WO2022105987A1

WO2022105987A1 - Formulations containing cyclodextrin for improving the effectiveness of fatty acids as non-selective herbicides

Info

Publication number: WO2022105987A1
Application number: PCT/EP2020/082411
Authority: WO
Inventors: Ingo Jeschke
Original assignee: Wacker Chemie Ag
Priority date: 2020-11-17
Filing date: 2020-11-17
Publication date: 2022-05-27

Abstract

The invention relates to a composition for use as a herbicide, containing (i) saturated or unsaturated fatty acids, salts or esters thereof and (ii) a cyclodextrin or cyclodextrin derivative, wherein, after (i) and (ii) are dissolved in a solvent, (ii) is present in the solution in a molar ratio to (i) of less than 1 (that is, the ratio of (i) : (ii) is 1 : less than 1 (mol : mol)). Furthermore, the invention relates to a formulation which contains said composition and is used as a herbicide, and to a method for controlling weeds, wherein said composition or the formulation containing the composition is applied to the areas to be treated.

Description

Cyclodextrin-containing formulations to improve

Efficacy of fatty acids as non-selective herbicides

The invention relates to a composition for use as a herbicide containing (i) saturated or unsaturated fatty acids, their salts or esters and (11) a cyclodextrin or cyclodextrin derivative, wherein after dissolving (i) and (ii) in a solvent in the solution (ii) is in a molar ratio to (i) of less than 1 (i.e. the ratio (i):(ii) is 1:less than 1 (mole:mole)). Furthermore, the invention relates to a formulation containing this composition, which is used as a herbicide, and a method for controlling weeds, in which this composition or the formulation containing the composition is applied to the areas to be treated.

Herbicides (weed killers) are substances designed to kill offending plants. They are mainly used in agriculture, but also on non-crop land. Crops compete with weeds for water, nutrients and light. Dense weed growth can make the harvest very difficult and significantly reduce it. Weeds can be decimated manually, with machines or with herbicides.

A distinction is made between selective herbicides, which are effective against certain plants, and broad-spectrum or total herbicides, which are effective against a large number of plants.

Especially when cultivating organic agricultural products, the options for controlling weeds, which lead to a reduction in yield, are very limited. Here one would like to do without synthetic chemical herbicides as far as possible. Mechanical methods often have to be used. The use of synthetic chemical herbicides can generally lead to further disadvantages, such as the development of resistance, contamination of groundwater, a reduction in biodiversity and adverse health effects for people applying these products or consuming crops treated with them.

Saturated and unsaturated fatty acids and their salts, as well as esters, have long been known as environmentally friendly herbicides that can be used for organic farming and are therefore also referred to as natural herbicides. These include primarily fatty acids with a chain length of 6 to 20 carbon atoms, but above all caprylic acid (C8), pelargonic acid (C9), capric acid (CIO), undecanoic acid (CII) and lauric acid (C12). The effect with shorter or longer chains is not as strong.

These fatty acids are usually offered as concentrates that are diluted with water to form an oil-in-water emulsion before use. In addition, other components such as surfactants and biocides or other classes of active ingredients such as growth regulators can be included in the products.

The application rate can vary depending on the weed species and is generally in the range of 30 to 60 kg of fatty acids per hectare applied with a water volume of 800 to 1,200 liters.

The use of unsaturated undecylic acid as a herbicide was described for the first time in US Pat. No. 2,626,862. In US Pat. No. 4,975,110, US Pat. No. 5,035,741, US Pat. No. 5,098,467 and US Pat. Also in US 5,284,819 monoglycol esters of the fatty acids were used as herbicides in admixture with the free fatty acids deployed. US Patent 8,569,211 describes aqueous formulations of herbicidal fatty acids containing larger amounts of emulsifiers. British Patent GB 2247621 discloses aqueous formulations of herbicidal fatty acids which contain the fatty acids in a partially neutralized form. The formulation also contains volatile alcohol as a solvent. WO 93/09669 and US 6,323,156 describe aqueous formulations of organoammonium salts of herbicidal fatty acids. Alkylamine salts in particular have a strong odor or are more difficult to biodegrade. Finally, EP 0 868 849 describes partially hydrolyzed ammonium salts of fatty acids. In patent US 2004/0186022, succinic acid or other acids of the Krebs cycle are said to improve the herbicidal effect of the fatty acids. Finally, WO 2011/161133 describes a pelargonic acid formulation in the form of an oil-in-water emulsion.

