DE2617743A1 - FUNGICIDAL COMPOSITIONS BASED ON HYPOPHOSPHITES AND THEIR USE - Google Patents

Description

The invention relates to fungicidal compositions based on hypophosphorous acid or its salts, in particular compositions which are suitable for combating parasitic plant fungi and as active ingredients contain at least hypophosphorous acid and / or its mineral salts.

Examples of this are the alkali salts such as the lithium, Sodium and potassium salts, the ammonium salts and the alkaline earth salts such as the magnesium, calcium, barium or Strontium salts and salts of heavy metals such as copper, iron, nickel, manganese, zinc or aluminum. The salts can be in both anhydrous and more or less hydrated form.

The compounds used according to the invention are known per se (cf. in particular Nouveau Traite de Chimie Minerale, editor Paul Pascal-Masson); the Most of these compounds are available in stores.

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borrowed, from these the other salts according to conventional Processes such as more or less strong neutralization of the acid or double conversion or decomposition can be produced. Hypophosphorous acid and some of its salts are soluble in water, while others insoluble in water.

Certain organophosphorus compounds and in particular Phosphites have already been specified as fungicidal active ingredients; however, none are found in the literature Indications of the fungicidal properties of hypophosphites.

The surprising plague now lies with the invention based on the fact that the compounds according to the invention have excellent fungicidal properties and are advantageous can be used as an active ingredient in compositions for protecting plants against fungal diseases.

The following connections were investigated ":

1) Commercially available hypophosphorous acid in 60 ^ iger aqueous solution, density 1.26

2) Ammonium hypophosphite (NH ^) HgPO ₂ , P. 100 ⁰ C

3) Sodium hypophosphite NaHgPO ₂ «HgO, pure, commercially available

4) Potassium hypophosphite KPHgOg, pure, commercially available

5) Calcium hypophosphite Ca (PH ₂ O ₂ ) ₂ , pure, commercially available

6) Magnesium _{hypophosphite Mg (PH 2} Og) ₂ * 6HgO, pure, commercially available

7) Barium hypophosphite Ba (PHgOg) ₂ , chemically pure, commercially available, water-soluble

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8) Manganese (II) hypophosphite Mn (PH ₂ Og) ₂ * H ₂ O, commercially available

9) Iron (III) hypophosphite Pe (PH ₂ O ₂ ) -, pure, commercially available.

The fungicidal properties of the compounds according to the invention are different, but particular of particular interest in the case of grapevine powdery mildew, as shown in the following examples:

Example 1: In vitro mycelial growth test:

The effect of the products according to the invention on mycelial growth was investigated in the following fungi:

Pythium de Baryanum ( Phycomycet ),

responsible for seed rot (beet root burn),

Rhizoctonia sölani ( Basidiomycet ),

responsible for the neck or root neck necrosis (root killer disease),

Botrytis cinerea ( Ascomycete ),

responsible for the gray rot as well

Septoria apii (Fungi Imperfecti ),

responsible for celery septoriosis.

The so-called Agar plate was used for the investigations dilution 'method applied. At a temperature of

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about 50 ^° C., a mixture of 5 ml of nutrient medium and 0.5 ml of an acetone solution or a wettable powder which contains the substance to be examined in a concentration of 1 g / l is placed in a test tube.

The wettable powder is made by mixing the following ingredients in a knife mill for 1 minute:

active ingredient to be examined 20 %

anti-flocculant (calcium lignosulfate) 5 %

Wetting agent (alkylarylsulfonate-Na) 1 %

Filler (aluminum silicate) 74 %.

For use with a desired dose, the wettable powder is then with an appropriate Amount of water mixed.

The nutrient mixture is allowed to harden; on it are slices of mycelium cultures of the corresponding Mycetes upset. An analog test tube is used as a comparison, but its nutrient medium does not contain any active substance contains.

After 4 days at 20 ⁰ C, the area of the observed zone of inhibition is determined and expressed as a percentage with respect to the Impffläche.

