WO2011065831A2 - Improved formulations comprising heteropolysaccharides - Google Patents

Abstract

The invention relates to biocidal compositions, comprising a biocide, preferably a copper-based biocide, and a heteropolysaccharide. Preferred heteropolysaccharides comprise xanthan and/or succinoglycan. Preferred biocides are fungicides and pesticides. The invention further relates to a composition comprising a heteropolysaccharide and a liquid selected from a surfactant and a hydrophilic aprotic solvent, or a combination thereof, methods for preparing this composition, and use of this composition.

Description

Title: Improved formulations comprising heteropolysaccharides

Field: The present invention discloses formulations for pesticides comprising a biocide, especially a copper-based biocide, and a heteropolysaccharide that have an improved efficacy of the biocide, for example copper-based biocide. In addition, the invention relates to concentrated formulations of a heteropolysaccharide with a high dissolution rate in water.

Agricultural production worldwide is under permanent threat from numerous phytopathogenic fungi and bacteria. For the protection of yield and quality of products and to avoid economic losses, the application of agents that control plant diseases is an absolute requirement. Although the need for pesticides is generally acknowledged, there is an ongoing public concern about the negative impact of pesticides on the environment and on human health. As a consequence, the demands with respect to sustainability of chemical pest control are continually increasing.

In principle, reduced impact of chemical pesticides on the environment can be achieved by bringing new, environmentally sound pesticide products to the market or by increasing the efficacy and thereby reducing the dose rate of existing products. Because governmental procedures to approve new chemicals are often difficult and slow, few new active ingredients have been approved in recent years. Therefore, much attention has been given to increase efficacy of crop protection products by improving the formulation of these products, often by optimizing the adjuvants in the formulation. One of the oldest active ingredients of fungicides that is still widely used, is copper. Copper is applied in the form of a range of copper salts and copper complexes with organic molecules. It has a broad spectrum of activity against true fungi, oomycetes and bacteria. Resistance against copper fungicides is not known. Copper is most commonly used in fungicides in the form of copper hydroxide (Cu(OH)2 ), copper oxychloride (CuCb -3Cu(OH)₂) and Bordeaux mixture (CuS04.3Cu(OH)₂.3CaS0₄), although a number of other salts and copper complexes of organic compounds are on the market or have been sold in the past.

The use of biocides such as copper fungicides is known to cause environmental issues, related to accumulation of copper in the soil and water bodies. Many organisms, like earthworms, species of zooplankton and fish are sensitive to copper. For this reason, considerable research effort is targeted towards more efficient copper fungicidal formulations that allow lower dose rates of copper. Another important reason for development of lower dose rate copper fungicides is the price increase for copper on the world market. Since the 1960's the price of copper has increased more than fivefold. Although after the economic downturn of 2008 the copper price has fallen to the level of 2004, longer term price increases are expected, which incites the producers of copper fungicides to keep searching for low dosage application techniques.

One trend in the development towards a reduction of the dosage of copper in fungicides is the optimization of copper particles. Due to a better surface— to-volume ratio, the fungicidal efficacy of small crystals of copper salt is higher that the efficacy of large crystals, thus allowing a lower dose rate. Modern copper hydroxide- based fungicides, with an optimized surface-to-volume ratio, are applied at a dose rate of around 1.6 kg /ha / spray active ingredient, as used for example in viticulture, compared to up to 6 kg active ingredient / ha/ spray for Bordeaux mixture. Other techniques for decreasing the dose rate of copper fungicides use complexation of copper ions to organic molecules. Chelators that specifically bind metal ions like copper are used in various formulations of copper- based fungicides (e.g. USPTO Patent Application 20090136581; and US 6,562,757) and several compositions in which copper is combined with other types of organic molecules like octanoate (Commercial product: Copper Soap™, Neudorff, USA); napthenate (Commercial product CuNape^ Merichem, USA) or terpenes (US patent 6,849,276).

However, there is still a need to provide further means and methods that allow a further decrease in the dose rate of biocides and especially copper-based biocides such as copper- based fungicides.

A group of pesticide formulation ingredients increasingly receiving attention is the class of heteropolysaccharides, polymers of sugars consisting of more than one type of sugar monomer. These heteropolysaccharides are used in pesticide formulations as binders, structuring agents and rheology modifiers. The present invention relates to novel uses of heteropolysaccharides in biocides, for example in combination with the biocidal metal copper and to novel techniques of producing hetero polysaccharide containing

formulations. The present invention discloses the use of a combination of heteropolysaccharides with biocides such as commonly used copper-based biocides. The invention allows a significant dose reduction for biocides, especially copper-based biocides, without loss of efficacy.

Therefore, in one embodiment the invention provides a biocidal composition comprising at least a biocide, for example a copper-based biocide or a copper-based additive, and a heteropolysaccharide.

A heteropolysaccharide that is used in a composition according to the invention comprises succinoglycan and/or xanthan.

The term "xanthan", as used herein, refers to the polysaccharide that is produced by fermentation of glucose or sucrose by the Xanthomonas campestris bacterium. Xanthan consists of pentasaccharide repeating units, further containing several organic acids. A typical xanthan produced for industrial purposes comprises glucose, mannose, glucuronic acid, acetate,and pyruvate. Because of its wide applications in the oil, food, textile, agrochemistry, cosmetic and pharmaceutical industries, the output of xanthan gum is now the largest of the natural exopolysaccharides. Xanthan gum is used in food, cosmetics and medical applications as thickener and emulsion stabilizer. In pesticide formulations xanthan gum is used for suspension stabilization (structuring agent), improved sprayability, drift reduction and for increased cling and permanence of the spray (sticker). In the oil industry, xanthan gum is used among others for lubrication or friction reduction in drill-hole, stabilization of drill muds and enhanced oil recovery through reduction of water mobility by increasing viscosity and decreasing permeability. A preferred xanthan is the commercial product Rhodopol® (Rhodia, France) or Kelzan® (Kelco Company, USA).

The term "xanthan-like" refers to polysaccharides with pentasaccharide repeating units similar to xanthan, but with different levels of glucoronic, acetic and pyruvic acids. Such xanthan-like compounds can be produced by other bacterial species, related to

Xanthomonas campestris, or by Xanthomonas campestris grown under non-standard conditions (Sutherland, I. W. (1985) Annual Review of Microbiology 39: 243-270). The term "xanthan" and "xanthan4ike" includes chemical modifications of xanthan and xanthan4ike gums, respectively. A preferred modified xanthan is a xanthan gum-glyoxal complex comprising the reaction product of xanthomonas gum and glyoxal, and which comprises from about 0.02% to about 5% (w/w) glyoxal based upon the weight of dry xanthomonas gum.

The term "succinoglycan" refers to a high-molecular-weight polymer composed of repeating octasaccharide subunits, comprising one galactose residue and seven glucose residues, and further comprising acetate, succinate, and pyruvate residues. A typical composition of succinoglycan is glucose, galactose, pyruvate, succinate and acetate in the ratios 7: 1: 1: 1: 1. Certain succinoglycans exhibit rheological properties comparable to those of xanthan gum and are, furthermore, characterized by an increased stability to temperature, acid and basic pHs and strongly saline media (US Patent 5831042). A preferred succinoglycan is the commercial product Rheozan®; Rhodia (France).