For example, a commercial product is Scythe®, which contains 57% pelargonic acid and 3% related fatty acids and is proposed for use in combination with synthetic herbicides. The product Finalsan® contains 18.67% pelargonic acid and 3% of a growth regulator and is recommended for home and garden use.

These products are used as non-systemic, non-selective contact herbicides and are well suited in agricultural applications for use on the so-called 'false seedbed', in front of a crop and between the rows in row crops. Furthermore, these products are often used in the home and garden to control weeds and moss on seedbeds or on all other areas that should be free of weeds, such as garage driveways, terraces or similar. The way it works is that the fatty acids contained in the herbicide attack the cell membranes of the weeds, which leads to a loss of cell fluid. This eventually dries out the weeds. As soon as a sufficiently large part of the meristem (cell formation tissue) is affected, the plant will die.

A problem with the previously known formulations of herbicidal fatty acids is the volatility of the fatty acids, which is why the products only have a low stability after application. The effectiveness decreases after just a few days and fresh weeds form on areas that have already been treated. This problem leads to the disadvantage that herbicidal formulations containing fatty acids have to be used repeatedly and/or in increased concentration.

Another disadvantage of the previously known herbicidal formulations containing fatty acids can be seen in relation to grassy weeds. Due to the small leaf surface, these are only insufficiently wetted, so that here again they have to be treated several times or the application rate has to be increased.

Finally, a sufficiently good effect of these natural herbicides can almost only be achieved on young weeds with a maximum height of 0.05 m. For weeds with a height of 0.05 m or more, the application rate has to be increased.

For the reasons mentioned, the known natural herbicides are not interesting for widespread use from an economic point of view because of their high price.

Cyclodextrins are cyclic oligosaccharides containing six (oc-), seven (ß-) or eight (y-) D-glucopyranose units connected to one another via a-(1,4) bonds and which are obtained enzymatically from starch. Because of their circular molecular structure with a hydrophobic cavity, cyclodextrins can form reversible complexes with hydrophobic guest molecules form. Due to the hydrophilic surface of cyclodextrins, they can be used to improve the water solubility of hydrophobic substances. At the same time, it is possible to reduce the volatility of volatile substances by forming complexes with cyclodextrins and to achieve delayed release.

WO 19/215645 and WO 20/084572 describe that pesticide-cyclodextrin complexes are particularly effective since they increase the solubility of the pesticide, which improves bioavailability, which was investigated with the active ingredients tau fluvalinate and prothioconazole. For this purpose, the active substances were treated with an equimolar amount or with a molar excess of cyclodextrin.

WO 2018/050211 describes that it is advantageous for the effective action of a complex of cyclodextrin and insect repellent, i.e. an agent that is active in the air, if the active substance is not completely complexed so that a sufficient proportion is available in the ambient air .

The use of cyclodextrins to improve the effectiveness of natural herbicides has not previously been explored.

The object of the invention was to provide a composition containing natural herbicides which is effective as a herbicide and can therefore be made available for economical use in many fields of application.

This object was achieved in that a composition for use as a herbicide containing (i) saturated or unsaturated fatty acids, their salts or esters and (ii) a cyclodextrin or cyclodextrin derivative, wherein after dissolving (i) and (ii) in one Solvent in the solution (ii) is in a molar ratio to (i) of less than 1 (i.e. the

(ii) is 1:less than 1 (mole:mole)).

The composition is a mixture of components (i) and (ii). The saturated or unsaturated fatty acids, their salts or esters are the natural herbicide, i.e. (i) is the herbicidal part and is therefore also referred to as the active ingredient part.

The composition can be used as a herbicide, i.e. it achieves a herbicidal effect.

The herbicidal effect is defined as applying a sample dissolved in 100 ml of solvent to an area of 1 m ² in dry weather and at an ambient temperature of at least 10 °C, the area containing monocotyledonous and dicotyledonous weeds. The maximum growth height of the weeds is 0.05 m to 0.1 m. The solution is applied in such a way that the solution is sprayed out, ie it is sprayed onto the weeds from a distance of approx. 20-30 cm. The areas are then quantified after different times with regard to their weed growth, with a classification from 0 (no impairment of weed growth) to 10 (complete death of the weeds) being made.

