CN115943962B - Sterilization composition for preventing and treating banded sclerotial blight of wheat - Google Patents

Abstract

The invention belongs to the technical field of pesticides, and in particular relates to a bactericidal composition for preventing and treating banded sclerotial blight of wheat. A bactericidal composition for preventing and treating wheat sheath blight is prepared by compounding flutriafol and penflufen or fluopicolide. The sterilization composition has different action mechanisms of the flutriafol and the penflufen or the fluopicolide, and can inhibit pathogenic bacteria from different action sites when being used in combination, so that the development of pathogen resistance can be delayed, and the service life of the medicament can be prolonged. In addition, the bactericidal composition disclosed by the invention has a synergistic effect on inhibiting rhizoctonia cerealis which is a pathogenic bacterium of the sheath blight of wheat, and can improve the control effect on the sheath blight of wheat, so that the application dosage of pesticides can be reduced, and the control cost is reduced.

Description

A kind of bactericidal composition for preventing and controlling wheat sheath blight

Technical Field

The invention belongs to the technical field of pesticides, and in particular belongs to a bactericidal composition for preventing and treating wheat sheath blight.

Background technique

Wheat is an important food crop in my country. At present, wheat sheath blight caused by Rhizoctonia cerealis has become a worldwide soil-borne fungal disease. According to incomplete statistics, wheat sheath blight generally causes 5-40% yield loss, and even causes no grain harvest in severe cases. At the same time, due to the lack of stable disease-resistant wheat varieties to wheat sheath blight, coupled with global warming, increased field nitrogen fertilizer use and straw return to the field in recent years, the disease has become an important disease in my country's main wheat producing areas such as Henan Province, Shandong Province, and Anhui Province, and has seriously affected the high quality and high yield of wheat. Existing reported agents for the prevention and control of wheat sheath blight include: thiophanate-methyl, tebuconazole, diniconazole, tebuconazole and propiconazole, but due to continuous single use for many years, the resistance problem has developed rapidly, the detection rate of resistant strains has increased sharply, and the prevention effect has decreased year by year. Therefore, it is necessary to develop new alternative agents or new compound agents.

Fluopicolide is a pyrazoleamide fungicide developed by Bayer. The fungicide is a succinate dehydrogenase inhibitor that mainly acts on the electron transfer complex II of the respiratory chain to block energy metabolism. It can be used to control soil-borne or seed-borne diseases caused by Basidiomycetes and Ascomycetes in a variety of crops such as potatoes, corn, rice, cotton, wheat, alfalfa, vegetables and rapeseed, such as potato black mole, wheat sheath blight, rice sheath blight and corn leaf spot.

Fluopyram is a pyridine amide fungicide developed by Bayer, which acts on spectrin, thereby affecting cell mitosis. It is mainly used in crops such as rice, and has excellent activity against most pathogens of the Basidiomycetes, and has a good control effect on plant diseases caused by Rhizoctonia, such as rice sheath blight, rice sclerotinia and white rot.

Flutriafol is a triazole sterol demethylation inhibitor fungicide developed by Syngenta Group Co., Ltd. Flutriafol can effectively inhibit the biosynthesis of ergosterol and cause the rupture of fungal cell walls. It has a broad spectrum of antibacterial activity and strong systemicity, and has good protective and therapeutic effects on many fungal diseases caused by basidiomycetes and ascomycetes. The prior art has disclosed the compounding of flutriafol and other chemical agents. For example, CN201410788209.9 discloses a compound composition and fungicide containing mesotrione and flutriafol, and specifically discloses that mesotrione and flutriafol can be used to prevent and treat bacterial and fungal diseases after compounding, such as rice bacterial leaf streak, citrus canker, tomato bacterial wilt and peanut leaf spot. In addition, CN201310061385.8 also discloses a fungicide composition containing fluopyram, and specifically discloses that the combination of fluopyram and flutriafol has high activity against a variety of diseases on a variety of crops, and has a significant synergistic effect and an expanded fungicide spectrum.

So far, there are no reports on the combination of flutriafol and carbendazim, thiram or enoxamil.

The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

Summary of the invention

The object of the present invention is to provide a fungicide composition for preventing and controlling wheat sheath blight, which can improve the prevention and control effect on wheat sheath blight and solve the problems existing when using a single chemical agent.

To achieve the above object, the present invention provides the following technical solutions:

The first object of the present invention is to provide a fungicide composition for preventing and controlling wheat sheath blight, which is compounded by flutriafol and trifloxystrobin or trifloxystrobin.

Preferably, the mass ratio of flutriafol to pentofenac is 1-40:30-1.

Preferably, the mass ratio of flutriafol to fluopyram is 1-15:15-1.

The second object of the present invention is to provide a fungicide, comprising the fungicide composition for preventing and controlling wheat stripe blight and auxiliary components, wherein the auxiliary components are selected from one or more of a dispersant, a wetting agent, an emulsifier, a solvent, a binder, a disintegrant, a thickener, a filler, an antifreeze agent, a stabilizer, a preservative, and a defoaming agent.

Compared with the prior art, the present invention has the following beneficial effects:

(1) Flutriafol and trifloxystrobin or fluopyram in the fungicidal composition of the present invention have different mechanisms of action. When used in combination, they can inhibit pathogens from different action sites, thereby delaying the development of pathogen resistance and extending the service life of the agent.

(2) The fungicidal composition of the present invention exhibits a synergistic effect on inhibiting the pathogen of wheat sheath blight, Rhizoctonia graminearum, which can improve the control effect of wheat sheath blight, thereby reducing the application dosage of pesticides and reducing the control cost.