. Under these conditions it was found that compound 2 leads to 51 and 62% inhibition in Botrytis cinerea and Septoria apii and compound 5 in Pythium de Baryanum and Rhizoctonia solani

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results in a 77 or 48 sequence inhibition,

Example 2; In-vivo test on Plasmopara viticola (family the Phycomycetes) in grapevines;

a) Preventive treatment;

Vines (Gamay vines) were cultivated in pots by spraying or atomizing with the gun down to the low limit on the underside of the leaves with an aqueous one Treated suspension of a wettable powder of the following weight composition:

active ingredient to be tested 20 %

Deflocculant (calcium lignosulfate) 5 %

Wetting agent (alkylarylsulfonate-Na) 1 % filler (aluminum silioate) 74 % \

the suspension was diluted to the desired value and contained the active ingredient to be tested in the appropriate dose. Each test was repeated three times.

After 48 hours, the undersides of the leaves were sprayed or spray contaminated with an aqueous suspension of about 80,000 units / ml fungal spores.

The pots were then incubated at 100% relative humidity and 20 ^{° C. for 48 hours.}

The plants were checked 9 days after the infestation.

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Under these conditions it was found that compounds 1, 2, 4, 6 and 7 at a dose of 0 * 5 g / 1 lead to good protection and the connections J5, 5 and 8 show a good protective effect at a dose of 1 g / l.

It should also be emphasized that none of the products investigated had even the slightest phytotoxicity exhibited.

b) Systemia test through root absorption:

Several trunks of grapevines (Gamay vines), each in a bucket with vermiculite and a nutrient solution, were poured with 40 ml of a solution of 0.5 g / l of the substance to be tested. After 2 days, the vines were contaminated with an aqueous suspension of 100,000 spores / ml of Plasmopara viticola. It was then allowed to incubate for 48 h in a room at 20 ^° C. and 100 % relative humidity.

The degree of infestation was observed after about 9 days; infected plants were used for comparison, which had been poured with 40 ml of distilled water.

Under these conditions it was found that compounds 1-4, 7 and 9 were absorbed by the roots lead to a complete protection of the vine leaves against powdery mildew, from which the systemic character of these compounds becomes clearly visible.

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c) Systemic test for treatment after contamination:

Several trunks of grapevines (Gamay vines), each in a bucket with vermiculite and a nutrient solution, were contaminated with 40 ml / plant of an aqueous suspension containing 100,000 spores / ml of Plasmopara viticola . This was followed by incubation for 48 hours in a room at 20 ^° C. and 100 % relative humidity.

After 2 days the plants became one at 40 ml / plant Poured solution of 2.5 g / l of the active ingredient to be tested.

The degree of infestation was determined after about 9 days; infected control plants were used for comparison, which had been poured with 40 ml of distilled water.

Under these conditions, compound 6 was found to be complete at a dose of 2.5 g / l and the compounds 5, 8 and 9 lead to a good protection of the vine leaves against powdery mildew, from which the systemic character of these compounds is also clearly evident.

The examples show the preventive as well as systemic fungicidal action of the compounds according to the invention clearly visible to fungi belonging to the families of the Phycomycetes, Basidiomycetes, Ascomycetes and Fungi Imperfect! belong, especially the remarkable effect against powdery mildew of the grapevine.

In addition, certain inventive methods

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bindings also effective against other types of powdery mildew, especially with tobacco ( Peronospora tabacina ) and hops (Peronospora humili ) as well as with various Phytopl ^ ora species that attack temperate or tropical crops.

Accordingly, the compounds are particularly suitable for use in preventive as well as the curative treatment of parasitic plant fungi of the above families.

The compounds according to the invention can be combined with other fungicidal and powdery mildew phosphorus derivatives be mixed, especially the 2-hydroxy-l, j5,2-dioxaphospholanes, ß-hydroxyethyl phosphites, phosphorous acid and its salts, phosphonic acid mono- and diesters, cyclic diphosphorus compounds, aminophosphites, 2-hydroxy-1,3 * 2-dioxaphosphorinanes, y-hydroxypropyl phosphites, phosphorus-containing trialkylimides and 2H-2-thio-1, j5> 2-dioxaphospholanes and -phosphorinanes and Thioalkyl phosphites (see FR patent applications 73-01.803, 73-37.994, 73-43.081, 73-4-5.627, 74-08.995, 74-10.988, 74-13-246, 74-34.529, 74-34.530, 75-04.394 as well as 75-08,642 or the corresponding DT patent applications P 2 365 06I, P 2 453 401, P 2 456 627, P 2 510 O34, P 2 512 556, P 2 515 428, P 2 545 148, P 2 545 150, P 2 606 761 and P 2 602 8o4 by the same applicant) .