The composition can also be used in powder form as a herbicide and applied to the area to be treated. In this case, the molar ratio of (i):(ii) according to the invention is achieved when the composition dissolves, for example in rainwater in rainwater or in morning dew water. The amount of (i) and (ii) to be used to achieve the molar ratio according to the invention results from their molecular weight and is therefore easy to calculate. For example, the molar ratio of (i):(ii) = 0.5:1 can be adjusted by mixing x grams (i) and 2y grams (ii). if (i) has a molecular weight of xg/mol and (ii) has a molecular weight of yg/mol.

It was surprising that the cyclodextrins used could be added in a less than equimolar ratio to the active ingredient.

In addition, it was found in another experiment that the application rate of the saturated or unsaturated fatty acids, their salts or esters through the addition of cyclodextrins or Cyclodextrin derivatives could be lowered, which led to a saving of material, so that the broad application of these herbicides could be made more economical. Example 1 shows that the commercially available formulation containing pelargonic acid allowed the weeds to regrow on the treated area after just a few days, while all areas treated with formulations containing cyclodextrin remained free of weeds for a significantly longer period of time. Example 2 also proves that the use of formulations in which pelargonic acid was contained in combination with cyclodextrins made it possible to use significantly lower amounts of active substance in comparison to using the same formulation without the addition of cyclodextrins in order to achieve the same herbicidal effect.

As an advantage of the more effective effectiveness of the herbicide-cyclodextrin complexes, the application frequency of the herbicides can also be lowered, which led to large savings in time and material.

Finally, it could be shown that the combination of cyclodextrins with saturated or unsaturated fatty acids, their salts or esters meant that not only young weeds with a growth height of less than 0.05 m could be treated sufficiently well, but also weeds with a much larger growth height (see example 3) . In addition, grass-like weeds, which are otherwise very difficult to control with fatty acids (considered in Example 3), could also be controlled very well in this way. It could thus be shown that the possible uses of this class of herbicides can be significantly increased if they are combined with cyclodextrins.

By adding (ii), the effectiveness of (i) can be significantly improved when using the composition as a herbicide, resulting in a reduction in the proportion of (i) (active ingredient proportion), a temporal extension of the herbicidal effect, i.e. prolonged duration of action and a Improvement in the possible uses of the herbicide, e.g. also on weeds with a greater growth height.

The presence of (ii) in the composition for use as a herbicide ensures that part of the active ingredient (i) remains longer on the site of action after its application, which means that the time of action is significantly prolonged, or the concentration of (i ) can be reduced and the possible uses extended to older and grassy weeds.

It is of particular advantage that the composition for use as a herbicide contains an active ingredient (i) which belongs to the class of natural herbicides and is therefore environmentally friendly and can also be used in organic farming.

The area to be treated is an agricultural, forestry or horticultural area that should remain weed-free. In addition, in the run-up to a crop, for example, the soil can be treated before sowing. Preference is given to the to treated area around a green area, particularly preferably around a grassy area.

Weeds are plants of the spontaneous "accompanying vegetation" in crop stands, grassland or gardens that are not deliberately cultivated there and develop from the seed potential of the soil, via root runners or by the seeds flying in. Alternatively, weeds or crop companions are often spoken of today Undesirable weeds include girsch, thistles, nettles, celandine, clover and dandelion.

The composition is suitable for use as a herbicide, which is a non-selective herbicide, i.e. it acts not only against certain plants, but as a broad spectrum or total herbicide. The composition is preferably used as a herbicide, particularly preferably as a non-selective herbicide.

A solvent (also solvent or solvent) is a substance that can dissolve or dilute gases, liquids or solids without chemical reactions occurring between the dissolved substance and the solvent. Water, alcohols or ketones can be used as solvents, preferably alcohol mixed with water, the solvent is particularly preferably an ethanol-water mixture and particularly preferably water.

