Propamidine and tetraconazole compound composition, bactericide and application

Abstract

The invention provides a compound composition of propamidine and tetraconazole, a bactericide and application. The composition comprises propamidine and tetraconazole, and the mass ratio of propamidine to tetraconazole is (1-10): (10-1). Propamidine and tetraconazole are compounded to be used for preventing and treating corn northern leaf blight, powdery mildew of fruits, vegetables and grains, gray mold, rice blast and other crop fungal diseases, an obvious synergistic interaction effect is achieved, the dosage of the pesticide can be remarkably reduced, and the compounded preparation has the potential of being developed into a new generation of environment-friendly, efficient and low-toxicity agricultural fungicide.

Description

Technical Field

[0001] The invention belongs to the field of agricultural fungicides, and specifically relates to a compound composition of propanamidine and tetrafluthriae, a fungicide and application thereof. The compound of the two compounds is used to prevent and treat corn leaf blight, powdery mildew of fruits, vegetables and grains, gray mold and rice blast, and belongs to a new use of fungicides and an invention of application technology thereof. Background Art

[0002] Crop diseases caused by pathogens cause serious damage to food production around the world every year, resulting in huge economic losses. At present, the use of chemical fungicides is the main measure to prevent and control crop diseases. However, due to the large-scale repeated use of a single chemical pesticide, it is easy to cause pesticide resistance. The purpose of mixing pesticides is mainly to expand the scope of prevention and control, reduce the number of times of application, and use their synergistic effects to inhibit and delay resistance. The reasonable mixing of pesticides, especially the mixing of pesticides with different mechanisms of action and obvious synergistic effects, is one of the effective measures to delay resistance.

[0003] Propamidine belongs to the class of alkyl amidine compounds and is a new fungicide variety developed by the Shaanxi Provincial Biopesticide Engineering Technology Research Center. The research team's preliminary studies have found that propamidine has a broad-spectrum antibacterial activity and has both protective and therapeutic effects. Propamidine is a low-toxic compound that not only has good systemic transport properties, but also has protective and therapeutic effects; propamidine has high toxicity to rapeseed sclerotinia, cabbage black spot and apple rot, especially to Botrytis cinerea. The raw materials of propamidine are inexpensive and the synthesis process is simple. Propamidine does not have cross-resistance with existing fungicides, and its antibacterial molecular target is unique.

[0004] Epoxiconazole is a new type of triazole fungicide developed by SEG in Italy. It has the characteristics of broad fungicide spectrum, strong systemicity and long lasting effect. It has good control effect on various pathogens of cereals. Epoxiconazole will neither interfere with the normal biosynthesis of gibberellins in plants nor inhibit the normal growth of crops. It can be used at any stage of crop growth, even in high temperature and high humidity environment, and no phytotoxicity occurs. At the same time, it can also effectively prevent wheat loose smut, rust, bunt, barley moire, loose smut, rice blast, corn head smut, sorghum head smut, banana leaf spot, apple leaf spot, pear black spot, etc. It can be used for stem and leaf spray or seed treatment. Since Epoxiconazole belongs to triazole fungicides, its action site is relatively single, so it is easy to develop drug resistance. Therefore, the alternating use of Epoxiconazole with other agents with different action mechanisms, or the combined use with other agents, is an important way to slow down the occurrence and spread of Epoxiconazole resistance and extend its service life. The research team's previous studies have shown that tetrafluconazole has good antibacterial activity against the corn leaf blight pathogen, but at present tetrafluconazole has not yet been registered for the prevention and treatment of corn leaf blight. Summary of the invention

[0005] The invention aims to provide a compound composition of propanamidine and tetrafluconazole, a fungicide and application thereof. The binary compound of propanamidine and tetrafluconazole can be used for the prevention and treatment of corn leaf blight, powdery mildew, gray mold and rice blast.

[0006] To achieve the above object, the technical solution adopted by the present invention includes:

[0007] A composite composition of propaneamidine and tetrafluconazole, comprising propaneamidine and tetrafluconazole in a mass ratio of (1-10):(10-1).

[0008] Optionally, the mass ratio of propaneamidine to tetrafluthrin is (1-4):(8-1).

[0009] Optionally, the mass ratio of propaneamidine to tetrafluthrin is 1:2.

[0010] The use of any compound composition of propaneamidine and tetrafluconazole described in the present invention for preparing a compound fungicide.