The term "succinoglycan-like" refers to polysaccharides with octasaccharide subunits as succinoglycan, but with different levels of pyruvate, succinate or acetate. Such succinoglycan-like compounds can be produced by other bacterial species, related to the group of Pseudomonas, Rhizobium, Alcaligenes and Agrobacterium, or by these bacteria, if grown under non-standard conditions (Zevenhuizen, L.P.T.M. (1997) Carbohydrate polymers 33: 139 - 144). The term "succinoglycan" and "succinoglycan-like" includes chemical modifications of succinoglycan and succinoglycan-like gums, respectively. Further preferred are mixtures of xanthan and/or xanthan-like heteropolysaccharides and succinoglycan and/or succinoglycan-like heteropolysaccharides. A preferred mixture comprises xanthan and succinoglycan.

The term "biocide" refers to a chemical substance capable of killing living organisms. Biocides are commonly used in medicine, agriculture, forestry, and in industry where they prevent the fouling of, for example, water, agricultural products including seed, and oil pipelines. A biocide can be a pesticide, including a fungicide, herbicide, insecticide, algicide, molluscicide, miticide and rodenticide; and/or an antimicrobial such as a germicide, antibiotic, antibacterial, antiviral, antifungal, antiprotozoal and/or antiparasite. A preferred biocide is a fungicide. Preferred antifungal compounds or fungicides comprise compounds such as imazalil (Janssen Pharmaceutica NV, Belgium), thiabendazole (e.g. the commercial product TECTO® Flowable SC of Syngenta, USA), benomyl, captan (nonsystemic phthalimide fungicide), prochloraz (N-propyl-N- [2-(2,4,6- trichlorophenoxy) ethyl] imidazole- 1-carboxamide), thioallophanate (e.g. the commercial product TOPSIN® M Cerexagri Inc), orange oil, D-limonene, and fluazinam (commercial product: (SHIRLAN® Syngenta, Switzerland). Further suitable antifungal compounds can be found in Gewasbeschermingsgids 2006, Gids voor gewasbescherming in de land- en tuinbouw en het openbaar en particulier groen, Plantenziektenkundige Dienst, 2006, 560 pages, Paperback, Gewasbeschermingsgids - ISSN 1571-201X, Volume 18, which is hereby incorporated by reference. A most preferred fungicide is Shirlan®.

A further preferred biocide is a pesticide. Pesticidal agents include compounds to combat insects, nematodes, mites and bacteria. Examples of such compounds are imidacloprid (commercial product ADMIRE® Bayer), pirimiphos- methyl (commercial product ACTELLIC® Syngenta, Switserland), Pyrethroids (commercial product BAYGON® (Bayer), bifenazate (e.g. Uniroyal), dichlorvos (e.g. Amvac Chemical Corporation), imidacloprid (e.g. Bayer), fenamiphos (e.g. Mobay Chemical Corporation), orange oil, D- limonene, oxamyl (e.g. Dupont). A most preferred pecticide is pirimiphos -methyl (commercial product ACTELLIC®).

Suitable copper-based biocides are copper hydroxide (Cu(OH)2 ), copper oxychloride (CuC12 · 3Cu(OH)2), tribasic copper sulphate (CuS04.3Cu(OH)2) and Bordeaux mixture (CuS04.3Cu(OH)2.3CaS04).

Suitable copper-based additives comprise Bordeaux mixture, Burgundy mixture, Cheshunt mixture, copper acetate, basic copper carbonate, copper hydroxide, copper naphthenate, copper oleate, copper oxychloride, copper silicate, copper sulfate, copper zinc chromate, basic copper sulfate, cufraneb, cuprobam, cuprous oxide, mancopper and oxine-copper.

In one embodiment, a composition according to the invention comprises two of more biocides, such as two or more fungicides, two or more pesticides, or one or more fungicide and one or more pesticide. A preferred composition according to the invention comprises a copper-based biocide and a further biocide, preferably a fungicide and/or a pesticide. A preferred composition according to the invention is a solid and comprises between 0, 1% and 60% (w/w; based on the total product) of a biocide, preferably between 2 and 10%, most preferred about 3%. A preferred solid composition according to the invention comprises between 1 % and 25 % (w/w, based on the total product) of a

heteropolysaccharide, more preferred between 5 % and 20 %, most preferred about 14 %. It will be clear to the skilled person that a composition according to the invention can be suspended in an aqueous solution, for example water, to a ready to use composition comprising between 0,0001% and 1% (w/w; based on the total product) of a biocide), preferably between 0,001 and 0, 1%, most preferred about 0,01%. A preferred diluted ready to use concentration composition comprises between 0,001 % and 2,5 % (w/w, based on the total product) of a heteropolysaccharide, more preferred between 0,01% and 1 %, most preferred about 0,04 % of a heteropolysaccharide.

A preferred composition according to the invention contains one or more

heteropolysaccharides in a weight to weight ratio of copper to heteropolysaccharide ranging from 1:2 to 1: 10 (based on copper ions only, disregarding other ions or organic compounds), more preferable the copper to heteropolysaccharide ratio is less than 1:8, and ranges between 1:2 to 1:8, preferably between 1:3 to 1:7, more preferred between 1:4 to 1:7. A composition according to the invention can be in the form of a dry powder, a tablet, a suspension, a granule, a paste, a concentrates, a dust, an emulsion, or a liquid solution that is made thereof. Said liquid solution preferably is an aqueous solution.

In a further embodiment, the composition comprises at least one additional compound selected from the group consisting of a sticking agent, a surfactant, an emulsifier, a detergent, a preservative, a stabilizer, a spreading agent, an antioxidant, an anti-foam- forming agent, a wetting agent, a thickening agent, a filler, a spray oil, a dispersing agent, and a flow additive. Examples of sticking agents comprise, but are not limited to, latex based products like Prolong® (Holland Fyto B.V., The Netherlands) and Bond® (Loveland Industries Ltd), pilonene/terpene based products like Nu-film® (Hygrotech Saad) and Spray- Fast® (Mandops) and long chain polysaccharides like locust bean gum and guar gum.

Alternatively, the sticking agent may be a polymer or co-polymer from a type of polymer such as polyacrylate and polyethylene e.g. Neocryl® (DSM, The Netherlands). A composition of the invention may also comprise two or more different sticking agents.

Examples of surfactants, detergents, emulsifiers, spreading agent and wetting agents comprise, but are not limited to, anionic tensides such as sodium lauryl sulphate or polyethylene alkyl ethers or polyoxyethylethers, e.g Tween® 60, 61 or 65. Other examples of useful surfactants are organo silicones, sulfosuccmates, alcohol ethoxylates, fatty acid ethoxylates, fatty acid propoxylates and the commercial product Zipper® (Moodify BV, The Netherlands). A composition of the invention may also comprise two or more different of the above mentioned agents.