Preferably, the composition is characterized in that after dissolving (i) and (ii) in a solvent, the molar ratio of (i):(ii) in the solution is between 1:0.01 and 1:0.5 (mol: mol) lies. Particularly preferably, after dissolving (i) and (ii) in a solvent, the molar ratio of (i):(ii) in the solution is 1:0.05 (mol:mol). The composition is preferably characterized in that (ii) is selected from the group consisting of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, hydroxypropyl-α-cyclodextrin, acetyl-α-cyclodextrin, hydroxypropyl-β- Cyclodextrin, hydroxypropyl-γ-cyclodextrin, acetyl-β-cyclodextrin, methyl-β-cyclodextrin, acetyl-γ-cyclodextrin and mixtures thereof. (ii) is particularly preferably a native cyclodextrin such as α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin or a mixture thereof, particularly preferably α-cyclodextrin and/or β-cyclodextrin. When (ii) is a cyclodextrin derivative such as hydroxypropyl-α-cyclodextrin, acetyl-α-cyclodextrin, hydroxypropyl-β-cyclodextrin, hydroxypropyl-γ-cyclodextrin, acetyl-β-cyclodextrin, methyl-β-cyclodextrin, acetyl -γ-cyclodextrin or mixtures thereof, it is particularly preferred that (ii) is hydroxypropyl-α-cyclodextrin, methyl-β-cyclodextrin or hydroxypropyl-β-cyclodextrin.

Numerous derivatives with different properties have been developed on the basis of the native cyclodextrins. For example, the methyl-ß-cyclodextrin and the hydroxypropyl-ß-cyclodextrin have a water solubility that is many times higher than that of the native ß-cyclodextrin. The same applies to derivatives of a- and y-cyclodextrin. Ultimately, there are endless possibilities for replacing hydrogen atoms in the hydroxyl groups of native cyclodextrins with radicals in order to influence the properties of the cyclodextrins, such as their water solubility.

Saturated or unsaturated fatty acids, their salts or esters can be used as herbicidal active ingredients. The composition is preferably characterized in that (i) has a chain length of 6 to 20 carbon atoms. Particular preference is given to (i) being selected from the group consisting of caprylic acid (C8), pelargonic acid (C9), capric acid (CIO), undecanoic acid (CII), lauric acid (C12) and mixtures thereof. Especially (i) is preferably caprylic acid (C8), pelargonic acid (C9), capric acid (CIO) or a mixture thereof, particularly preferably pelargonic acid (C9).

In a preferred embodiment, the composition is characterized in that after dissolving (i) and (ii) in a solvent, the percentage of (i) in the solution is 3%, more preferably 2% and most preferably 1%. The percentage refers to the total concentration of (i) in the composition, i.e. if (i) is a mixture of, for example, three different fatty acids and each is present at 1%, the percentage of (i) total is 3% .

As described above, the composition can be used as a herbicide. The composition according to the invention can also serve as a basis for the production of a formulation. A further object of the invention is therefore a formulation containing the composition according to the invention, characterized in that it is used as a herbicide. In addition to the composition, a formulation can contain components such as solvents, biocides, surfactants, viscosity regulators, antifoams, preservatives, emulsifiers and/or other classes of active ingredients such as growth regulators. The aim of the formulation is to optimize the biological effect of the composition in the target organism and, at the same time, to bring the finished product into a form that can be used in technical equipment. In this way, not only the effectiveness but also, for example, the shelf life of the formulation should be optimized.

By adding (ii), the effectiveness of (i) in the formulation can be significantly improved, resulting in a reduction in the proportion of (i) (active ingredient proportion), a temporal extension of the Ef fects and an improvement in the possible uses as a herbicide result.

In a preferred embodiment, the formulation additionally contains a solvent. The definition given above applies to the solvent, it being particularly preferred that water is used as the solvent.

The herbicidal formulation is produced in a known manner by combining all the components to form a formulation.

The cyclodextrin complexes can be prepared by any of the methods known in the prior art, preferably by the co-precipitation process, the melting-in process or the paste process.

In the co-precipitation process, the fatty acid is dissolved in a suitable solvent and added in the desired ratio to an aqueous solution of the cyclodextrin or cyclodextrin derivative heated to 20 to 70.degree. C., preferably to 50.degree. The solution is stirred for a period of 16 hours and then the solvent is removed. The residue is dried at 40° C. The solvent is preferably acetone, methanol or ethanol.

In the melting-in process, the cyclodextrin or cyclodextrin derivative is placed in water and heated to 20 to 70.degree. C., preferably 50.degree. The fatty acid is added in portions and the mixture is stirred at the stated temperature for 16 hours. Uncomplexed fatty acids are filtered off and the complex is isolated by freeze drying.