[0011] Optionally, the compound fungicide is used to prevent and control corn leaf blight, powdery mildew, gray mold and / or rice blast.

[0012] Optionally, the formulation of the compound fungicide includes a suspension and a water-dispersible granule; in terms of mass percentage, the propanemidine content of the compound fungicide is 1% to 30%, and the tetrafluconazole content is 1% to 40%.

[0013] A compound fungicide, wherein the compound fungicide is in the form of a suspension;

[0014] The suspension agent is composed of the following components by mass percentage:

[0015] Propanamidine 1%-20%, tetrafluthrin 1%-40%, emulsifier 1%-10%, wetting dispersant 1%-5%, thickener 1%-5%, defoamer 0.15%-4%, antifreeze 1%-5%, preservative 1%-5%, make up to 100% with water.

[0016] Optionally, the emulsifier is an anionic emulsifier or a nonionic emulsifier;

[0017] The wetting and dispersing agent is at least one of alkylphenol resin polyethylene ether, alkylbenzene sulfonate, long-chain fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, and fatty alcohol sulfate;

[0018] The thickener is polyvinyl alcohol, xanthan gum, sodium alginate, xanthan gum or hydroxypropyl methylcellulose;

[0019] The defoamer is an acetylenediol wetting defoamer or an organosilicon defoamer;

[0020] The antifreeze agent is selected from at least one of ethylene glycol, propylene glycol, glycerol and polyethylene glycol;

[0021] The preservative is sodium benzoate.

[0022] A compound fungicide, the dosage form of the compound fungicide is water dispersible granules, and the components and weight percentages of the water dispersible granules are:

[0023] Propanamidine 20%-40%, tetrafluthrin 20%-40%, wetting agent 1%-10%, dispersant 1%-10%, disintegrant 1%-5%, binder 0.5%-5%, stabilizer 1%-5%, filler 1%-10%, the total amount is 100%.

[0024] Optionally, the wetting agent is lakai powder, the dispersant is magnesium aluminum silicate, the disintegrant is starch, the binder is sodium carboxymethyl cellulose, the stabilizer is ascorbic acid, and the filler is kaolin.

[0025] Compared with the prior art, the advantages of the present invention are:

[0026] (1) The present invention has found through a series of ratio experiments that propamidine and tetrafluconazole have obvious synergistic effects at a certain dosage ratio, and can be used to prepare agricultural compound fungicides; propamidine and tetrafluconazole have an additive effect when compounded at a ratio of 1:10 to 10:1, especially at 1:2, showing a significant synergistic effect.

[0027] (2) Through specific disease control efficacy tests, it was found that the compound fungicide prepared from propanemidine and tetrafluconazole of the present invention has good control effects on corn leaf blight, powdery mildew, gray mold, and rice blast. DETAILED DESCRIPTION

[0028] The following detailed description of the present invention is exemplary and does not limit the scope of the present invention. Based on the embodiments of the present invention, for ordinary technicians in the field, all uncreative improvements should be considered as the protection scope of the present invention without departing from the present invention.

[0029] The invention provides a compound composition of propanamidine and tetrafluconazole, a fungicide and application thereof; in terms of mass ratio, propanamidine:tetrafluconazole=1:10-10:1. The compound of propanamidine and tetrafluconazole is used to prevent and treat various fungal diseases of crops such as corn leaf blight, powdery mildew of fruits, vegetables and grains, gray mold, and rice blast, and has an obvious synergistic effect and can significantly reduce the amount of the agent used. The compound preparation has the potential to be developed into a new generation of environmentally friendly, efficient and low-toxic agricultural fungicides.

[0030] Example 1: Determination of in vitro antibacterial activity of propanamidine and tetrafluconazole

[0031] The single-dose inhibition rate and mycelial growth rate methods were used to determine the primary and secondary screening antibacterial activities of the compounds propanamidine and tetrafluconazole against pathogens. Propanamidine and tetrafluconazole were dissolved in methanol to prepare a series of mother solutions of different concentrations. After the PDA culture medium was cooled to about 50°C, 0.2mL of the above mother solution was mixed with 100mL / bottle of PDA culture medium to prepare a series of drug-containing culture media. After shaking well, the culture medium was quickly poured into 6 culture dishes with a diameter of 9cm. After solidification, a mycelial block of pathogens with a diameter of 0.5cm on the edge of the colony was placed in the center of the culture dish (mycelium facing down), and 0.2mL of methanol was added as a blank control. After inoculation and culture in a 25°C incubator for 6 days, the colony diameters were measured by the cross method. The blank control was used as the standard, and the inhibition rate was calculated according to the following formula to calculate its effective inhibition concentration EC 50 The value is in μg / mL.

