JPH0472803B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for stabilizing a fungicidal composition for agricultural and horticultural use. More specifically, the group of fungicidal guanidine compounds and certain fungicidal N-(polychloroalkylthio)-
Formic acid, oxalic acid, or a composition of the general formula R ₂
(COOH) _o2 (Note: R ₂ is an organic group having 1 to 3 carbon atoms, and n ₂ is 1 or 2) for stabilizing the composition. Bactericidal guanidine compounds and certain bactericidal N-
Agricultural and horticultural fungicidal compositions using (polychloroalkylthio)-dicarboximide as a single agent are known. Specific examples of the former include the following two. That is, they are 1,1'-iminiodi(octamethylene)diguanidinium triacetate (hereinafter abbreviated as guazatine) or N-dodecylguanidinium acetate (hereinafter abbreviated as dodine). Specific examples of the latter include the following three. That is, N-(trichloromethylthio)-4
-Cyclohexene-1,2-dicarboximide (hereinafter abbreviated as captan), N-(1,1,2,2
-tetrachloroethylthio)-4-cyclohexene-1,2-dicarboximide (hereinafter abbreviated as captafol) and N-(trichloromethylthio)phthalimide (hereinafter abbreviated as phorpet). Both the former and the latter can be used alone as agricultural and horticultural fungicides, but by using them together, it is said that it is possible to stabilize the efficacy and reduce the concentration of the drug against the same disease target. It has characteristics. For example, guazatine is known as an agricultural and horticultural agent for treating plants infected with pathogenic fungi or pathogenic bacteria (Japanese Patent Publication No. 43-27335).
In addition, in recent years, it has been shown to be effective against apple rot, late rot of grapes, storage diseases of citrus, discolored rice, spotted leaf disease of wheat, smut, snow rot, and leaf blight of grass. Confirmed. Captan, on the other hand, is a fungicide that has been in official use for many years. Using a mixture of guazatine and captan can stabilize the efficacy against the same disease and lower the concentration of the drug as described above, as well as reduce the possibility of the emergence of drug-resistant bacteria due to continuous spraying compared to using a single drug. I can do it. Moreover, the mixed drug can be stably applied to a wide range of diseases such as: Botrytis, black rot, downy mildew and powdery mildew of grapes; scab and leaf spot of apple; botrytis of molinia or peach; Phuomopsis rot of tobacco; These include sclerotium, pear black spot, and sclerotia. Therefore, the significance of using it as a mixed drug is significant. However, such mixed drugs have the following drawback: storage stability is extremely poor. This problem is so large that it cannot be predicted from the stability of each single drug. Regarding the storage stability of the single drug, for example, the above-mentioned guazatine is so stable that it does not decompose even when boiled under acidic conditions. However, it only decomposes under strong alkaline conditions. On the other hand, the aforementioned captan is said to be stable under acidic conditions and unstable under alkaline conditions. but,
Both drugs are stable when used as single agents and do not require the addition of storage stabilizers. However, when both drugs are mixed, it becomes extremely unstable. That is, the mixed drug can be stored at room temperature for one year, and guazatine can be stored for 40 days.
% captan also decomposes by 5%, and the mixed drug loses its commercial value after storage. The mechanism of drug degradation in mixed drugs has not been completely elucidated.
However, according to research conducted by the present inventors, it has been confirmed that the following substances are generated by mixing and heating guazatine and captan. They are tetrahydrophthalimide, chloride ions, isothiocyanates and acetic acid. The reaction mechanism is that the N-(polychloroalkylthio)dicarboximide moiety of captan is the guanidino group of guazatine.