Examples of suitable preservatives comprise, but are not limited to, weak acid preservatives such as sorbic acid, lactic acid, benzoic acid, propionic acid, citric acid, acetic acid, or an alkali metal or alkali earth metal salt thereof; inorganic acids such as hydrochloric acid; imidazoles such as imazalil or any antifungal compound known in the art as a preservative for food products, crop protection or after harvest treatment of fruits, vegetables or cereals; ethyl parabenzoate; borax; calcium bisulfite; calcium disodium EDTA; dehydroacetic acid; isothiazoles (e.g. cit/mit); and antimicrobials capable of preventing bacterial growth in the composition. The composition of the invention may also comprise two or more different preservatives.

Examples of suitable stabilizers comprise, but are not limited to, agar, alginic acid, alginate, calcium lactobionate, carrageenan, gellan gum, locust bean gum, and guar gum. A composition of the invention may also comprise two or more different stabilizing agents.

Examples of suitable antioxidants comprise, but are not limited to, amino acids (e.g. glycine, histidine, tyrosine, tryptophan) and their derivatives, imidazole (e.g. urocanic acid) and derivatives, vitamin C and derivatives (such as ascorbylpalmitate and ascorbyltetraisopalmitate, Mg-ascorbylphosphate, Na-ascorbylphosphate, ascorbyl- acetate), tocopherol and derivates (such as vitamin-E-acetate), mixtures of vitamin E, vitamin A and derivatives (vitamin-A-palmitate and -acetate) as well as

coniferylbenzoate, rutinic acid and derivatives, a-glycosylrutin, ferulic acid, furfurylideneglucitol, carnosine, butylhydroxytoluene, butylhydroxyanisole, and trihydroxybutyrophenone. A composition of the invention may also comprise two or more different antioxidants.

Examples of suitable anti-foam forming agents comprise, but are not limited to,

Polyethylene glycol 8000, polymethylsiloxane, simethicone octanol, and silicone oils. A composition of the invention may also comprise two or more different anti-foam forming agents.

Examples of suitable thickening agents comprise, but are not limited to, agar, alginic acid, alginate, carrageenan, gellan gum, guar gum, locust bean gum, acetylated distarch adipate, acetylated oxidised starch, arabinogalactan, ethyl cellulose, methyl cellulose, locust bean gum, starch sodium octenylsuccinate, and triethyl citrate. A composition of the invention may also comprise two or more different thickening agents.

Examples of suitable fillers comprise, but are not limited to, montmorillonite, kaolin, veegum, bentonite, and talcum. A composition of the invention may also comprise two or more different fillers. A most preferred filler is veegum.

Examples of suitable dispersing agents include, but are not limited to sulfonated aromatic polymer (commercial product MORWET D-425® Akzo Nobel), Ethylene Oxide/Propylene Oxide Block Copolymer (commercial product: PLURONIC P®; BASF) and organosilicones (e.g. SILWET L-77®; Helena chemical company). A composition of the invention may also comprise two or more different dispersing agents. A most preferred disperging agent is calcium lignosulfonate Examples of suitable spray oils comprise, but are not limited to, Banole®, Banole® W, BANOLE® UBV, SprayTex M®, Orchex 692®, sunspray 11 E®. A composition of the invention may also comprise two or more different spray oils. A most preferred spray oil is BANOLE®. Examples of suitable flow additives comprise, but are not limited to, kaolin, talcum, polymethylsilsesquioxane (commercial product: Wacker-Belsil® PMS MK),

trimethylsiloxysilicate (commercial product: Wacker-Belsil® TMS 803), magnesium trisilicate, sodium aluminosilicate, bentonite, and polydimethylsiloxane. A composition of the invention may also comprise two or more different flow additives. A most preferred flow additive is polydimethylsiloxane.

The invention further provides a method for protecting an agricultural plant from a plant disease, preferably a fungal disease, the method comprising applying to said agricultural plant a biocidal composition according to the invention, comprising a biocide and a heteropolysaccharide. Said biocide preferably is a copper-based biocide or comprises a copper-based additive.

Said agricultural plant is preferably a crop plant, preferably a vegetable, or a fruit. Said plant disease is preferably a disease that is caused by a pathogen. Said pathogen preferably is a fungus. Said fungus preferably belongs to the order Oomycetes (esp. Phytophthora sp. , Plasmapara viticola).

A composition according to the invention may be diluted to a ready to use concentration comprising between 0,01 and 25 gram/liter of a heteropolysaccharide, more preferred between 0, 1 and 10 gram/liter, most preferred about 0,4 gram/liter.

The invention further provides a method of producing a composition comprising a biocide with enhanced efficacy, the method comprising adding a heteropolysaccharide to the composition. Said biocide preferably is a copper-based biocide or a biocide comprising a copper-based additive.

A limitation to the use of xanthan and xanthan-like gum and of succinoglycan and succinoglycan-like gum is the slow dissolution rate and the tendency of formation of lumps during dissolution although some physical means have been used to improve dispersibility. (Sandford, P. A. , Baird, J., & Cottrell, I. W. (1981). In: Solution Properties of Polysaccharides, ACS Symposium Series, Vol. 150. Ed: David A. Brant; , pp. 31-38.). Like that of other polymers, the dissolution process of gums includes two steps (V an Krevelen, D. W. (1976). Properties of polymers— Their estimation and correlation with chemical structure. New York: Elsevier.): Firstly solvent penetrates the solute, causing the solute to swell. Secondly the solute dissolves into the solvent phase. Hydrocolloids such as xanthan and succinoglycan gums can form 'fish-eyes' (Sandford et al., 1981, ibid) during dissolution. That is to say, when gum particles begin to hydrate, a gelatinous layer of partially hydrated gum forms on the outside of the particle. The gum cannot leave the particle surface rapidly through the gelatinous layer, which also prevents water from penetrating to complete hydration and from dissolving the particle.

The most common technique to reduce lumping of gums consists of some kind of pre- swelling, after which the gum is mixed in water under vigorous agitation or stirring. Misting with water can achieve the swelling of the gum without causing gellification, but the gum in the swollen form cannot be stored and the process is unpractical for large quantities of gum.

Another approach is to pre-swell the gum in a polar solvent like ethylene glycol (ethane- 1,2-diol) or mono propylene glycol (propane- 1,2-diol), sometimes combined with heating (Andersson, M., Ciullo, P.A. (2000). SOFW-Journal, 6 (126), 32-36). Pre -swelling in ethylene glycol or mono propylene glycol reduces the formation of lumps as well as the solution time of xanthan or succinoglycan gums, but xanthan and succinoglycan gum do gellify in both ethylene glycol and mono propylene glycol. This implies that the pre- swollen gums have to be diluted shortly after the gums have been added to the swelling agent, thus precluding the option of preparing stock preparations that can be stored for longer periods of time.

