Strawberry nutrient solution and application thereof

Abstract

The present application relates to the technical field of plant cultivation, and particularly discloses a kind of strawberry nutrient solution and application thereof, the strawberry nutrient solution includes nutrient solution A, nutrient solution B, nutrient solution C and biocontrol agent, the biocontrol agent is 3-8x10 7 CFU / mL of bacillus siamensis bacterial liquid. The strawberry nutrient solution provided by the present application can not only promote the growth and development of strawberry, significantly increase the plant height, stem diameter and leaf area of strawberry, but also improve the quality and yield of strawberry. It also has a control effect on strawberry leaf spot and strawberry anthracnose.

Description

Technical Field

[0001] This invention relates to the field of plant cultivation technology, specifically to a strawberry nutrient solution and its application. Background Technology

[0002] Strawberry (Fragaria × ananassa Duch.) is a perennial herbaceous plant belonging to the genus Fragaria in the family Rosaceae. Strawberry plants have shallow root systems, and their stems can be divided into new stems, rhizomes, and stolons. Strawberry leaves are basal trifoliate compound leaves with long petioles. The vast majority of flowers are bisexual, and the inflorescence is a determinate cyme.

[0003] Strawberries possess high nutritional, medicinal, and ecological value. Fragrant, juicy, and rich in nutrients, strawberries are known as the "Queen of Fruits" and are among the earliest fruits to ripen, earning them the nickname "First Fruit of Early Spring." Strawberries contain high levels of vitamins, calcium, phosphorus, iron, and other nutrients. They also contain numerous active substances that can quench thirst, aid digestion, and provide certain medicinal benefits, as documented in literature. Strawberries are also used as ornamental and landscaping plants and have become a crop contributing to economic development.

[0004] Strawberry leaf spot, also known as strawberry white spot disease or snake eye disease, is a common fungal disease that primarily affects strawberry leaves. Initially, it appears as water-soaked, reddish-brown, irregularly shaped lesions on the lower surface of the leaves. As the lesions enlarge, they become angular due to the confinement of fine leaf veins, hence the name angular leaf spot. Infected leaves often dry out and break apart. In severe cases, the growing point of the plant turns black and dies.

[0005] Most strawberry nutrient solutions on the market are based on potassium fertilizer, and their single composition makes it difficult to meet the needs of strawberry growth and development throughout the entire period. Furthermore, they are difficult to effectively prevent and control diseases that occur during the growth of strawberries, which seriously affects the final yield and quality of strawberries. Summary of the Invention

[0006] To develop a new strawberry nutrient solution that can both meet the nutritional needs of strawberry growth and development and prevent and control diseases, this invention provides a strawberry nutrient solution, its preparation method, and its application. The strawberry nutrient solution provided by this invention can not only promote the growth and development of strawberries, significantly increase strawberry plant height, stem diameter, and leaf area, but also prevent and control strawberry leaf spot and strawberry anthracnose.

[0007] This invention provides a strawberry nutrient solution, which is composed of nutrient solution A, nutrient solution B, nutrient solution C and a biocontrol agent;

[0008] The nutrient solution is prepared by mixing nutrient solution A, nutrient solution B, nutrient solution C and water in a volume ratio of 2.5-5:2.5-5:2.5-5:1000.

[0009] Every 1000L of the nutrient solution A comprises the following raw materials in the following weight-to-volume ratio: 10-18g / L ammonium calcium nitrate (5Ca(NO3)2NH4NO3·10H2O), 9-10g / L potassium nitrate (KNO3), 4-5g / L potassium chloride, 1.2-1.55g / L iron fertilizer, with the remainder being water;

[0010] Every 1000L of the nutrient solution B comprises the following raw materials in the following weight-to-volume ratio: 8-10g / L magnesium sulfate, 5-6g / L potassium dihydrogen phosphate, 2-3g / L potassium nitrate, 4-13g / L potassium sulfate, 0.17-0.4g / L manganese, 0.06-0.12g / L zinc, 0.08-0.16g / L boron, 0.01-0.02g / L copper, 0.01-0.012g / L ammonium molybdate, with the balance being water;

[0011] Every 1000L of the nutrient solution C comprises the following raw materials in the following weight-volume ratio: 1.5-2.5mL / L nitric acid, with the remainder being water;

[0012] The biocontrol agent has a viable bacterial count of 5-8 x 10. 7 CFU / mL Bacillus sicca bacterial suspension.