[Formula] and the decomposition products such as thiophosgene (CSCl ₂ ) and chlorine gas generated by the reaction are also highly reactive and promote the decomposition of guazatine by reacting with the guanidino group mentioned above. It is presumed that. Conventionally, guazatine has been considered to be extremely stable, but no method for stabilizing it is known. The present inventors have studied methods for stabilizing a mixture of two or more drugs selected from both of the above groups. In particular, we researched various acids as stabilizers. Result is,
Various inorganic acids, such as hydrochloric acid, sulfuric acid, and nitric acid, cannot be used because they react with the carrier of the formulation, and phosphoric acid, which is usually used as an acidic stabilizer,
Pyrophosphoric acid, PAP (mixture of diisopropyl phosphate, isopropyl phosphate, etc.) (trade name) and the strong acids toluenesulfonic acid, benzenesulfonic acid, and sulfamic acid may not have sufficient stabilizing effects. found. Surprisingly, the inventors discovered that various organic acids described below are extremely effective, and completed the present invention. As is clear from the above description, the object of the present invention is to provide a sterilizer for agricultural and horticultural use containing a guanidine-based fungicide and an N-(polychloroalkylthio)dicarboximide-based fungicide as active ingredients, which have significantly improved storage stability. To provide a composition. Other purposes will become clear from the description below. The present invention has the following main components. (1) One or more fungicidal guanidine compounds selected from 1,1′-iminiodi(octamethylene)diguanidinium triacetate or N-dodecylguanidinium acetate and structural formula (However, R ₁ is a 4-cyclohexene group or a benzene group, n ₁ is 1 or 2, and X is H or Cl
Formic acid or oxalic acid or structural formula R ₂ (COOH) _o2 ( R ₂ here
is a hydrocarbon group having 1 to 3 carbon atoms or a hydrocarbon group having a hydroxyl group, and n ₂ is 1 or 2. Law. The configuration and effects of the present invention will be explained in detail below. B. Germicidal guanidine compound: In addition to the above-mentioned guazatine or dodine, any guanidine compound having germicidal properties can be used in the composition of the present invention. B Structural formula (R ₁ is a 4-cyclohexene group or a benzene group, respectively, n ₁ is 1 or 2, and X is H or Cl
) A compound that is an N-(polychloroalkylthio)dicarboximide and has bactericidal properties:
Specific examples include the aforementioned captan, captafor, and fluorpette. However, it is not limited to these specific examples as long as it has the above-mentioned chemical structure and bactericidal properties. C Organic acid used in the present invention: formic acid, oxalic acid, or structural formula R ₂ (COOH) _o2
(herein, R ₂ is a hydrocarbon group having 1 to 3 carbon atoms or a hydrocarbon group having a hydroxyl group, and n ₂ is 1 or 2) can be effectively used. D. Other general compounding agents and compounding methods: The composition according to the present invention can be compounded with various commonly used auxiliary agents depending on the form of the intended preparation, and these auxiliary agents and the present invention can be combined with each other. The order of mixing the components of the composition according to the invention is not limited. That is, in the case of a powder, a powder improver and a carrier are added in addition to the essential ingredients of the present invention, and the powder is ground and mixed to form a preparation. In the case of granules, in addition to the above-mentioned essential ingredients, a binder, a lubricant, an extender, and a carrier are added, and the mixture is pulverized, mixed, and then granulated and dried to form a preparation. In the case of a wettable powder, a lubricant, a dispersant, and a carrier are added to the above-mentioned essential ingredients, and the mixture is ground and mixed to form a preparation. Furthermore, in the case of a sol, a lubricant, a thickener, an antifoaming agent, an antifreeze agent, and water are added to the above-mentioned essential ingredients, and the mixture is pulverized and mixed to form a preparation. However, the effects of the present invention are independent of the use or non-use of these auxiliaries, the grinding and mixing method, and the form of the preparation. When formulating the composition according to the present invention, the surfactant used is preferably a nonionic active agent, and the carrier is preferably one that does not have ion adsorption properties. These circumstances are the same as when a guanidine compound is used alone as a fungicidal active ingredient. The organic acid used as a stabilizer to be mixed and used in the composition of the present invention does not cause any phytotoxicity to crops at the practical concentration during use, i.e., when it is sprayed, and is a normal toxic substance for humans and animals (note: it is a non-medicinal deleterious substance). , non-toxic substances) and are highly safe. The method and effects of the present invention will be explained in detail below with reference to Examples and Usage Examples, but the present invention is not limited thereto. All parts and % in the examples mean parts by weight and % by weight. Example 1 Guazatine 10 parts Captan 60 parts Stabilizer 5-10 parts Polyoxyethylene alkyl allyl ether
3 parts white carbon 14 parts diatomaceous earth 8-3 parts Add the above raw materials in the proportions listed so that the total amount is 100 parts, adjusting the amount of diatomaceous earth according to the amount of stabilizer, and mix uniformly. Use as a hydrating agent. This was sealed in an ampoule and stored in a thermostat at 40°C or 50°C for a predetermined period of time, and then the sample after storage was analyzed for guazatine by high performance liquid chromatography. The results of this time course test are shown in Table 1 along with the results of a control test in which no stabilizer was added.

