GB2059773A

GB2059773A - Fungicidal compositions

Info

Publication number: GB2059773A
Application number: GB8030874A
Authority: GB
Original assignee: Boots Co PLC
Current assignee: Boots Co PLC
Priority date: 1979-10-12
Filing date: 1980-09-25
Publication date: 1981-04-29
Also published as: GB2059773B

Abstract

Fungicidal compositions contain prochloraz with carbendazim, a preferred fungicidal composition is prepared by dispersing carbendazim in a solution of prochloraz and one or more emulsifying agents in a non aqueous solvent. The composition is dispersed in water to provide a preparation which is applied to growing crops to control fungal diseases, e.g. of cereal crops.

Description

SPECIFICATION Fungicidal compositions The present invention relates to fungicidal compositions and in particular to fungicidal compositions containing the fungicidal compound prochloraz. Prochloraz, 1 - [N - propyl - N - 2 - (2,4,6 trichlorophenoxy)ethylcarbamoyjl imidazole, has been found to have a wide range of fungicide activity as described in U.S. Patent Specifications, 3,991,071 and 4,080,462.

It has now been found that prochloraz can be mixed with carbendazim to provide a composition having particularly beneficial fungicidal activity.

According to a first aspect ofthe invention there is provided a fungicidal composition containing prochloraz with carbendazim.

The ratio of the amount of prochlorazto the amount of carbendazim in the compositions of the present invention conveniently falls in the range 1:4 to 25:1 preferably 1:1 to 10:1.

The compositions of prochloraz and carbendazim have fungicidal activity and the present invention includes a method of controlling a phytopathogenic fungus on a growing crop which comprises applying to the crop or its habitat a composition according to the invention.

When applied to a cereal crop the compositions of the present invention provide control of several fungal diseases such as powdery mildew (Erysiphe gramminis) on wheat, barley, oats and rye and other foliar diseases such as glume blotch (Septoria nodorum), leaf blotch (Rhyncosporium secalis) and eyespot (Cercosporella herpotrichoides) and ear diseases such asAlternaria, Fusarium and Cladosporium species. The compositions can also be applied to rice for control of rice blast (Pyricularia oryzae), apples for control of scab (Venturia inaequalis) and mildew (Podosphaera leucotricha), roses for control of mildew (Sphaerothega pannosa) and black spot (Diplocarpon rosae), cucurbits for control of powdery mildew (Erysiphe cichoracearum) or tomatoes to control early blight (Alternaria solani).

The concentration of active ingredients in the composition which is to be applied to a growing crop conveniently falls within the range 0.0005 to 10 per cent by weight of the composition preferably 0.001 to 5 per cent by weight. The amount of composition applied to the crop for example, by spraying, is preferably such that the amount of combined active material which is applied to a cereal crop is in the range 100 to 2000 g/ha preferably 200 to 1000 g/ha and the amount of combined active material which is applied to a horticultural crop is in the range 5 to 1000 g/ha preferably 10 to 500 glha.

The compositions of the present invention may be employed in many forms and are often most conveniently prepared in aqueous form immediately prior to use. One method of preparing such a composition is referred to as "tank mixing" in which two or more fungicidal ingredients in their commercially available form are mixed together by the farmer in a quantity of water for direct application.

In addition to tank mixing immediately prior to use the compositions containing prochloraz and carbendazim may be formulated into a more concentrated primary composition which is diluted with water or other diluent before use to provide a preparation which can be applied to the crop by spraying. Such compositions may comprise a surface active agent in addition to the active ingredients and typical examples are an emulsifiable concentrate, a dispersible powder or a dusting powder. As a concentrated primary composition the concentration of active ingredients can vary widely and can be for example from 5 to 95 per cent by weight of the composition.

The primary composition is diluted to give compositions for application to a growing crop in which the amount of active ingredient applied to the crop is as specified above.

An emulsifiable concentrate, also known as a "miscible liquid", comprises a solution of the active ingredients in a non aqueous solvent in association with one or more emulsifying agents. An emulsion is formed when the emulsifiable concentrate is mixed with water.

A dispersible powder comprises the active ingredients in finely divided form in association with one or more dispersing agents so that a stable aqueous dispersion of the active ingredients is formed on mixing the powder with water. A finely divided inert solid diluent such as kaolin or diatomaceous earth sold under the Registered Trade Mark CELITE is generally incorporated in the dispersible powder.