[0013] Furthermore, each 1000L of the nutrient solution A comprises the following raw materials in the following weight-volume ratio: 18g / L ammonium calcium nitrate (5Ca(NO3)2NH4NO3·10H2O), 10g / L potassium nitrate (KNO3), 5g / L potassium chloride (KCl), 1.55g / L iron (Fe-EDTA, wherein the Fe content is 6%), and the balance being water.

[0014] Furthermore, each 1000L nutrient solution B comprises the following raw materials in the following weight-to-volume ratio: 10g / L magnesium sulfate (MgSO4·7H2O), 6g / L potassium dihydrogen phosphate (KH2PO4), 3g / L potassium nitrate (KNO3), 13g / L potassium sulfate (K2SO4), 0.4g / L manganese (MnSO4), 0.12g / L zinc (ZnSO4), 0.16g / L boron (H3BO3), 0.02g / L copper (CuSO4), 0.012g / L ammonium molybdate (H8MoN2O4), with the remainder being water.

[0015] Furthermore, each 1000L nutrient solution C includes the following raw materials in the following weight-to-volume ratio: 2.5mL / L nitric acid (HNO3), with the remainder being water.

[0016] Furthermore, the biocontrol agent has a viable count of 8 x 10⁻⁶. 7 CFU / mL Bacillus sicca bacterial suspension.

[0017] Further, the preparation process of the *Bacillus sicca* bacterial culture is as follows: *Bacillus sicca* is inoculated onto LB solid plates for purification and cultured at 37-38℃ for 23-24 hours, and subcultured three times. Then, a single colony is picked and inoculated into fresh LB liquid medium and cultured at 37-38℃ and 170-180 rpm for 23-24 hours. The concentration of *Bacillus sicca* bacterial culture is adjusted to 8 × 10 using LB liquid medium. 7 CFU / mL was used to obtain a biocontrol agent.

[0018] The present invention also provides the application of the strawberry nutrient solution in strawberry cultivation, which can promote the growth and development of strawberry plants and prevent plant diseases.

[0019] Furthermore, the strawberry nutrient solution can increase strawberry plant height, stem diameter, and leaf area.

[0020] Furthermore, the plant diseases mentioned include, but are not limited to, strawberry leaf spot and strawberry anthracnose.

[0021] Furthermore, the pathogen of strawberry leaf spot disease is Xanthomonas fragarice, and the pathogen of strawberry anthracnose is Colletotrichum gloeosporioides.

[0022] Furthermore, the strawberry nutrient solution can also inhibit the growth of pathogens.

[0023] Furthermore, the pathogens include Xanthomonas fragarice, Colletotrichum gloeosporioides, Fusarium solani, and Cylindrocarpon destructans.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. The strawberry nutrient solution provided by this invention has a reasonable ratio of macro- and micro-elements. The formula may seem simple, but the perfect ratio of each element has a significant regulatory effect on the growth and development of strawberries. Combined with biocontrol agents, it promotes the growth and development of strawberries and is also beneficial for disease control.

[0026] The strawberry nutrient solution of this invention can not only promote the growth and development of strawberries, significantly increase strawberry plant height, stem diameter and leaf area, but also has a preventive and control effect on strawberry leaf spot and strawberry anthracnose, with a control efficacy of 76.9% against strawberry bacterial leaf spot. Detailed Implementation

[0027] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods described in the embodiments of the present invention are conventional methods, and the materials and reagents used in the following embodiments are commercially available unless otherwise specified.

[0028] Example 1: A strawberry nutrient solution.

[0029] Strawberry nutrient solution consists of a nutrient mixture and a biocontrol agent;

[0030] The nutrient solution is prepared by mixing 2894 mL of nutrient solution A, 2894 mL of nutrient solution B, 2894 mL of nutrient solution C, and 1000 L of water.

[0031] The nutrient solution A is a calcium salt mixed solution, the nutrient solution B is a phosphate mixed solution, and the nutrient solution C is an acid solution;

[0032] Every 1000L of nutrient solution A includes the following raw materials in the following weight-to-volume ratio: 18g / L ammonium calcium nitrate (5Ca(NO3)2NH4NO3·10H2O), 10g / L potassium nitrate (KNO3), 5g / L potassium chloride (KCl), 1.55g / L Fe-EDTA (of which the Fe content is 6%), and the remainder is water;

