow to 2 - 3 true leaves, apply 2 kg / mu of urea; after the watermelon vines extend, top - dress with a nitrogen - phosphorus - potassium compound fertilizer, 5 kg / mu; when the young watermelon fruits grow to the size of an egg, top - dress with a melon - swelling fertilizer (commercially available nitrate - sulfur - based compound fertilizer) 10 kg / mu. During this period, carry out routine daily management (without using chemical methods to prevent and control diseases).

[0061] Example 2

[0062] A method for reducing the incidence of watermelon under high humidity and heat conditions, comprising the following steps:

[0063] S1. The same as in Example 1;

[0064] S2. Weigh nano - clinoptilolite and trace elements according to the mass ratio of 10∶5, mix them and dissolve them in the above - mentioned aqueous solution, where the total addition amount of nano - clinoptilolite and trace elements in the aqueous solution is 10 wt.%.

[0065] S3 - S6. The same as in Example 1.

[0066] Example 3

[0067] A method for reducing the incidence rate of watermelons under high - humidity and high - temperature conditions, comprising the following steps:

[0068] S1. The same as in Example 1;

[0069] S2. Weigh nano - clinoptilolite and trace elements according to the mass ratio of 10∶4, mix them and dissolve them in the above - mentioned aqueous solution, where the total addition amount of nano - clinoptilolite and trace elements in the aqueous solution is 10 wt.%.

[0070] S3 - S6. The same as in Example 1.

[0071] Example 4

[0072] A method for reducing the incidence rate of watermelons under high - humidity and high - temperature conditions, comprising the following steps:

[0073] S1 - S2. The same as in Example 1;

[0074] S3. Prepare a composite soil conditioner according to the following weight parts: 100 parts of calcined diatomite, 15 parts of perlite, 13 parts of bentonite, 9 parts of biomass charcoal, 5 parts of dried coconut coir and 8 parts of composite microbial inoculum.

[0075] S4 - S6. The same as in Example 1.

[0076] Example 5

[0077] A method for reducing the incidence rate of watermelons under high - humidity and high - temperature conditions, comprising the following steps:

[0078] S1 - S2. The same as in Example 1;

[0079] S3. Prepare a composite soil conditioner according to the following weight parts: 100 parts of calcined diatomite, 12 parts of perlite, 10 parts of bentonite, 10 parts of biomass charcoal, 8 parts of dried coconut coir and 6 parts of composite microbial inoculum.

[0080] S4 - S6. The same as in Example 1.

[0081] Example 6

[0082] A method for reducing the incidence rate of watermelons under high - humidity and high - temperature conditions is the same as in Example 1, except that in step S4, the application amount of the composite soil conditioner is 60 kg / mu.

[0083] Example 7

[0084] A method for reducing the incidence rate of watermelon under high humidity and heat conditions is the same as that in Example 1, except that in step S4, the application amount of the composite soil conditioner is 90 kg / mu.

[0085] Comparative Example 1

[0086] It is the same as Example 1, except that perlite and bentonite are replaced with calcined diatomaceous earth in equal mass.

[0087] Comparative Example 2

[0088] It is the same as Example 1, except that bentonite is replaced with perlite in equal mass.

[0089] Comparative Example 3

[0090] It is the same as Example 1, except that calcined diatomaceous earth is replaced with diatomaceous earth.

[0091] Comparative Example 4

[0092] It is the same as Example 1, except that calcined diatomaceous earth, perlite and bentonite are replaced with fine river sand in equal mass.

[0093] Comparative Example 5

[0094] It is the same as Example 1, except that dry coconut coir and biomass charcoal are replaced with decomposed organic matter in equal mass.

[0095] Comparative Example 6

[0096] It is the same as Example 1, except that the addition of nano - clinoptilolite is omitted during watermelon seed coating.

[0097] Comparative Example 7

[0098] It is the same as Example 1, except that the watermelon seeds are not coated.

