JPH0434539B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to novel salts of organophosphorus derivatives, processes for the preparation of these compounds, and fungicidal compositions containing these compounds and their use for the protection of plants. The novel compounds according to the invention have the general formula: [In the formula, R ₁ is a hydrogen atom, a hydroxyl group, a lower alkyl group having 1 to 4 carbon atoms and optionally substituted with a halogen atom, a hydroxy group or a hydroxylamino group, an appropriately substituted phenyl group or a group OR ₅ (where R ₅ represents an alkyl group having 1 to 4 carbon atoms), and R ₂ and R ₃ may be the same or different and represent an alkyl group having 1 to 5 carbon atoms. , or an optionally substituted phenyl group, and further R ₂ and R ₃ can also be taken together to form the group -(CH ₂ ) _n -, where m is an integer equal to 4 or 5. , R ₄ represents an optionally substituted alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, or an optionally substituted benzyl or phenyl group, and n is 0 or is an integer equal to 1]. For bactericidal properties, R ₁ in the formula is a hydrogen atom,
hydroxyl group, alkyl group having 1 to 4 carbon atoms or alkoxy group having 1 to 4 carbon atoms, and R ₂ and R ₃ are each 1 to 4
an alkyl group having 12 carbon atoms, in particular a methyl and ethyl group, R ₄ being a methyl group or
Compounds that are linear alkyl groups with 16 carbon atoms are preferred. Compounds of the general formula have the formula: Reaction formula for reacting the compound with sulfonium salt or sulfoxonium salt in an aqueous medium: [In the formula, R ₁ , R ₂ , R ₃ , R ₄ and n have the same meanings as in the formula, and M is a hydrogen atom, in which case Y is a halogen atom, and x and z
is equal to 1, or M is an alkaline earth metal atom in which case Y is a sulfate ion and x and z are equal to 2]. This method can be broadly divided into two variants: The first variant has the reaction formula: [In the formula, R ₁ , R ₂ , R ₃ , R ₄ and n have the same meanings as in the formula, R ₆ is a hydrogen atom or a methyl group, and X is a halogen atom, i.e. chlorine, bromine, iodine or According to the formula: acid with a sulfonium or sulfoxonium halide in an aqueous medium in the presence of a hydrogen acid acceptor, such as an alkylene oxide (eg ethylene oxide or propylene oxide). For monosubstituted phosphites (i.e. R ₁
= OR ₅ ), the phosphoric acid ester has the reaction formula: prepared in situ by hydrolysis of the corresponding dialkyl phosphite. The second variant is the reaction equation: [wherein R ₁ , R ₂ , R ₃ , R ₄ and n have the abovementioned meanings] Accordingly, sulfonium sulfate or sulfoxonium sulfate is combined with a metal M which forms an insoluble sulfate, in particular calcium, for example. Alternatively, it consists of reacting an alkaline earth metal such as barium with a substituted phosphite. The insoluble sulfate is precipitated and separated off, and the liquid is concentrated and purified if necessary. The following examples demonstrate the preparation of compounds according to the invention as well as their fungicidal properties. The structures of these compounds were confirmed by nuclear magnetic resonance spectroscopy (NMR) at 60 MHz. A compound is considered to have complete protection against fungal diseases if the protection rate is at least 95% in examples showing biological properties, and if the protection rate is at least 80% (but less than 95%) The protection was judged to be good. Example 1 Sulfo(xo)nium alkylphosphinate and phenylphosphinate: Monoethylphosphinic acid (3.8g) and trimethylsulfoxonium iodide (8.8g) were mixed with water (80ml).
dissolved in it. To this was added propylene oxide (20ml). The medium was then heated at 35°C for 3 hours,
Concentrate under reduced pressure (15-20 mmHg). This results in
A colorless oil was obtained which crystallized at room temperature. This crude product was dissolved in acetonitrile (50ml) at 40°C. The solution was cooled in a bath of acetone and solid carbon dioxide to precipitate the product. The precipitate was separated and washed with ice-cold acetonitrile (10ml) and ether (10ml). The product was dried in a vacuum oven. This gives a white hygroscopic solid (4 g) which melts at 118° C. and corresponds to the ethylphosphinate of trimethylsulfoxonium (compound no. 1). Using phenylphosphinic acid and trimethylsulfoxonium iodide as starting materials and following the same procedure, phenylphosphinate of trimethylsulfoxonium (compound no.