[0033] Each 1000L nutrient solution B contains the following raw materials in the following weight-to-volume ratio: 10g / L magnesium sulfate (MgSO4·7H2O), 6g / L potassium dihydrogen phosphate (KH2PO4), 3g / L potassium nitrate (KNO3), 13g / L potassium sulfate (K2SO4), 0.4g / L manganese (MnSO4), 0.12g / L zinc (ZnSO4), 0.16g / L boron (H3BO3), 0.02g / L copper (CuSO4), 0.012g / L ammonium molybdate (H8MoN2O4), with the remainder being water;

[0034] Every 1000L of nutrient solution C includes the following raw materials in the following weight-to-volume ratio: 2.5mL / L nitric acid (HNO3), with the remainder being water;

[0035] The biocontrol agent has a viable count of 8 x 10. 7 CFU / mL Bacillus sicca bacterial suspension: Bacillus sicca (CGMCC NO. 12903) was inoculated onto LB agar plates for purification and cultured at 37°C for 24 h. This process was repeated three times. Then, single colonies were picked and inoculated into fresh LB liquid medium and cultured at 37°C and 180 rpm for 24 h. The concentration of Bacillus sicca was adjusted to 8 × 10 using LB liquid medium.7 CFU / mL was used to obtain a biocontrol agent.

[0036] Example 2: A strawberry nutrient solution.

[0037] Strawberry nutrient solution consists of a nutrient mixture and a biocontrol agent;

[0038] The nutrient solution is prepared by mixing 2500 mL of nutrient solution A, 2500 mL of nutrient solution B, 2500 mL of nutrient solution C and 1000 L of water.

[0039] The nutrient solution A is a calcium salt mixed solution, the nutrient solution B is a phosphate mixed solution, and the nutrient solution C is an acid solution;

[0040] Every 1000L of nutrient solution A contains the following raw materials in the following weight-to-volume ratio: 10g / L ammonium calcium nitrate (5Ca(NO3)2NH4NO3·10H2O), 9g / L potassium nitrate (KNO3), 4g / L potassium chloride, 1.2g / L Fe-EDTA (of which the Fe content is 6%), and the remainder is water;

[0041] Each 1000L nutrient solution B contains the following raw materials in the following weight-to-volume ratio: 8g / L magnesium sulfate (MgSO4·7H2O), 5g / L potassium dihydrogen phosphate (KH2PO4), 2g / L potassium nitrate (KNO3), 4g / L potassium sulfate (K2SO4), 0.17g / L manganese (MnSO4), 0.06g / L zinc (ZnSO4), 0.08g / L boron (H3BO3), 0.01g / L copper (CuSO4), 0.01g / L ammonium molybdate (H8MoN2O4), with the remainder being water;

[0042] Each 1000L nutrient solution C includes the following raw materials in the following weight-to-volume ratio: 1.5mL / L nitric acid (HNO3), with the remainder being water;

[0043] The biocontrol agent has a viable count of 5 x 10. 7 CFU / mL Bacillus sicca bacterial culture: Bacillus sicca (CGMCC NO. 12903) was inoculated onto LB agar plates for purification and cultured at 37°C for 24 h. This process was repeated three times. Single colonies were then picked and inoculated into fresh LB liquid medium and cultured at 37°C and 180 rpm for 24 h. The concentration of Bacillus sicca was adjusted to 5 × 10⁻⁶ using LB liquid medium. 7 CFU / mL was used to obtain a biocontrol agent;

[0044] Example 3: A strawberry nutrient solution.

[0045] Strawberry nutrient solution consists of a nutrient mixture and a biocontrol agent;

[0046] The nutrient solution is prepared by mixing 3000 mL of nutrient solution A, 3000 mL of nutrient solution B, 3000 mL of nutrient solution C and 1000 L of water.

[0047] The nutrient solution A is a calcium salt mixed solution, the nutrient solution B is a phosphate mixed solution, and the nutrient solution C is an acid solution;

[0048] Every 1000L of nutrient solution A contains the following raw materials in the following weight-to-volume ratio: 14g / L ammonium calcium nitrate (5Ca(NO3)2NH4NO3·10H2O), 9.5g / L potassium nitrate (KNO3), 4.5g / L potassium chloride, 1.35g / L Fe-EDTA (of which the Fe content is 6%), with the remainder being water;

