Application of wheat straw wood vinegar as prothioconazole synergist

Abstract

The invention relates to application of wheat straw wood vinegar as a prothioconazole synergist, and belongs to the technical field of pesticide compounding. The invention provides application of wheat straw wood vinegar as a bactericidal synergist of a bactericide in prevention and treatment of wheat scab. According to the invention, the wheat straw pyroligneous liquor is used as a bactericidal synergist of prothioconazole, so that the pesticide effect of prothioconazole can be remarkably improved, the dosage of prothioconazole can be greatly reduced under the same control effect, the pesticide resistance of pests is overcome or delayed, and the pesticide effect of prothioconazole is improved. The composition prepared by mixing the wheat straw pyroligneous liquor with prothioconazole can reduce DON toxin in wheat grains in the harvesting period and has a remarkable effect on preventing and treating wheat scab, the wheat straw pyroligneous liquor is wide in raw material source, the extraction method is simple and convenient, and the wheat straw pyroligneous liquor has the advantages of being safe, environmentally friendly and capable of reducing environmental pollution. And the advantages of difficult generation of cross resistance with chemical pesticides and easy degradation of plant-derived synergists are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of pesticide compounding, and in particular to application of wheat straw wood vinegar as a prothioconazole synergist. Background Art

[0002] Wheat is an important food crop in my country, with a planting area second only to corn and rice. In recent years, it has stabilized at about 360 million mu, with an annual output of about 130 million tons, accounting for about 20% of my country's total grain output. Wheat scab is a disease that occurs worldwide. It is more likely to occur in rainy and humid areas, especially during the ear stage of wheat growth. It is reported that wheat scab in my country has become one of the most serious diseases in wheat production. Fusarium scab seriously threatens wheat production safety. Severe outbreaks can cause 10% to 40% yield losses, and can lead to 100% yield losses under extreme epidemic conditions. The occurrence of wheat scab not only causes a significant reduction in production, but also the Fusarium toxins in wheat grains seriously endanger the health of humans and animals. Fusarium toxins are of various types and complex toxicity, especially vomitoxin (DON) and zearalenone (ZEN) pollution is the most prominent. Wheat fusarium head blight frequently occurs in the middle and lower reaches of the Yangtze River in my country. From 2015 to 2018, the rate of excessive vomitoxin in wheat in the Huaihe River Basin of Jiangsu Province and its southern wheat areas, which were severely affected, remained high. In severe years, the rate of excessive vomitoxin in wheat was as high as 71.2%. The average toxin content in wheat in the province was 2,300 micrograms / kg, far exceeding the national food safety limit standard (1,000 micrograms / kg), seriously affecting the quality of wheat and posing a serious threat to human and animal safety and food security. There are many pathogens that cause wheat fusarium head blight in my country, among which Fusarium graminearum and Fusarium asiaticum are the most common. The former is mostly distributed in the Huanghuai River Basin and the northern region, and the latter is mostly distributed in the middle and lower reaches of the Yangtze River. In recent years, due to the promotion of conservation tillage technologies such as straw return to the field and no-tillage and the combined influence of factors such as global warming, wheat fusarium head blight has continued to expand and spread worldwide. It has begun to spread and worsen in the wheat areas of North China and Northwest my country, seriously affecting the production and safety of wheat.