European patent EP0016640 teaches the use of suspensions of xanthan gum in mineral oil, diesel oil, kerosene, alcohols (six to twelve carbons), vegetable oil, ester- alcohols, polyol ethers, and the like. Additional compounds necessary in these preparations include suspending agents, dispersants, and thinning agents. The xanthan gum in these preparations is not pre-swollen, which means that the dissolution time and lumping are still important issues. Commercial products in which xanthan is suspended in liquid are, for instance, LIQUID FLOWZAN® Biopolymer and GREENBASE™ FLOWZAN®

Biopolymer (both marketed by Chevron Phillips Chemical Company LLC, USA) in which xanthan gum is suspended in mineral oil and a glycol ether, respectively. Although these products yield fine dispersions in water upon mixing, lumping still occurs upon dilution and the dilution time is not optimal. In addition to the above mentioned methods, a variety of convenient methods of making the dissolution of xanthan gum in water has been proposed. Examples thereof are a method in which xanthan gum is treated with a surface active agent (US patent

5416206), a method in which xanthan is co-precipitated with silica (United States Patent 4357260) and a method in which xanthan is treated with glyoxal (United States Patent 4363669). All these methods include one or more steps in which xanthan is suspended, treated with chemicals and precipitated and dried to obtain the modified product. These steps complicate the production process of xanthan products and increase the price of the xanthan products.

In a further aspect, the present invention solves the problem of preparing a concentrated heteropolysaccharide suspension. Therefore, the invention provides a composition comprising a heteropolysaccharide and a liquid selected from a water-free surfactant and a hydrophilic aprotic solvent, or a combination thereof. Surprisingly, it was found that heteropolysaccharides such as xanthan and succinoglycan gums can be suspended in liquid, water-free surfactants and in water-free aprotic hydrophilic solvents.

Furthermore, these liquids allow pre-swelling of the gum without gellification.

Suitable examples of heteropolysaccharides comprise xanthan and xanthan-like heteropolysaccharides produced by bacteria comprising the genus Xanthomonas, containing structural units derived from glucose, mannose, glucuronic acid and pyruvic and acetic acid and salts of such acids. Further preferred heteropolysachharides comprise succinoglycan and succinoglycan-like heteropolysaccharides produced, for example, by bacteria of the genera Pseudomonas, Rhizobium, Alcaligenes and

Agrobacterium.

Furthermore, it will be clear to the skilled person that also chemical modifications of xanthan-like and succinoglycan gums can be used in embodiments of the present invention such as, for example, a xanthan gum-glyoxal complex comprising the reaction product of xanthomonas gum and glyoxal, whereby the complex comprises from about 0.02% to 5% by weight of glyoxal based upon the weight of dry xanthomonas gum. In preferred embodiments xanthan (e.g. the commercial products Rhodopol® (Rhodia, France) or Kelzan® (Kelco Company, USA) or succinoglycan (e.g. the commercial product Rheozan®; Rhodia) are used. Further embodiments of the invention comprise mixtures of xanthan-like heteropolysaccharides and succinoglycan-like heteropolysaccharides. A preferred mixture comprises xanthan and succinoglycan.

In a preferred embodiment, a composition according to the invention further comprises a heteropolysaccharide of the galactomannan type, such as fenugreek gum, guar gum, tara gum and locust bean gum or carob gum. Heteropolysaccharides of the galactomannan type are known for synergistic interaction with xanthan and succinoglycan, resulting in a higher viscosity of suspensions of mixed heteropolysaccharides than could be expected from the viscosity of suspensions of the heteropolysaccharides by themselves (US Patent 5350524; Casas, J.A. and Garcia-Ochoa (1999). Journal of the Science of Food and Agriculture 79: 25-31; Casa, J. A., Mohedano, A.F. and Garcia-Ochoa (2000) Journal of the Science of Food and Agriculture 80: 1722-1727.

In a further preferred embodiment, the relative amount of the heteropolysaccharide in a composition according to the invention is between 10 and 500 g /kg, more preferred between 20 and 250 g /kg, more preferred between 50 and 100 g /kg. Xanthan and succinoglycan gums are used in many applications in which the final product comprises a number of different compounds. Examples are sauces, cremes, pesticide formulations and printing dyes. In such applications, it would be advantageous to have a concentrated preparation containing all ingredients that can be diluted with water to the ready-to-use product.

Such concentrated heteropolysaccharide is for instance especially useful for preparing a concentrated formulation for pesticides, comprising a copper-based biocide or a copper- based additive. A pesticide formulation comprising a copper-based biocide or a copper- based additive, a heteropolysaccharide and a liquid selected from a water-free surfactant and a hydrophilic aprotic solvent, or a combination thereof for instance reduces the transport and storage costs. The concentrated pesticide composition can be easily diluted with water prior to use.

In one embodiment, the invention thus provides a pesticide formulation comprising a copper-based biocide or a copper-based additive, a heteropolysaccharide and a liquid selected from a water-free surfactant and a hydrophilic aprotic solvent, or a combination thereof. In a preferred embodiment, the relative amount of the heteropolysaccharide in a pesticide formulation according to the invention is between 10 and 500 g /kg, more preferred between 20 and 250 g /kg, more preferred between 50 and 100 g /kg.

The possibility to use concentrated stock preparations, including xanthan or succinoglycan gums, is limited by the low maximal dilution rate achievable with the gums in water-based preparations. For instance, xanthan gum in water at

concentrations of 20 g /l or more turns into a gel that cannot be poured out of the container. Typical concentrations for use of xanthan gum in final formulations are 0.5— 10 g/ 1 (F. Garcia-Ochoa, V.E. Santos, J.A. Casas, E. Gomez (2000). Biotechnology Advances 18: 549-579). This indicates that useful dilution rates from a composition of the invention are between 50 and 1000 times.

Suitable examples of water-free surfactants comprise alcohol alkoxylates (e.g. alcohol ethoxy- propoxylate), sorbitan ester ethoxylates (e.g. POE (20) eorbitan mono-oleate), ethylene oxide / propylene oxide copolymers (e.g. polyoxyalkylene glycol butyl ether), polyglycerol esters of fatty acids and sorbitan esters of fatty acids. In one embodiment, a composition comprises two or more different surfactants.

The class of aprotic hydrophilic solvents are also suitable solvents for high concentration of a heteropolysaccharide such as xanthan and succinoglycan. Suitable examples of aprotic solvents comprise dimethyl sulfoxide, dimethyl formamide, dimethylacetamide, acetonitrile and methoxy propoxy propanol.

In a further embodiment, a composition of the invention comprises one or more surfactants and one or more aprotic hydrophilic solvents.