【table】

[Table] Example 2 Guazatine 5 parts Captan 30 parts Stabilizer 5 parts Polyoxyethylene higher alcohol ether
5 parts Special high molecular weight organic compound 10 parts Water 45 parts The above raw materials are ground and mixed using a sand grinder to form a sol. Enclose this in an ampoule for 50
After storage for 7 days in an incubator at 0.degree. C., the stored samples were analyzed for guazatine. The results of this time-course test are shown in Table 2 along with the results of a control test in which no stabilizer was added.

[Table] Example 3 Dodine 10 parts Captan 60 parts Stabilizer 5 parts Polyoxyethylene alkyl allyl ether
3 parts white carbon 14 parts diatomaceous earth 8 parts Mix the above raw materials uniformly to make a wettable powder.
This was sealed in an ampoule and stored in a thermostat at 50°C for 7 days, and then the stored sample was analyzed for dodine by high performance liquid chromatography. The results of this time-course test are shown in Table 3 along with the results of a control test in which no stabilizer was added.

[Table] Example 4 Guazatine 10 parts Captafor or Folpet 60 parts Stabilizer (oxalic acid) 5 parts Polyoxyethylene alkyl allyl ether
3 parts white carbon 14 parts diatomaceous earth 8 parts Mix the above raw materials uniformly to make a wettable powder.
This was sealed in an ampoule and stored in a thermostat at 50° C. for 7 days, and then the sample was analyzed for guazatine. The results of this time course test are shown in Table 4 along with the results of a control test in which no stabilizer was added.

[Table] Examples Guazatine 10 parts Captan 60 parts Stabilizer 7 parts Polyoxyethylene alkyl allyl ether
3 parts white carbon 14 parts diatomaceous earth 6 parts Mix the above raw materials uniformly to make a wettable powder.
This was sealed in an ampoule and stored in a thermostat at 50° C. for a certain period of time, and the captan attached to the sample after storage was analyzed by gas chromatography. The results of this time course test are shown in Table 5 together with the results of a control test in which no stabilizer was added.

[Table] Usage example Based on Example 1, tobacco seedlings (quality: Kanto Matsukawa, Hakuenshū) grown in a glass house were transplanted into a 1/5000a Wagner pot and grew to about 7 to 8 true leaves. The hydrating powder prepared in this way was sufficiently sprayed three times at one-week intervals, and the presence or absence of chemical damage to tobacco was examined. In addition, potted apples (varieties: Star King, Delicious, Fudo) and pears (varieties: Kosui,
Chojuro) was placed in a glass house from the open air, and a hydrating agent formulated based on Example 1 was thoroughly sprayed on the new branches that had grown within 10 cm or more, three times every other week, in the same manner as tobacco. We observed chemical damage to pears.