[0049] Each 1000L nutrient solution B contains the following raw materials in the following weight-to-volume ratio: 9g / L magnesium sulfate (MgSO4·7H2O), 5.5g / L potassium dihydrogen phosphate (KH2PO4), 2.5g / L potassium nitrate (KNO3), 9g / L potassium sulfate (K2SO4), 0.3g / L manganese (MnSO4), 0.09g / L zinc (ZnSO4), 0.12g / L boron (H3BO3), 0.02g / L copper (CuSO4), 0.012g / L ammonium molybdate (H8MoN2O4), with the remainder being water;

[0050] Each 1000L nutrient solution C contains the following raw materials in the following weight-to-volume ratio: 2mL / L nitric acid (HNO3), with the remainder being water;

[0051] The biocontrol agent has a viable count of 6 x 10. 7 CFU / mL Bacillus sicca bacterial suspension: Bacillus sicca (CGMCC NO. 12903) was inoculated onto LB agar plates for purification and cultured at 37°C for 24 h. This process was repeated three times. Single colonies were then picked and inoculated into fresh LB liquid medium and cultured at 37°C and 180 rpm for 24 h. The concentration of Bacillus sicca was adjusted to 6 × 10 using LB liquid medium. 7 CFU / mL was used to obtain a biocontrol agent.

[0052] Example 4: A strawberry nutrient solution.

[0053] Strawberry nutrient solution consists of a nutrient mixture and a biocontrol agent;

[0054] The nutrient solution is prepared by mixing 3500 mL of nutrient solution A, 3500 mL of nutrient solution B, 3500 mL of nutrient solution C, and 1000 L of water.

[0055] The nutrient solution A is a calcium salt mixed solution, the nutrient solution B is a phosphate mixed solution, and the nutrient solution C is an acid solution;

[0056] Every 1000L of nutrient solution A contains the following raw materials in the following weight-to-volume ratio: 15g / L ammonium calcium nitrate (5Ca(NO3)2NH4NO3·10H2O), 9g / L potassium nitrate (KNO3), 5g / L potassium chloride, 1.25g / L Fe-EDTA (of which the Fe content is 6%), and the remainder is water;

[0057] Each 1000L nutrient solution B contains the following raw materials in the following weight-to-volume ratio: 8g / L magnesium sulfate (MgSO4·7H2O), 6g / L potassium dihydrogen phosphate (KH2PO4), 3g / L potassium nitrate (KNO3), 11g / L potassium sulfate (K2SO4), 0.19g / L manganese (MnSO4), 0.08g / L zinc (ZnSO4), 0.09g / L boron (H3BO3), 0.02g / L copper (CuSO4), 0.012g / L ammonium molybdate (H8MoN2O4), with the remainder being water;

[0058] Each 1000L nutrient solution C includes the following raw materials in the following weight-to-volume ratio: 1.8mL / L nitric acid (HNO3), with the remainder being water;

[0059] The biocontrol agent has a viable count of 6 x 10. 7 CFU / mL Bacillus sicca bacterial suspension: Bacillus sicca (CGMCC NO. 12903) was inoculated onto LB agar plates for purification and cultured at 37°C for 24 h. This process was repeated three times. Single colonies were then picked and inoculated into fresh LB liquid medium and cultured at 37°C and 180 rpm for 24 h. The concentration of Bacillus sicca was adjusted to 6 × 10 using LB liquid medium. 7 CFU / mL was used to obtain a biocontrol agent.

[0060] Example 5: A strawberry nutrient solution.

[0061] Strawberry nutrient solution consists of a nutrient mixture and a biocontrol agent;

[0062] The nutrient solution is prepared by mixing 3500 mL of nutrient solution A, 3500 mL of nutrient solution B, 3500 mL of nutrient solution C, and 1000 L of water.

[0063] The nutrient solution A is a calcium salt mixed solution, the nutrient solution B is a phosphate mixed solution, and the nutrient solution C is an acid solution;

[0064] Every 1000L of nutrient solution A contains the following raw materials in the following weight-to-volume ratio: 15g / L ammonium calcium nitrate (5Ca(NO3)2NH4NO3·10H2O), 9.3g / L potassium nitrate (KNO3), 4.5g / L potassium chloride, 1.5g / L Fe-EDTA (of which the Fe content is 6%), and the remainder is water;

[0065] Each 1000L nutrient solution B contains the following raw materials in the following weight-to-volume ratio: 10g / L magnesium sulfate (MgSO4·7H2O), 5g / L potassium dihydrogen phosphate (KH2PO4), 2g / L potassium nitrate (KNO3), 8g / L potassium sulfate (K2SO4), 0.3g / L manganese (MnSO4), 0.1g / L zinc (ZnSO4), 0.12g / L boron (H3BO3), 0.01g / L copper (CuSO4), 0.012g / L ammonium molybdate (H8MoN2O4), with the remainder being water;