[0032]

[0033] Table 1 Inhibition rate of propanemidine and tetrafluconazole 10 μg / mL on mycelial growth of 9 pathogens (%)

[0034]

[0035] As shown in Table 1, propamidine and tetrafluconazole have good antibacterial activity against corn leaf blight, tomato gray mold, and rice blast, and the inhibition rate of the above three pathogens at 10 μg / mL is above 95%. Therefore, the above three pathogens were selected for rescreening.

[0036] Table 2 Toxicity test of propanamidine and tetrafluconazole against three pathogens

[0037]

[0038] As shown in Table 2, propamidine and tetrafluconazole have good antibacterial activity against corn leaf blight, tomato gray mold, and rice blast. The toxicity of tetrafluconazole against the three pathogens is better than that of propamidine. Its EC 50 The values ​​were all less than 1 μg / mL. The EC values ​​of propanemidine against the above three pathogens were 50 The values ​​were all less than 1.5 μg / mL.

[0039] Example 2: Synergistic effect of propaneamidine and tetrafluconazole

[0040] Using the mycelium growth rate method, fresh bacterial discs (Ø5mm) were taken from the edge of the corn leaf blight colony cultured on PDA for 6 days and inoculated on PDA plates containing a series of concentrations of tetrafluconazole or propamidine, and also on PDA plates containing tetrafluconazole (abbreviated as "tetrafluconazole", the same below) and propamidine (abbreviated as "propamidine", the same below) mixed in a series of different proportions. The colony diameter was measured after 6 days of cultivation at 25°C, and each treatment was repeated 3 times. The inhibition percentage of the agent was calculated by comparing with the control without any agent. The probability value analysis method was used to calculate the effective inhibitory concentration of each agent on the mycelial growth of the target bacteria, and the synergistic coefficient of the mixed agent was calculated according to the following formula. A synergistic coefficient exceeding 1.5 is a synergistic effect, between 0.5-1.5 is an additive effect, and less than 0.5 is an antagonistic effect (a and b are the proportions of propamidine and tetrafluconazole in the compound, EC 50 (A) and EC 50 (B) is an effective medium concentration of propanemidine and tetrafluthrin, EC 50 (Exp) is the theoretical inhibitory concentration, EC 50 (Obs) is the actual measured concentration).

[0041]

[0042] Table 3 The toxicity of different ratios of propanamidine and tetrafluconazole to corn leaf blight pathogen

[0043]

[0044] The data in Table 3 show that the different ratios of propanamidine and tetrafluconazole have an effect on the EC 50are different, with synergistic coefficient values ​​ranging from 0.5578 to 2.1530. When the ratio is 1:10 to 10:1, the synergistic coefficients are all greater than 0.5, indicating that they have an additive effect under the above ratio, especially at 1:2, with a synergistic effect of 2.1530, indicating that propanamidine and tetrafluthriae at this ratio work together to control corn leaf blight with significant synergistic effect.

[0045] Example 3: Production of 10% propaneamidine and 20% tetrafluthrin combination suspension A

[0046] Accurately weigh 111 kg of 90% propaneamidine technical, 210 kg of 95% tetrafluthrin technical, 90 kg of emulsifier calcium dodecylbenzenesulfonate, 40 kg of wetting dispersant long-chain fatty alcohol polyoxyethylene ether, 20 kg of thickener polyvinyl alcohol, 20 kg of defoamer silicone, 10 kg of antifreeze propylene glycol, and 5 kg of preservative sodium benzoate and put them into the mixing tank, stir them thoroughly in the mixing tank, add water to make up to 1000 kg, stirring while adding.

[0047] The sampled product contained 10% propaneamidine and 20% tetrafluthrin, and finally 1 ton of product with a total content of 30% effective components was obtained.

[0048] Example 4: Production of water dispersible granules B of a 1:2 composition of propaneamidine and tetrafluconazole

[0049] This embodiment provides a formula of a 1:2 compound water-dispersible granule of propanamidine and tetrafluconazole. The prepared compound water-dispersible granule is composed of the following raw materials: 222 kg of 90% propanamidine original drug, 420 kg of 95% tetrafluconazole original drug, 100 kg of dispersant magnesium aluminum silicate, 50 kg of wetting agent pull-opening powder, 50 kg of disintegrant dry starch, 8 kg of binder sodium carboxymethyl cellulose, 50 kg of stabilizer ascorbic acid, and 100 kg of filler kaolin.

