Foliar fertilizer and application thereof in assisting tomato to resist bacterial leaf spot disease

Abstract

The invention relates to a foliar fertilizer and application thereof in assisting tomatoes in resisting bacterial leaf spot disease, and belongs to the technical field of ecological prevention and control of tomato facility cultivation diseases. In order to solve the problems that an existing calcium regulator is weak in pertinence and cannot efficiently assist in improving the control effect of facility cultivation tomatoes on bacterial leaf spot, the invention provides a foliar fertilizer which comprises the following components in percentage by mass: 0.2-0.3% of calcium chloride, 2-4% of a polyhydroxy compound, 1-2% of an amino acid mixture and the balance of distilled water. According to the foliar fertilizer provided by the invention, the calcium ion concentration and the auxiliary ratio of the foliar fertilizer are adjusted according to the characteristics of the bacterial leaf spot disease, the bacterial leaf spot disease prevention capability of the tomato cultivated by the facility is enhanced through a synergistic effect, the prevention of the bacterial leaf spot disease in the production process of different stubbles of the tomato is met, and the disease infection degree is reduced; and the production yield and quality of protected tomatoes are effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of ecological prevention and control of tomato facility cultivation diseases, and in particular relates to a foliar fertilizer and application thereof in helping tomatoes resist bacterial leaf spot disease. Background Art

[0002] Tomatoes occupy a vital position in the global fruit and vegetable trade. As one of the world's top five tomato producers, my country's annual production reached 69.7 million tons by 2023. With the continuous advancement of agricultural technology, tomato cultivation in specialized facilities such as plastic greenhouses and solar greenhouses has become widespread, better meeting the market's demand for both yield and quality. In northern China, the widespread adoption of tomato cultivation in greenhouses has not only significantly increased annual tomato production but also effectively ensured a stable year-round supply.

[0003] However, recent changes in the atmospheric environment are impacting global crop production. Tomato disease outbreaks are becoming increasingly frequent under diverse agricultural practices, and greenhouse-grown tomatoes are more susceptible to bacterial diseases due to their high humidity. Bacterial leaf spot, caused by various bacterial pathogens such as Pseudomonas syringae, primarily manifests as bacterial spots on tomato leaves, but can also occur on fruit, affecting tomato quality and yield. Currently, pesticide spraying is the most common method of controlling bacterial leaf spot in agricultural production. While this can reduce yield losses to a certain extent, it also limits fruit quality, increases the risk of drug resistance in tomatoes, and increases the cost of subsequent prevention and control. The accompanying residual hazards and environmental pollution will also seriously hinder the sustainable development of agriculture.

[0004] Ecological control technology for tomato diseases involves developing non-pesticide regulators based on the tomato's own nutritional system to ensure the production needs of tomatoes in different seasons and crops. The preventive and regulatory effects of exogenous spraying of calcium derivatives on plant diseases are widely recognized. Calcium substances have strong advantages in terms of application costs, plant metabolic residues, environmental pollution, and soil circulation. However, different bacterial diseases harm to tomato plants to varying degrees and in varying ways. Although there are a variety of calcium regulators on the market, there is still a lack of highly targeted calcium derivatives that can effectively assist in improving the prevention and control of bacterial leaf spot in greenhouse-grown tomatoes. Summary of the Invention

[0005] In order to solve the problem that existing calcium regulators have weak specificity and cannot effectively assist in improving the prevention and control effect of bacterial leaf spot disease in facility-cultivated tomatoes, the present invention provides a foliar fertilizer and its application in helping tomatoes resist bacterial leaf spot disease.

[0006] The technical solution of the present invention:

[0007] A foliar fertilizer contains the following components in percentage by mass: 0.2-0.3% calcium chloride, 2-4% polyol and 1-2% amino acid mixture, with the balance being distilled water.

[0008] Furthermore, the components of the polyhydroxy compound include sorbitol, mannitol, xylitol and ethylene glycol, and the mass ratio of the sorbitol, mannitol, xylitol and ethylene glycol is 2:1:2:1.

[0009] Furthermore, the components of the amino acid mixture include alanine, glutamic acid, histidine and lysine, and the mass ratio of alanine, glutamic acid, histidine and lysine is 2:1:2:1.

[0010] Furthermore, the foliar fertilizer is prepared by chelating calcium chloride, polyhydroxy compounds and an amino acid mixture in distilled water, and the stirring temperature of the chelation is 60-80°C.

[0011] Application of a foliar fertilizer in assisting tomatoes in resisting bacterial leaf spot disease.

[0012] Furthermore, the tomato is a facility-grown tomato.

[0013] Furthermore, the foliar fertilizer is applied when the temperature in the facility exceeds 23° C. for 3 to 5 consecutive days, or the relative humidity is higher than 75% for 2 to 3 consecutive days, or when it is rainy or snowy.