[0066] Every 1000L of nutrient solution C includes the following raw materials in the following weight-to-volume ratio: 2.5mL / L nitric acid (HNO3), with the remainder being water;

[0067] The biocontrol agent has a viable count of 8 x 10. 7 CFU / mL Bacillus sicca bacterial suspension: Bacillus sicca (CGMCC NO. 12903) was inoculated onto LB agar plates for purification and cultured at 37°C for 24 h. This process was repeated three times. Then, single colonies were picked and inoculated into fresh LB liquid medium and cultured at 37°C and 180 rpm for 24 h. The concentration of Bacillus sicca was adjusted to 8 × 10 using LB liquid medium. 7 CFU / mL was used to obtain a biocontrol agent.

[0068] Comparative Example 1: A strawberry nutrient solution.

[0069] The strawberry nutrient solution provided in Comparative Example 1 was prepared by mixing 2894 mL of nutrient solution A, 2894 mL of nutrient solution B, 2894 mL of nutrient solution C, and 1000 L of water; it does not contain any biocontrol agents.

[0070] The nutrient solution A, nutrient solution B and nutrient solution C are all the same as the components in Example 1.

[0071] Comparative Example 2: A strawberry nutrient solution.

[0072] The strawberry nutrient solution provided in Comparative Example 2 was prepared by mixing 2894 mL of nutrient solution A, 2894 mL of nutrient solution B, and 1000 L of water; it does not contain biocontrol agents.

[0073] The nutrient solution A and nutrient solution B are both consistent with the components of Example 1.

[0074] Comparative Example 3: A strawberry nutrient solution.

[0075] The strawberry nutrient solution provided in Comparative Example 3 was prepared by mixing 2894 mL of nutrient solution A, 2894 mL of nutrient solution C, and 1000 L of water; it does not contain biocontrol agents.

[0076] Nutrient solution A and nutrient solution C are both identical to the components in Example 1.

[0077] Comparative Example 4: A strawberry nutrient solution.

[0078] The strawberry nutrient solution provided in Comparative Example 4 was prepared by mixing 2894 mL of nutrient solution B, 2894 mL of nutrient solution C, and 1000 L of water; it does not contain biocontrol agents.

[0079] Nutrient solution B and nutrient solution C are both identical to the components in Example 1.

[0080] Comparative Example 5: A strawberry nutrient solution.

[0081] The strawberry nutrient solution provided in Comparative Example 5 consists of a nutrient mixture and a biocontrol agent.

[0082] The nutrient solution is prepared by mixing 2894 mL of nutrient solution A, 2894 mL of nutrient solution B, and 1000 L of water.

[0083] Nutrient solution A and nutrient solution B are identical to those in Example 1. The biocontrol agent is the same as in Example 1.

[0084] Comparative Example 6: A strawberry nutrient solution.

[0085] The strawberry nutrient solution provided in Comparative Example 6 consists of a nutrient mixture and a biocontrol agent.

[0086] The nutrient solution is prepared by mixing 2894 mL of nutrient solution A, 2894 mL of nutrient solution C, and 1000 L of water.

[0087] Nutrient solution A and nutrient solution C are identical to those in Example 1. The biocontrol agent is the same as in Example 1.

[0088] Comparative Example 7: A strawberry nutrient solution.

[0089] The strawberry nutrient solution provided in Comparative Example 7 consists of a nutrient mixture and a biocontrol agent.

[0090] The nutrient solution is prepared by mixing 2894 mL of nutrient solution B, 2894 mL of nutrient solution C, and 1000 L of water.

[0091] Nutrient solution B and nutrient solution C are identical to those in Example 1. The biocontrol agent is the same as in Example 1.

[0092] The effects of strawberry nutrient solutions prepared using Examples 1-5 and Comparative Examples 1-7 on strawberry growth, development, and disease resistance were studied. Specific experimental methods are shown below:

[0093] I. Experimental Materials and Methods

[0094] The pot experiment was conducted in a greenhouse at the Jilin Academy of Agricultural Sciences from September 2017 to May 2018. The field experiment was conducted from September 2018 to March 2024 at fruit and vegetable bases in Gongzhuling Vegetable Safety Production Nursery of the Jilin Academy of Agricultural Sciences, Ningjiang District of Songyuan City, Rangzi Town and Dabusu Town of Qian'an County of Songyuan City, Leshan Town of Yitong County of Changchun City, Fanjiatun Town of Changchun City, and Shuangyang District of Changchun City.

