CN115553296A

CN115553296A - Thiediazole and pyraclostrobin compounded konjak root rot resistant bactericidal composition

Info

Publication number: CN115553296A
Application number: CN202211145991.3A
Authority: CN
Inventors: 饶家瑞; 罗林丽; 周雪; 周玉锋; 赵兴丽; 张欣; 孟泽洪; 李帅; 张金峰
Original assignee: Guizhou tea research institute; Guizhou Institute Of Biotechnology Guizhou Key Laboratory Of Biotechnology Guizhou Potato Research Institute Guizhou Food Processing Research Institute
Current assignee: Guizhou tea research institute; Guizhou Institute Of Biotechnology Guizhou Key Laboratory Of Biotechnology Guizhou Potato Research Institute Guizhou Food Processing Research Institute
Priority date: 2022-09-20
Filing date: 2022-09-20
Publication date: 2023-01-03

Abstract

The invention relates to an agricultural bactericide composition, in particular to a bactericide composition containing thiabendazole and pyraclostrobin, wherein the mass ratio of thiabendazole to pyraclostrobin is 95-20. Compared with a single agent, the sterilization composition has a relatively obvious synergistic effect on the fusarium oxysporum and improves the control effect; the medicine consumption is reduced, the low toxicity and the low residue are realized, and the pollution to the environment is reduced; due to the difference of the antibacterial mechanisms of the two raw medicines, the generation of drug resistance is favorably slowed down. The invention has no obvious adverse effect on the leaves and the growth of the konjak, meets the safety requirement of pesticide preparations, and has good prevention effect on the fusarium oxysporum of the konjak.

Description

Thiediazole and pyraclostrobin compounded konjak root rot resistant bactericidal composition

Technical Field

The invention relates to wettable pesticide powder and a pesticide suspending agent, in particular to wettable pesticide powder and a pesticide suspending agent compounded by thiabendazole and pyraclostrobin.

Background

Konjak, also known as Spanish Maranta, amorphophallus konjac, etc., has important medicinal health care functions. The konjak tuber is rich in glucomannan (KGM), can be widely used in the industries of food, medical treatment, agriculture and the like, and is an important economic crop in Guizhou. China is a large country for producing konjak and accounts for more than 60% of the total world production. The suitable growth area of the konjak in the Guizhou mountain area occupies the front row of the country, so that the konjak planting becomes an important way for increasing the income of vast farmers in Guizhou. However, with the increase of planting area and age, the konjac root rot can cause severe yield reduction of konjac, and the healthy development of the konjac industry is restricted.

The Thiabendazole is white to off-white odorless powder with the name of Thiabendazole and the chemical formula of C ₁₀ H ₇ N ₃ S, melting point 298 ℃, CAS No.: 148-79-8, acute oral LD of rat ₅₀ About 6100mg/kg, has mild irritation to rabbit eyes, and no irritation to skin. The bactericide has no carcinogenic, teratogenic and mutagenic effects under the test dosage, and is a low-toxicity bactericide.

Pyraclostrobin is white to light beige odorless crystal, having English name pyraclotrobine and chemical formula C ₁₉ H ₁₈ ClN ₃ O ₄ Melting point 63.7 ℃, CAS No.: 175013-18-0. Original drug rat acute oral LD ₅₀ >5000mg/kg, no irritation to eyes and skin of rabbits, and is a novel broad-spectrum bactericide. The structural formula is as follows:

the single medicament is used for preventing and treating diseases, and the diseases easily generate drug resistance due to the same antibacterial mechanism, so that the reagent control effect of the medicament is quickly reduced, and a large amount of economic loss of crops due to disease outbreak is caused. Therefore, it is urgent to reduce the generation speed of drug resistance and increase the prevention effect of the drug in the field.

Disclosure of Invention

The invention aims to overcome the problems that the control effect of a single bactericide is reduced due to the rise of drug resistance and the generation of the drug resistance is delayed. Finally, the bactericidal composition with good bactericidal effect, low cost and slow drug resistance generation is provided.

The probenazole is an imidazole bactericide, has an action mechanism of inhibiting the formation of tubulin in the mitosis process of fungi, has the performance of internal absorption to apical conduction, has protection and treatment effects, and is a high-efficiency, broad-spectrum and internationally universal bactericide. Pyraclostrobin is strobilurin fungicide, mainly leads to cell death by inhibiting mitochondrial respiration, and has the functions of protection, treatment and leaf penetration and conduction. Pyraclostrobin has direct effect on pathogenic bacteria, and can induce physiological phenomena of many crops, such as improving nitrogen absorption and promoting crop rapid growth, thereby increasing crop yield. The invention hopes that the aim of enhancing the toxicity strength is achieved by combining two agricultural medicines with different antibacterial mechanisms, so that the aims of reducing toxicity, improving antibacterial activity and delaying drug resistance are fulfilled.