The doses used can vary widely according to the virulence of the fungus and the climatic conditions Conditions vary. In general,

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Compositions between 0.01 and 5 g / l of active ingredient are favorable.

The compounds according to the invention are seldom used alone for practical application. Most frequently they are part of formulations which, in addition to the active ingredient according to the invention, generally contain a carrier and / or contain a surfactant.

In the context of the present description, the term 'carrier' denotes an organic or inorganic, natural or synthetic substance to which the active ingredient is used to facilitate use on plants, Seed or soil and bound for ease of transport or handling. The wearer can do this solid (clays, natural or synthetic silicates, resins, waxes, solid fertilizers or the like) or liquid (water, Alcohols, ketones, petroleum fractions, chlorinated hydrocarbons, liquefied gases or the like.).

The surfactant can be an emulsifier, dispersant or wetting agent and can have ionic or nonionic properties. Examples are salts of polyacrylic acids or lignosulfonic acids and condensation products of ethylene oxide with fatty alcohols, fatty acids or fatty amines.

The compositions according to the invention can be used as wettable powders or wettable powders, as soluble powders, as powder for dusting, as granules, solutions, emulsifiable concentrates, emulsions, concentrates in suspension or suspensions as well as aerosols.

The wettable powders are usually produced in this way

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found to be 20 - contained $> substance and usually in addition to a solid support 0-5 wt - - 95 wt..% of a wetting agent, 3-10 wt .- ^ of a dispersing agent and, where necessary 0-10 wt .- ^ one or several stabilizers and / or other additives such as penetrants, adhesives or agents preventing clumping, coloring agents or the like. contain.

A wettable powder has the following composition, for example:

Active ingredient 50 %

Calcium lignosulfate (deflocculant) 5 %

anionic wetting agent 1 %

Silicic acid (anti-clumping agent) 5 %

Kaolin (filler) 39 %.

The water-soluble powders are obtained by mixing 20 - receive 1% of a wetting agent 95 wt .- ^ active ingredient, 0-10 - -% of an anti-clumping and 0;. the rest consists of a water-soluble filler, mainly a salt.

A water-soluble powder has the following composition, for example:

Active ingredient 70 % anionic wetting agent 0.5 %

Silicic acid (anti-clumping agent) 5 %

Sodium sulfate (soluble filler) 24.5 #.

Aqueous dispersions and emulsions, for example

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by diluting a wettable powder according to the invention or an emulsifiable powder according to the invention Compositions obtainable in concentrate with water are also included in the general concept of the invention. Emulsions can be of the water-in-oil or oil-in-water type and have a dense consistency such as mayonnaise.

The compounds according to the invention can also contain other constituents, for example protective colloids, adhesives or thixotropic agents Substances, stabilizers or masking agents as well as other known active ingredients with pesticidal properties, especially acaricide or insecticide.

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Claims (10)

- 12 claims / Iy fungicidal compositions for combating plant fungal diseases, characterized in that it uses an inorganic hypophosphite as an active ingredient contain. 2. Composition according to claim I _3, characterized by an alkali hypophosphite as the active ingredient. J5. Composition according to Claim 1, characterized by Ammonium hypophosphite as an active ingredient. 4. Composition according to claim 1, characterized by an alkaline earth hypophosphite as the active ingredient. 5. Composition according to claim K ₃ characterized by calcium hypophosphite as an active ingredient. 6. Composition according to claim K ₃ characterized by magnesium hypophosphite as an active ingredient. 7. Composition according to claim I _3, characterized by iron, copper, nickel, manganese, zinc or aluminum hypophosphite as the active ingredient. 8. A method for the preventive or curative treatment of plants against fungal diseases, characterized by the use of a composition according to any one of claims 1-7. 809845/1064 9. The method according to claim 8 for preventive or curative Treatment of plants against by fungi of the families of the Phycomycetes, Ascomycetes, Basidiomycetes and / or diseases caused by the fungi imperfecti, characterized by use a composition according to any one of claims 1-7 10. The method according to claim 9, characterized by using a composition according to any one of claims 1-7 to combat wine mildew. 609845/1064