NL2030013A

NL2030013A - Pesticides comprising fatty acids

Info

Publication number: NL2030013A
Application number: NL2030013A
Authority: NL
Inventors: Jacobus Van Stralen Nicolaas; Foeke Van Dorp Jeroen; Bernard Johan Alexander Oltheten Maurice
Original assignee: Chaincraft B V
Priority date: 2021-12-03
Filing date: 2021-12-03
Publication date: 2023-06-20
Also published as: NL2030013B1

Abstract

The present invention relates to a pesticide concentrate comprising a mixture of at least C4 and/or C5, and/or C6 fatty acids or their salts or esters as active ingredient. The present invention furthermore relates to the use of the pesticide concentrate as insecticide, herbicide or fungicide.

Description

Pesticides comprising fatty acids

Field of the invention

The present invention relates to pesticides comprising fatty acids, particularly prepared via enzymatic carbon chain elongation of organic compounds. Such pesticides are widely used in applications for control of weed growth.

Background of the invention

A variety of pesticides are well known in the art and are widely used in agricultural and conunercial applications. Pesticides can save farmers’ money by preventing crop losses to insects and other pests; in the U.S., farmers get an estimated fourfold return on money they spend on pesticides. Although useful in controlling insect and mite populations as well as the growth of unwanted flora and fungi, many pesticides have been found to be harmful to the environment as well as to humans, other mammals, birds and fish.

A pesticide is any substance used to kill, repel, or control certain forms of plant, fungi or animal life that are considered to be pests. Pesticides include herbicides for destroying weeds and other unwanted vegetation, insecticides for controlling a wide variety of insects, fungicides used to prevent the growth of molds and mildew, disinfectants for preventing the spread of bacteria, and compounds used to control mice and rats. Because of the widespread use of agricultural chemicals in food production, people are exposed to low levels of pesticide residues through their diets. Scientists do not yet have a clear understanding of the health effects of these pesticide residues. The most common of these are herbicides which account for approximately 80% of all pesticide use.

Herbicides are mainly used to eliminate unwanted weeds in agriculture and gardening. Without intervention, these weeds would compete for light and nutrients with the crop or be a nuisance in gardens. The use of herbicides can prevent substantial yield losses. A disadvantage of the currently available herbicides is that they comprise synthetic active compounds. With synthetic active compounds we refer to chemicals designed based on fossil fuels as main resources and developed for pesticide functionality. Synthetic active compounds are typically not present elsewhere in nature and have uncertain effects on environment and human health. Because of fears of their side-effects, regulations are becoming increasingly strict and growing numbers of farmers and other herbicide users are looking for safer alternatives. A number of such alternative herbicides are currently available. A popular class of non-synthetic herbicides is based on pelargonic acid, as for example described in WO-A-9105472.

A disadvantage of the above mentioned pelargonic acid class of herbicides is that these do not effectively combat all weed types. A further disadvantage of the pelargonic acid class of herbicides is that the required volumes and consequent costs of treatment are high and the production of the active ingredient pelargonic acid involves substantial greenhouse gas (GHG) emissions.

Accordingly, there is a demand for replacing the currently available herbicides comprising synthetic active compounds. There is additionally a demand for additional, complementary non-synthetic herbicides. There is furthermore a demand for replacing or supplementing the currently available active ingredient pelargonic acid. There is also a demand for simplification and improvement of the re-use of organic compounds. There is also a demand for simplification and improvement of the production of C4 to Cg fatty acids in order to reduce environmental burdens and cost price.

Summary of the invention

It is an object of the present invention to provide a pesticide concentrate that is based on natural obtainable ingredients and is removing pests from various locations, like killing weeds from basketball fields, between paving stones, between railways, between vegetable crops. or use as haulm killing agent, etc. It is a further object of the present invention to provide a pesticide concentrate that is environmental friendly and contributes to the recycling of organic waste and thereby reduces the need for on-purpose developed and often non-sustainable resources such as crude- or -palm oils. It is furthermore an object of the present invention to provide a safe process for preparing such pesticides. It is yet another object of the present invention to develop a practical manufacturing process that can be easily scaled up.

Accordingly, the present invention relates to claim 1. The present invention relates to a pesticide concentrate comprising a mixture of at least C4 and/or Cs, and/or Ce fatty acids or their salts or esters as active ingredient.

The present invention also relates to the use of the pesticide concentrate comprising an aqueous mixture of at least Cq and/or Cs, and/or Cg fatty acids or their salts or esters as active ingredient as herbicide or fungicide.

Detailed description of the invention

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art which this invention belongs to. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The term “fatty acid” as used herein, includes a molecule that consists of a chain of carbon atoms, with hydrogen atoms along the length of the chain and at one end of the chain and a carboxyl group (—COOH) at the other end. It is that carboxyl group that makes it an acid (carboxylic acid). If the carbon-to-carbon bonds are all single, the acid is saturated; if any of the bonds is double or triple, the acid is unsaturated and is more reactive. A few fatty acids have branched chains: others contain ring structures (e.g., prostaglandins). Short-chain fatty acids (SCFAs) are fatty acids with fewer than 6 carbon atoms. SCFAs all possess varying degrees of water solubility, which distinguishes them from longer chain fatty acids that are practically immiscible. Medium-chain fatty acid (MCFA) are fatty acids with 6 to 12 carbon atoms.