Another object of the present invention is to provide the use of the fungicidal composition for the prevention and control of root rot of konjak caused by Fusarium oxysporum (Ak-XY-2).

In order to achieve the above purpose, the present invention provides a bactericidal composition, wherein the mass ratio of tebuconazole to thymol is 95-20.

The bactericidal composition also comprises one or a mixture of more of a protective agent, a growth regulator, a plant nutrient or a soil regulator.

The invention also provides a bactericide, wherein the bactericide contains 1-40% of the effective components of probenazole and pyraclostrobin; contains 0.1 to 50 percent of the composition and the balance of carriers and auxiliary agents acceptable to pesticides.

According to a preferred embodiment of the fungicide of the present invention, the formulation thereof is wettable powder and suspension.

The invention also provides application of the bactericidal composition in preventing and treating fusarium oxysporum.

The invention also provides a method for controlling crop diseases, which is to apply the bactericidal composition to the root, the rhizome or the leaf of the konjak before or after the konjak is infected with the diseases or to the soil where the konjak grows.

The technical solution of the present invention will be described in more detail below:

the invention provides a bactericidal composition, which contains probenazole and pyraclostrobin, wherein the mass ratio of the probenazole to the pyraclostrobin is 95-20.

Preferably, the mass ratio of the thiabendazole to the pyraclostrobin is 95.

For wettable powder, 4% calcium lignosulfonate, 4% NNO, 1%K-12, 5% white carbon black and light calcium are added to 100%, and the product is obtained after uniform mixing and crushing.

And for the suspending agent, FS3000 (phosphate anionic surfactant), NS-500LQ (nonionic hydroxy polyethylene oxide block copolymer), 0.1% of xanthan gum, 0.1% of magnesium aluminum silicate, 5% of ethylene glycol and 0.3% of organic modified siloxane defoaming agent are used, and the balance is deionized water added to 100%, so that slurry is prepared and then is subjected to sanding to obtain the product.

All the "%" referred to in the present invention are "mass%" unless otherwise specified.

The bactericidal composition also comprises one or a mixture of more of a protective agent, a growth regulator, a plant nutrient or a soil regulator. The protectant, growth regulator, plant nutrient or soil conditioner is a commercially available product.

The auxiliary agents for the wettable powder are as follows: the dispersant is selected from: polycarboxylates, lignosulfonates, alkylnaphthalenesulfonates; the wetting agent is selected from: alkyl sulfates, alkyl sulfonates; the filler is selected from: diatomite, kaolin, white carbon black, light calcium carbonate, talcum powder and the like.

For the selection of the processing aid for the suspending agent, the dispersing agent is selected from: lignosulfonates, alkylnaphthalene sulfonates, FS3000 (phosphate type anionic surfactants); the wetting agent is selected from: alkyl phenol polyoxyethylene polyether formaldehyde condensate sulfate, alkyl phenol polyoxyethylene ether phosphate, alkyl sulfate, alkyl sulfonate, naphthalene sulfonate, NS-500LQ (nonionic hydroxy polyethylene oxide block copolymer); the thickener is selected from: xanthan gum, magnesium aluminum silicate and bentonite; the defoaming agent is: an organomodified silicone defoamer; the antifreeze is selected from: ethylene glycol, propylene glycol, glycerol.

The bactericidal composition can be provided in the form of a finished preparation, namely, all the substances in the composition are mixed; it can also be provided in a single dose formulation, mixed directly in a tub (tank) prior to use. The concentrates of the invention are typically mixed with water to give the desired concentration of active.

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

(1) Compared with a single agent, the compounded bactericidal composition has a remarkable synergistic effect on the antibacterial effect due to the synergistic effect of different antibacterial mechanisms under the same mass concentration, and the prevention and control effect of the bactericide can be improved.

(2) Two raw medicines forming the bactericidal composition, namely thiabendazole, have the action mechanism of inhibiting the formation of tubulin in the mitosis process of fungi, and pyraclostrobin finally causes cell death mainly through the action of inhibiting mitochondrial respiration. The two medicines with different antibacterial mechanisms are compounded, so that the killing property of the composition on diseases can be improved, and the generation time of drug resistance can be delayed.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the invention to these embodiments. It will be appreciated by those skilled in the art that the present invention encompasses all alternatives, modifications and equivalents as may be included within the scope of the claims.

1. Preparation examples

The percentage contents in all the preparation ratios are mass percentages.

1. Wettable powder

According to the formula requirement, various auxiliary agents, fillers and original drugs of a crusher are mixed by coarse powder in advance, and then the mixture is fully crushed and mixed in a jet mill to prepare wettable powder.