[0050] Propanamidine technical, tetrafluconazole technical, wetting agent, dispersant, disintegrant, stabilizer and filler are mixed evenly, crushed by air flow mill to make ultrafine wettable powder, then a certain amount of water is added, granulated by extrusion granulator, dried by air flow drying, and sieved to obtain water dispersible granules.

[0051] Example 5: Effect of propamidine and tetrafluconazole on the prevention of corn leaf blight

[0052] Corn was sown on June 15, 2023 at the Caoxinzhuang Experimental Station of Northwest Agriculture and Forestry University. The first application was on July 22 and the second application was on August 1, a total of 2 times, with a water consumption of 750L / hm 2No pesticides for controlling other pests and diseases were used during the experiment. A total of 8 treatments were set up in the experiment, namely, 10% propamidine and 20% tetrafluconazole suspension A; propamidine and tetrafluconazole 1:2 water dispersible granules B; 10% propamidine suspension alone; 12.5% ​​tetrafluconazole emulsion in water alone; control agent 45% mancozeb aqueous solution; spraying an equal amount of clean water as a blank control; each concentration treatment set three plots, each plot 33m 2 , randomized block arrangement. The results of the investigation were investigated on August 16, 15 days after the second application of pesticides, according to GB_T 17980.107-2004 "Guidelines for Field Efficacy Tests of Pesticides (II) Part 107_Fungicides for Control of Corn Large and Small Spots". The grading standards for corn large spot are as follows:

[0053] Level 0: no lesions;

[0054] Level 1: The lesion area accounts for less than 5% of the entire leaf area;

[0055] Level 3: The lesion area accounts for 6% to 10% of the entire leaf area;

[0056] Level 5: The lesion area accounts for 11% to 25% of the entire leaf area;

[0057] Level 7: The lesion area accounts for 26% to 50% of the entire leaf area;

[0058] Level 9: The area of ​​lesions accounts for more than 51% of the total leaf area.

[0059] The efficacy calculation method is as follows:

[0060] Disease index = [Σ(number of diseased leaves at each level × relative level value) / (total number of leaves investigated × 9)] × 100;

[0061] Control effect (%) = [(disease index of blank control area - disease index of treated area) / disease index of blank control area] × 100;

[0062] Table 4 The control effect of propanamidine and tetrafluconazole compound on corn leaf blight

[0063]

[0064] As shown in Table 4, the results of the field test show that the combination of propamidine and tetrafluconazole has a significant synergistic effect in preventing and controlling corn leaf blight. The control effect of the compound suspension concentrate A and the compound water-dispersible granules B on corn leaf blight at 300 μg / mL is equivalent, both above 90%, significantly better than the control effect of propamidine and tetrafluconazole at the same concentration, and significantly higher than the control effect of the control agent mancozeb.

[0065] Example 6: Effect of propaneamidine and tetrafluconazole compound on strawberry powdery mildew and gray mold

[0066] The test was conducted in a strawberry greenhouse. Seven days after the application of the pesticide, the incidence of young fruit was investigated. Three replicates were set for each concentration treatment. 50 young fruit were randomly investigated in each replicate, and a total of 150 young fruit were investigated. The incidence was the number of diseased fruit divided by the total number of inspections multiplied by 100%. The control effect was obtained by subtracting the incidence in the treatment area from the incidence in the control area, dividing the result by the incidence in the control area and multiplying it by 100%.

[0067] Table 5 The control effect of propaneamidine and tetrafluconazole compound on strawberry gray mold

[0068]

[0069]

[0070] Table 6 The efficacy of propaneamidine and tetrafluconazole compound on strawberry powdery mildew

[0071]

[0072] As shown in Tables 5 and 6 above, the compound preparation of propanemidine and tetrafluconazole has good control effect on strawberry gray mold and powdery mildew, and the control effect is above 85%. The control effect of the suspension is slightly better than that of its water dispersible granules. The control effect of the compound preparation is higher than or equivalent to the control effect of the single agent, and is higher than the control effect of the control agent. At the same dosage, the dosage of the single agent can be reduced.