11) was obtained. Following the same procedure using the appropriate phosphonic acid and the appropriate sulfonium iodide as starting materials,
The following compounds were obtained:

【table】

[Table] Example 2 Production of ethyl phosphinate of trimethylsulfonium (Compound No. 3): Diethyl phosphinate (5.5 g) and trimethylsulfonium iodide (8.2 g) were dissolved in water (80 ml). . To this was added propylene oxide (20ml) and the mixture was then heated at 35°C for 6 hours. Concentration of the medium under reduced pressure gave a colorless oil (7.9 g);
This was crystallized at room temperature. This crude product was dissolved in acetonitrile (25ml) at room temperature. The solution was cooled with an acetone ice bath. The precipitated product was separated and then dried in a vacuum oven. This gave a white, highly hygroscopic solid (4 g) which melted at 58°C. Following the same procedure using the appropriate reactants as starting materials, the following compounds were prepared:

【table】

[Table] Example 3 Trimethylsulfonium hypophosphite (compound
Production of No. 9): Add a solution of trimethylsulfonium sulfate (7.5 g) and water (20 ml) to calcium phosphite (5.12 g).
(50 ml) and the medium was stirred to precipitate calcium sulfate. Stirring was continued for 0.5 hour at room temperature, after which the precipitate was separated. Concentrate the liquid and dissolve the residual oil in acetonitrile (100 ml).
Then, insoluble materials were separated. Concentrate the organic solution;
The resulting oil was then triturated in ether (200ml) to form crystals, which were dispersed in the solvent. The precipitate was separated and dried in a vacuum oven. Under these conditions a white hygroscopic solid (6 g) was obtained which melts at 115-118°C. Calcium hypophosphite or 1-
Following the same procedure using hydroxyethyl phosphite and the appropriate trialkylsulfonium sulfate, the following compounds were obtained:

[Table] Example 4 Plasmopara viticola, which causes grape downy mildew in grape plants.
Viticola) in vivo test (protection (prevention)
Treatment: The leaves of potted grape plants (CHARDONNAY variety) were sprayed on both sides with an aqueous emulsion containing the active ingredient to be tested. An emulsion consisting of the following components was sprayed: - active ingredient to be tested (40 mg) - water (40 ml) - Tween 80 (surfactant consisting of oleate of polycondensate of ethylene oxide/sorbitol)
(0.02ml). An aqueous emulsion of this composition contains 1 g/g of the active ingredient to be tested. In order to obtain a spray emulsion with a concentration of less than 1 g/g of the active ingredient to be tested, the composition is such that an aqueous emulsion is diluted with water. After 48 hours, the leaves were contaminated by spraying the underside of the leaves with an aqueous suspension of fungi spores (approximately 80,000 units/ml). These pots are then brought to relative humidity
100% and placed in a 20°C culture tank for 48 hours. Plants were examined 9 days after contamination. Under these conditions the following was observed: Compounds No. 3, 25, 31 and
34 gave complete protection and compounds No. 10, 17 and 28 gave good protection; - At a dose of 0.33 g/ Compounds No. 1, 19, 21 and 30 gave complete protection and Compound No. 2,
9, 18, 26 and 27 give good protection. Example 5 Phytophthora infestans , which causes tomato downy mildew
In vivo studies: 60-75 day old tomato plants (Marmande variety) grown in a greenhouse were treated with an aqueous emulsion prepared as shown in Example 3 and containing the active ingredient to be tested at various concentrations. Treated by spraying. After 48 hours, these treated plants were contaminated with an aqueous suspension of spores (zoospores) obtained from a culture of ``Phytophthora intafuestans'' grown for 20 days on a chickpea flour-based medium. . The tomato plants were kept indoors for 48 hours at a temperature of 16-18°C and 100% relative humidity. The relative humidity was then reduced to 80%. Results were observed 8 days after contamination. The results are determined by observing the leaf area attacked by the fungus and determining the "% protection", i.e. 100 (1-A/Ac) [where A is the area attacked by the fungus on the plant in question and Ac is the area of the untreated plant. This is the area of control plants invaded by the fungus. As in the previous examples, results are given below as complete protection or good protection. Under these conditions, compounds No. 4 and 10 were found to give complete protection at a dose of 1 g/g. Example 6 In vivo test against Erysiphe graminis (barley powdery mildew) on barley: An aqueous emulsion containing the active ingredient to be tested and having the following composition was prepared by micronization: - Activity to be tested Ingredients...40mg - Tween 80 (surfactant consisting of oleate of polycondensate of ethylene oxide/sorbitan)