A composition of the present invention will generally contain 10-500 g /kg of heteropolysaccharide suspended in a suitable surfactant. In a preferred embodiment the heteropolysaccharide is xanthan and the suspension liquid is alcohol ethoxy propoxylate (commercial product:Genapol EP 2584®, marketed by Clariant, Germany). In a further preferred embodiment the heteropolysaccharide is xanthan and the suspension liquid is methoxy propoxy propanol (commercial product Acrosolv®; Lyonell, USA). In a further preferred embodiment the heteropolysaccharide is xanthan and the suspension liquid is a mixture of 50 % (v/v/) Genapol EP 2584 and 50 % (v/v) methoxy propoxy propanol. In a further preferred embodiment the heteropolysaccharide is succinoglycan and the suspension liquid is alcohol ethoxy propoxylate (commercial product: Genapol EP 2584®) In a further preferred embodiment the heteropolysaccharide is succinoglycan and the suspension liquid is methoxy propoxy propanol. In a further preferred embodiment the heteropolysaccharide is succinoglycan and the suspension liquid is a mixture of 50 % (v/v/) alcohol ethoxy propoxylate (commercial product: Genapol EP 2584®) and 50 % (v/v) methoxy propoxy propanol.

In a further embodiment, a composition of the invention further comprises one or more of a medicinal compound including, but not limited to, hydrocortisone, acyclovir, propolis and, preferably, natamycin; a colorant including, but not limited to, Brilliant Blue FCF, tartrazine, Sunset Yellow FCF and, preferably, erythrosine; a flavoring compound including, but not limited to, citral, menthol, isoamyl acetate and, preferably, vanillin; a fungicidal or insecticidal compound including, but not limited to, imazalil, thiabendazole, benomyl, natamycin, phosphite and salts of phosphite, orange oil, limonene, Bacillus thuringiensis (Bt) and, preferably, folpet; a bactericidal compound including, but not limited to, benzalkonium chloride, daptomycin, gentamycin and , preferably,

metronidazole; and/or a nematicidal compound including, but not limited to,

phenamiphos, oxamyl, aldicarbcarbofuran and, preferably, neem tree oil.

In a further aspect, the invention provides a method of preparing an aqueous

composition comprising a heteropolysaccharide, the method comprising diluting a composition according to the invention in water. The high dilution rate in water of between 50 and 1000 times renders a composition of the invention very suitable for storage and transport of the composition from the production site to an end user. The solvent that is used in a composition of the invention is freely miscible with water to allow simple dilution of the concentrated heteropolysaccharide suspension to the desired concentration in water resulting in a fast and lump-free dissolution of the

heteropolysaccharide in water.

In a further aspect, invention provides the use of a composition according to the invention in the preparation of a composition comprising a heteropolysaccharide in water. In yet a further aspect, the invention provides an aqueous composition comprising one of more heteropolysaccharides, water, and a liquid selected from a surfactant and a hydrophilic aprotic solvent, or a combination thereof. A typical aqueous composition comprises between 0.1 and 20 g/1 of one or more heteropolysaccharides, more preferred between 0.5 and 10 g/ 1, more preferred between 1 and 5 g/1. The concentration of the surfactant and/or hydrophilic aprotic solvent is preferably at most 10 % (v/v), more preferred at most 1 % (v/v), more preferred at most 0.5 % (v/v), more preferred at most 0.1 % (v/v), more preferred at most 0.01 % (v/v). In yet a further aspect, the invention provides the use of an aqueous composition according to the invention as thickener or as emulsion stabilizer. For example, a food product, a cosmetic product or a medical application product may comprise a

heteropolysaccharide as a thickener or as an emulsion stabilizer, whereby the heteropolysaccharide is applied by the use of an aqueous composition according to the invention.

In yet a further aspect, the invention provides the use of an aqueous composition according to the invention for lubrication or friction reduction. For example, a heteropolysaccharide is used in the oil industry for lubrication or friction reduction in drill-hole, stabilization of drill muds and enhanced oil recovery through reduction of water mobility by increasing viscosity and decreasing permeability.

In yet a further aspect, the invention provides the use of an aqueous composition according to the invention in a pesticide, bacteriocide, fungicide, or nematocide. For example, a heteropolysaccharide is used in pesticide formulations for suspension stabilization (structuring agent), for improved sprayability, and/or for drift reduction and increased cling and permanence of the spray.

The verb "to comprise" and its conjugations as used in this description and in the claims is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. In addition, reference to an element by the infinite article "a" or "an" does not exclude the possibility that more than one of the elements are present, unless the context clearly requires that there is one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one".

The following examples are given for purely illustrative and non-limiting purposes for the present invention.

Examples

Example 1

Synergistic effect of addition of xanthan to three different copper-based fungicides in control of powdery mildew of rose.

The experimental design is a randomized block design with a plot size of 4 m2 per plot and 25 plants per plot. The experiment has 4 replications. During the experiment the plants are sprayed weekly with a dose rate of 0.8 1/plot, using a backpack sprayer. The composition and the dose rate of the different treatments are given in Table 1.

Composition and dose rates are adjusted so that each plot receives the same amount of active ingredients and adjuvants (as applicable). To allow detection of synergism

between xanthan and the copper fungicides, the experimental setup includes treatments with each of the copper-based fungicides alone, xanthan alone, and the combination of xanthan with each of the copper fungicides. A control is added that consists of only the adjuvant components (a surfactant and a dispersant).

Disease ratings are performed weekly by visual estimation of the fraction of leaf area attacked by the disease.

Table 1: Concentration (g/kg composition) of different ingredients and the dose rate for various compositions 1 - 7 used in the experiments

comp. 1 comp. 2 comp. 3 comp. 4 comp. 5 comp.6 comp. 7 control

Copper sulfate 183 0,0 0,0 0,0 145 0,0 0,0 0,0 Copper

hydroxide 0,0 0,0 78,9 0,0 0,0 0,0 61,0 0,0 Copper

oxychloride 0,0 89,1 0,0 0,0 0,0 69,1 0,0 0,0

Xanthan 0,0 0,0 0,0 241 206 224 226,0 0,0 Sulfosuccinate

surfactant 229 256 258 213 182 198 200 281 Lignosulfonate

dispersant 588 655 663 546 467 509 513 719 g/1 spray 2,7 2,4 2,4 2,9 3,4 3,1 3,1 2,2 Data processing: the area under the disease curves is calculated by trapezoidal integration (Campbell, C. L. and L. V. Madden (1990). Introduction to Plant Disease Epidemiology. John Wiley & Sons. New York, Chichester, Brisbane, Toronto, Singapore, 532 pp.) and submitted to two-way Analysis of Variance and the Fisher Least Significant Difference test. Synergistic activity of the two active ingredients in the compositions is tested in the Analysis of Variance model using the treatment interaction stratum (Slinker B.K., 1998. The Statistics of Synergism. Journal of Molecular and Cellular Cardiology 30 (4), 723-731). The results of the experiment are presented in Table 2.

Table 2: Effect of xanthan on the efficacy of copper fungicides against powdery mildew of rose

Treatment Disease score Significance¹ Relative Interaction

efficacy (%)² coefficient³

Composition 1 240 b 40 -

Composition 2 240 b 40 -

Composition 3 240 b 40 -

Composition 4 400 c 0 -

Composition 5 40 a 90 225

Composition 6 40 a 90 225

Composition 7 40 a 90 225

Untreated 400 c 0 - control

¹ Means with different letters are significantly different (p< 0.05)

² ((value control— value treatment)/value control) * 100

³ (effect combined treatment / (effect copper fungicide alone + xanthan alone) *

100. An interaction coefficient larger than 100 indicates positive interaction or synergism Conclusion: Although xanthan itself is not active against the disease, it strongly stimulates the activity of the different copper fungicides. Example 2

Synergistic effect of addition of succinoglycan to three different copper-based fungicides in control of powdery mildew of rose.

