Method for preventing and treating muskmelon bacterial angular leaf spot by using bactericidal composition

Abstract

The invention relates to a method for preventing and treating muskmelon bacterial angular leaf spot by using a bactericidal composition, in particular to a method for preventing and treating muskmelon bacterial angular leaf spot by using a bactericidal composition containing benziothiazolinone and bromothalonil. The effective components of the bactericidal composition are benziothiazolinone and bromothalonil, the weight ratio of the benziothiazolinone to the bromothalonil is 3: 1-1: 3, the composition can be prepared into wettable powder, the composition is sprayed and used before the bacterial angular leaf spot of muskmelon or at the initial stage of the bacterial angular leaf spot of muskmelon, the pesticide is applied three times, and the pesticide application interval is 7-10 days. The bactericidal composition not only can effectively prevent and treat muskmelon bacterial angular leaf spot, but also can solve the problem of muskmelon land hardening, increase the yield of muskmelons and enhance the disease-resistant immunity of plants.

Description

Technical Field

[0001] The present invention belongs to the technical field of pesticides, and particularly relates to a control method for preventing and treating bacterial angular leaf spot of melons. The bactericidal composition contains thiabendazole, bromothalonil and auxiliaries. Background Art

[0002] Thiabendazole is a new type of broad-spectrum bactericide, mainly used for preventing and treating various bacterial and fungal diseases such as bacterial angular leaf spot of cucumbers, pear scab, apple scab, citrus anthracnose, and grape black rot. Its bactericidal mechanism mainly includes two aspects: destroying the nuclear structure of the pathogen, causing it to die of exhaustion due to losing its heart part, and interfering with the metabolism of the pathogen's cells, causing its physiological disorder and ultimately leading to death.

[0003] Bromothalonil is a novel compound with low toxicity and broad spectrum, having the properties of bactericidal, mildew-proof and algaecidal. It can inhibit and eradicate the growth of bacteria, fungi and algae, and is suitable for the anti-corrosion and mildew-proof of textiles, leather, etc., and the treatment of industrial wastewater. It is also used in the production of medicine and cosmetics abroad, and mainly used in the prevention and treatment of crop diseases, the removal of algae in fish ponds and the treatment of industrial wastewater in China. It is an effective agent for preventing and treating anthracnose of various crops among domestic bactericides.

[0004] Melons prefer loose and breathable soil. However, with watering, applying pesticides, fertilizing and years of cultivation, it is easy to cause soil compaction, the occurrence of soil-borne diseases, and imbalance of soil acidity and alkalinity, resulting in a decrease in melon production capacity and a deterioration in taste. How to solve the problem of soil compaction is an urgent problem for melon farmers at present.

[0005] The inventor found through experiments that by making a bactericidal composition with thiabendazole and bromothalonil with different action mechanisms in a certain proportion, not only can the control effect on bacterial angular leaf spot of melons be effectively improved, the control cost be reduced, but also the problem of soil compaction of melon fields can be solved, the melon yield be increased, the disease resistance and immunity of melons be enhanced, and it is highly safe for crops. Summary of the Invention

[0006] The purpose of the present invention is to provide a control method for preventing and treating bacterial angular leaf spot of melons with a bactericidal composition.

[0007] The technical solution of the present invention is as follows:

[0008] A control method for preventing and treating bacterial angular leaf spot of melons with a bactericidal composition, characterized in that: the effective active ingredients of the bactericidal composition are thiabendazole and bromothalonil, and the weight ratio of thiabendazole to bromothalonil is 3:1 to 1:3, and preferably the weight ratio of thiabendazole to bromothalonil is 1:2.

[0009] The described bactericidal composition contains thiabendazole, bromothalonil and auxiliaries, and is made into a wettable powder; the auxiliaries are selected from one or more of synergists, dispersants, wetting agents, binders, defoamers, pH regulators, and fillers. The synergist is selected from one or more of seaweed extracts, amino acids or polypeptides.

[0010] The weight ratio of the effective active ingredient to the synergist is 1:1 to 10:1.

[0011] Furthermore, the total weight of thiabendazole and bromothalonil in the bactericidal composition is 20% - 70%, preferably 20% - 40%, and optimally 30%.