The term “pesticide” as used herein, includes any substance or mixture of substances intended for preventing, destroying, or controlling any pest, including vectors of human or animal disease, unwanted species or parts of plants, fungi or animals, causing harm during or otherwise interfering with the production, processing, storage, transport, or marketing of food, agricultural commodities. wood and wood products or animal feedstuffs, or substances that may be administered to animals for the control of insects, arachnids, or other pests in or on their bodies. The term includes substances intended for use as a plant growth regulator, defoliant, desiccant, or agent for thinning fruit or preventing the premature fall of fruit. Also used as substances applied to crops either before or after harvest to protect the commodity from deterioration during storage and transport. Pesticides can be classified by target organism (e.g., herbicides, insecticides, fungicides, rodenticides, and pediculicides), chemical structure (e.g., organic, inorganic, synthetic, or biological (biopesticide)), and physical state (e.g. gaseous (fumigant)).

The term “fungicides” as used herein, includes biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. For the scope of this invention it is used for both fungicides and fungistatic inhibitors. A fungistatic agent inhibits the growth of fungi. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, and profit. Fungicides can either be classified as contact, translaminar or systemic based on their method of performance. Contact fungicides are not taken up into the plant tissue and protect only the plant where the spray is deposited.

Translaminar fungicides redistribute the fungicide from the upper, sprayed leaf surface to the lower, unsprayed surface. Systemic fungicides are taken up and redistributed through the xylem vessels. Few fungicides move to all parts of a plant. Some are locally systemic, and some move upwardly.

The term “‘herbicides” as used herein, also commonly known as weedkillers, includes substances used to control unwanted plants. Selective herbicides control specific weed species, while leaving the desired crop relatively unharmed, while non-selective herbicides might be used to clear waste ground, industrial and construction sites, railways and railway embankments as they kill all plant material with which they come into contact.

Apart from selective/non-selective, other important distinctions include persistence (also known as residual action: how long the product stays in place and remains active), means of uptake (whether it is absorbed by above-ground foliage only, through the roots, or by other means), and mechanism of action (how it works). Historically, products such as common salt (NaCl) and other metal salts were used as herbicides, however these have gradually fallen out of favour and in some countries a number of these are banned due to their persistence in soil, and toxicity and groundwater contamination concerns.

The term “caproic acid” as used herein, also known as hexanoic acid, includes the 5 carboxylic acid derived from hexane with the chemical formula CH3(CH2)4COOH. It comprises 6 carbon atoms, thus is also used herein as Ce fatty acid. It is a fatty acid found naturally in various animal fats and oils, and is one of the chemicals that gives the decomposing fleshy seed coat of the ginkgo its characteristic unpleasant odor. The primary use of caproic acid is in the manufacture of its esters for use as artificial flavors, and in the manufacture of hexyl derivatives, such as hexylphenols. Salts and esters of caproic acid are known as caproates or hexanoates.

The term “valeric acid” or “pentanoic acid” as used herein, includes the carboxylic acid derived from pentane with the chemical formula CH3(CH2); COOH. It comprises 5 carbon atoms, thus is also used herein as Cs fatty acid. Like other low-molecular-weight carboxylic acids, it has an unpleasant odor. It is found in the perennial flowering plant

Valeriana officinalis, from which it gets its name. Its primary use is in the synthesis of its esters. Salts and esters of valeric acid are known as valerates or pentanoates. Volatile esters of valeric acid tend to have pleasant odors and are used in perfumes and cosmetics.

Isovaleric acid and 2-methylbutyric acid are isomers.

The term “butyric acid” as used herein, also known as butanoic acid, includes a straight-chain alkyl carboxylic acid with the chemical formula CH3CH:CH:CO:H. It comprises 4 carbon atoms, thus is also used herein as Ca fatty acid. It is an oily, colourless liquid with an unpleasant odour. Isobutyric acid (2-methylpropanoic acid) is an isomer.

Salts and esters of butyric acid are known as butyrates or butanoates. Butter composes for 3-4% of butyric acid triglycerides, when butter turns rancid the butyric acid is released from the glyceride by hydrolysis. Butyric acid plays an important role in the digestive tract of mammals and the esters of butyric acid are widespread in nature. It is a common industrial chemical.

The terms “C+” and “Cs” fatty acid as used herein, are known as heptanoic acid or enanthic acid and as octanoic acid or caprylic acid respectively, and the isomers thereof.