...0.4 ml - water...40 ml This aqueous emulsion was then diluted with water to the desired concentration. Potted barley sown in a mixture with peat volcanic ash was treated at a height of 10 cm by spraying with an aqueous emulsion at the concentrations indicated below. This process was repeated twice. After 48 hours, the barley plants were sprinkled with Erysiphae graminis spores prepared from diseased plants. Results were observed 10 days after contamination. Under these conditions, compound No. 2 at a dose of 1 g/g gave complete protection, and compounds No. 6, 9
and 12 were found to give good protection. Example 7 In vitro test against Pythium de Baryanum , which causes wood blight, and Botrytis cinerea , which causes gray mold: An acetone solution (1%) of the compound to be tested concentration)
was introduced into a test tube containing sterile medium at a temperature above its melting point (70°C). After mixing, the medium containing the compounds was placed into Petri dishes (10 cm) under sterile conditions. A series of Petri dishes containing varying amounts of active ingredient were thus prepared. 24 hours later,
The centers of these Petri dishes were deposited with a mycelial inoculum (diameter 9 mm) of the fungus to be tested ( Pythium ) or inoculated with a drop of a spore suspension ( Botrytis ). The growth rate of the fungus in the medium without the compound (control) was then compared to the growth rate of the fungus in the medium containing the above dosages. Fungal growth rate was evaluated by measuring colony diameter. Under these conditions, the compound at a dose of 0.1 g/
Compound No. 4 completely inhibited the growth of Pythium, whereas compounds No. 2, 3, 9, 12, 13, 14, 15, 16,
18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29 and 30 showed good inhibition. Furthermore, compounds No. 3 and 6 showed good inhibition against Botrytis cinerea at the same dose. Example 8 Inhibition against Puccinia recondita , which causes brown rust of cereals
In vivo test: Wheat plants (TALENT variety) grown in a greenhouse and reaching a height of about 10 cm were treated with aqueous emulsions prepared as shown in Example 3 and containing various concentrations of the compounds according to the invention. was sprayed. After 48 hours, treated plants contained approximately 80,000 spores/ml prepared from already contaminated plants.
contaminated aqueous suspensions of Puccinia recondita spores. These wheat plants were grown at a temperature of approximately 20°C and a relative humidity of 100°C.
% indoors for 48 hours. Then set the relative humidity to 60
%. The condition of the plants was examined on the 15th day after contamination and the % protection was determined as described in Example 3. Under these conditions, the following was observed: Compounds No. 13, 14 and 30 at a dose of 1 g/
gives complete protection, and compounds No. 15, 17,
23, 31 and 34 gave good protection. Compounds No. 16, 24, 26, at a dose of −0.3 g/
28 and 29 showed good inhibition. At a dose of -0.1 g/, compounds No. 18, 19, 20 and 27 gave complete protection. In vitro test against bacteria: Agar medium (20 ml) was placed in a series of 9 mm diameter Petri dishes while hot and the medium was then allowed to cool. 1% of the substance to be tested in an organic or aqueous solvent that is inert to bacterial growth under the conditions of the experiment.
The solutions containing the following concentrations were simultaneously injected into each Petri dish using a metered pipette. After 24 hours, the contents of the Petri dishes were inoculated with specific bacteria and then observed in a room at 22°C ± 2°C. The plants were examined 3 days after inoculation by visual comparison of bacterial colony growth with a control containing no inhibitor (substance to be tested). Under these conditions the following was observed: - Erwinia amylovora
amylovora, INRA: CNBP1430), Compound No. 11, 12, at a dose of 30 mg/
15, 16, 19, 22, 23, 24 and 27 as well as compounds No. 13, 14 and 21 at a dose of 10 mg/1 completely inhibited the growth of bacteria - Xanthomonas oryzae ( Xanthomonas oryzae).
oryzae, INRA: CNBP1951), Compound No. 27 at a dose of 30 mg/Compound No. 22 at a dose of 10 mg/Compound No. 13, 14, 16, 17 at a dose of 3 mg/
18, 21, 24, 25, 26 and 28 and compounds No. 11, 12 at a dose of 1 mg/
15, 19 and 23 completely inhibit bacterial growth;
Additionally, - Corynebacterium michiganense (INRA:
CNBP2108), Compounds No. 11, 12, 19 and
27. Compound No. 13, 14, 15, 16 at a dose of 3 mg/
17, 18, 21, 22, 23, 24 and 26 and compounds No. 25 and 28 at a dose of 1 mg/
completely inhibited bacterial growth. The above embodiments are applicable to various fungi, particularly e.g.