[0095] 1. Test materials

[0096] (1) Nutrient solution:

[0097] The strawberry nutrient solutions prepared in Examples 1-8 and Comparative Examples 1-6.

[0098] (2) Strawberry tested: Sui-type strawberry;

[0099] Strawberry cultivation substrate: The strawberry culture substrate used in this invention is REMMY buffered coir pith from India, purchased from Qingdao REMMY Trading Co., Ltd.

[0100] Prepare as needed for use: spray water washing desalination, particle size 0-6 mm, EC: <0.3 mS / cm, pH: 5.8-7.0, Na(BaCl2-H2O) <1.0 mmol / L, K(BaCl2-H2O) <2.0 mmol / L, water content: <18%.

[0101] (3) Test strains

[0102] The *Bacillus sicca* strain was provided by the Jilin Academy of Agricultural Sciences, with accession number CGMCCNO.12903.

[0103] Pathogens: *Colletotrichum gloeosporioides* ATCC12097; *Xanthomonas fragarice* preserved by Jilin Academy of Agricultural Sciences; *Fusarium solani* purchased from Shanghai Guyan Industrial Co., Ltd.; *Cylindrocarpon destructans*, the causal agent of ginseng rust, was provided by Jilin Agricultural University and described in the journal (Bai Ronglin. Research on Integrated Control of Ginseng Rust [J]. Chinese Agricultural Science).

[0104] 2. The cultivation process of strawberries

[0105] The strawberry nutrient solutions prepared in Examples 1-8 were all used to irrigate the strawberries according to the following methods;

[0106] Distribute the strawberry cultivation substrate into round pots measuring 16.5cm × 30cm × 16.6cm (bottom diameter × top diameter × height), filling the substrate to 2 / 3 of the pot's height. Transplant strawberries of similar growth stages into the pots, planting 3 plants per pot, for a total of 3 pots. Transplant the strawberries after they have developed 3 true leaves. Two days after transplanting, begin drip irrigation with the prepared nutrient solution mixture at a rate of 1 minute per 667 square meters. Every two days, increase the amount of nutrient solution A, B, and C by 400mL each before drip irrigation, continuing this process until a total increase of 1600mL is reached. Repeat this cycle until the entire strawberry growth cycle is complete.

[0107] The biocontrol agent was sprayed on the leaves 16 days after transplanting at a rate of 3L / acre, and then sprayed again at the same rate after a one-week interval.

[0108] For the strawberry nutrient solution in Comparative Examples 1-4, refer to the drip irrigation method described above. For the nutrient mixture in Comparative Examples 5-7, follow the drip irrigation method described above.

[0109] During the growth of strawberries, pay attention to proper thinning of flowers and fruits, removal of old leaves, and removal of excess runners.

[0110] 3. Detection of strawberry growth and development indicators

[0111] (1) Measurement of strawberry plant height, stem diameter, and leaf area

[0112] Strawberry plants were tested for height, stem diameter, and leaf area on day 38. The height of the strawberry plant was measured with a ruler, the stem diameter was measured with a vernier caliper, and the length and width of the leaves were measured. The leaf area of ​​the strawberry leaves was calculated using the formula length × width × 0.73.

[0113] Strawberry yield: Collect strawberries after 5 months, weigh and record the weight and quantity.

[0114] 4. Inhibitory effect of Bacillus sicca on pathogens

[0115] (1) Prepare the bacterial culture of Bacillus sicca according to the method of Example 1.

[0116] (2) The inhibitory effects of Bacillus sicca on pathogens Xanthomonas fragarice, Colletotrichum gloeosporioides, Fusarium solani, and Cylindrocarpon destructans were determined by plate confrontation culture method.

[0117] The specific steps are as follows: Inoculate the above-mentioned pathogens onto PDA solid medium and incubate for 48 hours. Use a 5mm diameter punch to create a mycelial cake from the edge of the colony and inoculate it into the center of a fresh blank PDA solid medium plate. Inoculate 2μL of Bacillus sicca bacterial suspension on both sides at a distance of 2.0cm from the mycelial cake. Use sterile water as a control. Incubate at a constant temperature of 28℃ and observe the antibacterial effect. Each treatment is repeated three times. When the pathogen hyphae in the control group PDA solid medium plate have covered the entire plate, measure the growth radius of the pathogen colony and calculate the antibacterial rate using the following formula.