Heptanoic acid or enanthic acid is an oily liquid with an unpleasant, rancid odor. It is slightly soluble in water, and very soluble in ethanol and ether. Salts and esters of enanthic acid are called enanthates or heptanoates. Compounds of octanoic acid are found naturally in the milk of various mammals and as a minor constituent of coconut oil and palm kernel oil. Salts and esters of caprylic acid are called caprylates or octanoates.

The present invention is a pesticide concentrate comprising an aqueous mixture of at least C4 and/or Cs and/or Cs fatty acids or their salts or esters as active ingredient. One of the advantages of this pesticide concentrate is that it is a contact pesticide. Contact herbicides only harm parts of the plant they are in contact with. Another advantage is that the aqueous mixture of at least C4 and/or Cs and/or Cs fatty acids or their salts or esters are well-soluble, therefore no emulsifiers are needed unlike for example is the case with pelargonic acid which has low solubility in water. A further advantage is that the aqueous mixture of at least C4 and/or Cs and/or Ce fatty acids or their salts or esters are very effective in controlling unwanted weeds, even more effective in some cases than for example the more commonly used pelargonic acid, or acetic acid. Another advantage is that the Ca and/or Cs and/or Cg fatty acids or their salts or esters are might have an organic origin. It has preferably been made out of organic C2-C4 compounds via enzymatic carbon chain elongation.

The Cy fatty acid is a short chain fatty acid with four carbon atoms that can be branched (isobutyric acid or 2-methylpropanoic acid) or have a straight chain, and can be saturated or unsaturated. Advantageously, the Ca fatty acid is butyric acid, also known under the systematic name butanoic acid, a straight-chain alkyl carboxylic acid with the chemical formula CH3CH2CH2CO:H.

The Cs fatty acid is a short chain fatty acid with five carbon atoms that can be branched (isovaleric acid or 2-methylbutyric acid) or have a straight chain, and can be saturated or unsaturated. Advantageously, the Cs fatty acid is valeric acid, also known under the systematic name pentanoic acid, a straight-chain alkyl carboxylic acid with the chemical formula CH3CHsCH:CH;CO:H.

The Ce fatty acid is a medium chain fatty acid with 6 carbon atoms that can be straight or branched, and saturated or unsaturated monocarboxylic acids. Examples are caproic acid and 4-methylpentanoic acid. Advantageously, the pesticide concentrate comprises as the Ce fatty acid caproic acid, or the salts thereof. Caproic acid, also known as hexanoic acid, is the carboxylic acid derived from hexane with the chemical formula

CH:(CH:):COOH. Salts and esters of caproic acid are known as caproates or hexanoates.

Advantageously, the pesticide concentrate comprises as the Cy fatty acid butyric acid, as the Cs fatty acid valeric acid and as the Cs fatty acid caproic acid, or the salts or esters thereof, more preferably the acids or salts thereof.

Advantageously, the pesticide concentrate comprises a mixture of at least C4 and

Cs tatty acids or their salts or esters as active ingredient.

The pesticide concentrate of the current invention comprises a mixture of the fatty acids. This might be in dry form, or as a concentrated solution in for example water, ethyl- hexyl lactate, ethanol, hexanol, or other alcohols. Advantageously, the pesticide concentrate comprises an aqueous mixture of the fatty acids.

Preferably, the mixture of the pesticide concentrate comprises in the range of from 40 up to 80 wt% of sodium caproate or caproic acid, based on total weight of the fatty acids in salt, ester or acidic form in the concentrate. In the final application, in use, the pesticide concentrate will be further diluted with for example water, such that the concentration of sodium caproate in the final mixture will be around 1 to 25 wt%, based on the total weight of the diluted pesticide mixture. More preferably, the pesticide concentrate furthermore comprises in the range of from 10 up to 50 wt% of sodium butyrate, in the range of from 5 up to 15 wt% sodium acetate, in the range of from 0.1 up to 5 wt% of sodium propionate, in the range of from 1 up to 5 wt% of sodium valerate, in the range of from 0.1 up to 5 wt% of sodium heptanoate and in the range of from 0.5 up to 5 wt% sodium caprylate, based on total weight of the fatty acids in salt, ester or acidic form in the concentrate. Instead of sodium, also other cations such as potassium, calcium and/or ammonium or combinations thereof can be used in the salts of the fatty acids.

Advantageously, the pesticide concentrate is preferably a herbicide or a fungicide, more preferably a herbicide. The herbicidal properties of the fatty acids of the invention preferably derive from the fact that they break through the cuticle, the waxy layer on the leaves of a plant. After breaking through the cuticle the fatty acids disrupt the cell membranes, causing eventually desiccation and death of the plant tissue. Thus the fatty acid comprising pesticides have herbicidal effects on the seedling and leaves of plants.

This has consequences for the use of the fatty acids on the field. The conclusions that can be drawn from the mechanism and effects of the fatty acids are as follows and are valid for most, if not all crops: the fields are preferably treated before potential crops are sown, because the fatty acids can disturb growth of the radicle of the crops. Advantageously, after the crops have germinated targeted treatment is possible. Care has to be taken that only the weed is affected. A number of preferred post-emergence applications are: e treatment of weeds under fruit trees, as the bark suffers no negative effects from the herbicide. e spraying in between crop rows. e spot treatment with handheld sprayers. e selective removal of plant parts, e.g. haulm killing.