Example (b): 40% probenazole-pyraclostrobin (effective component ratio 95

Weighing 38% of thiabendazole original drug, 2% of pyraclostrobin original drug, 4% of calcium lignosulfonate, 4% of NNO, 1%K-12 and 5% of white carbon black, adding the light calcium to 100%, uniformly mixing, and crushing to obtain the product.

2. Suspending agent

According to the formula proportion, the ionic water is used as a medium, the original drug, the dispersing agent, the suspending agent, the antifreezing agent and the like are added into a high-shear emulsifying machine for shearing for 30min, and then a sand mill is used for sanding to obtain the suspending agent.

Example (b): 30% probenazole-pyraclostrobin (effective ingredient ratio 95

28.5% thiabendazole technical, 1.5% pyraclostrobin technical, 3.5% FS3000 (phosphate anionic surfactant), 1% NS-500LQ (nonionic hydroxy polyethylene oxide block copolymer), 0.1% xanthan gum, 0.1% magnesium aluminum silicate, 5% ethylene glycol, 0.3% organic modified siloxane defoamer and deionized water are weighed to 100% to prepare slurry and sand the slurry to obtain the product.

2. Biological activity assay

The biological activity test is divided into an indoor toxicity test and a living body control effect test

Activity experiment 1: indoor toxicity determination of thiabendazole-pyraclostrobin compound bactericide on fusarium konjac

Fusarium oxysporum (Ak-XY-2) of konjak is provided by the research institute of biotechnology of agricultural academy of sciences of Guizhou province, and the joint toxicity strength of different compound formulas is evaluated by a co-toxicity coefficient method in the experiment, so that the reasonable proportion is determined.

The PDA culture medium preparation and fungus activation method comprises the following steps:

weighing 800 g of peeled potatoes, boiling, filtering, adding 80g of agar and 80g of glucose, uniformly mixing and dissolving, transferring 45mL of agar and 80g of glucose into a 100mL conical flask, sealing, autoclaving at 120 ℃ for 30min, and cooling for later use. The mycelia were picked and placed on sterilized PDA plates, and cultured in an incubator at 25 ℃ and 70% humidity for 3 days.

Formulation of the drug solution and EC ₅₀ The test method comprises the following steps:

based on the predicted probenazole pyraclostrobin EC ₅₀ Values, established as a built test concentration gradient of 1. Mu.g/mL, 0.5. Mu.g/mL, 0.25. Mu.g/mL, 0.125. Mu.g/mL, and 0.0625. Mu.g/mL, respectively. The mass ratio of the probenazole-pyraclostrobin test is 95-20. The experiment is divided into 7 groups of compound combinations with different mass ratios, a culture medium containing dimethyl sulfoxide is used as a blank control CK, and 3 experiments in each group are arranged in parallel. The adding amount of probenazole and pyraclostrobin is calculated according to the mass concentration ratio, the probenazole and pyraclostrobin are respectively added into 5mL of deionized water containing Tween 80, the deionized water and the Tween 80 are evenly mixed, the mixture is poured into the 45mL of PDA culture medium to be evenly mixed, the mixture is poured into 3 flat plates on average, and the flat plates are left for 2 hours to be used. The bacterial cake was inoculated on the above culture medium containing the drug solution by punching with a 4mm punch, and cultured in an incubator at 25 ℃ and a humidity of 70% for 7 days. Finally, the growth diameter of each cake was measured by the cross method. And the inhibition ratio I (%) was calculated according to the following formula:

the colony growth diameters after blank and agent treatments are indicated by C and T, respectively.

According to the logarithm of the concentration and the bacteriostasis rate of the medicament, a regression line and EC are obtained ₅₀ And a correlation coefficient R ² . Obtaining an Actual Toxicity Index (ATI) according to a calculation method of the Sun Yunpei; the Theoretical Toxicity Index (TTI) is calculated according to the compounding ratio, and the co-toxicity coefficient (CTC) of the compounding formula is calculated according to the following formula.

S: EC of standard fungicide ₅₀

M: EC of the mixture ₅₀

TTI＝TI _A ×P _A +TI _B ×P _B

TI _A The toxicity intensity of a single agent of the A medicament; p _A Is the percentage content of the A medicament in the mixture

TI _B The virulence strength of a single agent of the B medicament; p is _B Is the percentage content of the B medicament in the mixture

If the co-toxicity coefficient is more than 120, the synergistic effect is shown; 120-100 shows that the additive effect is achieved; antagonism is indicated below 100

TABLE 1 indoor toxicity of Thiedipham and pyraclostrobin for compounding pair of Fusarium amorphophalli ^a

“ ^a "Each experiment was repeated three times.