[0003] At present, the use of chemical agents to prevent and control diseases caused by Fusarium and toxin pollution is one of the most effective measures, but long-term reliance on chemical pesticides has caused a prominent risk of drug resistance. The frequency of resistance to carbendazim in Fusarium isolated from the Jianghuai wheat area has exceeded 50%. In addition, some triazole agents can also stimulate the synthesis of Fusarium toxins at low concentrations. In recent years, the green control technology of using plant-derived compounds to control pests has shown broad application prospects, but in practical applications, it often shows many problems such as low prevention efficiency and instability. Studies have shown that wood vinegar prepared from corn straw waste has a fresh-keeping effect on fruits and vegetables such as tomatoes and cherries (publication number CN108576203A), and can inhibit common decay fungi and bacteria, such as Staphylococcus aureus, Penicillium, Salmonella, etc.; wood vinegar prepared from wheat straw waste significantly inhibits the growth of wheat Fusarium graminearum, and can effectively prevent wheat scab (publication number CN110692659B). Using plant-derived compounds as synergists or compounding agents added to chemical pesticides can, on the one hand, significantly reduce the use of chemical pesticides, and on the other hand, improve the utilization rate of biological pesticides. However, there are no reports on the study of straw wood vinegar as a plant-derived synergist for fungicides.

[0004] Based on this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide the application of wheat straw wood vinegar as a prothioconazole synergist to solve the problems in the prior art of long-term reliance on chemical pesticides resulting in prominent resistance risks and the problem that some pesticides can stimulate the synthesis of Fusarium toxins when acting at low concentrations.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The invention provides application of wheat straw wood vinegar as a fungicide synergist of a fungicide in preventing and treating wheat scab.

[0008] Preferably, the fungicide is prothioconazole.

[0009] The invention provides a composition for preventing and treating wheat fusarium head blight, comprising wheat straw wood vinegar and prothioconazole, wherein the mass ratio of the wheat straw wood vinegar to the prothioconazole is 0.1-1:1.

[0010] The invention provides a preparation method of the composition, wherein wheat straw wood vinegar and prothioconazole are weighed according to a mass ratio, mixed, and a composition for preventing and treating wheat fusarium head blight is obtained.

[0011] The present invention provides application of the composition or the composition prepared by the preparation method in preparing products for preventing and treating wheat scab.

[0012] The present invention also provides a method for using the composition for preventing and treating wheat scab, which comprises spraying the composition at the early stage of wheat flowering;

[0013] The composition is the composition or the composition prepared by the preparation method.

[0014] Preferably, the composition is sprayed 2 to 3 times at the early stage of wheat flowering, the spraying interval is 5 to 7 days, and the amount of each spraying is 15 to 20 kg / mu.

[0015] The present invention has the following technical effects and advantages:

[0016] (1) The present invention uses wheat straw wood vinegar as a synergist of prothioconazole, and can significantly improve the efficacy of prothioconazole through a reasonable ratio. Under the same protective effect, the dosage of prothioconazole can be greatly reduced, thereby overcoming or delaying the drug resistance of pests.

[0017] (2) The composition prepared by mixing wheat straw wood vinegar with prothioconazole in the present invention can reduce DON toxins in wheat grains at the harvest stage and has a significant effect in preventing and controlling wheat fusarium head blight.

[0018] (3) Wheat straw wood vinegar is a plant-based enhancer of prothioconazole. It has a wide range of raw material sources and a simple extraction method. It is safe and environmentally friendly and reduces environmental pollution. It also has the advantages of not easily producing cross-resistance with chemical pesticides and being an easily degradable plant-based enhancer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The effect of different ratios of compositions on the mycelial growth of Fusarium graminearum. DETAILED DESCRIPTION

[0020] The invention provides application of wheat straw wood vinegar as a fungicide synergist of a fungicide in preventing and treating wheat scab.

[0021] In the present invention, the fungicide is prothioconazole.

[0022] In the present invention, the prothioconazole is preferably a 30 wt% prothioconazole dispersible oil suspension concentrate.

[0023] The invention provides a composition for preventing and treating wheat fusarium head blight, comprising wheat straw wood vinegar and prothioconazole, wherein the mass ratio of the wheat straw wood vinegar to the prothioconazole is 0.1-1:1, preferably 0.5:1.

[0024] The invention provides a preparation method of the composition, wherein wheat straw wood vinegar and prothioconazole are weighed and mixed according to a mass ratio to obtain a composition for preventing and treating wheat fusarium head blight.