The aqueous mixture pesticide concentrate is preferably prepared via enzymatic carbon chain elongation. The process comprises the steps of: i) providing organic C:-Cé compounds; ii) subjecting the organic C2-C4 compounds to enzymatic carbon chain elongation in the presence of an electron donor: and ii) separating and/or concentrating the formed mixture of C2-C4 fatty acids or fatty acid salts.

The process is based on the insight that organic C: - Cé compounds could be subjected to enzymatic carbon chain elongation thereby providing organic compounds with an extended carbon chain. The process is also described in WO-A-2009083 174. This carbon chain elongation is an enzymatic process which could be carried out by microorganisms. This enzymatic carbon chain elongation requires the presence of an electron donor. The organic Cz - Cs compounds are enzymatically reacting with one another thereby forming organic compounds having an elongated carbon chain. Formed are valuable organic compounds namely a mix of mainly Cs, - Cg fatty acids as a dilute solution. Not bound by any theory or hypothesis, it is considered that the carbon chain elongation increases by at least two carbon atoms or by more carbon atoms when in the elongation step Cz - Cs organic compounds are involved and/or a dimerization or oligomerization takes place. At this point it is noted that throughout the description the fatty acid may be referred to as a fatty acid or as its deprotonated form. Accordingly, acetic acid and acetate will refer to the same type of compound unless specifically indicated.

Accordingly, the term acetic acid and acetate may be used interchangeably. The shortcuts

C2 - Cg fatty acids will also refer to both the fatty acid or its deprotonated form unless specifically indicated.

The starting organic C: - Cé compounds may be any suitable organic compound.

However, the enzymatic carbon chain elongation proceeds effectively and at a better yield when the organic Cz - Cé compounds comprise organic Cz - Cg carboxylic acids and/or C: -

Cs alcohols. Specific examples of suitable organic Cs - Cs compounds are acetate, n- propionate, i- propionate, n-butyrate, i-butyrate, succinate, n-valerate, i-valerate, n- caproate, i-caproate, ethanol, methanol, propanol, lactic acid, n-butanol, and i- butanol.

Best results (considering yield and/or conversion rate) are obtained with acetate, n- propionate, i-propionate, n-butyrate, ethanol, methanol, lactic acid and/or n-butanol.

Any source for organic Ca - Ce compounds is suitable for use in the enzymatic carbon chain elongation according to the present invention. Biomass as such may be used.

However, it is preferred to use pretreated biomass in which the pretreatment resulted in a release or an improved availability for the enzymatic reaction of the required organic Cs -

Cs compounds. Such pretreatments may comprise fermentation or other enzymatic reactions and a treatment of biomass (such as wood) with super critical water. Obviously, any carbon source comprising fat, protein, carbohydrate and/or mixtures thereof is in essence suitable provided that directly or by chemical treatment organic Ca - Cé compounds are released or made available. Furthermore, it is possible that the pretreatment comprises a mechanical or physical treatment. A mechanical treatment comprises milling, grinding, pressing and the like. Physical pretreatments comprise an exposure to heat, water, steam and the like. Accordingly, there is a preference for using biomass, pretreated biomass, fermented biomass or fractions thereof.

As indicated here and before, the enzymatic carbon chain elongation proceeds with the required presence of an electron donor. Accordingly, any inorganic or organic compound which could provide electrons for the carbon chain elongation during the enzymatic conversion is suitable. In essence, any organic compound which can be used as a metabolic energy source for providing electrons may be used.

In general are suitable on the one hand inorganic compounds such as hydrogen, formate and carbon monoxide. On the other hand are suitable organic Ci - Cé compounds having a degree of reduction higher than 4. The degree of reduction indicates the capacity of a compound to reduce other compounds. It is expressed in number of electrons that are involved in the half reaction of the compound with the compounds in the reference oxidation state. Compounds in the reference oxidation state are HCO: ‚ NO: , SO: water and protons; and have by definition a degree of reduction zero.

The degree of reduction is the amount of electrons involved. in this oxidizing half reaction per carbon atom of the compound (see McCarty, P. L., ed. Energetics of organic matter degradation. Water pollution microbiology, ed. R. Mitchell. Vol. 2. 1972, John

Wiley & Sons: New York. 91- 118) . Thus the degree of reduction higher than 4 means that at least 4 electrons are involved in the half reaction of the electron donor.

In case of organic Cz - Cé compounds the degree of reduction divided by four gives the moles of O: needed per C-atom in the organic compound needed for full oxidation to

CO: and H:0. The degree of reduction is maximally 8 for methane. Advantageously, the electron donor is selected from the group comprising hydrogen, formate, carbon monoxide, organic Cj - Cs compounds with a degree of reduction higher than 4 and/or mixtures of the electron donors.