A dusting powder comprises the active ingredients intimately mixed with a solid pulverant diluent, for example kaolin.

Compositions containing prochloraz may be most conveniently prepared as emulsifiable concentrates in which the prochloraz and one or more emulsifying agents are dissolved in a non aqueous solvent. Carbendazim is not soluble to any appreciable extent in the non aqueous solvents normally employed and so it is possible to incorporate it as dispersions in emulsifiable concentrates of prochloraz. Such compositions are the preferred primary compositions of the invention and a further aspect of the present invention provides a fungicidal composition which comprises a dispersion of carbendazim in a solution of prochloraz and one or more emulsifying agents in a non-aqueous solvent.

In the preferred compositions described in the preceding paragraph the amount of prochloraz may be in the range 5 to 70% by weight preferably 20 to 60% and the amount of carbendazim may be in the range 1 to 40% preferably 5 to 20%.

The emulsifying agents employed may be any of those commonly used in the art and are preferably nonioniasurfactants, anionic surfactants, a blend of nonionic and anionic surfactants or cationic surfactants. The amount of emulsifier present may be up to 30% of the total composition. Nonionic compounds include for example, ethoxylated alkylphenols such as nonylphenol ethoxylates; ethoxylated aliphatic alcohols; ethoxylated esters; arylphenols; ethoxylated alkylolamides; block polymers/copolymers of ethylene oxide and propylene oxide; or alkylolamides. Anioniccompounds include for example, sulphonates such as alkylaryl sulphonates or petroleum sulphonates; sulphates such as alcohol sulphates or ether sulphates; phosphate esters; or sulphosuccinates.Suitable surfactants having cationic properties include ethoxylated aliphatic amines, acetates or oleates of primary or secondary aliphatic amines and quaternary ammonium compounds.

The non-aqueous solvent employed is preferably a water-immiscible solvent and suitable solvents include petroleum based aromatic or aliphatic hydrocarbons such as benzene, alkyl benzenes for example toluene orxylene, heavy aromatic naphtha and kerosene; naphthalene and alkyl substituted naphthalene; chlorinated hydrocarbons such as the chlorobenzenes; chlorinated alkyl benzenes and chlorinated alkanes for example chloroform, carbon tetrachloride and 1,1,1-trichloroethane; ketonic solvents such as isophorone cyclohexanone, methyl isobutyl ketone, diisobutyl ketone or N-methyl pyrrolidone and esters such as butyl benzoate, dibutyl phthalate or dimethyl phthalate. The non aqueous solvent may however be miscible with water and suitable miscible solvents include propoxyglycol ethers, diacetone alcohol, dipropyleneglycol, dimethylformamide and dimethylsulphoxide.The particle size of the 2-benzimidazole carbamate is conveniently in the range 0.5 to 20 microns and is preferably such that the size of more than 90% of the particles falls in the range 1 to 10 microns. The particle size may be reduced to the desired size range by ball milling, bead milling or homogenising.

The preferred compositions may be prepared by dissolving the prochloraz and the emulsifying agent in the solvent and then dispersing the carbendazim in the solution. Alternatively a solution of prochloraz in part of the solvent may be mixed with a dispersion of the carbendazim in the remaining solvent or the prochloraz may be dissolved in a dispersion of the carbendazim in the solvent.

The preferred compositions of the present invention are mixed with water to form an aqueous preparation which may be applied to a growing crop by spraying. The invention also embraces a method of treating fungal diseases in growing crops which comprises applying to the crop such an aqueous preparation. The compositions are conveniently added to 10 to 1000 volumes of water and agitated to provide the aqueous preparation which is to be sprayed. The amount of the aqueous preparation which is applied to the crop is preferably such that the prochloraz is applied to the crop at a rate of 150 to 1000 g/ha and the carbendazim is applied at a rate of 40to 500 glha.It has been found to be particularly advantageous where the crop to be treated is a cereal crop e.g. wheat or barley to apply a composition according to the invention in such a way that the amount of prochloraz applied to the crop is in the range 300 to 600 g/ha and the amount of carbendazim applied to the crop is in the range 80 to 200 g/ha. When applied to a cereal crop the preferred compositions of the present invention provide control of several fungal diseases such as powdery mildew (Erysiphe gramminis) on wheat, barley, oats and rye and other foliar diseases such as glume blotch (Septoria nodorum), leaf blotch (Rhyncosporium secalis), eyespot (Cercosporella herpotrichoides) and ear diseases such asAlternaria, Fusarium and Cladosporium species.The compositions can also be applied to rice for control of rice blast and to horticultural crops such as apples, roses, cucurbits and tomatoes.