Detailed ways

The present invention can be better understood according to the following examples. However, it is easy for those skilled in the art to understand that the contents described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

Example : Screening of control agents

1. Test strain: Rhizoctonia cerealis, collected from diseased wheat strains in the Xinlianxin Experimental Base in Langgongmiao Town, Xinxiang County, Henan Province, isolated in the laboratory, and preserved on PDA culture medium.

2. Test Drugs

95% flutriafol TC (commercially available), 95% fluopicolide TC (commercially available), 97% fluopicolide TC (commercially available)

The test agent was first dissolved in dimethyl sulfoxide and then diluted with 0.1% Tween-80 aqueous solution to prepare a single-dose stock solution. Multiple groups of proportions were set, and each single dose and proportioned mixture was set with 5 mass concentration gradients according to the equal ratio method.

3. Test methods

The mycelium growth rate method was used. 9 mL of pre-melted PDA medium was added to a sterile conical flask, and 1 mL of the drug solution was quantitatively drawn from low concentration to high concentration, respectively, and added to the above conical flasks. After being fully shaken, it was poured into a culture dish with a diameter of 9 cm to make a drug-containing plate of the corresponding concentration; and a treatment without drug was set as a blank control, and 10 replicates were set for each treatment. A 5 mm diameter puncher was used to cut the bacterial cake at the edge of the test strain colony, inoculated in the center of the drug-containing plate and the blank control plate, covered with a dish cover, and placed in a 25°C constant temperature box for culture. When the diameter of the blank control colony reached more than 2/3 of the diameter of the culture dish, the colony diameter was measured by the cross method, and the mycelium growth inhibition rate of different treatments was calculated.

4. Data analysis: DPS software was used for data statistical analysis. Linear regression was performed with the logarithmic value of fungicide concentration as x and the corresponding probability value of mycelium growth inhibition rate as y to obtain the toxicity regression equation and the toxicity _EC50 value of the agent to the target pathogen. The co-toxicity coefficient (CTC) was calculated according to the Sun Yunpei method.

In the above formula: ATI - the toxicity index of the mixture measured; S - the EC ₅₀ of the standard agent, the unit is mg/L; M - the EC ₅₀ of the mixture, the unit is mg/L.

TTI＝TI _A × _PA +TI _B × _PB

In the above formula: TTI is the theoretical toxicological index of the mixture; TI _A is the toxicity index of agent A; _PA is the percentage of agent A in the mixture, in percentage (%); TI _B is the toxicity index of agent B; _PB is the percentage of agent B in the mixture, in percentage (%).

In the above formula: CTC--co-toxicity coefficient; ATI--actual toxicity index of the mixture; TTI--theoretical toxicity index of the mixture.

5. Measurement results

The synergistic effect of the drug was evaluated based on the calculated co-toxicity coefficient (CTC), CTC≤80 was antagonistic effect, 80＜CTC＜120 was additive effect, and CTC≥120 was synergistic effect. The results are shown in Table 1-3.

Table 1 Indoor bioactivity determination of flutriafol and trifloxystrobin against Rhizoctonia cerealis

Drug name and ratio EC50(mg/L) ATI TTI CTC Flutriafol 0.8316 100.0000 -- -- Fluoxathiapiprolin 4.4651 18.7252 -- -- Flutriafol 1: Flutriafol 30 3.1497 26.5454 21.3470 124.3519 Flutriafol 1: Flutriafol 20 2.5781 32.4309 22.5955 143.5283 Flutriafol 1: Flutriafol 10 0.9857 84.8230 26.1138 324.8200 Flutriafol 1: Flutriafol 5 1.9704 42.4330 32.2710 131.4895 Flutriafol 1: Flutriafol 1 0.4782 174.8432 59.3626 294.5341 Flutriafol 5: Flutriafol 1 0.6467 129.2872 86.4542 149.5441 Flutriafol 10: Flutriafol 1 0.4453 187.7611 92.6114 202.7408 Flutriafol 20: Flutriafol 1 0.1256 665.6847 96.1298 692.4855 Flutriafol 30: Flutriafol 1 0.4162 200.8890 97.3782 206.2976 Flutriafol 40: Flutriafol 1 0.6095 137.1780 98.0177 139.9523

As shown in Table 1, after flutriafol and trifloxystrobin were compounded, the co-toxicity coefficients against Rhizoctonia graminearum were all greater than 120 in the mass ratio range of 1-40:30-1, showing a synergistic effect.

Table 2 Indoor bioactivity determination of flutriafol and fluopyram against Rhizoctonia cerealis

As shown in Table 2, after fluopicolide and fluopicolide were compounded, the co-toxicity coefficients against Rhizoctonia graminearum were all greater than 120 in the mass ratio range of 1-15:15-1, showing a synergistic effect.

In summary, when flutriafol and trifloxystrobin or fluopyram are compounded in the fungicidal composition of the present invention, they show a synergistic effect in inhibiting the pathogen of wheat sheath blight, which can improve the control effect of wheat sheath blight, thereby reducing the application dosage of pesticides and reducing the control cost.

The above is only a preferred embodiment of the present invention. Those skilled in the art may make appropriate improvements without departing from the principle of the present invention. These improvements are also within the protection scope of the present invention.

Claims (3)

1. A bactericidal composition for preventing and controlling wheat sheath blight, characterized in that it is compounded by flutriafol and fluopyram, and the mass ratio of flutriafol to fluopyram is 1-15:15-1. 2. A fungicide, characterized in that it comprises the fungicide composition for preventing and controlling wheat stripe blight according to claim 1 and auxiliary components. 3. The fungicide according to claim 2, characterized in that the auxiliary ingredients are selected from one or more of a dispersant, a wetting agent, an emulsifier, a solvent, a binder, a disintegrant, a thickener, a filler, an antifreeze agent, a stabilizer, a preservative, and a defoaming agent.