More suitable electron donors are ethanol, formate, carbon monoxide, methanol, glycerol, lactate, 1,3-dipropanol, acetate, n-propionate, i-propionate, n-butyrate, i-butyrate, succinate, n-valerate, i-valerate, n-caproate, i-caproate, propanol, n-butanol, i-butanol.

Most preferred are as an electron donor hydrogen, ethanol, n-butanol, methanol, lactate and/or mixtures thereof.

The enzymatic reaction may be carried out using enzymes and/or enzyme mixtures and/or enzyme complexes. Practically is the use of microorganisms to carry out this enzymatic reaction. These microorganisms should be suitable for carrying out the carbon chain elongation. Microorganisms suitable for the enzymatic carbon chain elongation under anaerobic conditions may be found in anaerobic sewage sludge or in the sludge of a reactor fermenting acetate and/or ethanol (or other organic Cz - Cs compounds).

Accordingly, the microorganisms may originate from an inoculum of such anaerobic sewage sludge or reactor. However, other sources of microorganisms may be used. For example, sources for fermentative bacteria, such as Clostridia.

When using an inoculum comprising a variety of microorganisms, then it is preferred to inhibit parallel enzymatic reactions, such as the formation of methane.

Accordingly, it is preferred that during the enzymatic carbon chain elongation methane formation is substantially inhibited. According to one embodiment the methane formation is suppressed or even inhibited by carrying out a heat pretreatment. Other pretreatments comprise carrying out the method at relatively low (acidic) pH, subjecting the inoculum to an acid treatment. Finally, another option comprises the removal from the reaction system of any present carbon dioxide. An alternative or concomitant treatment comprises the addition of a methane formation inhibiting agent. An example of such methane formation inhibiting agent is 2-bromo-ethanosulfonic acid.

The method for preparation of the pesticide according to the invention provides in an elegant manner, starting from organic Cz - Cs compounds in the provision of a mixture of Cz - Cs fatty alcohols and/or Ca - Cs fatty acids. Preferred from an enzymatic point of view are Cz - Cg fatty alcohols and Cz - Cs fatty acids. A preferred produced fatty alcohol is n-hexanol. Preferred fatty acid are butyric acid and caproic acid. Due to the relatively large carbon chain, are the formed Cy - Cs fatty alcohols slightly or insoluble in the aqueous medium in which the enzymatic carbon chain elongation is carried out.

Accordingly, the produced fatty alcohol and/or fatty acid may be relatively easily separated from the aqueous medium. Suitable separation procedures are for example extraction, precipitation, flotation, concentration, phase separation, distillation, liquid/liquid separation, sedimentation and/or absorption. Phase separation using for instance selective membranes is an alternative possible solution. Obviously, in view of a particular produced C4 - Cs fatty alcohols and/or Cy - Cs fatty acid the skilled person may select by routine experimentation the best suitable separation procedure under the residing circumstances.

In general is the pH during the enzymatic production accordingly to the invention maintained between 4-8. The pH may also be chosen dependent on the various steps of the method for the enzymatic production. Accordingly, the pH may be neutral during the enzymatic carbon chain elongation. A suitable pH may be within the range of 6-8, more preferably a pH in the range of 6.5 - 7.5, such as pH 7.

The separation of the fatty alcohol and/or fatty acid according to the invention may however take place at a relatively acidic pH, such as at a pH of 1-7, more preferably a pH of 2-6, such as a pH of 2.5-5. Obviously, the skilled person may select the separation pH even in dependence of the intended separation of the C4 - Cg fatty alcohols and/or C4 - Cg fatty acid. Even the pH may be selected dependent on a longer or shorter fatty acid or fatty alcohol produced.

The enzymatic method according to the present invention may be carried out continuously or batch wise, such as fed batch wise. Batch wise production has the advantage of having the option of adjusting the temperature and pH in relation to the stage of the method. Furthermore, is provided the possibility of carrying out the pre-treatment of the biomass and/or the inoculums whenever required.

The fatty acid concentrate is preferably produced as an aqueous solution of 50wt% fatty acid salts, based on the total weight of the product. The fatty acids salts may however be concentrated further up to a powder or wax form, but as this additional drying adds cost, it is not preferred. Alternatively, the concentrate can be produced as a blend of fatty acids in their acidic form. The concentrate can in this form be applied through, for instance, as suspension concentrate (SC) or emulsion concentrate (EC) formulations.

The pesticide concentrate can be diluted depending on the exact pesticidal need. To use the prepared fatty acids as herbicide in the field, the dosage of pesticide concentrate is adjusted, as using too little results in poor weed control and too much is wasteful and too costly for the farmer and pesticide producer. From tests with the pesticide concentrate mixture according to the invention it has been found that without any additives the fatty acid concentration is preferably greater than 1 wt% and preferably up to 40 wt%, more preferably 10-30 wt to reliably control weeds. Other herbicides usually recommend a minimum fatty acid concentration of 1.7-2.4 wt% to a maximum of 5.7-7.2 wt%. but this might be due to the use of additives to increase the effectiveness of its pesticides. If the right additives are added to the pesticide concentrate according to the invention they might also be used in lower concentrations. Suitably, the pesticide concentrate furthermore comprises wetting agents and/or emulsifiers and/or (de)foaming agents and/or co-solvents and/or pH regulators.