[0014] Furthermore, the foliar fertilizer application cycle is 3 days, and the foliar fertilizer is evenly sprayed on the surface of tomato leaves at 10 am every day, once a day.

[0015] Furthermore, the spraying dosage of the foliar fertilizer is: 25-30 mL for a single tomato plant in the seedling stage; 65-80 mL for a single tomato plant in the growth stage; 115-130 mL for a single tomato plant in the fruiting stage, and the foliar fertilizer is in the form of liquid without dripping.

[0016] Beneficial effects of the present invention:

[0017] The foliar fertilizer provided by the present invention adjusts the calcium ion concentration and adjuvant ratio of the foliar fertilizer based on the characteristics of bacterial leaf spot disease. Calcium chloride is used as a calcium source to enhance the disease resistance of tomatoes. A hydroxyl compound and an amino acid mixture are used as adjuvants to improve the absorption efficiency of the foliar fertilizer. Through synergistic effects, the ability of facility-grown tomatoes to prevent bacterial leaf spot disease is enhanced. The pre-spraying of the foliar fertilizer of the present invention can meet the prevention of bacterial leaf spot disease during the production of different tomato crops and reduce the degree of disease infection, especially for the production of oversummer and late autumn tomatoes in facilities. The preventive effect of the foliar fertilizer against bacterial leaf spot disease can last for 2 to 3 weeks, supporting continuous spraying during the cropping period.

[0018] The foliar fertilizer of the present invention fills the gap in the application of calcium regulators in facility production to assist in resisting bacterial leaf spot of tomatoes. It can greenly and efficiently reduce the incidence of bacterial leaf spot of facility tomatoes at different stages, significantly enhance their disease resistance, and effectively improve the per-acre yield and fruit quality of facility tomatoes.

[0019] The foliar fertilizer of the present invention has a simple preparation process, adopts a non-pesticide / plant growth regulator formula, has low cost, can be stably stored, is green and harmless, and does not increase the burden of fertilizer use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 These are photos of tomato leaves in the control group and the foliar fertilizer treatment group at different infection cycles in Example 4;

[0021] Figure 2 This is a photo comparing the growth of bacterial leaf spot pathogen (PstDC3000) on culture plates in tomato leaves in the control group and the foliar fertilizer treatment group in Example 5;

[0022] Figure 3 This is a comparison chart of the growth of bacterial leaf spot pathogen (PstDC3000) in tomato leaves in the control group and the foliar fertilizer treatment group in Example 5. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described below with reference to the embodiments, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention shall be included in the scope of protection of the present invention. The process equipment or devices not specifically noted in the following examples are all conventional equipment or devices in the art. Unless otherwise specified, the raw materials used in the examples of the present invention can be obtained commercially; unless otherwise specified, the technical means used in the examples of the present invention are all conventional means well known to those skilled in the art.

[0024] Example 1

[0025] This embodiment provides a foliar fertilizer for helping tomatoes resist bacterial leaf spot disease and a preparation method thereof.

[0026] The foliar fertilizer of this embodiment contains the following components by weight: 0.2% calcium chloride, 2% polyol, and 1% amino acid mixture, with the balance being distilled water. The polyol components of this embodiment include sorbitol, mannitol, xylitol, and ethylene glycol, with the mass ratio of sorbitol, mannitol, xylitol, and ethylene glycol being 2:1:2:1. The amino acid mixture components include alanine, glutamic acid, histidine, and lysine, with the mass ratio of alanine, glutamic acid, histidine, and lysine being 2:1:2:1.

[0027] All chemicals used in this example were commercially available, with no special requirements. The foliar fertilizer was prepared by chelating calcium chloride, a polyol, and an amino acid mixture in distilled water, with stirring at 60°C. A storable stock solution of 2% calcium chloride, 20% polyol, and 10% amino acid mixture was preferably prepared, which was diluted 10-fold with water upon use.

[0028] Example 2

[0029] This embodiment provides a foliar fertilizer for helping tomatoes resist bacterial leaf spot disease and a preparation method thereof.

[0030] The foliar fertilizer of this embodiment contains the following components by weight: 0.3% calcium chloride, 4% polyol, and 2% amino acid mixture, with the balance being distilled water. The polyol components of this embodiment include sorbitol, mannitol, xylitol, and ethylene glycol, with the mass ratio of sorbitol, mannitol, xylitol, and ethylene glycol being 2:1:2:1. The amino acid mixture components include alanine, glutamic acid, histidine, and lysine, with the mass ratio of alanine, glutamic acid, histidine, and lysine being 2:1:2:1.

[0031] All chemicals used in this example were commercially available, with no special requirements. The foliar fertilizer was prepared by chelating calcium chloride, a polyol, and an amino acid mixture in distilled water, with stirring at 60°C. A storable stock solution of 3% calcium chloride, 40% polyol, and 20% amino acid mixture was preferably prepared, which was diluted 10-fold with water upon use.