[0118] Relative inhibition rate = (Control colony radius - Treated colony radius) / Control colony radius × 100%

[0119] 5. Study on the control efficacy of Bacillus sicca against bacterial leaf spot disease of strawberry

[0120] Prepare several round pots measuring 16.5cm × 30cm × 16.6cm (bottom diameter × top diameter × height). Dispense strawberry cultivation substrate according to the aforementioned steps and transplant the pots into the pots for strawberry cultivation. Other steps remain the same, except that after the initial drip irrigation of strawberry nutrient solution (or after spraying the biocontrol agent for pots containing biocontrol agents), each treatment group was sprayed with 5mL of Xanthomonas fragarice spore solution at 4-day intervals. An equal volume of sterile water was sprayed as a control. Ten days after treatment, the leaf spot disease control effect was graded and evaluated. Leaf grading standards are shown in Table 1.

[0121] Table 1 Grading Standards for Strawberry Leaves

[0122] 0 No lesions 1 The lesions cover 0-5% of the leaf area, and the spots are semi-transparent. 2 The lesions cover 5% to 20% of the leaf area, turn brown, and develop yellow bacterial ooze when humidity is high. 3 The lesions cover 20% to 50% of the leaf area and are brown. 4 The lesions cover more than 50% of the leaf area, and the plant wilts.

[0123] The formula for calculating the disease index and prevention and control effectiveness is as follows:

[0124] Disease index = ∑(number of leaves at each level × corresponding level value) / (total number of leaves investigated × 4) × 100%

[0125] Prevention and control effect = [1 - (disease index before treatment in control group, disease index after treatment in treatment group) / (disease index after treatment in control group x disease index before treatment in treatment group)] × 100%

[0126] Preparation of Xanthomonas fragarice spore solution: Xanthomonas fragarice strain was inoculated onto PDA solid medium plates and cultured at 30℃ for 7 days until spores grew. Then, sterile water was added to the plates, and the spores were scraped off and the spore solution was collected, which is Xanthomonas fragarice spore solution.

[0127] II. Experimental Results

[0128] 1. Effects of different strawberry nutrient solutions on strawberry growth and development indicators

[0129] The results are shown in Table 2. The strawberry nutrient solutions prepared in Examples 1-8 of this invention...

[0130] Table 2. Effects of different strawberry nutrient solutions on strawberry growth and development indicators.

[0131]

[0132]

[0133] As can be seen from Table 2, Examples 1-5 of the present invention have a significant promoting effect on the growth and development of strawberries. By comparing with Comparative Example 1, it can be seen that the biocontrol agents added in the examples of the present invention have the effect of promoting strawberry plant height, stem thickness and leaf area, and at the same time have the effect of promoting strawberry single fruit weight and yield.

[0134] By comparing Comparative Examples 2-4 with the embodiments of this application, it can be seen that nutrient solution A, nutrient solution B and nutrient solution C all have a significant impact on the growth and development of strawberries. In this application, nutrient solution A, nutrient solution B and nutrient solution C and biocontrol agents are used to synergistically promote the growth and development of strawberries.

[0135] 2. Inhibitory effect of Bacillus sicca on pathogens

[0136] Table 3. Inhibition rate of Bacillus sicca against pathogens.

[0137] Xanthomonas fragarice 68.6 Colletotrichum gloeosporioides 49.8 Fusarium solani 36.4 Ginseng rust rot fungus (Cylindrocarpon destructans) 28.7

[0138] As shown in Table 3, the Bacillus sicca in this invention has inhibitory effects on Xanthomonas fragarice, Fusarium solani, and Cylindrocarpondestructans, with the highest inhibition rate against Xanthomonas fragarice at 68.6%.

[0139] Table 4. Study on the efficacy of the strawberry nutrient solution prepared in this invention against bacterial leaf spot disease of strawberries.

[0140] Example 1 76.9 Comparative Example 1 33.7 Comparative Example 2 24.5 Comparative Example 3 18.9 Comparative Example 4 17.7 Comparative Example 5 66.7 Comparative Example 6 63.6 Comparative Example 7 60.5

[0141] As shown in Table 4, the nutrient solution formula of the present invention, which is a mixture of nutrient solution A, nutrient solution B, nutrient solution C and water, also has a certain preventive effect against bacterial leaf spot disease of strawberries. By combining it with treatment with Bacillus sicca bacterial solution, the preventive effect against bacterial leaf spot disease of strawberries is significantly increased from 33.7% to 76.9%.