[0025] In the present invention, the preparation method of the wheat straw wood vinegar is to mix the wheat straw waste at 0.1-0.3 m 3 / min flow rate of nitrogen, heating to 350-450°C at a heating rate of 5-15°C / min for closed cracking, cracking for 1-2h, condensing the volatile gas generated in the cracking process and collecting the condensate, while controlling the yield of the condensate to 20%-30% of the weight of the wheat straw waste, to obtain wheat straw wood vinegar;

[0026] The flow rate of the nitrogen is preferably 0.2 m 3 / min, the heating rate is preferably 10°C / min, the heating temperature is preferably 400°C, the pyrolysis time is preferably 1.5h, and the yield of the condensate is preferably 25% of the weight of the wheat straw waste.

[0027] The present invention provides application of the composition or the composition prepared by the preparation method in preparing products for preventing and treating wheat scab.

[0028] The present invention provides a method for using a composition for preventing and treating wheat scab, wherein the composition is sprayed at the early stage of wheat flowering;

[0029] The composition is the composition or the composition prepared by the preparation method.

[0030] In the present invention, the composition is sprayed 2 to 3 times, preferably 3 times, at the early stage of wheat flowering, with an interval of 5 to 7 days, preferably 6 days, and the amount of each spraying is 15 to 20 kg / mu, preferably 20 kg / mu.

[0031] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0032] The preparation method of the wheat straw wood vinegar described in the embodiment and application example is as follows: the wheat straw is collected, dried to a moisture content of 20%, and crushed, passed through a 1 cm sieve, 1 kg of the crushed wheat straw is weighed and placed in a muffle furnace at 0.1 m 3 / min rate of nitrogen, the temperature was increased to 400 ° C at a heating rate of 10 ° C / min, and maintained at this temperature for 1.5h, then condensed the volatile gas generated in the cracking process and collected the condensate, while controlling the yield of the condensate to 21.8%, to obtain 218g of condensate, to obtain wheat straw wood vinegar stock solution, after standing for 2 months, passed through a 0.22μm pore size bacterial filter, to obtain a wheat straw wood vinegar with a concentration of 1mg / mL, for standby use.

[0033] The concentration of prothioconazole described in the embodiment is 1 mg / mL, and the preparation method is to dissolve 98% prothioconazole original powder purchased from Jiangsu Pesticide Research Institute Co., Ltd. in acetone to prepare a concentration of 1 mg / mL.

[0034] Example 1

[0035] 1 mL of wheat straw wood vinegar was mixed with 10 mL of prothioconazole to prepare a composition for preventing and controlling wheat fusarium head blight in which the mass ratio of wheat straw wood vinegar to prothioconazole was 0.1:1.

[0036] Example 2

[0037] 5 mL of wheat straw wood vinegar was mixed with 10 mL of prothioconazole to prepare a composition for preventing and controlling wheat fusarium head blight in which the mass ratio of wheat straw wood vinegar to prothioconazole was 0.5:1.

[0038] Example 3

[0039] 5 mL of wheat straw wood vinegar was mixed with 5 mL of prothioconazole to prepare a composition for preventing and controlling wheat fusarium head blight in which the mass ratio of wheat straw wood vinegar to prothioconazole was 1:1.

[0040] Comparative Example 1

[0041] 10 mL of wheat straw wood vinegar was mixed with 2 mL of prothioconazole to prepare a composition for preventing and controlling wheat fusarium head blight in which the mass ratio of wheat straw wood vinegar to prothioconazole was 5:1.

[0042] Comparative Example 2

[0043] 10 mL of wheat straw wood vinegar was mixed with 1 mL of prothioconazole to prepare a composition for preventing and controlling wheat fusarium head blight in which the mass ratio of wheat straw wood vinegar to prothioconazole was 10:1.