[0012] The dispersant is selected from one or more of alkylphenol polyoxyethylene ether formaldehyde condensate sulfates, alkylphenol polyoxyethylene ether formaldehyde condensate phosphates, sodium methylene bisnaphthalene sulfonate, sodium or calcium lignosulfonate, alkyl naphthalene sulfonates, styrene phenol polyoxyethylene ether phosphates, alkyl naphthalene formaldehyde condensate sulfonates, alkylphenol polyoxyethylene ether sulfonates, phenethylphenol polyoxyethylene ether phosphates, alkyl polyoxyethylene ether sulfonates, polyoxyethylene polyoxypropylene block copolymers, dodecyl polyoxyethylene ether phosphates, fatty alcohol polyoxyethylene ether phosphates, sodium naphthalene sulfonic acid formaldehyde condensate block copolymers, comb-shaped polycarboxylates, and sodium polycarboxylates;

[0013] The wetting agent is selected from one or more of sodium dodecylbenzenesulfonate, sodium diisobutylnaphthalenesulfonate, sodium sulfosuccinate octyl ester, alkyl sulfosuccinates, phenethylphenol polyoxyethylene ether phosphates, alkyl sulfates, alkyl sulfonates, alkyl naphthalene sulfonates, triphenylethylphenol polypropylene oxide polyoxyethylene block polymer, sodium dodecyl sulfate, styrylphenol formaldehyde resin propylene oxide block polyether, fatty alcohol polyoxyethylene ether, alkyl glycosides, and sodium fatty alcohol polyoxyethylene ether sulfonate;

[0014] The pH regulator is selected from one or more of citric acid and potassium dihydrogen phosphate;

[0015] The defoamer is selected from one or more of silicone, fatty alcohols, and fatty acids;

[0016] The filler is selected from one or more of silica, ammonium sulfate, potassium sulfate, magnesium sulfate, sodium sulfate, ammonium chloride, urea, calcined kaolin, and washed kaolin.

[0017] Furthermore, the dosage of the active ingredient of the bactericidal composition is 60 - 150 grams per hectare.

[0018] When the bactericidal composition is made into a wettable powder, it contains the following components and contents: thiabendazole 5% - 30%, bromothalonil 10% - 40%, synergist 1% - 20%, dispersant 1% - 15%, wetting agent 1% - 10%, defoamer 0 - 3%, pH regulator 0 - 4%, filler added to 100%.

[0019] Compared with the prior art, the control method of the present invention has the following beneficial effects: (1) Compared with single agents, the composition has a more significant effect on controlling bacterial angular leaf spot of melons; (2) It can solve the hardening of melon soil, increase the yield of melons, enhance the disease resistance and immunity of melons, and has high safety for crops. Detailed implementation mode

[0020] The following further illustrates the present invention in conjunction with embodiments. The percentages in the embodiments are all weight percentages, but the present invention is not limited thereto.

[0021] Application Example 1

[0022] Example 1 30% thiabendazole·bromothalonil wettable powder

[0023] Thiabendazole 10%, bromothalonil 20%, polyglutamic acid 5%, alkylnaphthalene sulfonate 5%, sodium dodecylbenzene sulfonate 3%, citric acid 0.5%, fatty acid defoamer 0.5%, silica white 20%, sodium sulfate balance, to obtain 30% thiabendazole·bromothalonil wettable powder.

[0024] Example 2 30% thiabendazole·bromothalonil wettable powder

[0025] Thiabendazole 10%, bromothalonil 20%, glycine 10%, alkylphenol polyoxyethylene ether sulfonate 6%, sodium diisobutylnaphthalene sulfonate 4%, potassium dihydrogen phosphate 0.5%, silica white 18%, calcined kaolin balance, to obtain 30% thiabendazole·bromothalonil wettable powder.

[0026] Example 3 30% thiabendazole·bromothalonil wettable powder

[0027] Thiabendazole 10%, bromothalonil 20%, seaweed essence 5%, sodium or calcium lignosulfonate 7%, sodium sulfosuccinate octyl ester 4%, citric acid 0.5%, fatty alcohol 0.6%, silica white 15%, ammonium chloride balance, to obtain 30% thiabendazole·bromothalonil wettable powder.

[0028] Example 4 21% thiabendazole·bromothalonil wettable powder

[0029] Thiabendazole 7%, bromothalonil 14%, fish protein 8%, alkylnaphthalene formaldehyde condensate sulfonate 5%, alkyl succinic acid sulfonate 5%, citric acid 0.5%, fatty acid 0.6%, silica white 20%, magnesium sulfate balance, to obtain 21% thiabendazole·bromothalonil wettable powder.