The experimental setup is the same as shown in example 1. The composition and the dose rate of the different treatments are given in Table 3. Composition and dose rates are adjusted so that each plot receives the same amount of active ingredients and adjuvants (as applicable).

Data processing for this example was the same as for example 1.

The results of this example are presented in Table 4.

Table 3: Concentration (g/kg composition) of different ingredients and the dose rate for various compositions 8 - 14 used in the experiments

comp. comp. comp comp.

comp. 8 comp.9 10 11 comp.13 14 control

Copper sulfate 183 0,0 0,0 0,0 145 0,0 0,0 0,0 Copper

hydroxide 0,0 0,0 78,9 0,0 0,0 0,0 61,0 0,0 Copper

oxychloride 0,0 89,1 0,0 0,0 0,0 69,1 0,0 0,0 Succinoglycan 0,0 0,0 0,0 241 206 224 226,0 0,0 Sulfosuccinate

surfactant 229 256 258 213 182 198 200 281 Lignosulfonate

dispergant 588 655 663 546 467 509 513 719 g/1 spray 2,7 2,4 2,4 2,9 3,4 3,1 3,1 2,2 Table 4: Effect of succmoglycan on the efficacy of copper fungicides against powdery mildew of rose

Treatment Disease score Significance Relative Interaction efficacy² coefficient³

Composition 8 240 b 40

Composition 9 240 b 40

Composition 10 240 b 40

Composition 11 400 c 0

Composition 12 40 a 90 225

Composition 13 40 a 90 225

Composition 14 40 a 90 225

Untreated 400 c 0

control

¹ Means with different letters are significantly different (p< 0.05)

² ((value control— value treatment)/value control) * 100

³ (effect combined treatment / (effect copper fungicide alone + succinoglycan alone) * 100. An interaction coefficient larger than 100 indicates positive interaction or synergism

Conclusion: Although sucinoglycan itself is not active against the disease, it strongly stimulates the activity of the different copper fungicides.

Example 3

Synergistic effect of addition of xanthan to three different copper-based fungicides in control of late blight of tomato. The experimental design is a randomized block design with a plot size of 4 m² per plot and 25 plants per plot. The experiment has 4 replications. During the experiment the plants are sprayed weekly with a dose rate of 0.8 1/plot, using a backpack sprayer. The composition and the dose rate of the different treatments are given in Table 1. Composition and dose rates are adjusted so that each plot receives the same amount of active ingredients and adjuvants (as applicable). To allow detection of synergism between xanthan and the copper fungicides, the experimental setup includes treatments with each of the copper-based fungicides alone, xanthan alone, and the combination of xanthan with each of the copper fungicides. A control is added that consists of only the adjuvant components (a surfactant and a dispersant).

Disease ratings are performed weekly by visual estimation of the fraction of leaf area attacked by the disease. Data processing is performed as for example 1

The results are presented in Table 5

Table 5: Effect of xanthan on the efficacy of copper fungicides against late blight of tomato

Treatment Disease score Significance Relative Interaction efficacy² coefficient³

Composition 1 240 b 40

Composition 2 240 b 40

Composition 3 240 b 40

Composition 4 400 c 0

Composition 5 40 a 90 225

Composition 6 40 a 90 225

Composition 7 40 a 90 225

Untreated 400 c 0

control

¹ Means with different letters are significantly different (p< 0.05)

² ((value control— value treatment)/value control) * 100

³ (effect combined treatment / (effect copper fungicide alone + xanthan alone) * 100. An interaction coefficient larger than 100 indicates positive interaction or synergism

Conclusion: Although xanthan itself is not active against the disease, it strongly stimulates the activity of the different copper fungicides.

Example 4

Synergistic effect of addition of succmoglycan to three different copper-based fungicides in control of late blight of tomato.

The experimental setup is the same as shown in example 3. The composition and the dose rate of the different treatments are given in Table 3. Composition and dose rates are adjusted so that each plot receives the same amount of active ingredients and adjuvants (as applicable).

Data processing for this example is the same as for example 1.

The results of this example are presented in Table 6.

Table 6: Effect of succinoglycan on the efficacy of copper fungicides against late blight of tomato

Treatment Disease score Significance Relative Interaction

efficacy² coefficient³

Composition 8 240 b 40

Composition 9 240 b 40

Composition 10 240 b 40

Composition 11 400 c 0

Composition 12 40 a 90 225

Composition 13 40 a 90 225

Composition 14 40 a 90 225

Untreated 400 c 0

control

¹ Means with different letters are significantly different (p< 0.05)

² ((value control— value treatment)/value control) * 100

³ (effect combined treatment / (effect copper fungicide alone + succinoglycan alone) * 100. An interaction coefficient larger than 100 indicates positive interaction or synergism

Conclusion: Though sucinoglycan itself is not active against the disease, it strongly stimulates the activity of the different copper fungicides. Example 5

Effect of adding different binders to a copper-based fungicide in control of powdery mildew of rose. The copper fungicide copper sulfate is formulated with dispersant and surfactant as shown in Table 7.

Table 7: composition of formulated copper sulfate- based fungicidal composition (g /kg composition) as used in example 5 and 6.

Copper sulfate 183

Sulfosuccinate

surfactant 229

Lignosulfonate

dispergant 588

g/1 spray 2,7

To spray solution of copper sulfate fungicide, prepared as in Table 7, different binders were added: artificial latex (commercial product: Prolong, Holland Fyto, Netherlands); ethylene vinyl acetate copolymer (commercial product: Atlox Semkote E- 105, Uniqema, USA) pinolene (commercial product: Nu-film 17, (Miller Chemical and Fertilizer

Corporation, USA). All these products were added at 5 ml /l spray solution, which is within the range given by the instructions for use of each of the products. These products cover the range of commonly used agricultural binders (D. Pimentel (2002) Encyclopedia of Pest Management. M. Dekker, New York, Basel, 2002, 929 pp). Xanthan (commercial product: Rhodopol, Rhodia, France) and succinoglycan (commercial product: Rheozan, Rhodia, France) were each added to the spray solution at 5 g/1. One extra treatment consists of copper sulfate fungicide without additional binder.

The different formulations of copper sulfate fungicide are tested against powdery mildew of roses as described in example 1. Data processing is done as described in example 1. The results are given in Table 8. Table 8: effect of different binders on the efficacy of copper sulfate fungicide

Disease score Significance

70 B

70 B

70 B

30 A

30 A

100 C

Means with different letters are significantly different (p< 0.05) The conclusion of this experiment is that conventional binders increase the efficacy of copper sulfate fungicide, but the heteropolysaccharides show a better effect in increasing the efficacy of copper sulfate fungicide against powdery mildew of rose.

Example 6

Effect of adding different binders to a copper-based fungicide in control of late blight of tomato.

The copper fungicide copper sulfate is formulated with dispersant and surfactant as shown in Table 7 and different binders are added as shown in example 5.

The different formulations of copper sulfate fungicide are tested against late blight of tomato as described in example 2. Data processing is done as described in example 1.

The results are given in Table 9.

Table 9: effect of different binders on the efficacy of copper sulfate fungicide against late blight of tomato

Binder Disease score Significance

Prolong 70 B

Semkote E-105 70 B

Nu-film 17 70 B

Rhodopol 23 (xanthan) 30 A

Rheozan (succinoglycan) 30 A

No binder 100 C

The conclusion of this experiment is that conventional binders increase the efficacy of copper sulfate fungicide, but the heteropolysaccharides show a better effect in increasing the efficacy of copper sulfate fungicide against late blight of tomato.

Example 7

Xanthan suspension in Genapol EP 2584.

A suspension is prepared of 50 g of xanthan (commercial product RHODOPOL 23 ®, Rhodia, France) in 50 g of alcohol ethoxy propoxylate (commercial product:Genapol EP 2584®) . The suspension exhibits good pourability without gellification. This

characteristic is retained after storage at 54 °C for two weeks, which is equivalent to two years of storage at room temperature (CIPAC, method MT 46). Upon mixing with water a fine dispersion of xanthan is formed, that dissolves within 3 minutes.

Example 8

Succinoglycan suspension in methoxy propoxy propanol.

A suspension is prepared of 50 g of succinoglycan (commercial product Rheozan, Rhodia, France) in 50 g of methoxy propoxy propanol. The suspension exhibits good pourability without gellification. This characteristic is retained after storage at 54 °C for two weeks, which is equivalent to two years of storage at room temperature. Upon mixing with water a fine dispersion of succinoglycan is formed, that dissolved within 2 minutes. Example 9

Xanthan suspension in Polyoxyethylene (20) sorbitan monolaurate.

A suspension is prepared of 10 g of xanthan (commercial product Rhodopol 23®, Rhodia, France) in 50 g of Polyoxyethylene (20) sorbitan monolaurate (commercial product:

Tween 20, Croda, UK). The suspension exhibits good pourability without gellification. This characteristic is retained after storage at 54 °C for two weeks, which is equivalent to two years of storage at room temperature. Upon mixing with water a fine dispersion of xanthan is formed, that dissolved within 5 minutes. Example 10

Dissolution in water of various heteropolysaccharide preparations.

Suspensions in water are prepared of

1. xanthan (commercial product Rhodopol 23, Rhodia, France) suspended at 250 g/1 in alcohol ethoxy propoxylate (commercial product:Genapol EP 2584®) 2. succinoglycan (commercial product Rheozan, Rhodia, France), suspended at 250 g/1 in alcohol ethoxy propoxylate (commercial product: Genapol EP 2584®)

3. xanthan powder

4. succinoglycan powder

5. high-purity xanthan gum biopolymer, suspended in a glycol ether (commercial product: GREENBASE™ FLOWZAN® biopolymer)

6. high-purity xanthan gum biopolymer, suspended in an ultra-clean mineral oil (commercial product: LIQUID FLOWZAN® biopolymer),

7. xanthan (commercial product Rhodopol 23, Rhodia, France) suspended at 250 g/1 in methyl oleate (derivate of vegetable oil)

8. succinoglycan (commercial product Rheozan, Rhodia, France), suspended at 250 g/1 methyl oleate (derivate of vegetable oil)

9. xanthan (commercial product Rhodopol 23, Rhodia, France) suspended at 250 g/1 in mineral oil (Banole spray oil (Total))

10. succinoglycan (commercial product Rheozan, Rhodia, France), suspended at 250 g/1 in mineral oil (BANOLE ® spray oil (Total))

The final concentration of the heteropolysaccharides is 10 g /l for all suspensions in water.

The suspensions in water are stirred at 500 rpm with a propeller, at 22 °C. The time is noted between the formation of the suspension in water and the occurrence of a lump- free solution of the heteropolysaccharides in water. Results are presented in Table 10. Table 10. Time for different heteropolysaccharide preparations to completely (lumpfree) dissolve in water.

Heteropolysaccharide preparation Time until lump-free dissolution (min.)

1 Xanthan in Genapol EP 2584 2

2 Succinoglycan in Genapol EP 2584 2

3 Xanthan powder 20

4 Succinoglycan powder 20

5 Greenbase TM Flowzan® biopolymer 15

6 Liquid Flowzan® biopolymer 15

7 Xanthan in methyl oleate 20

8 Succinoglycan in methyl oleate 20 9 Xanthan in mineral oil 20

10 Succinoglycan in mineral oil 20

Conclusion: It is shown that dissolution and formation of a lump-free solution is much faster for suspensions of the heteropolysaccharides in alcohol ethoxy propoxylate (commercial product:Genapol EP 2584®)

Example 11

Concentrated stock preparation of natamycin with xanthan gum in a mixture of 50% (v/v) of alcohol ethoxy propoxylate (commercial product:Genapol EP 2584®)and 50% of methoxy propoxy propanol.

Natamycin is a polyene anti-mycotic used mostly in food preservation. New applications of natamycin in agriculture have been recently patented. Natamycin is a crystalline product. Therefore natamycin liquid formulations need a structuring agent. Xanthan or succinoglycan have excellent properties as structuring agents for natamycin

formulations. The natamycin used in this example is the commercial product

DELVOCID® Instant (DSM, The Netherlands).

The following stock preparation was prepared:

Natamycin 125 g/1

xanthan gum 250 g/1

Genapol EP 2584 480 ml/1

ethoxy propoxy propanol 480 ml/1

mono propylene glycol 40 ml/1

This suspension can be mixed easily. The addition of 40 ml/1 mono propylene glycol results in thickening of the suspension, avoiding deposition of natamycin and xanthan gum. For use, the stock preparation is diluted 500 times in water, resulting in a final concentration of natamycin of 250 mg/1. After mixing with the water and stirring at 500 rpm with a propeller, at 22 °C, the suspension yields a lump-free composition within 4 minutes. Xanthan gum, at 0.5 g/1 in the final preparation, functions as a structuring agent for the natamycin suspension, alcohol ethoxy propoxylate (commercial product: Genapol EP 2584®), at 0,96 ml/1 in the final preparation functions as spreader. Example 12

Concentrated stock preparation (suspension concentrate) of an experimental fungicide.

An experimental fungicide is made up with succinoglycan as binder. The experimental fungicide is formulated as a suspension concentrate in oil (methyl oleate, containing alcohol ethoxy propoxylate (commercial product:Genapol EP 2584®)and dodecyl benzene sulfonic acid as surfactants.). The succinoglycan is added to the oil formulation as a 50 % (w/w) suspension in alcohol ethoxy propoxylate (commercial product:Genapol EP 2584®). The concentrated stock preparation (suspension concentrate) is prepared as follows:

Suspension A

Methyl oleate 309 g

Genapol EP 2584 26 g

Dodecyl benzene sulfonic acid 16 g

experimental fungicide 440 g

Suspension B

50 % w/w suspension of Rheozan

in Genapol EP 2584 209 g

Suspension A and B are mixed to obtain the final concentrated formulation

The concentrated stock preparation (suspension concentrate) can be dissolved 200 times in water to the desired concentration of 5 g/1. The ready-to-use dilution yields a clear, lump free solution within 4 minutes of stirring at 500 rpm with a propeller, at 22 °C. The ready-to-use preparation contains 0.52 g/1 of xanthan and 0.68 g/1 alcohol ethoxy propoxylate (commercial product:Genapol EP 2584®), which concentrations are well within the range of, respectively, binder and surfactant concentrations commonly used in spray solutions of pesticides.

Example 13

Xanthan / guar gum suspension in alcohol ethoxy propoxylate (commercial

product: Genapol EP 2584®). A suspension is prepared of 25 g of xanthan (commercial product Rhodopol 23, Rhodia, France) and 25 g guar gum (Brenntag, The Netherlands) in 50 g of alcohol ethoxy propoxylate (commercial product:Genapol EP 2584®). The suspension exhibits good pourability without gellification. This characteristic was retained after storage at 54 °C for two weeks, which is equivalent to two years of storage at room temperature (CIPAC, method MT 46). Upon mixing with water a fine dispersion of the mixed

heteropolysaccharides is formed, that dissolves within 3 minutes.

Example 14

Succinoglycan / locust bean gum suspension in methoxy propoxy propanol.

A suspension is prepared of 25 g of succinoglycan (commercial product Rheozan, Rhodia, France) and 25 g of locust bean gum (Brenntag, The Netherlands) in 50 g of methoxy propoxy propoanol. The suspension exhibits good pourability without gellification. This characteristic is retained after storage at 54 °C for two weeks, which is equivalent to two years of storage at room temperature. Upon mixing with water a fine dispersion of succinoglycan is formed, that dissolves within 2 minutes.

Example 15

Synergistic effect of addition of xanthan on two different copper-based fungicides in control of powdery mildew of rose.

The experimental design was similar to the experimental design of Example 1. The composition and the dose rate of the different treatments are given in Table 11.

Disease ratings were performed weekly by visual estimation of the fraction of leaf area infected by the disease. Table 11: Concentration (g/kg composition) of different ingredients and the dose rate for various compositions 1 - 7 used in the experiments comp. comp. comp.3 comp. control

1 2 4

Copper 0,0 78,9 0,0 61,0 0,0

hydroxide

Copper 89,1 0,0 69,1 0,0 0,0

oxychloride

Xanthan 0,0 0,0 224 226,0 0,0

Sulfosuccinate 256 258 198 200 281

surfactant

Lignosulfonate 655 663 509 513 719

dispersant

g/1 spray 2,7 2,4 3,4 3,1 3,1

Composition and dose rates were adjusted so that each plot receives the same amount of active ingredients and adjuvants (as applicable). To allow detection of synergism between xanthan and the copper fungicides, the experimental setup includes treatments with each of the copper-based fungicides alone, xanthan alone, and the combination of xanthan with each of the copper fungicides. A control is added that consists of only the adjuvant components (a surfactant and a dispersant). The results of the experiment are presented in Table 12.

Table 12: Effect of xanthan on the efficacy of copper fungicides against powdery mildew of rose

Treatment Mean % severity Significance Relative efficacy

(%)

Composition 7,828 de 79,869

1

1

Composition 12,779 C 67,139

A

Composition 3,345 de 91,398

Q

O

Composition 7,887 de 79,720

A

Control 38,888 a 0,000 It can be concluded that the addition of xanthan to copper hydroxide and copper oxychloride formulation increases the efficacy of the formulation and reduced severity.

Example 16

Effect of adding xanthan to a copper-based fungicide in control of powdery mildew of rose. The copper fungicide copper sulfate is formulated with dispersant and surfactant as shown in Table 13.

Table 13: composition 2 of formulated copper sulfate- based fungicidal composition (g /kg composition).

Copper sulfate 183

Sulfosuccinate

surfactant 229

Lignosulfonate

dispergant 588

g/1 spray 2,7

Xanthan (commercial product: Rhodopol, Rhodia, France) was added to the spray solution at 5 g/1 (composition 1). Table 14: Effect of adding xanthan to a copper-based fungicide in control of powdery mildew of rose.

Treatment % Severity Significance

Composition 1 13,952 d

Composition 2 17,629 cd

The addition of xanthan to the formulation (composition 1) resulted in reduced severity compared to the control without xanthan (composition 2).

Claims

Claims

1. A biocidal composition, comprising a biocide and a heteropolysaccharide.

2. The composition of claim 1, wherein said biocide is a copper-based biocide or comprises a copper-based additive.

3. The composition of claim 1 or claim 2, wherein said heteropolysaccharide is selected from the group consisting of xanthan and succinoglycan, and mixtures thereof.

4. The composition according to claim 2 or 3, wherein the ratio of copper to heteropolysaccharide ranges from 1:4 (w/w) to 1:7 (w/w).

5. The composition according to any one of claims 1-4, wherein the biocide is a fungicide.

6. The composition according to any one of claims 1-4, wherein the biocide is a pesticide.

7. A composition comprising a heteropolysaccharide and a liquid selected from a surfactant and a hydrophilic aprotic solvent, or a combination thereof.

8. The composition of claim 7, in which the heteropolysaccharide is selected from xanthan, succinoglycan and a mixture of xanthan and succinoglycan.

9. The composition of any one claims 7 or 8, further comprising a

heteropolysaccharide of the galactomannan type.

10. Composition of ony one of claims 7-9, in which the concentration of the heteropolysaccharide is 10 - 500 g /kg.

11. The composition of any one of claims 7-9, in which the aprotic solvent is selected from alcohol ethoxy propoxylate and methoxy propoxy propanol.

12. The composition of any one of claims 7-9, in which the surfactant is selected from dimethyl sulfoxide, dimethyl formamide, dimethylacetamide, acetonitrile and methoxy propoxy propanol.

13. The composition of any one of claims 7- 12, further comprising one or more of a medicinal compound, a colorant, a flavoring compound, a fungicidal compound, a bactericidal compound, and/or a nematicidal compound.

14. A method of preparing an aqueous composition comprising a

heteropolysaccharide, the method comprising diluting a composition according to any one of claims 1-9 in water.

15. A method for protecting an agricultural plant from a plant disease, preferably a fungal disease, comprising applying to said agricultural plant a biocidal composition according to any one of claims 1-6.

16. A method of producing a composition comprising a biocide with enhanced efficacy, the method comprising adding a heteropolysaccharide to the composition.

17. The method of claim 16, wherein the biocide is a copper-based biocide or a biocide comprising a copper-based additive.