[0044] Experimental example

[0045] Test on the control effect of wheat straw wood vinegar and prothioconazole on wheat fusarium

[0046] 1. Test materials

[0047] The standard strain of Fusarium graminearum, PH-1, was stored by the Institute of Agricultural Product Quality and Safety of Jiangsu Academy of Agricultural Sciences for future use. The strain was stored on a potato sucrose agar (PDA) slant (4°C). After transferring once on a PDA medium plate in the laboratory, it was pre-cultured at 25°C for 5 days, and a 5mm diameter cake was taken from the edge of the colony and inoculated into the PDA medium. The wheat fusarium was cultured at a temperature of 25°C and a photoperiod of L:D=12:12h (L is the light time, D is the dark time).

[0048] 2. Test methods

[0049] During the preparation of potato dextrose agar (PDA), prothioconazole, the composition of Examples 1 to 3, and the composition of Comparative Examples 1 to 2 were added in a gradient, and then sterilized to obtain culture media with prothioconazole, the composition of Examples 1 to 3, and the composition of Comparative Examples 1 to 2, respectively, at concentrations of 0, 0.1, 0.5, 1, 1.5, and 2 mg / L. The culture media with prothioconazole added was used as the control group, and the culture media with the composition of Examples 1 to 3 and the composition of Comparative Examples 1 to 2 were used as the treatment group. The mycelium growth rate method was used to determine the indoor biological activity of wheat straw wood vinegar and prothioconazole against wheat fusarium. Under aseptic conditions, when the diameter of the activated cultured wheat fusarium reached 6 cm, a bacterial cake with a diameter of 5 mm was obtained by punching holes along the edge of the colony, and was inoculated into the culture media of the control group and the treatment group, respectively. Each group contained 3 culture media, and repeated 3 times. After being placed in an incubator and cultured for 72 hours, the diameter of each colony was measured by the cross method, the average was taken, and the growth inhibition rate was calculated.

[0050] 3. Calculation formula

[0051] SPSS 25.0 software was used to perform regression analysis with the logarithmic value of the concentration of the agent as the horizontal axis and the value of the mycelium growth inhibition rate as the vertical axis to calculate the agent concentration that resulted in a 50% mycelium growth inhibition rate, i.e., 50% mycelium growth inhibition rate (EC 50 )value.

[0052]

[0053] The diameter of the bacterial cake is the diameter of the bacterial cake at the time of inoculation.

[0054]

[0055] Among them, a synergistic ratio of 1 indicates no synergistic effect; a synergistic ratio greater than 1 indicates a synergistic effect; and a synergistic ratio less than 1 indicates an antagonistic effect.

[0056] 4. Experimental Results

[0057] The colony growth of the control group and the treatment group was observed. Figure 1 shown.

[0058] The synergistic ratio between the control group and the treatment group was determined, and the results are shown in Table 1.

[0059] Table 1 Synergistic ratio between control group and treatment group

[0060] name <![CDATA[EC 50 (mg / L)]]> <![CDATA[R 2 ]]> 95% confidence interval (mg / L) Efficiency ratio Control group 0.36 0.97 0.21～0.53 / Example 1 0.18 0.98 0.13～0.24 2 Example 2 0.16 0.97 0.10～0.22 2.25 Example 3 0.24 0.99 0.13～0.36 1.5 Comparative Example 1 2.01 0.96 0.72～11.06 0.18 Comparative Example 2 18.41 0.96 / 0.02

[0061] Depend on Figure 1As shown in Table 1, in the compositions of Examples 1 to 3, the wheat straw wood vinegar has a significant synergistic effect on the prevention and treatment of wheat scab by prothioconazole, and the synergistic ratios are 2, 2.25 and 1.5, respectively. In the compositions of Comparative Examples 1 to 2, the wheat straw wood vinegar has an antagonistic effect on the prevention and treatment of wheat scab by prothioconazole, and the synergistic ratios are 0.18 and 0.02, respectively.