[0030] Example 5: 40% Validamycin·Bromothalonil Wettable Powder

[0031] Validamycin 20%, Bromothalonil 20%, Lysine 7%, Comb-shaped polycarboxylate 7%, Sodium dioctyl sulfosuccinate 5%, Potassium dihydrogen phosphate 0.5%, Fatty alcohol 0.6%, White carbon black 18%, Ammonium sulfate the balance, to obtain 40% Validamycin·Bromothalonil wettable powder.

[0032] Example 6: 60% Validamycin·Bromothalonil Wettable Powder

[0033] Validamycin 20%, Bromothalonil 40%, Arginine 7%, Alkylphenol polyoxyethylene ether sulfonate 5%, Alkylnaphthalene sulfonate 4%, Citric acid 0.8%, Fatty alcohol 0.5%, White carbon black 17%, Washed kaolin the balance, to obtain 60% Validamycin·Bromothalonil wettable powder.

[0034] Example of Application 2:

[0035] Virulence determination of the mixture of validamycin and bromothalonil against Pseudomonas syringae pv. lachrymans

[0036] According to the standards of NY / T1156.16 - 2008 and NY / T1156.6 - 2006, the turbidimetry method was used to determine the virulence of validamycin, bromothalonil and their mixtures in the ratios of 1:3, 1:2, 1:1, 2:1 and 3:1 against Pseudomonas syringae pv. lachrymans. The results showed that the mixtures of validamycin and bromothalonil in the above 5 ratios showed synergistic effects on Pseudomonas syringae pv. lachrymans. The experimental process is as follows:

[0037] 1 Test purpose

[0038] The virulence of validamycin, bromothalonil and their mixtures in different ratios was determined indoors against Pseudomonas syringae pv. lachrymans, and the synergistic effect was evaluated to clarify their compatibility and provide a scientific basis for the research and development of the mixture of validamycin and bromothalonil.

[0039] 2 Test conditions

[0040] 2.1 Test target

[0041] Pseudomonas syringae pv. lachrymans, preserved and provided by the experimental unit.

[0042] 2.2 Culture conditions

[0043] The culture conditions for the test target and the target after the test were a temperature of 25 ± 5°C and a relative humidity of 65 ± 5% or more.

[0044] 2.3 Instrument and equipment

[0045] Beakers, pipettes, Erlenmeyer flasks, autoclaves, constant temperature shaking incubators, ultraviolet spectrophotometers, etc.

[0046] 3 Experimental Design

[0047] 3.1 Experimental Agents

[0048] Benziothiazolinone 98% technical material; Bromothalonil 95% technical material.

[0049] 3.2 Design of Agent Concentrations and Preparation of Solutions

[0050] Benziothiazolinone solution: Weigh 0.1000 g of 98% benziothiazolinone technical material, dissolve it with 0.5 mL of DMF, add 195.5 mL of clear water containing 0.1% Tween 80 emulsifier, stir evenly, prepare a 500 mg / L mother liquor, and then dilute it with sterile water containing 0.1% Tween 80 emulsifier to concentrations of 250, 125, 62.5, 31.25, and 15.625 mg / L for standby;

[0051] Bromothalonil solution: Weigh 0.1000 g of 95% bromothalonil technical material, dissolve it with 0.5 mL of DMF, add 189.5 mL of clear water containing 0.1% Tween 80 emulsifier, stir evenly, prepare a 500 mg / L mother liquor, and then dilute it with sterile water to concentrations of 250, 125, 62.5, 31.25, and 15.625 mg / L for standby;

[0052] Each mixed solution: Take 45, 30, 25, 15, and 15 mL of 500 mg / L bromothalonil solution and add them to 15, 15, 25, 30, and 45 mL of 500 mg / L benziothiazolinone solution respectively to prepare 500 mg / L bromothalonil·benziothiazolinone 3:1, 2:1, 1:1, 1:2, and 1:3 solutions, and then dilute them with sterile water containing 0.1% Tween 80 emulsifier to concentrations of 250, 125, 62.5, 31.25, and 15.625 mg / L for standby;

[0053] Control solution: 0.5 mL of DMF plus 99.5 mL of sterile water containing 0.1% Tween 80 emulsifier.