It has been proven that the pesticide concentrate with fatty acids of mainly chain lengths of four and six carbon atoms have insecticidal properties against various insects.

While this can be a useful side-effect to get rid of insect pests, this may also cause harm to useful insects such as bees or predatory insects like ladybugs and parasitic wasps as fatty acids are non-selective in their insecticidal action. However, the risk to beneficial insects is minimal as long as proper precautions are taken, and the pesticide concentrate according to the invention might even be less toxic to those insects than other commercially available medium chain fatty acid pesticides.

Accordingly, the present invention is furthermore related to the use of the pesticide concentrate as described above as insecticide, herbicide or fungicide, preferably as herbicide. Preferably, the pesticide concentrate is diluted with a diluent, more preferably water.

To increase the effectiveness of the pesticides upon use, additives are preferably being added. Advantageously, the diluted pesticide furthermore comprises wetting agents, and/or emulsifiers, and/or (de)foaming agents and/or co-solvents and/or pH regulators.

The pesticide concentrate has been tested on a number of different weeds to test its effectivity as herbicide. For a number of weeds the mixture was very effective as herbicide. It is preferred to use the pesticide concentrate according to the invention to effectively control saltbushes, redshank, wind grass, couch grass, clover and small ragwort, more preferably clover, small ragwort, couch grass, saltbushes and redshank.

Currently, most chemical fungicides are either synthetic active compounds or simple inorganic compounds. As with herbicides, there are increasing concerns about the side-effects of synthetic fungicides. For this reason, there is a search for alternatives, with inorganic fungicides being one of the most used class of alternatives. The pesticide concentrate comprising an aqueous mixture of at least C4 and/or Cs and/or Cg fatty acids or their salts or esters as active ingredient may also be used to treat plant diseases, as a fungicide.

Fatty acids harm fungi by the same mechanism by which they harm plants: the disruption of the cell membrane. Analogous to the fact that each plant species has a different sensitivity to a certain fatty acid, the same holds for different fungus species.

There is comparatively little data on the use of medium chain fatty acids as fungicides, but it appears that a number of fungal plant pathogens can be successfully treated by fatty acids.

Because the pesticide concentrate has both fungicidal and herbicidal properties, it is important that the concentration needed to reliably kill a fungus is lower than the concentration needed to harm the plant on which the fungus grows. For the pesticide concentrate it has been found that the preferred minimum harmful concentration to plants is somewhere in between 2% to 40% of fatty acids or fatty acids salt in the final product. If a fungus requiring a large dose of fatty acid infects a sensitive plant, treatment may not be possible without harming the plant if the fungal infection takes place on the leaves. For this reason, current commercial medium fatty acid chain fungicide formulations, based on potassium laurate, provide a list of moderate and very sensitive plants and recommend performing test sprays on these plants. The pesticide concentrate can also be used in any concentration and for any crop when applied prior to crop germination to remove any fungicides present in the field.

The following non-limiting figures show the present invention further.

Figure 1 illustrates the results of various treatments on wind grass.

Figure 2 illustrates the results of various treatments on couch grass, saltbushes and redshank.

Figure 3 illustrates the results of various treatments on clovers.

Figure 4 illustrates the results of various treatments on saltbushes.

Figure 5 illustrates the results of various treatments on small ragwort.

Figure 6 illustrates the results of the treatments on Candida albicans.

The following, non-limiting examples are provided to illustrate the invention.

Example 1

As an example of the present invention a diluted mixture of C4 and Cé faity acid salts was tested on their effectiveness in the control of 6 types of weeds. The mixture of C4 and Cg fatty acid sodium salts was primarily composed of potassium caproate and butyrate.

The share of dry weight was 30 wt% potassium butyrate and 70 wt% potassium caproate

A soil tray trial was sown with weed species; small ragwort, saltbushes, redshank, couch grass, wind grass and cleavers. The trial was grown in a greenhouse until the desired stage of the plant was reached. After emergence, the sprays were applied as a contact herbicide at different growth stages of the plant. The spraying equipment used was a hand sprayer with a spray boom of 1.50 meters. The products were sprayed in four repetitions.

An overview of the treatments is given in Table 1.

Table 1: Treatments

Cowes

The treatments were carried out on dry crops. Assessment took place on number of plants dead and percentage infestation per type of weed. Photos of the objects were taken with each assessment. A summary of the results is presented in Figures 1 and 2. The reference numbers in the table correspond with the numbers in the figures. The numbers on the y-axis represents the % weeded out per treatment.