[0062] Application Examples

[0063] 1. Test materials

[0064] Wheat, the variety is Jimai 22.

[0065] Drugs: 30% prothioconazole dispersible oil suspension (OP) was purchased from Anhui Jiuyi Agriculture Co., Ltd., and 50% carbendazim wettable powder (WP) was purchased from Sichuan Chuandong Pesticide Chemical Co., Ltd. The contents of the two agents are both mass percentages.

[0066] 2. Test time and location

[0067] Test time: The first control will be carried out at the early stage of wheat flowering (April 17, 2024); the second control will be carried out after an interval of 7 days.

[0068] Test location: Experimental field of Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu Province.

[0069] Climate conditions: On the day of the first wheat scab control, the temperature was 10-16℃, sunny, and the wind direction was level 2 northeasterly wind; on the second wheat scab control, the temperature was 16-25℃, cloudy, and the wind direction was level 3 southeasterly wind. From the first control to the wheat harvest (April to June), the climate in the experimental field was mild, with an average temperature of 25℃ and moderate rainfall.

[0070] Cultivation conditions: The soil is paddy soil, with an organic matter content of 20g / kg and a pH value of 7.1, which is a wheat scab prone area. The test site has medium fertility, flat terrain, and a complete drainage and irrigation system. During the test, the wheat was in good growth condition, with a uniform growth period and was in the early stage of wheat flowering. The soil fertility, cultivation and fertilization management levels of the selected test plots are consistent and consistent with the actual local agricultural production.

[0071] 3. Experimental design based on plot setting

[0072] The experimental design was carried out in accordance with the standard operating requirements of NY / T788-2018 Pesticide Residue Test Guidelines in Crops. Each treatment was repeated three times, and the plot area was 5m×10m.

[0073] The experimental design is shown in Table 2, where treatments A, B, C, and D were the application areas, treatment E was the control area, each treatment was repeated 3 times, and a total of 15 plots were set up.

[0074] Table 2 Field test design of wheat straw wood vinegar for enhancing the effect of prothioconazole on the control of wheat scab

[0075]

[0076] 4. Investigation methods for wheat fusarium head blight

[0077] Five points were selected diagonally near the middle of the experimental plot, and 100 wheat plant segments were cut from each point, for a total of 500 plants. The number of diseased ears at all levels of fusarium head blight was recorded to calculate the diseased ear rate, disease index, diseased ear control effect, and disease index control effect of fusarium head blight. The experimental data were analyzed using Microsoft Excel 2010 and SPSS 25.0.

[0078] Grading standards for the severity of wheat fusarium wilt and classification of wheat ear disease conditions, grading method:

[0079] Level 0: The whole ear is disease-free;

[0080] Level 1: The area of ​​diseased spikelets accounts for less than 1 / 4 of the whole spike area;

[0081] Level 3: The area of ​​diseased spikelets accounts for 1 / 4 to 1 / 2 of the whole spike area;

[0082] Level 5: The area of ​​diseased spikelets accounts for 1 / 2 to 3 / 4 of the whole spike area;

[0083] Level 7: The area of ​​diseased spikelets accounts for more than 3 / 4 of the total spike area.

[0084]

[0085] 5. Wheat seed toxin extraction method

[0086] The collected wheat samples were ground and set aside for use to extract vomitoxin (DON) as follows:

[0087] (1) Weigh 5.0 g of the sample to be tested into a 50 mL centrifuge tube, add 20 mL of extraction solution (50% acetonitrile water containing 1% formic acid), shake at 2500 g for 5 min, and centrifuge at 3400 g for 5 min;

[0088] (2) Pipette 2 mL of supernatant into a 5 mL centrifuge tube, add a salt pack (200 mg MgSO4, 100 mg C6H5Na3O7, 100 mg NaCl, 100 mg C18), shake at 2500 g for 2 min, and centrifuge at 3400 g for 5 min;

[0089] (3) The supernatant was pipetted into a clean glass test tube, concentrated by nitrogen blowing, and the product was re-dissolved with 0.5 mL of a reconstitution solution (50% chromatographic acetonitrile water containing 0.1% formic acid), filtered through a 0.22 μm filter membrane to remove impurities, and placed in a liquid phase vial. The content of DON toxin in the sample was determined by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS / MS).