[0054] 4 Experimental Methods

[0055] Referring to the bioassay standard method NY / T1156.16 - 2008, the turbidity method is adopted: Take 5 mL of the liquid medicine of each single agent series concentration, add it to 45 mL of NB medium cooled to 45 °C to prepare a medicated medium with the required final concentration. Dilute the bacterial strain growing on the slant of NA medium with sterile water to 1×10 7Suspension with a concentration of [[[spores / mL]]], inoculate 100 μL of the bacterial solution into each treatment medium, with 4 replicates for each treatment. After the treatment, place it in a shaking incubator at 28°C - 30°C (120 r / min), measure the absorbance value after 12 h, and calculate the growth inhibition rate.

[0056] 5 Data investigation and statistical analysis

[0057] 5.1 Investigation method

[0058] Measure the absorbance value of each treatment before starting the culture. When the control treatment reaches the logarithmic growth phase, measure and record the absorbance value of each treatment. The measurement wavelength is 660 nm. Calculate the growth inhibition rate (%).

[0059]

[0060] In the formula: P represents the growth inhibition rate; A0 represents the increase in absorbance value of the blank control; A1 represents the increase in absorbance value of the medicament treatment.

[0061] 5.2 Evaluation method for synergistic effect

[0062] Referring to the Guidelines for Indoor Bioassay of Pesticides NY / T 1156.6-2006, the synergistic effect of the mixed use of medicaments is evaluated according to the co-toxicity coefficient method (CTC) of Sun & Johnson (1960), that is, CTC ≤ 80 is antagonistic effect, 80 < CTC < 120 is additive effect, and CTC ≥ 120 is synergistic effect.

[0063]

[0064] The theoretical toxicity index (TTI) of the mixture = the toxicity index of medicament A × the percentage of medicament A in the mixture (%) + the toxicity index of medicament B × the percentage of medicament B in the mixture (%)

[0065]

[0066] 5.3 Data statistical analysis

[0067] All experimental data were analyzed using the SAS 6.12 statistical software. Calculate the mycelial growth inhibition rate (%) based on the experimental data, and obtain the toxicity regression equation, correlation coefficient (r), and EC 50 (95% confidence limit).

[0068] 6 Result analysis and discussion

[0069] 6.1 Efficacy evaluation

[0070] The results of the virulence determination of the mixed combinations of difenoconazole and bromothalonil at different ratios against Pseudomonas syringae pv. lachrymans of melon are shown in Table 1. As can be seen from Table 1, the mixtures of difenoconazole and bromothalonil at the ratios of 3:1, 2:1, 1:1, 1:2 and 1:3 all showed synergistic effects against Pseudomonas syringae pv. lachrymans of melon, and their EC 50 values were 8.09, 8.28, 8.42, 8.47 and 10.52 mg / L respectively, and the co-toxicity coefficients were 136.86, 137.34, 142.80, 150.59, 125.04 respectively. Among them, the mixture at the ratio of 1:2 had a better synergistic effect.

[0071] Table 1 Results of the virulence determination of the mixture of difenoconazole and bromothalonil against Pseudomonas syringae pv. lachrymans of melon

[0072]

[0073]

[0074] 6.2 Discussion and conclusions

[0075] The results of the indoor bioassay showed that the mixtures of bromothalonil and difenoconazole at the ratios of 3:1, 2:1, 1:1, 1:2 and 1:3 showed synergistic effects against Pseudomonas syringae pv. lachrymans of melon. Among them, the mixture at the ratio of 1:2 had the most obvious synergistic effect. Therefore, 1:2 can be regarded as the optimal ratio of the mixture of difenoconazole and bromothalonil.

[0076] Application Example 3: Field efficacy experiment of 30% difenoconazole·bromothalonil wettable powder against Pseudomonas syringae pv. lachrymans of melon

[0077] This test complies with the "Quality Management Specification for Pesticide Registration Tests" and GB / T17980.110 - 2004.

[0078] Test crop: Melon

[0079] Control object: Pseudomonas syringae pv. lachrymans

[0080] 1 Basic information of the test

[0081] 1.1 Test name

[0082] Field efficacy test of 30% difenoconazole·bromothalonil wettable powder against Pseudomonas syringae pv. lachrymans of melon.

[0083] 1.2 Test purpose

[0084] To clarify the control effect, applicable dosage and safety of the 30% difenoconazole·bromothalonil wettable powder provided by the applicant against Pseudomonas syringae pv. lachrymans of melon, and to provide a basis for the registration and promotion of the test agent.

[0085] 2 Environmental and facility cultivation conditions

[0086] 2.1 Test location

[0087] Shaanxi Province, Jiangxi Province.