Plasmapora viticola, Phytophthora and
Algal fungi like Pythium or for example Erysiphe
sp. (downy mildew) or against cystic fungi such as P. botrytis or basidiomycetes such as e.g. Puccinia recondita or deuteromycetes such as e.g. It clearly indicates that it has. Major agricultural bacteria, such as Erwinia type, Xanthomonas type and other
Corynebacterium sp. The compounds according to the invention also have an excellent bactericidal action. Finally, they have good selectivity for crops. These are 0.05-5Kg/ha, preferably 0.1-2
It is advantageously applied at a dose of Kg/ha. In practical use, the compounds according to the invention are rarely used alone. In most cases this will form part of the composition. These compositions which can be used to protect plants against fungal diseases contain a compound according to the invention as active ingredient, for example as described above, an agriculturally acceptable solid or liquid carrier and an agriculturally acceptable surface active agent. Contained in combination with an agent. In particular, conventional inert carriers and conventional surfactants can be used. In addition, these compositions contain all kinds of other ingredients, such as protective colloids, adhesives, thickeners, thixotropic agents, penetrants, stabilizers, sequestrants, etc., as well as insecticidal properties (in particular insecticidal or fungicidal agents). ), plant growth promoting substances (in particular fertilizers) or any other known active ingredients having plant growth regulating properties. More generally, the compounds according to the invention can also be used in combination with any solid or liquid additives according to conventional formulation techniques. The amount of the compound according to the invention used as a fungicide can vary within a wide range, depending in particular on the degree of fungal attack and on the climatic conditions. Generally, compositions containing from 0.5 to 5000 ppm of active ingredient are suitable; these figures are given for ready-to-use compositions. "ppm" means "parts/million parts". 0.5～
The range of 5000ppm is 5×10 ^-5 % to 0.5% (weight%)
corresponds to the range of Compositions containing from 0.5 to 95% by weight of active substance are particularly advantageously suitable for storage and transport. Compositions according to the invention for agricultural use therefore contain from 5×10 ⁻⁵ to 95% by weight of active ingredients according to the invention.
It can be contained in proportions that vary over a very wide range. As mentioned above, the compounds according to the invention are generally used in combination with a carrier and optionally a surfactant. As used herein, the term "carrier" refers to an organic or inorganic natural or synthetic substance that is combined with an active ingredient to facilitate application to plants, seeds or soil. Therefore, the carrier must be generally inert and agriculturally acceptable, especially for the plants being treated.
Carriers can be solid (clays, natural or synthetic silicates, silica, resins, waxes, solid fertilizers, etc.) or liquid (water, alcohols, ketones, petroleum distillates, etc.).
aromatic or paraffinic hydrocarbons, chlorohydrocarbons, liquefied gases, etc.). Surfactants can be ionic or nonionic emulsifiers, dispersants or wetting agents.
Examples which may be mentioned are polyacrylates, lignosulfonates, phenylsulfonates, naphthalenesulfonates, polycondensates of ethylene oxide with aliphatic alcohols, fatty acids or aliphatic amines, substituted phenols (in particular alkylphenols or arylphenol) sulfosuccinic acid esters, taurine derivatives (especially alkyltaurates), and phosphoric acid esters of polycondensates of ethylene oxide and alcohols or phenols. If the active ingredient and/or the inert carrier are water-insoluble and the vehicle used is water, the presence of at least one surfactant is generally essential. In use, therefore, the compounds of the formula are generally in the form of compositions, and these compositions according to the invention are in a fairly wide variety of solid or liquid forms. In the form of solid compositions, dusting or sprinkling powders (which may contain up to 100% of the compound of the formula) and granules, in particular by extrusion, compaction, impregnation of granular carriers, or formation of powders from powders, can be used. (The content of the compound of the formula in these granules is in the latter case from 1 to 80%) may be mentioned. Forms of liquid compositions or compositions which can be constituted into liquid compositions for use include solutions, especially water-soluble concentrates, emulsifiable concentrates, emulsions, suspension concentrates, aerosols, hydratable powders (or sprayables). powder) and paste. In most cases, emulsifiable or soluble concentrates are 10
Consisting of ~80% active ingredient, ready-made emulsions or solutions contain 0.01-20% active ingredient. In addition to the solvent, emulsifying concentrates can be used as needed.