The invention will be illustrated by the following Example which describes the preparation and use of a composition according to the invention.

Example Afungicidal composition was made up having the following components, % wlv prochloraz, 30 carbendazim, 8 a blend of calcium dodecylbenzene sulphonate, nonylphenylethoxylate and a linear alcohol ethoxylate sold under the trade name Emcol N500B, 15 tristyrylphenolethylene oxide condensatesold underthetrade name SoproporBSU, 5 Xyleneto 100 The prochloraz and the surfactantswere dissolved in xylene and the carbendazim dispersed in the solution. The resulting composition was found to be stable in storage and to be readily dispersible in water even after a long storage period.

The fungicidal activity of the composition was investigated in the following experiment.

The composition described above was dispersed in water to give an aqueous preparation containing 10 ppm prochloraz and 2.66 ppm carbendazim. The preparation was sprayed onto growing Maris Ranger wheat which was at the one leaf growth stage.

Twenty four hours laterthe plant was inoculated with an aqueous spore suspension of the pathogen Septoria nodorum. The plants were then kept under humid conditions for 7 days and the leaf area affected by the pathogen assessed visually. It was found that the area of leaf affected was considerably less than was observed with plants that had not been treated with the aqueous preparation showing that the aqueous preparation acted as a protectant against attack by the pathogen. When other Maris Ranger plants were treated with an aqueous preparation containing 10 ppm prochloraz or an aqueous preparation containing 2.66 ppm carbendazim under the condtions described above there was only a negligible amount of protestant action.

Claims

1. Afungicidal composition containing prochloraz and carbendazim.

2. A fungicidal composition as claimed in claim 1 wherein the ratio of the amount of prochloraz to the amount of carbendazim falls in the range 1 :4to 25:1.

3. Afungicidal composition as claimed in any one of the preceding claims wherein the ratio of the amount of prochloraz to the amount of carbendazim falls in the range 1:1 or 10:1.

4. A method of controlling a phytopathogenic fungus on a growing crop which comprises applying to the crop or its habitat a fungicidal composition as claimed in any preceding claim.

5. A method as claimed in claim 4 wherein the crop is a cereal crop and the amount of combined active material applied to the crop is in the range of 100 to 2000 glha.

6. A method as claimed in claim 4 wherein the crop is a cereal crop and the amount of combined active material applied to the crop is in the range 200 to 1000 g/ha.

7. A method as claimed in claim 4 wherein the crop is a horticultural crop and the amount of combined active material applied to the crop is in the range 5 to 1000 g/ha.

8. A method as claimed in claim 4 wherein the crop is a horticultural crop and the amount of combined active material applied to the crop is in the range 10 to 500 g/ha.

9. A fungicidal composition comprising a dispersion ofcarbendazim in a solution of prochloraz and one or more emulsifiers in a non-aqueous solvent.

10. A fungicidal composition as claimed in claim 9 wherein the ratio by weight of prochloraz to carbendazim is in the range 1:4 to 25:1.

11. A fungicidal composition as claimed in claim 10 wherein the ratio by weight of prochloraz to carbendazim is in the range 1:1 to 10:1.

12. Afungicidal composition as claimed in any one of claims 9 to 11 which contains 1 to 40% by weight of carbendazim.

13. Afungicidal composition as claimed in any one of claims 9 to 12 which contains 5 to 20% by weight of carbendazim.

14. Afungicidal composition as claimed in any one of claims 9 to 13 which contains 5 to 70% by weight of prochloraz.

15. A fungicidal composition as claimed in any one of claims 9 to 14 which contains 20 to 60% by weight of prochloraz.

16. A method of treating fungal diseases in growing crops which comprises applying to the crop an effective amount of an aqueous preparation prepared by adding the composition of any one of claims 9 to 15 to water.

17. A method as claimed in claim 16 wherein the amount of prochloraz applied to the crop is in the range 150 to 1000 g/ha and the amount of carbendazim applied to the crop is in the range 40 to 500 g/ha.

18. A method as claimed in claim 16 wherein the amount of prochloraz applied to the crop is in the range 300 to 600 g/ha and the amount of carbendazim applied to the crop is in the range 80 to 200 g/ha.