[0090] 6. Experimental Results

[0091] The control effect of wheat straw wood vinegar combined with prothioconazole on wheat fusarium scab was determined. The results are shown in Table 3. The crop growth in the treated area was visually observed 1 day, 3 days, and 7 days after application, and the wheat grew normally without any pesticide damage.

[0092] Table 3 Effects of different applied pesticides on the control of wheat scab

[0093]

[0094] As can be seen from Table 3, the synergistic use of wheat straw wood vinegar and prothioconazole in a reasonable ratio in the present invention can effectively prevent and reduce the actual incidence of wheat scab in the field. The application dosage is 40 mg / mu 30% prothioconazole OD combined with 6 mL / mu wheat straw wood vinegar (the mass ratio of wheat straw wood vinegar to prothioconazole effective ingredients is 0.5:1), which is equivalent to the application dosage of 30 mg / mu 30% prothioconazole OD combined with 4.5 mL / mu wheat straw wood vinegar (the mass ratio of wheat straw wood vinegar to prothioconazole effective ingredients is 0.5:1). The control effect is comparable, and the average disease index control effect is 12.26% and 9.38% higher than that of 30% prothioconazole OD sprayed alone, and 35.26% and 33.13% higher than that of the control agent 50% carbendazim WP. As shown in the data, the synergist of the present invention can significantly improve the efficacy of prothioconazole, significantly reduce toxicity under the same medication conditions, reduce the amount of chemical pesticides used, and effectively overcome and delay the drug resistance of wheat fusarium head blight.

[0095] As can be seen from the above embodiments, the present invention provides the application of wheat straw wood vinegar as a fungicide synergist of a fungicide in preventing and controlling wheat scab. The present invention uses wheat straw wood vinegar as a fungicide synergist of a fungicide, which can significantly improve the efficacy of prothioconazole, greatly reduce the amount of prothioconazole under the same prevention effect, overcome or delay the medicinal properties of harmful organisms, and the composition prepared by mixing with prothioconazole has a significant effect on preventing and controlling wheat scab, significantly reducing the pollution of DON toxins in wheat grains, and the raw material source is wide, and the extraction method is simple, with the advantages of safety, environmental protection, and reducing environmental pollution, and adhering to the advantages of not easily generating cross-resistance with chemical pesticides and easily degradable plant-derived synergists.

[0096] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Application of wheat straw wood vinegar as a fungicide synergist in the prevention and treatment of wheat ergot.

2. The use according to claim 1, characterized in that: The fungicide is prothioconazole.

3. A composition for preventing and treating wheat scab, characterized in that: The invention comprises wheat straw wood vinegar and prothioconazole, and the mass ratio of the wheat straw wood vinegar to prothioconazole is 0.1-1:

1.

4. The method for preparing the composition according to claim 3, characterized in that: Wheat straw wood vinegar and prothioconazole are weighed according to a mass ratio, mixed, and a composition for preventing and controlling wheat fusarium head blight is obtained.

5. Use of the composition according to claim 3 or the composition prepared by the preparation method according to claim 4 in preparing products for preventing and treating wheat scab.

6. A method for using a composition for preventing and treating wheat scab, characterized in that: Spraying the composition at the early stage of wheat flowering; The composition is the composition according to claim 3 or the composition prepared by the preparation method according to claim 4.

7. The method of use according to claim 6, characterized in that: The composition is sprayed 2-3 times at the early stage of wheat flowering, the spraying time interval is 5-7 days, and the amount of each spraying is 15-20 kg / mu.

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