Figure 1 illustrates the results of various treatments according to table 1 on wind grass. The weeds were treated twice with 3 weeks in between. It can be seen from the results in the figure that there is a comparable efficacy of the short and medium chain fatty acid potassium salts (6wt% dose, pH 5) according to the invention to pelargonic acid and a far better efficacy compared to acetic acid. The synthetic glyphosate outperforms the fatty acid products.

Figure 2 illustrates the results of various treatments according to table 2 on couch grass, saltbushes and redshank. It can be seen from the results in the figure that there is a far better efficacy of the short and medium chain fatty acid potassium salts (6wt% dose, pH 5) according to the invention to pelargonic acid and also a far better efficacy compared to acetic acid. Also here the synthetic glyphosate outperforms the fatty acid products.

Example 2

As an example of the present invention a mixture of Ca, Cs and Cs fatty acid salts was tested on their effectiveness in the control of 3 types of weeds. The mixture of C4, Cs and Ce fatty acid salts was aqueous and primarily composed of sodium caproate and butyrate. The share of dry weight was 28 wt% sodium butyrate, 3 wt% sodium valerate and 58 wt% sodium caproate.

A soil tray trial was sown with lilies and several weed species. Each tray consisted of 10 lilies and 1 type of weed. The weeds included in the experiment were clover, saltbushes and small ragwort and were all analyzed separately. The trial was grown in a greenhouse until the desired stage of the plant was reached. For all weeds and products, 3 spray treatments were applied at spray volume of 50 mi/m}?. The sprays were applied as a contact herbicide at different growth stages of the plant, indicated in Table 2. An overview of the treatments is given in Table 3, two different types of commercial pelargonic acid herbicides were evaluated {A and B).

Table 2: Spray treatment timing 10-11-2020 5 leaves 3 proper leaves

Test clovers 18-11-2020 First bud 4 proper leaves 25-11-2020 3 buds 4 proper leaves 18-11-2020 First bud 3 proper leaves

Test saltbushes 25-11-2020 3 buds 4 proper leaves 25-11-2020 5 buds 6 proper leaves 18-11-2020 First bud 3 proper leaves

Test small ragwort | 25-11-2020 3 buds 4 proper leaves 25-11-2020 5 buds 6 proper leaves

Table 3: Treatments

Object Dose clovers Dose saltbushes and small ragwort

Pelargonic acid (Co) herbicide A 0.8 ml/m? 0.8 ml/m?

Pelargonic acid (Co) herbicide A 0.2 ml/m? 0.2 ml/m? 4 Pelargonic acid (Cs) herbicide B 0.4 ml/m? 0.4 ml/m?

Assessment took place on number of plants dead. Several photos of the objects were taken. A summary of the results is presented in Figures 3, 4 and 5. The reference numbers in the table correspond with the numbers in the figures. The numbers on the y- axis represents the % weeded out per treatment.

Figure 3 illustrates the results of various treatments according to table 3 on clovers.

It can be seen from the results in the figure that there is a stronger efficacy of the C4, Cs and Ce fatty acid sodium salts (10%) according to the invention to both pelargonic acid herbicides A and B at typical dosages.

Figure 4 illustrates the results of various treatments according to table 3 on saltbushes. It can be seen from the results in the figure that there is a comparable efficacy of the Ca, Cs and Cg fatty acid sodium salts (5%) according to the invention to both pelargonic acid herbicides A and B at typical dosages.

Figure 5 illustrates the results of various treatments according to table 3 on small ragwort. It can be seen from the results in the figure that there is a stronger efficacy of the

C4, Cs and Ce fatty acid sodium salts (5%) according to the invention to pelargonic acid herbicides A and pelargonic acid herbicide B at dosage 0.2 mi/m? and efficacy comparable to the pelargonic acid herbicide B at dosage 0.4 mi/m>.

Example 3

As an example of the present invention a mixture of C4, Cs and Cg fatty acids was tested on their effectiveness against growth of a fungus. The mixture of Ca, Cs and Cs fatty acids was primarily composed of caproic acid and butyric acid. The share of dry weight was 28 wt% butyric acid, 3 wt% valeric acid and 57 wt% caproic acid.

In order to assess the effect of the C4, Cs and Cs fatty acid mixture on growth of a fungi. a micro-broth dilution test was performed on a specific tribe of fungi: Candida

Albicans (ATCC®10231™), In each of the wells of a 96-well plate 100pL of Müller-

Hinton growth medium was added. Then the products indicated in Table 4 were inserted in different concentrations. Subsequently, an amount of 0.5 McFarland of Candida Albicans corresponding to 2.5 x 10° colony forming units (CFU) was added. The plates were incubated for 48 hours at 37°C after which they were read in a Thunderbolt at 630 nm for

Optical Density as representation for Candida growth. As a blank control, MH broth without additives was used. An overview of the different products and dilutions tested is given in Table 4.