In the paste process, the cyclodextrin or cyclodextrin derivative is combined with the fatty acid in the desired Ratio mixed and water added at a level of 30% by weight of the two components. The resulting paste is kept in a closed glass vessel at 70° C. for a period of eight hours and mixed hourly with a spatula. After eight hours, the paste is dried and ground for further use.

In addition, the cyclodextrin complex can easily be obtained as a physical mixture by metering the cyclodextrins into a formulation already containing the active ingredients.

A combination of cyclodextrin complexes with physical mixtures is also possible.

A further subject matter is a method for controlling weeds, characterized in that the formulation is applied to the areas to be treated.

The herbicidal formulation containing saturated or unsaturated fatty acids, their salts or esters and cyclodextrins or cyclodextrin derivatives and optionally other components such as a solvent is currently typically applied in agriculture at an application rate of 30 kg to 60 kg of active ingredient per hectare (Ha). applied , which means that it is applied with 800 to 1200 liters of water per ha . The application takes place by means of spray aircraft or spray vehicles or smaller spray devices. The active substance content refers here to the content of fatty acids, their salts or esters. If the saturated or unsaturated fatty acids, their salts or esters are combined with cyclodextrins in the ratios given above, the amount used can be reduced to 10 kg to 20 kg of active ingredient per hectare. The herbicidal formulation is sprayed onto the weeds using standard methods. Not only young weeds with a growth height below 0.05 m, but also taller weeds can be treated. In addition, not only broadleaf weeds but also grassy weeds can be treated with it.

The following examples serve to further explain the invention.

Example 1 Use of a commercial concentration of fatty acids in combination with cyclodextrins

3.09 g perlagic acid (Sigma Aldrich, purity 97%, molecular weight 158.2 g/mol) were dissolved in 50 ml ethanol and made up to 100 ml with water to produce a commercially available concentration of 3% active ingredient as required for control of weeds on an area of 1 m ² is used (formulation 1). Different amounts of methylated beta-cyclodextrin (M-ß-CD, Wacker Chemie AG, molecular weight 1310 g/mol) were added to this solution. By adding 24.90 g M-ß-CD an active ingredient to cyclodextrin ratio of 1: 1 (mole: mole) (formulation 2), by adding 12.41 g M-ß-CD an active ingredient to cyclodextrin ratio of 1:0.5 (mol:mol) (formulation 3) and by adding 1.24 g of M-ß-CD an active ingredient to cyclodextrin ratio of 1:0.05 (mol:mol) (formulation 4).

Girsch, thistles, nettle, celandine, clover and dandelion were planted in a greenhouse for 8 days. After the plantlets had each developed more than 2 leaves, they were planted in a mixed state in an open space. An area of 1 m ² each was treated in the morning at 10:00 a.m. with 100 ml of the individual formulations using a hand-held sprayer. The weather was dry and the outside temperature was 10°C. The areas were then assessed after different times. The growth of the treated areas with the planted weeds was assessed on a scale from 0 to 10 (0=no impairment of the weeds and 10=complete death of the weeds).

Example 2 Lowering of the commercially available concentration of fatty acids with the aid of cyclodextrins

3.09 g perlagic acid (Sigma Aldrich, purity 97%, molecular weight 158.2 g/mol) were dissolved in 100 ml water to produce a commercial concentration of 3% active ingredient, such as is used to control weeds on an area of 1 m ² is used (formulation 1). Furthermore, formulations with lower concentrations of perlagic acid were produced and provided with cyclodextrins. For this purpose, 2.06 g perlagic acid were dissolved in 10 ml ethanol and made up to 100 ml water with water, which corresponds to a concentration of 20% active substance. 0.94 g of hydroxypropylated beta-cyclodextrin (HP-ß-CD, Wacker Chemie AG, molecular weight 1380 g/mol) were added to this batch, which corresponds to an active ingredient to cyclodextrin ratio of 1:0.05 (mol:mol) ( Formulation 5) . Finally, 1.03 g of perlagic acid were dissolved in 10 ml of ethanol and made up to 100 ml with water, which corresponds to a concentration of 10% active substance. 0.47 g of hydroxypropylated beta-cyclodextrin (HP-ß-CD) was added to this batch, which corresponds to an active substance to cyclodextrin ratio of 1:0.05 (mol:mol) (formulation 6).