[0142] By comparing Comparative Examples 1-7, it can be seen that nutrient solution A, nutrient solution B, nutrient solution C and Bacillus sicca bacterial solution have a synergistic effect on the prevention and control of bacterial leaf spot disease in strawberries. The absence of any one component will reduce the control efficacy. However, among them, Bacillus sicca bacterial solution plays a decisive role in the prevention and control of bacterial leaf spot disease in strawberries.

[0143] It should be noted that this invention can also be equipped with a fertilizer applicator. By setting the EC value, the amount of drip irrigation nutrient solution A, nutrient solution B, and nutrient solution C can be accurately measured, mixed with water, and drip-irrigated to the strawberry roots.

[0144] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0145] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A strawberry nutrient solution, characterized in that, The strawberry nutrient solution is composed of a nutrient mixture and a biocontrol agent; The nutrient solution is prepared by mixing nutrient solution A, nutrient solution B, nutrient solution C and water in a volume ratio of 2.5-5:2.5-5:2.5-5:1000. Nutrient solution A per 1000L comprises the following ingredients: 10-18g / L ammonium calcium nitrate, 9-10g / L potassium nitrate, 4-5g / L potassium chloride, 1.2-1.55g / L iron, with the remainder being water; Nutrient solution B per 1000L comprises the following ingredients: 8-10 g / L magnesium sulfate, 5-6 g / L potassium dihydrogen phosphate, 2-3 g / L potassium nitrate, 4-13 g / L potassium sulfate, 0.17-0.4 g / L manganese, 0.06-0.12 g / L zinc, 0.08-0.16 g / L boron, 0.01-0.02 g / L copper, 0.01-0.012 g / L ammonium molybdate, with the balance being water; Each 1000L of the nutrient solution C comprises the following raw materials: 1.5-2.5mL / L nitric acid, with the remainder being water; The biocontrol agent has a viable bacterial count of 5 × 10⁶. 7 CFU / mL - 8 × 10 7 CFU / mL Bacillus sicca bacterial suspension; The Bacillus sicca is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC NO.12903.

2. The strawberry nutrient solution according to claim 1, characterized in that, Nutrient solution A per 1000L comprises the following ingredients: 18g / L ammonium calcium nitrate, 10g / L potassium nitrate, 5g / L potassium chloride, 1.55g / L iron, with the remainder being water.

3. The strawberry nutrient solution according to claim 1, characterized in that, Nutrient solution B per 1000L comprises the following ingredients: 10 g / L magnesium sulfate, 6 g / L potassium dihydrogen phosphate, 3 g / L potassium nitrate, 13 g / L potassium sulfate, 0.4 g / L manganese, 0.12 g / L zinc, 0.16 g / L boron, 0.02 g / L copper, 0.012 g / L ammonium molybdate, with the balance being water.

4. The strawberry nutrient solution according to claim 1, characterized in that, Each 1000L of the nutrient solution C comprises the following raw materials: 2.5 mL / L nitric acid, with the remainder being water.

5. The strawberry nutrient solution according to claim 1, characterized in that, The biocontrol agent has a viable bacterial count of 8 × 10⁶. 7 CFU / mL Bacillus sicca bacterial suspension.

6. The strawberry nutrient solution according to claim 5, characterized in that, The preparation process of the biocontrol agent is as follows: *Bacillus sicca* is inoculated onto LB solid plates and cultured at 37-38℃ for 23-24 hours. This process is repeated three times by transfer purification. Then, a single colony is picked and inoculated into fresh LB liquid medium and cultured at 37-38℃ and 170-180 rpm for 23-24 hours to obtain *Bacillus sicca* bacterial suspension. The concentration of the *Bacillus sicca* bacterial suspension is adjusted to 8 × 10⁻⁶ using LB liquid medium. 7 CFU / mL was used to obtain a biocontrol agent.

7. The application of the strawberry nutrient solution according to any one of claims 1-6 in strawberry cultivation, characterized in that, The application is to promote the growth and development of strawberry plants and to prevent plant diseases.

8. The application of the strawberry nutrient solution according to claim 7 in strawberry cultivation, characterized in that, The promotion of strawberry plant growth and development refers to increasing strawberry plant height, stem diameter, and leaf area.

9. The application of the strawberry nutrient solution according to claim 7 in strawberry cultivation, characterized in that, The plant disease is strawberry leaf spot.

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