From the results in table 1, the blending of thiabendazole and pyraclostrobin shows a synergistic effect on fusarium konjac in a mass ratio of 95-20. The result shows that the probenazole and the pyraclostrobin have obvious synergistic effect and EC according to the mass ratio of 95 ₅₀ The value is better, and meanwhile, the specific gravity of the natural product is increased, so that the potential toxicity of the compound medicament can be further reduced, and the influence on the environment is reduced.

Activity experiment 2: in vivo efficacy test of Fusarium oxysporum

The konjak is planted in a flowerpot, and the experiment can be started after the growth height of the konjak is more than 20 cm. Under the growth condition of a large greenhouse, the protection and treatment effects of the compound combination after the potted konjak is inoculated with the fusarium oxysporum are evaluated. Day one, treatment group: cleaning rhizoma Amorphophalli root, cutting into 0.5cm thick pieces, perforating 4mm fungus cake with a puncher, inoculating to the surface of the pieces, and covering with wet cotton; protection group: uniformly spraying each liquid medicine with the concentration of 200 mug/mL on the cut surface; the following day, treatment group: uniformly spraying the liquid medicine with the concentration of 200 mug/mL on the cut surface; protection group: the procedure of the first day of the treatment group was repeated. Finally, the konjak was placed in a petri dish (the bottom of the dish was flooded with a small amount of water to the slices) and incubated in an incubator at 25 ℃ for 6d.

DSA is the percentage of disease determined by cutting the root section and according to the ratio of the diseased area to the total area, and the classification system classifies the cut surfaces as follows:

grade 1, DSA <5%;

grade 3, DSA is between 6 and 10 percent;

grade 5, DSA is between 11-20%;

grade 7, DSA is between 21 and 50 percent;

level 9, DSA >50%.

The disease index (C) is calculated as follows:

the disease control efficiency (I) is calculated as follows:

wherein C represents the disease index of the control group and T represents the disease index of the reconstituted group.

TABLE 2 in vivo control results for Fusarium oxysporum of Amorphophallus konjac

a: the wettable powder comprises 40 percent of active ingredients of probenazole and pyraclostrobin and the balance of various additives

b: the effective components of the suspending agent are 30 percent of probenazole and pyraclostrobin, and the rest is the various auxiliary agents

c: blank control

As can be seen from the results in Table 2, the control effect of the wettable powder is better than that of the suspending agent; both protective activities are superior to the therapeutic activity. Meanwhile, the control effect of the wettable powder is close to that of thiabendazole.

The indoor toxicity test and the living body control effect test show that:

(1) The bactericide composition reduces the problem of possible drug failure caused by ultraviolet, rainwater, drug adsorption and the like by adding a preparation. Compared with a single preparation, the wettable powder and the suspending agent respectively achieve the control effects of 76 percent and 62 percent of thiabendazole with the content of 40 percent and 30 percent under the same mass concentration. Proved by experiments, the two medicines with different antibacterial mechanisms play a more obvious synergistic role in the actual prevention effect of resisting the fusarium konjac.

(2) The composition consists of active ingredients with different antibacterial action mechanisms, and can delay the generation of drug resistance. The invention has no adverse effect on the leaves and the growth vigor of crops and meets the safety requirement of pesticide preparations.

The sterilization composition has good prevention effect on fusarium oxysporum of konjak.

Claims

1. The bactericidal composition is characterized by comprising the following components: the mass ratio of the thiabendazole to the pyraclostrobin is 95-20.

2. A formulation suitable for agricultural use, characterized by: the preparation is a compound pesticide sterilization composition containing thiabendazole and pyraclostrobin.

3. The composition of claim 1, wherein: the dosage form of the composition is wettable powder or suspension.

4. Use of the composition of claim 1 for controlling fusarium konjac.

5. The composition of claim 3, wherein: the wettable powder comprises the following components in parts by mass:

28 to 38 percent of thiabendazole;

12% -2% pyraclostrobin;

4% calcium lignosulfonate;

4％NNO；

1％K-12；

5% of white carbon black;

adding light calcium to 100%, mixing uniformly and grinding to obtain the product.

6. The composition of claim 3, wherein: the suspending agent comprises the following components in parts by mass:

22.5 to 28.5 percent of thiabendazole;

7.5 to 1.5 percent of pyraclostrobin;

3.5% of FS3000 (phosphate type anionic surfactant);

1% NS-500LQ (nonionic hydroxypolyethylene oxide block copolymer);

0.1% xanthan gum;

0.1% magnesium aluminum silicate;

5% ethylene glycol;

0.3% of an organomodified silicone defoamer;

deionized water is added to 100 percent to prepare slurry, and then sanding is carried out to obtain the product.