[0032] Example 3

[0033] This example provides the use of foliar fertilizer in helping tomatoes resist bacterial leaf spot disease.

[0034] Taking a 1-mu (667 square meters) greenhouse as an example, there are 2,000 autumn tomato plants, which require 50-60 L of foliar fertilizer during the seedling stage; 130-160 L during the growth period; and 230-260 L per tomato plant during the fruit-setting period, sprayed on the leaves of each plant.

[0035] Apply foliar fertilizer when the temperature in the facility exceeds 23°C for 3-5 consecutive days, when the relative humidity exceeds 75% for 2-3 consecutive days, or when it rains or snows. Apply foliar fertilizer evenly to tomato leaves at 10:00 AM daily for three days. The foliar fertilizer's effectiveness lasts for 2-3 weeks, and continuous spraying is recommended throughout the cropping period.

[0036] Example 4

[0037] This example verifies the effectiveness and duration of the foliar fertilizer provided in Example 1 in assisting tomatoes in resisting bacterial leaf spot disease.

[0038] The experiment was conducted in a solar greenhouse at Shenyang Agricultural University. The tomato variety used was Liaoyuan Duoli, grown in northern China. The tomato plants were germinated and sown in the autumn harvest. After uniformly cultivating until the seedlings had six leaves and a single bud, the individual tomato plants were randomly divided into specific groups for the experiment. One group served as a natural control group within the facility, where the leaves were sprayed with water for three days. The other group received a pre-foliar fertilizer treatment, where the leaves were sprayed with the fertilizer provided in Example 1 for three days. This treatment was performed at 10:00 AM on a clear day. A dosage of 25 mL was applied to each seedling during the seedling stage.

[0039] During this period, water was rationed and environmental conditions were uniformly managed. The conditions in the facility were: temperature 25 / 15°C (day / night), cycle 12 / 12 h, and light intensity was natural light intensity (600 μmol·m -2 ·s -1 ), the indoor CO2 concentration is about (400±50 μmol·mol -1 ), relative humidity is 65%.

[0040] During this period, the differences between the uninfected and infected plant groups were observed. Under the same growth environment, the growth conditions of tomatoes that were uninfected and infected with bacterial leaf spot were observed within 4 weeks and statistically analyzed. Figure 1 As shown, pre-foliar fertilization caused uninfected tomato leaves to stretch and remain vibrant green, reducing the incidence of bacterial leaf spot infection and significantly slowing the severity of infection. This helped the tomatoes resist bacterial leaf spot-induced leaf damage, reduced leaf spotting caused by bacterial infection, and decreased the area of ​​necrosis. The optimal effects of foliar fertilization lasted for 2-3 weeks.

[0041] Example 5

[0042] This example verifies the inhibitory effect of the foliar fertilizer provided in Example 1 on the pathogen of tomato bacterial leaf spot and the tomato pathogenicity analysis. The experimental treatment is the same as that in Example 2.

[0043] Tomato leaves infected for 4 weeks in the control group and the foliar fertilizer treatment group were separated from the plants for leaf bacterial growth and pathogenicity analysis. The surface of the tomato leaves was rinsed with sterile water, and 3 discs (1 cm in diameter) were obtained from each leaf using an autoclaved puncher. The discs were placed in 500 μL sterile ddH2O and ground with a plastic grinding rod until the leaves were completely broken. The collected liquid was diluted 1000 times (1:1000), 200 μL of the dilution was taken and inoculated on an agar medium containing rifampicin (25 mg / L) and kanamycin (50 mg / L), incubated at 28°C for 2 days, and the total number of tomato bacterial leaf spot pathogen PstDC3000 colonies in the culture plate was counted. The colony growth was as follows: Figure 2 The experiment was repeated three times, with three replicates per treatment. The bacterial counts from nine replicates were used to calculate the mean and standard error. All aseptic operations were performed on a clean bench, and all utensils used were sterile.

[0044] The results of the comparative experiment on bacterial growth in two groups of tomato leaves are as follows: Figure 3 Results are presented as mean ± SD for 3 × 3 = 9 independent biological replicates. Pre-foliar fertilizer application significantly reduced the growth of Pst DC3000 bacteria in leaves, reducing bacterial leaf spot-induced bacterial content by 29.76%. This result demonstrates that the foliar fertilizer provided in Example 1 can significantly mitigate the effects of bacterial leaf spot on tomato plant growth.

[0045] Example 6

[0046] This example verifies the beneficial effect of the foliar fertilizer provided in Example 1 on the growth of tomatoes at different stages (seedling stage, growth stage and fruit setting stage).