[0073] Example 7: Effect of propamidine and tetrafluconazole on the prevention of rice blast

[0074] The test of propanamidine and tetrafluconazole combination on rice blast was conducted in Nanzheng District, Hanzhong City, Shaanxi Province. The tested rice variety was Huazheyou 210. The occurrence of the disease was investigated 40 days after the application of the pesticide. The classification standards for rice blast are as follows:

[0075] Level 0: No disease

[0076] Level 1: less than 5% loss per ear (individual branches and stalks are diseased);

[0077] Level 3: Each ear loses about 6%-20% (about 1 / 3 of the branches and stalks are diseased);

[0078] Level 5: The loss of each ear is about 21%-50% (the neck or main axis of the ear is diseased, and the grains are half-shrunken);

[0079] Level 7: Each ear has a loss of about 51%-70% (the neck of the ear is diseased and most of the grains are shrunken);

[0080] Level 9: Each ear has a loss of about 71%-100% (the ear neck is diseased, resulting in white ears);

[0081] Table 7 The control effect of propanemidine and tetrafluconazole on rice blast

[0082]

[0083] As shown in Table 7 above, the compound preparation of propanemidine and tetrafluconazole has a good control effect on rice blast, and the control effect is above 80%. The control effect of the suspension is slightly better than that of its water dispersible granules. The control effect of the compound preparation is higher than or equivalent to that of the single agent, and significantly higher than that of the control agent.

[0084] In summary, propanemidine and tetrafluthrin have good control effects on corn leaf blight, powdery mildew, gray mold, and rice blast, and can be used as new alternative agents for the control of the above diseases. Although the present invention has been described in detail with general descriptions and specific embodiments above, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A composite composition of propaneamidine and tetrafluconazole, characterized in that: The composition comprises propaneamidine and tetrafluthrin, and the mass ratio of the two is (1-10):(10-1).

2. The composite composition of propaneamidine and tetrafluconazole according to claim 1, characterized in that: The mass ratio of propaneamidine to tetrafluthrin is (1-4):(8-1).

3. The composite composition of propaneamidine and tetrafluconazole according to claim 1, characterized in that: The mass ratio of propaneamidine to tetrafluthrin is 1:

2.

4. Use of the compound composition of propaneamidine and tetrafluconazole as claimed in any one of claims 1 to 3 for preparing a compound fungicide.

5. The use according to claim 4, characterized in that: The compound fungicide is used for preventing and controlling corn leaf blight, powdery mildew, gray mold and / or rice blast.

6. The use according to claim 4, characterized in that: The dosage forms of the compound fungicide include suspension and water dispersible granules; Calculated by mass percentage, in the compound fungicide, propanemidine accounts for 1% to 30% and tetrafluthrin accounts for 1% to 40%.

7. A compound fungicide, characterized in that: The dosage form of the compound fungicide is a suspension; The suspension agent is composed of the following components by mass percentage: Propanamidine 1%-20%, tetrafluthrin 1%-40%, emulsifier 1%-10%, wetting dispersant 1%-5%, thickener 1%-5%, defoamer 0.15%-4%, antifreeze 1%-5%, preservative 1%-5%, make up to 100% with water.

8. The compound fungicide according to claim 7, characterized in that: The emulsifier is an anionic emulsifier or a nonionic emulsifier; The wetting and dispersing agent is at least one of alkylphenol resin polyethylene ether, alkylbenzene sulfonate, long-chain fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, and fatty alcohol sulfate; The thickener is polyvinyl alcohol, xanthan gum, sodium alginate, xanthan gum or hydroxypropyl methylcellulose; The defoamer is an acetylenediol wetting defoamer or an organosilicon defoamer; The antifreeze agent is selected from at least one of ethylene glycol, propylene glycol, glycerol and polyethylene glycol; The preservative is sodium benzoate.

9. A compound fungicide, characterized in that: The formulation of the compound fungicide is water dispersible granules, and the components and weight percentages of the water dispersible granules are: Propanamidine 20%-40%, tetrafluthrin 20%-40%, wetting agent 1%-10%, dispersant 1%-10%, disintegrant 1%-5%, binder 0.5%-5%, stabilizer 1%-5%, filler 1%-10%, the total amount is 100%.

10. The compound fungicide according to claim 9, characterized in that: The wetting agent is lakai powder, the dispersant is magnesium aluminum silicate, the disintegrant is starch, the binder is sodium carboxymethyl cellulose, the stabilizer is ascorbic acid, and the filler is kaolin.

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