% of suitable additives such as stabilizers, surfactants, penetrants, corrosion inhibitors, dyes and adhesives. The composition of some concentrates is given below by way of example: Active ingredient 400g/alkali metal dodecylbenzene sulfonate
24g/10:1 ethylene oxide/nonylphenol condensate
16 g / cyclohexanone 200 g / aromatic solvent Remaining meter 1 Other composition of emulsifiable concentrate uses the following ingredients: Active ingredient 250 g Epoxidized vegetable oil 25 g Alkylaryl sulfonate and polyglycol ether of fatty alcohol and A mixture of 100 g dimethylformamide 50 g xylene 575 g These concentrates can be diluted with water to give an emulsion of the desired concentration, particularly suitable for application to leaves. In addition, suspension concentrates that can be applied by spraying can be prepared to obtain stable liquid products that do not form sediments, and these generally contain 10-75% active ingredient and 0.5-15% surface activity. 0.1 to 10% of a thixotropic agent and 0 to 10% of suitable additives, such as antifoaming agents, corrosion inhibitors, stabilizers, penetrants and adhesives, and water or organic liquids as a carrier, The active ingredient is sparingly soluble or insoluble in these carriers. Certain solid organic substances or inorganic salts can be dissolved in the carrier to help prevent settling or act as antifreeze agents for the water. Wettable powders (or sprayable powders) are generally 20
Formulated to contain ~95% active ingredient, these generally include a solid carrier plus 0-5% wetting agent, 3-10% dispersing agent and optionally 0-10% 1
Contains one or more stabilizers and/or other additives such as penetrants, adhesives, anti-caking agents, dyes, etc. Examples of various compositions of wettable powders are given below: Active ingredients 50% Calcium lignosulfonate (peptizer) 5% Isopropylnaphthalene sulfonate (anionic wetting agent) 1% Anticaking silica 5% Kaolin ( Filler) 39% 70% strength hydratable powder: Active ingredient 700 g Sodium dibutylnaphthylsulfonate 50 g 3:2:1 naphthalene sulfonic acid/phenylsulfonic acid/formaldehyde condensate 30 g Kaolin 100 g Shinyan punch yoke 120 g 40% Wettable powder at 25% strength: Active ingredient 400g Sodium lignosulfonate 50g Sodium dibutylnaphthalene sulfonate 10g Silica 540g Wettable powder at 25% strength: Active ingredient 250g Calcium lignosulfonate 45g Equivalent weight of syan punch yoke and hydroxyethyl cellulose Mixture 19 g Sodium dibutylnaphthalene sulfonate 15 g Silica 195 g Shiny punch yoke 195 g Kaolin 281 g 25% strength hydratable powder: Active ingredient 250 g Isooctylphenoxy-polyoxyethylene-
Ethanol 25 g Equal weight mixture of syan punch yoke and hydroxyethylcellulose 17 g Sodium aluminosilicate 543 g Diatomaceous earth 165 g 10% strength hydratable powder: Active ingredient 100 g Mixture of sodium salts of saturated fatty acid sulphates
30g naphthalenesulfonic acid/formaldehyde condensate
50 g Kaolin 820 g Water-soluble powders are usually obtained by mixing 20-95% by weight of active ingredient with 0-10% anti-caking filler, with the remainder consisting of a water-soluble solid carrier, especially salt. ing. The composition of a water-soluble powder is given by way of example below: Active ingredient (Compound No. 2) 70% Anionic wetting agent 0.5% Anti-caking silica 5% Sodium sulfate (solid carrier) 24.5% These hydrating or To obtain a water-soluble powder, the active ingredient is intimately mixed with the additional substances in a suitable mixer and the mixture is ground in a mill or other suitable grinding machine. This gives powders with advantageous wetting and suspending properties, which can be suspended or dissolved in water at the desired concentration. This suspension can be used with particular advantage for applying to the leaves of plants. As mentioned above, aqueous dispersions and emulsions, such as compositions obtained by diluting the hydratable powders or emulsifiable concentrates according to the invention with water, are encompassed within the scope of the invention. Emulsions can be water-in-oil or oil-in-water, and they can have a thick consistency, eg, like "mayonnaise." Granules intended to be applied to soil are generally 0.1 to 2 mm.