[0099] Use the methods of the above Examples 1 - 6 and Comparative Examples 1 - 7 to plant watermelons. The planting experimental area is selected from a suburb of Shanghai. This area enters the plum rain season in mid - June, and the total precipitation during the entire plum rain season is 338.0 mm. Divide the planting experimental area into 15 small plots evenly, and the size of each experimental plot is 667 m 2 , and randomly use the methods of the above Examples 1 - 7 and Comparative Examples 1 - 7 to plant watermelons respectively. In addition, set a blank control (on the basis of Example 1, omit the composite soil conditioner). The watermelon variety for planting is Kirin, the cultivation method is open - field cultivation, the sowing time is mid - April 2023, the harvesting time is from early July to mid - July, and the planting density is 700 plants / mu. Statistically analyze the growth and harvesting of watermelons in each plot, and the results are shown in Table 1.

[0100] Table 1 Statistics of watermelon incidence and yield results

[0101]

[0102]

[0103] Note: The calculation method of incidence rate is: number of diseased plants / 700×100%; the number of diseased plants refers to the number of plants infected with various pathogens and suffering from diseases.

[0104] As can be seen from Table 1, compared with the blank control group, the planting methods of Examples 1-7 can achieve an increase in yield by reducing the incidence of watermelon plants, especially in Example 7, the incidence is only 2%, the yield per mu reaches 3718kg / mu, and the single fruit weight is greater than 7 jin. Comparative Examples 1-3 changed the ratio of calcined diatomaceous earth, bentonite and perlite, which slightly increased the incidence and affected the yield. Comparative Example 4 directly replaced it with fine river sand, which greatly increased the incidence of watermelon, and both the single fruit weight and the yield per mu decreased significantly. Comparative Examples 6 and 7 changed the coating treatment method for watermelon seeds, which significantly reduced the incidence of watermelon plants, and the yield and single fruit weight also decreased significantly.

[0105] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for reducing the incidence of watermelon under high humidity and heat conditions, characterized in that: Before planting watermelons, apply base fertilizer and use compound soil conditioner to improve the soil; before sowing watermelons, coat the seeds and then sow them in the improved soil; The composite soil conditioner comprises the following components by weight: 100 parts of calcined diatomite, 10-15 parts of perlite, 10-13 parts of bentonite, 8-10 parts of biochar, 5-8 parts of dried coconut bran and 5-8 parts of composite microbial agent; The method for coating the seeds is as follows: mixing nano white zeolite and trace elements and dissolving them in an aqueous solution of sodium alginate, chitosan and ethylene glycol, adding watermelon seeds, mixing well, taking them out and air-drying them; the mass ratio of the nano white zeolite to the trace elements is 10:(3-5); The composite soil conditioner also includes a pH regulator, which is limestone powder, and the amount of the pH regulator added is such that the soil pH value is adjusted to 6.0 to 7; The preparation method of the calcined diatomite is to calcine the diatomite at 500-600° C. for 1-2 hours.

2. The method for reducing the incidence of watermelon under high humidity and heat conditions according to claim 1, characterized in that: The mass concentrations of the sodium alginate, chitosan and ethylene glycol in the aqueous solution are 1-2%, 1-2% and 5-6% respectively.

3. The method for reducing the incidence of watermelon under high humidity and heat conditions according to claim 1, characterized in that: The total amount of the nano white zeolite and trace elements added to the aqueous solution is 8-10 wt.%.

4. The method for reducing the incidence of watermelon under high humidity and heat conditions according to claim 1, characterized in that: The base fertilizer is decomposed organic matter; the decomposed organic matter is prepared by mixing animal excrement and plant straw in a mass ratio of (2-3):10, decomposing for 1-2 weeks, and then drying and crushing to 10-20 meshes.

5. The method for reducing the incidence of watermelon under high humidity and heat conditions according to claim 1, characterized in that: The trace elements are copper, iron, manganese, zinc, boron and molybdenum.

6. The method for reducing the morbidity of watermelon under high humidity and heat conditions according to claim 1, characterized in that: The composite microbial agent comprises Bacillus subtilis, Trichoderma viride, actinomycetes and Trichoderma harzianum; the content of each fungus is ≥1 billion / g.

7. The method for reducing the incidence of watermelon under high humidity and heat conditions according to claim 1, characterized in that: The mass ratio of the base fertilizer to the composite soil conditioner is 100:(4-6).

8. A method for growing watermelons in a hot and humid climate, characterized in that: In the early stage, the method for reducing the incidence of watermelon under high humidity and heat conditions as described in any one of claims 1 to 7 is used to reduce the incidence of watermelon, and in the later stage, conventional water and fertilizer management is carried out.

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