[0088] 2.2 Test target situation

[0089] Bacterial angular leaf spot of melon (Pseudomonas syringae)

[0090] 2.3 Test crops, varieties and growth conditions

[0091] Melons, with good growth.

[0092] 3 Test design and arrangement

[0093] 3.1 Test dosage and numbering

[0094] Table 2 Test design of tested medicaments

[0095]

[0096] 3.2 Application method

[0097] 3.2.1 Application period and method

[0098] Apply the first dose at the early flowering stage of melons and before the onset of bacterial angular leaf spot, and then apply the medicine once every 7 days and 14 days respectively for a total of 3 consecutive applications.

[0099] 3.2.2 Application volume

[0100] Spray, with the liquid medicine volume per hectare being about 675 - 900 liters.

[0101] 3.3 Investigation method, time and frequency

[0102] 3.3.1 Investigation time and frequency

[0103] The test is investigated before the onset of the disease, and the control effect is investigated 7 or 10 days after the last dose, with a total of 2 investigations.

[0104] 3.3.2 Investigation method

[0105] Take 5 samples at 5 points along the diagonal of each plot, with 3 plants at each point, investigate the disease occurrence of all leaves, and grade according to the percentage of the lesion area on each leaf.

[0106] Grading method (taking the leaf as the unit):

[0107] Grade 0: No lesions; Grade 1: The lesion area accounts for less than 5% of the entire leaf area; Grade 3: The lesion area accounts for 6% - 10% of the entire leaf area; Grade 5: The lesion area accounts for 11% - 20% of the entire leaf area; Grade 7: The lesion area accounts for 21% - 50% of the entire leaf area; Grade 9: The lesion area accounts for more than 51% of the entire leaf area.

[0108] 3.3.3 Medicinal Efficacy Calculation Method

[0109] The disease index and control effect are calculated according to formulas (1) and (2) respectively.

[0110] Disease index = [Σ(number of diseased plants at each level × relative level value) / (total number of surveyed plants × 9)] × 100………(1)

[0111] Control effect (%) = (disease index before spraying in the blank control area - disease index after spraying in the medicament treatment area) / disease index after spraying in the blank control area × 100………………………………(2)

[0112] 4 Results and Analysis

[0113] Table 3 Test Results of 30% thiabendazole·bromothalonil wettable powder against bacterial angular leaf spot of melon

[0114]

[0115] The test results show that: the test medicament 30% thiabendazole·bromothalonil wettable powder has a good control effect against bacterial angular leaf spot of melon. When the application rate of its active ingredient is 90 - 112.5 g / ha, the control effect is significantly better than that of the control single agent. Variance analysis shows that the test medicament shows a highly significant level compared with the control single agent.

[0116] It is known from the field systematic observation that: when the experimental medicament is applied before the occurrence or at the initial stage of bacterial angular leaf spot of melon, and then applied once again at intervals of 7 d and 14 d, with a total of 3 consecutive applications, and the water consumption per hectare is 600 - 900 L, when the application rate of the active ingredient is 90 - 112.5 g / ha, it can not only effectively control bacterial angular leaf spot of melon, but also is safe for melon, has a significant effect on adjusting the soil pH value, and the melon field does not become compacted. The yield measurement of melon shows that it has a certain yield increasing effect.

Claims

1. A control method for preventing and treating bacterial angular leaf spot of melons with a bactericidal composition, characterized in that: The effective active ingredients of the bactericidal composition are thiabendazole and bromothalonil, and the weight ratio of thiabendazole to bromothalonil is 3:1 to 1:

3.

2. The prevention and control method according to claim 1, characterized in that: The bactericidal composition contains thiabendazole, bromothalonil and auxiliaries, and is made into a wettable powder; The said auxiliaries are selected from one or more of synergists, dispersants, wetting agents, binders, defoamers, pH regulators, fillers.

3. The prevention and control method according to claim 1 or 2, characterized in that: The weight ratio of thiabendazole to bromothalonil is 1:

2.

4. The prevention and control method according to any one of claims 1-3, characterized in that: The total weight of thiabendazole and bromothalonil in the bactericidal composition is 20% - 70%.

5. The prevention and control method according to claim 4, characterized in that: The total weight of thiabendazole and bromothalonil in the bactericidal composition is 20% - 40%.

6. The prevention and control method according to claim 5, characterized in that: The total weight of thiabendazole and bromothalonil in the bactericidal composition is 30%.

7. The prevention and control method according to claim 2, characterized in that: The said synergist is selected from one or more of seaweed extracts, amino acids or polypeptides.

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