[0047] Investigation of bacterial leaf spot disease in 4 infected greenhouse tomatoes:

[0048] Three ridges at the east and west ends and three ridges in the middle of each greenhouse, a total of nine ridges of tomatoes, were randomly selected to investigate the diseased leaf rate, diseased plant rate and diseased fruit rate of tomatoes at different stages (%) = diseased leaves, diseased stems or diseased fruit plants / total number of plants × 100%.

[0049] According to the disease grade of individual tomato plants, the disease grade index of bacterial leaf spot was calculated as follows: disease grade index = Σ (number of plants in each disease grade × number of grades) / total number of plants surveyed.

[0050] The grading standards for bacterial leaf spot in tomato seedlings and growth stages are:

[0051] Level 0: no symptoms; Level 1: small lesions on leaves, no lesions on stems, and leaf area damage rate ≤5%;

[0052] Level 2: Limited lesions on leaves, no lesions on stems, 5%< leaf area damage rate≤15%;

[0053] Level 3: There are lesions on the leaves, but no lesions on the stems, and the leaf area damage rate is 15%<≤30%;

[0054] Level 4: There are lesions on the leaves, with a small number of lesions on the stems, and the leaf area damage rate is 30%<≤60%;

[0055] Level 5: There are lesions on the leaves, and the lesions are spreading on the stems. The leaf area damage rate is 60%<≤90%;

[0056] Level 6: There are spots on the leaves, the stems are severely damaged, the leaf area damage rate is >90%, and the plant may even die.

[0057] The grading standards for bacterial leaf spot during the tomato fruit setting period are:

[0058] Level 0: no diseased fruit; Level 1: diseased fruit rate ≤5%;

[0059] Level 2: 5%< diseased fruit rate≤15%;

[0060] Level 3: 15%< diseased fruit rate ≤ 30%;

[0061] Level 4: 30%< diseased fruit rate≤60%;

[0062] Level 5: 60%< diseased fruit rate≤90%;

[0063] Level 6: Diseased fruit rate >90%.

[0064] The results are shown in Table 1.

[0065] Table 1

[0066]

[0067] As shown in Table 1, a survey of four greenhouses affected by bacterial leaf spot in tomatoes found that pre-application of foliar fertilizer reduced the percentage of diseased leaves and plants in the seedling stage by 59.74%, the percentage of diseased plants by 61.81%, and the corresponding percentage of diseased fruits by 47.39%. This indicates that timely foliar fertilizer application during the seedling stage has a sustained effect, with the disease index reaching a low of only 8.07 in the later stages. Furthermore, it alleviated the effects of infection on plant height reduction and stem growth, increasing tomato yield per mu by 16.7% to 7,977.23 kg.

Claims

1. A foliar fertilizer, characterized in that The composition contains the following components in percentage by weight: 0.2-0.3% calcium chloride, 2-4% polyol and 1-2% amino acid mixture, with the balance being distilled water.

2. A foliar fertilizer according to claim 1, characterized in that, The components of the polyhydroxy compound include sorbitol, mannitol, xylitol and ethylene glycol, and the mass ratio of the sorbitol, mannitol, xylitol and ethylene glycol is 2:1:2:

1.

3. A foliar fertilizer according to claim 1 or 2, characterized in that, The components of the amino acid mixture include alanine, glutamic acid, histidine and lysine, and the mass ratio of alanine, glutamic acid, histidine and lysine is 2:1:2:

1.

4. A foliar fertilizer according to claim 3, characterized in that, The foliage fertilizer is prepared by chelating calcium chloride, polyhydroxy compounds and an amino acid mixture in distilled water, and the stirring temperature of the chelation is 60-80°C.

5. Use of the foliar fertilizer according to any one of claims 1 to 4 in helping tomatoes resist bacterial leaf spot disease.

6. Use of the foliar fertilizer according to claim 5 in assisting tomatoes in resisting bacterial leaf spot disease, characterized in that: The tomato is a facility-cultivated tomato.

7. Use of the foliar fertilizer according to claim 5 or 6 in assisting tomatoes in resisting bacterial leaf spot disease, characterized in that: The foliar fertilizer is applied when the temperature in the facility exceeds 23° C. for 3 to 5 consecutive days, or the relative humidity is higher than 75% for 2 to 3 consecutive days, or when it is raining or snowing.

8. Use of the foliar fertilizer according to claim 7 in assisting tomatoes in resisting bacterial leaf spot disease, characterized in that: The foliar fertilizer application cycle is 3 days, and the foliar fertilizer is evenly sprayed on the surface of tomato leaves at 10 am every day, once a day.

9. Use of the foliar fertilizer according to claim 8 in assisting tomatoes in resisting bacterial leaf spot disease, characterized in that: The spraying dosage of the foliar fertilizer is: 25-30 mL per tomato plant in the seedling stage; 65-80 mL per tomato plant in the growth stage; 115-130 mL per tomato plant in the fruiting stage, and the dosage is liquid but not dripping.

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