Table 4: Products tested for their effect on the growth of Candida u Product Dilutions tested

Butyric acid (C4) 0,8,9,10,11,12,13,14,15,16 mmol

Ca, Cs, Cs fatty acid mix 0,8,9,10,11,12,13,14,15,16 mmol

A summary of the results is presented in Figures 6. The reference numbers in the table correspond with the numbers in the figure. The numbers on the y-axis represents the optical density, the numbers on the x-axis represent the dilution of the products in mmol.

Figure 6 illustrates the results of the treatments according to table 4 on Candida albicans. It can be seen from the results in the figure that there is a stronger efficacy of the

C4, Cs and Cs fatty acid mix according to the invention to the butyric acid product. The Ca,

Cs and Cs fatty acid mix according to the invention demonstrates a stronger effect against growth of Candida at equal dilution of the butyric acid product.

In the above, the invention has been disclosed using examples thereof. However, the skilled person will understand that the invention is not limited to these examples and that many more examples are possible without departing from the scope of the present invention, which is defined by the appended claims and equivalents thereof.

Claims

Conclusions

1. Pesticide concentrate comprising as active ingredient a mixture of at least C4 and/or C8 and/or C fatty acids or their salts or esters.

A pesticide concentrate according to claim 1, wherein the C4-fatty acid is butyric acid, the C8-fatty acid is valeric acid and the C8-fatty acid is caproic acid, or the salts or esters thereof, preferably the acids or salts thereof.

A pesticide concentrate according to claim 1 or 2, wherein the concentrate comprises a mixture of at least C4 and C8 fatty acids or their salts or esters as active ingredient,

A pesticide concentrate according to any one of the preceding claims, wherein the concentrate comprises an aqueous mixture of the fatty acids.

A pesticide concentrate according to any one of the preceding claims, wherein the mixture comprises in the range of 40 to 80% by weight of caproate salts or esters, based on total dry weight.

The pesticide concentrate according to claim 5, wherein the pesticide concentrate further contains in the range of 10 to 50 wt% sodium butyrate, in the range of 5 to 15 wt% sodium acetate, in the range of 0.1 to 5 wt% sodium propionate, in the range from 1 to 5 wt.% sodium valerate, ranging from 0.1 to 5 wt. sodium heptanoate and in the range of 0.5 to 5 wt.% sodium caprylate, based on the total weight of fatty acids.

A pesticide concentrate according to any one of the preceding claims, wherein it is a herbicide or a fungicide, preferably a herbicide.

A pesticide concentrate according to any one of the preceding claims, wherein the aqueous mixture is prepared via enzymatic carbon chain extension comprising the steps of:

i) providing organic C2-C compounds; 11) subjecting the organic C2-C compounds to enzymatic carbon chain extension in the presence of an electron donor; and iii) separating and/or concentrating the formed mixture of C2-C5 fatty acids or S fatty acid salts.

A pesticide concentrate according to claim 8, wherein the organic C2-C8 compounds are acetate, n-propionate, i-propionate, n-butyrate, i-butyrate, succinate, n-valerate, i-valerate, n-caproate, i-caproate, ethanol include methanol, propanol, lactic acid, n-butanol and/or i-butanol.

A pesticide concentrate according to claim 9, wherein the organic C:-Ce compounds comprise acetate, n-propionate, i-propionate, n-butyrate, ethanol, methanol, lactic acid and/or n-butanol.

A pesticide concentrate according to claims 8 to 10, wherein the organic C:-C4 compounds are provided in the form of biomass, pre-treated biomass, fermented biomass and/or fractions thereof.

Pesticide concentrate according to claims 8 to 11, wherein the electron donor is selected from the group comprising hydrogen, formate, carbon monoxide, C1-C8 organic compounds with a reduction degree higher than 4 and/or mixtures of the electron donors.

A pesticide concentrate according to claim 12, wherein the electron donor is hydrogen, ethanol, n-butanol, methanol, lactate and/or mixtures thereof.

A pesticide concentrate according to claims 8 to 13, wherein the C:-C fatty acids are separated by extraction, precipitation, flotation, sedimentation and/or absorption.

A pesticide concentrate according to claim 14, wherein the separation of the C2-Cy fatty acids is carried out at pH 1-7, preferably at pH 2-6, such as pH 2.5-5.

A pesticide concentrate according to any one of the preceding claims, which additionally comprises wetting agents and/or emulsifiers and/or (de)foaming agents and/or auxiliary solvents and/or pH regulators.

A pesticide concentrate according to any one of the preceding claims, further comprising other active pesticide components, preferably pelargonic acid.

Use of the pesticide concentrate according to any one of the preceding claims as an insecticide, herbicide or fungicide, preferably as a herbicide.

Use of the pesticide concentrate according to claim 18, wherein the pesticide is diluted with a diluent, preferably water.

Use of the pesticide concentrate according to claim 19, wherein the diluted pesticide further comprises wetting agents and/or emulsifiers and/or (de)foaming agents and/or co-solvents and/or pH regulators.

Use of the pesticide concentrate according to any one of claims 18 to 20, for the effective control of salt bushes, redshank, wind grass and riparian grass, preferably salt bush and redshank.