【table】

[Table] Note. +: The unfolded leaf part is slightly curled.
±; The unfolded leaves are slightly curled.
-: No chemical damage No adverse effects were observed on tobacco and apples after spraying three times. A slight curl was observed in the pear, but this was also observed with guazatine alone and was not caused by the addition of oxalic acid. From the above results, the formulation containing oxalic acid as a stabilizer has no adverse effects on various crops. Effect test example 1 A hydrating powder formulated based on Example 5 was applied to cucumber seedlings (variety: Shinko A) grown in a glass house, transplanted into a 1/5000a Wagner pot, and grown to about 5 true leaves. Sprayed three times every other week,
We conducted an efficacy test against cucumber powdery mildew (naturally occurring). ●Test sample sample-A Guazatine 10 parts Captan 60 parts Oxalic acid 7 parts Polyoxyethylene alkyl phenyl ether
3 parts White carbon 14 parts Diatomaceous earth 6 parts Sample-B Guazatine 10 parts Captan 60 parts Polyoxyethylene alkyl phenyl ether
3 parts white carbon 14 parts diatomaceous earth 13 parts Sample-C Captan 60 parts polyoxyethylene alkyl phenyl ether
3 parts white carbon 14 parts diatomaceous earth 23 parts Sample-D Guazatine 10 parts polyoxyethylene alkyl phenyl ether
3 parts white carbon 14 parts diatomaceous earth 73 parts Disease severity and disease index 0: No disease onset 1: Diseased area less than 10% 2: Diseased area 10% or more and less than 25% 3: Diseased area 25% or more and less than 50% 4: Diseased area 10% or more and less than 25% Affected area: 50% or more and less than 75% 5: Affected area is 75% or more ○Note: Affected area is the ratio of lesion area to leaf area●Infection rate = Number of affected leaves (number of leaves) / Number of investigated leaves (sheets) x 100● Disease severity = Σ (infection index × number of leaves by index) / 5 × number of investigated leaves ● Control value = disease severity in non-sprayed plot - disease severity in sprayed plot / disease severity in sprayed plot × 100 ● Test results

[Table] Effect test example 2 Kiyu cucumber (variety: Tokiwa No. 3 P type) grown in a glass house was transplanted into a 1/5000a Wagner pot, and when it had grown to about 15 true leaves, Example 5
A hydrating powder formulated based on the above was sprayed three times at intervals of one week, and an effect test on cucumber downy mildew (inoculated with a spore suspension prepared from damaged leaves) was conducted. ●Test sample sample-A Guazatine 10 parts Captan 60 parts Oxalic acid 7 parts Polyoxyethylene alkyl phenyl ether
3 parts white carbon 14 parts diatomaceous earth 6 parts Sample-C Captan 60 parts polyoxyethylene alkyl phenyl ether
3 parts white carbon 14 parts diatomaceous earth 23 parts Sample-D Guazatine 10 parts polyoxyethylene alkyl phenyl ether
3 parts white carbon 14 parts diatomaceous earth 73 parts Disease severity and disease index 0: No disease onset 1: Diseased area less than 10% 2: Diseased area 10% or more and less than 25% 3: Diseased area 25% or more and less than 50% 4: Diseased area 10% or more and less than 25% Affected area: 50% or more and less than 75% 5: Affected area is 75% or more ○Note: Affected area is the ratio of lesion area to leaf area●Infection rate = Number of affected leaves (number of leaves) / Number of investigated leaves (sheets) x 100● Disease severity = Σ (infection index × number of leaves by index) / 5 × number of investigated leaves ● Control value = disease severity in non-sprayed plot - disease severity in sprayed plot / disease severity in sprayed plot × 100 ● Test results

[Table] As is clear from the results of Effect Test Examples 1 and 2 above, the combination of guazatine and captan exhibits an additive effect of each alone, but does not exhibit a synergistic effect. However, with the addition of oxalic acid, a stabilizer,
Shows a certain synergistic effect. This is thought to be because decomposition of the fungicide components captan or guazatine over time is suppressed even during the storage period of the preparation for about 3 weeks, and can be said to be an effect of the method of the present invention.

Claims (1)

[Scope of Claims] 1. One or more fungicidal guanidine compounds selected from 1,1'-iminiodi(octamethylene)diguanidium triacetate or N-dodecylguanidinium acetate and structural formula (However, R ₁ is a 4-cyclohexene group or a benzene group, n ₁ is 1 or 2, and X is H or Cl
means. ) A composition comprising one or more bactericidal active ingredients selected from the group of N-(polychloroalkylthio)dicarboximides represented by formic acid or oxalic acid or the structural formula R ₂ (COOH) _o2 (where R ₂
is a hydrocarbon group having 1 to 3 carbon atoms or a hydrocarbon group having a hydroxyl group, and n ₂ is 1 or 2. Law.