, which can be produced by agglomeration or impregnation. Typically, granules contain 0.5-25% active ingredient and 0-10% additives such as stabilizers, sustained release modifiers, binders and solvents. An example of a granule composition uses the following ingredients: Active ingredient 50g Epichlorohydrin 2.5g Cetyl polyglycol ether 2.5g Polyethylene glycol 35g Kaolin (particle size: 0.3-0.8mm) 910g In this particular example, the active ingredient Mix with epichlorohydrin and dissolve the mixture with 60 g of acetone, then add polyethylene glycol and cetyl polyglycol ether. The kaolin is wetted with the resulting solution and then the acetone is evaporated under reduced pressure. Microgranules of this type are advantageously used for combating fungi in soils. Additionally, the compounds of the formula can be used as dusting powders. It is also possible to use a composition consisting of active ingredient (50 g) and talc (950 g), as well as a composition consisting of active ingredient (20 g), finely divided silica (10 g) and talc (970 g). The ingredients are mixed, ground and the mixture is applied by spraying.

Claims (1)

[Claims] 1 Formula: [In the formula, R ₁ is a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a group OR ₅ (wherein R ₅ is an alkyl group having 1 to 4 carbon atoms) ), _R2 and _R3 are methyl and ethyl groups, respectively, _R4 is a methyl group or a linear alkyl group having 12 to 16 carbon atoms, and n is equal to 0 or 1 is an integer]. 2 In the formula, R ₁ is a hydroxyl group, 1 to 4
an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, R ₂ , R ₃
The derivative according to claim 1, wherein each of R 4 and R ₄ is a methyl group. 3. The derivative according to claim 1 or 2, wherein R ₁ in the formula is an ethyl group. 4 formula: [In the formula, R ₁ is a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a group OR ₅ (wherein R ₅ is an alkyl group having 1 to 4 carbon atoms) ), _R2 and _R3 are methyl and ethyl groups, respectively, _R4 is a methyl group or a linear alkyl group having 12 to 16 carbon atoms, and n is equal to 0 or 1 is an integer], the method comprises:
Reaction formula: [In the formula, R ₁ , R ₂ , R ₃ and R ₄ have the same meanings as above, R ₆ is a hydrogen atom or a methyl group, and X is a chlorine, bromine or iodine atom] The method described above is carried out in the presence of a hydrogen acid acceptor in a medium. 5 For a compound of the formula in which R ₁ is a group OR ₅ , the reaction formula for a phosphonate ester is: A method according to claim 4, which is produced according to. 6 formula: [In the formula, R ₁ is a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a group OR ₅ (wherein R ₅ is an alkyl group having 1 to 4 carbon atoms) ), _R2 and _R3 are methyl and ethyl groups, respectively, _R4 is a methyl group or a linear alkyl group having 12 to 16 carbon atoms, and n is equal to 0 or 1 is an integer], the method comprises:
Reaction formula for sulfonium(xonium) sulfate: said method, characterized in that it is reacted with a calcium or barium salt according to the method. 7 Formula as active ingredient: [In the formula, R ₁ is a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a group OR ₅ (wherein R ₅ is an alkyl group having 1 to 4 carbon atoms) ), _R2 and _R3 are methyl and ethyl groups, respectively, _R4 is a methyl group or a linear alkyl group having 12 to 16 carbon atoms, and n is equal to 0 or 1 is an integer] An agricultural fungicidal and/or agricultural bactericidal composition containing a salt of an organophosphorus derivative having the following. 8 Formula as active ingredient: [In the formula, R ₁ is a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 4 carbon atoms, a phenyl group, or a group OR ₅ (wherein R ₅ is an alkyl group having 1 to 4 carbon atoms) ), _R2 and _R3 are methyl and ethyl groups, respectively, _R4 is a methyl group or a linear alkyl group having 12 to 16 carbon atoms, and n is equal to 0 or 1 A method for protecting plants from fungal and/or bacterial diseases, characterized in that a fungicidal and/or bactericidal composition containing a salt of an organophosphorus derivative having the following formula is applied: