GB2124083A - Fungicidal formulations - Google Patents

Abstract

The invention provides a fungicidal formulation comprising sulphur and a compound of formula <IMAGE> where X is chlorine or fluorine. The formulations are of especial use in treating fungal infections of a variety of plants.

Description

SPECIFICATION Fungicidal formulations This invention relates to fungicidal formulations and to methods of treating fungal infections of cultivated plants.

The invention provides a fungicidal formulation comprising sulphur and a pyrimidine of formula

where Xis chlorine or fluorine.

We have discovered that this combination of ingredients is specially effective in controlling or combatting fungal infections of cultivated plants such as vines, top fruit and vegetables. These mixtures have been found to give good results against powdery mildew Uncinula necatoron vines, Podosphaera leucotricha on apples, and Erysiphe cichoracearum and Sphaerotheca fuliginea on cucurbits. The compounds of formula (I) are known fungicides described, for example, in British Patent 1 218 623, and their effectiveness is surprisingly improved by the presence of sulphur.

Accordingly the invention also includes a method of treating fungal infections of plants which comprises applying to the plants a fungicidally effective amount of a fungicidal formulation as defined above. The formulation is preferably applied by foliar application at any time before harvest of the crop. The amount and frequency of application will depend on the severity of the fungal disease and the condition of the crop. It has, however, been found that the frequency of treatment needed for fungal control can be reduced by the use of the formulation of the invention, and a valuable reduction in labour cost is achieved thereby.

With regard to the amount of the active ingredients to be employed, it is preferred to apply a foliar spray in which the sulphur is applied at a rate of from 1000 to 5000 g per hectar, and the component of the formula (I) at a rate of from 5 to 100 g per hectare. The ratio of sulphur and compounds of formula (I) is preferably from 1:1 or 10:1 to 1000:1, for example, from 10:1 to 500:1, such as from 50:1 to 500:1.

The sulphur component in the formulation of the invention may be in any of the convenient forms which allow satisfactory formulation with the compounds of formula (I), being preferably either micronised sulphur or colloidal sulphur, and the mean particle size of the end product is preferably between 1 and 20 microns. Of the two active compounds comprised by formula (I) above, fenarimol, the compound in which X is chlorine is preferred though nuarimol (X is fluorine) can equally be used. As noted above both compounds are well known in the fungicide art and can be employed with other compatible fungicides, although generally they are, together with sulphur, the sole active ingredients of the formulation.

The formulation of the invention will usually be associated with one or more inert, non-phytotoxic carrier and it is to be understood that the formulation can also include additional fungicide ingredients. In order to simplify manufacture, storage and transport, combinations are normally produced in concentrate form intended for dilution in water to the degree necessary to give the above mentioned application rates. Such concentrated formulations may contain from 0.5 to 90%, preferably from 5% to 90%, by weight of active ingredients associated with an inert non-phytotoxic carrier. Such formulations will usually be in the form of a wettable powder, dispersible granules or a suspension concentrate.

The concentrate formulations are intended for dilution with water or other suitable substances prior to use in conventional spray tanks or for aerial application and it is to be understood that the diluted formulations so produced are formulations in accordance with the invention in which the inert non-phytotoxic carrier is water or other suitable substance.

Wettable powders comprise an intimate mixture of the active ingredients, an inert carrier and an appropriate surfactant. The inert carrier may be chosen from for example alumina, attapulgite clays, montmorillonite clays, diatomaceous earths, precipitated silica, kaolines, micas, talcs and purified silicates.

Effective surfactants can be selected from sulfonated lignins, naphthalene sulfonates and condensed naphthalene sulfonates, alkyl succinates, alkylbenzene sulfonates, alkyl sulfates and nonionic surfactants such as alkyl or aryl initiated ethylene oxide adducts for example ethylene oxide adducts of phenol.

Examples of wettable powders are those having the following composition: Wettable Powders % by weight Formula I compound 0.1 to 2.5 Sulphur 40to90 Surfactants 4to 10 Anticaking agent Oto 15 Inert carrier to 100 Suspension concentrates comprise a suspension of the active ingredients, a surfactant, a suspending agent and water or a non-aqueous medium.Examples of suspension concentrates comprise the active ingredients and for example, surfactants, suspending agent, antifoaming agent, antifreezing agent and water, for example: Suspension Concentrates % by weight Formula I compound 0.1 to 2.5 Sulphur 40 to 80 Suspending agent 0.1 to 10 Surfactants 1 to 5 Antifoam 0.1 to 1.0 Antifreeze 5 to 20 Water to 100 Examples of dispersible granules are those having the following composition:: Dispersible Granules % by weight Formula I compound 0.1 to 2.5 Sulphur 40 to 80 Surfactants 4to 15 Anticaking agent Oto 10 Binder Oto 10 Disintegrant Oto 10 Inert carrier to 100 The invention also includes a method of preparing the preferred wettable powder formulation comprising as active ingredients sulphur and a pyrimidine of formula (I) above, which comprises blending the active ingredients with excipients and milling the blend to give the requisite particle size, preferably being a mean particle size of between 1 and 20 microns.

The pyrimidine of formula (I) in which Xis chlorine is known as fenarimol and is available from Eli Lilly and Company as for example Bloc, Rimidin and Rubigan, and the compound of formula (I) in which Xis fluorine is known as nuarimol, available from the same company as, for example, Trimidal and Triminol.

The following Examples illustrate the invention Example 1 The following wettable powder was prepared: % by weight Fenarimol or nuarimol 0.5 Sulphur 80 Alkyl naphthalene sulphonate 3 Sulphonated kraftsulphonate 3 Silicon dioxide 3 Kaolin to 100 The active ingredients were blended with the specified excipients in conventional mixing equipment. The blend was then milled in a fluid energy mill to a particle size distribution range of from 0 to 10 microns and finally the mixture was reblended and dearated prior to being packaged.

Example 2 The following suspension concentrate was prepared: % by weight Fenarimol or nuarimol 0.5 Sulphur 80 Polyaryl ethoxylated phosphate 3 Naphthalene formaldehyde condensate 3 Ethylene glycol 5 Silicon emulsion 0.5 Xanthan gum 0.2 Water to 100 The ingredients (with the exception of the suspending agent) were blended with part of the liquid phase and the slurry milled to a fine particle size of O to 10 microns.A gel comprising the suspending agent and remainder of the liquid phase was prepared and then mixed with the milled slurry to give the product. Exarnple3 Exarnple 3 The following dispersible granule composition was prepared: % by weight Fenarimol or nuarimol 1.5% Sulphur 80% Alkyl laurate 3% Sodium phenyl sulphonate 5% Alginic acid 5% Kaolin to 100 The ingredients were mixed and milled in a fluid energy mill to a size range of O to 10 microns and granulated.

Example 4 The following example illustrates the synergistic properties of the formulations of the invention.

Following intensive use of fenarimol over several years strains of Sphaerotheca fuliginea have developed which are less sensitive to fenarimol. Such strains were used in the following greenhouse experiment.

Cucumber plants at the one true leaf stage and contained in individual pots, were sprayed with aqueous suspension of sulphur, fenarimol and sulphur/fenarimol mixtures.

24 Hours after spraying, when the spray had thoroughly dried on the leaf surface, the leaf was inoculated with Sphaerotheca fuliginea. After a lapse of ten days the percentage fungal control was measured in relation to control plants which had not been treated with fungicide components, and the following results were obtained.

Sulphur (pom) Fenarimol (ppm) 0 50 100 0 0 16 55 5 45 87 93 When analysed bythewell known "Colby equation" (seeWeeds, 1520-22 (1967)) the above results clearly demonstrated synergism under the conditions of the test.

Claims (6)

1. Afungicidal formulation comprising sulphur and a compound of formula

where Xis chlorine or fluorine.

2. A formulation according to claim 1 in which the ratio of sulphur to compound of formula (I) is in the rangeoffrom 10:1 to 500:1.

3. A formulation according to either of claims 1 and.2 which comprises micrn,nised sulphur.

4. A method of treating fungal infections of plants which comprises applying to the plants a fungicidal formulation as defined in any of claims 1 to 3.

5. A method of treating vines according to claim 4.

6. A method of preparing a fungicidal formulation according to claim 1 which comprises bringing into intimate admixture sulphur and a compound of formula (1).