Areas of 1 m ² each were planted on an open area with heavy weed growth (creating the areas as in example 1 described) in the morning at 9:00 a.m. with 100 ml of the individual formulations using a hand sprayer. The weather was dry and the outside temperature was 12 °C. The areas were then assessed after different times. The growth of the treated areas with the planted weeds was assessed on a scale from 0 to 10 (0=no impairment of the weeds and 10=complete death of the weeds).

Example 3 Treatment of tall weeds and grassy weeds using fatty acids in combination with cyclodextrins

1.03 g perlagic acid (Sigma Aldrich, purity 97%, molecular weight 158.2 g/mol), 1.02 g caprylic acid (Sigma Aldrich, purity 98%, molecular weight 144.2 g/mol) and 1.02 g capric acid ( Sigma Aldrich, purity 98%, molecular weight 172.3 g/mol) were dissolved in 100 ml water to produce a commercial concentration of 3% active ingredient as used to control weeds on an area of 1 m ² (formulation 7) . Furthermore, a formulation was provided with cyclodextrins. For this purpose, 1.03 g perlagic acid, 1.02 g caprylic acid and 1.02 g capric acid were dissolved in 10 ml ethanol and made up to 100 ml water with water, which corresponds to a concentration of 3% active ingredient. For this purpose, 0.71 g of hydroxypropylated beta-cyclodextrin (HP-ß-CD, Wacker Chemie AG, molecular weight 1380 g/mol) and 0.65 g of methylated beta-cyclodextrin (M-ß-CD, Wacker Chemie AG, molecular weight 1310 g/mol), which corresponds to an active ingredient to cyclodextrin ratio of 1:0.05 (mol:mol) (formulation 8).

On an open area with weed growth with a growth height of more than 0.05 m (see Example 1, longer cultivation time), areas of 1 m ² each (preparation of the areas as described in Example 1, cultivation time until the specified growth height is reached) were planted. in the morning at 10:30 a.m. with 100 ml of the individual formulations using a hand sprayer. The weather was dry and the outside temperature was 15°C. The areas were then assessed after different times. The growth of the treated areas with the planted weeds was assessed on a scale from 0 to 10 (0=no impairment of the weeds and 10=complete death of the weeds).

Claims

patent claims

A composition for use as a herbicide containing

(i) saturated or unsaturated fatty acids, their salts or esters,

(ii) a cyclodextrin or cyclodextrin derivative wherein upon dissolution of (i) and (ii) in a solvent in the solution (ii) is in a molar ratio to (i) of less than 1 (i.e. the ratio (i) : (ii) is 1:less than 1 (mole:mole)).

2. Composition according to claim 1, characterized in that after dissolving (i) and (ii) in a solvent the molar ratio of (i):(ii) in the solution is between 1:0.01 and 1:0.5 (mol : mol) lies.

3. Composition according to one of claims 1 or 2, characterized in that after dissolving (i) and (ii) in a solvent, the molar ratio of (i): (ii) in the solution is 1: 0.05 (mol: mol ) amounts to.

4. Composition according to any one of claims 1 to 3, characterized in that (ii) is selected from the group consisting of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, hydroxypropyl-α-cyclodextrin, acetyl-α- Cyclodextrin, hydroxypropyl-β-cyclodextrin, hydroxypropyl-γ-cyclodextrin, acetyl-β-cyclodextrin, methyl-β-cyclodextrin, acetyl-γ-cyclodextrin and mixtures thereof.

5. Composition according to any one of claims 1 to 4, characterized in that (i) has a chain length of 6 to 20 carbon atoms.

6. Composition according to any one of claims 1 to 5, characterized in that (i) is selected from the group consisting of caprylic acid (C8), pelargonic acid (C9), capric acid (CIO), undecanoic acid (Cll), lauric acid (C12) and mixtures thereof.

7. Composition according to any one of Claims 1 to 6, characterized in that after dissolving (i) and (ii) in a solvent, the percentage content of (i) in the solution is 3%.

8. Formulation containing a composition according to any one of claims 1 to 7, characterized in that it is used as a herbicide.

9. Formulation according to claim 8, characterized in that it additionally contains a solvent.

10. Formulation according to one of claims 8 or 9, characterized in that the solvent used is water.

11. A method for controlling weeds, characterized in that a formulation according to any one of claims 8 to 10 is applied to the areas to be treated.