AU2003249899A1 - Fungicidal mixtures based on dithianon - Google Patents

Abstract

The invention relates to fungicidal mixtures containing, in a synergistically effective amount: A) the compound of formula (I), and; B) at least one imidazole derivative of formula (II), in which R<1> and R<2> represent halogen and phenyl, which can be substituted by halogen or alkyl, or R<1> and R<2>, together with the bridging C=C double bond, form a 3,4-difluoromethylene dioxyphenyl group; R<3> represents cyano or halogen, and; R<4> represents dialkylamino or isoxazol-4-yl that can carry two alkyl radicals. The invention also relates to methods for controlling harmful fungi by using mixtures of compounds (I) and (II), and to the use of compounds (I) and (II) for producing mixtures of this type.

Description

IN THE MATTER OF an Australian Application corresponding to PCT Application PCT/EPO3/06889 RWS Group Ltd, of Europa House, Marsham Way, Gerrards Cross, Buckinghamshire, England, hereby solemnly and sincerely declares that, to the best of its knowledge and belief, the following document, prepared by one of its translators competent in the art and conversant with the English and German languages, is a true and correct translation of the PCT Application filed under No. PCT/EPO3/06889. Date: 12 November 2004 S. ANTHONY Director For and on behalf of RWS Group Ltd 1 Fungicidal mixtures based on dithianon The present invention relates to fungicidal mixtures, comprising 5 A) the compound of the formula I O SICN 10 S CN and B) at least one imidazole derivative of the formula II 15 R R

S

2

-R

4 20 in which R I and R 2 are halogen and phenyl which may be substi tuted by halogen or C 1

-C

4 -alkyl, or

R

1 and R 2 together with the bridging C=C double bond form a 3,4-difluoromethylenedioxyphenyl group; 25

R

3 is cyano or halogen, and

R

4 is di-(C 1

-C

4 -alkyl)amino or isoxazol-4-yl which may carry two C 1

-C

4 -alkyl radicals; 30 in a synergistically effective amount. Moreover, the invention relates to methods for controlling harmful fungi using mixtures of the compounds I and II, and to 35 the use of the compounds I and II for preparing such mixtures. It is an object of the present invention to provide mixtures which have improved activity against harmful fungi combined with a reduced total amount of active compounds applied (synergistic 40 mixtures), with a view to reducing the application rates and improving the activity spectrum of the known compounds. We have found that this object is achieved by the mixtures defined at the outset. Moreover, we have found that applying the 45 compounds I and II simultaneously, i.e. together or separately, or applying the compounds I and II in succession provides better 2 control of harmful fungi than is possible with the individual compounds alone. The compound of the formula I (common name: dithianon) and 5 processes for its preparation are described in GB-A 857 383. Also known from the literature are the imidazole derivatives of the formula II, their preparation and their action against harmful fungi (EP-A 298 196, WO-A 97/06171). 10 The formula II represents in particular imidazole derivatives of the formula II in which R 1 is halogen, in particular chlorine, and

R

2 is tolyl, in particular p-tolyl. 15 Preference is also given to compounds of the formula II in which

R

4 is dimethylamino. Particular preference is given to the compound of the formula IIa (common name: cyazofamid). This compound is known from 20 EP-A 298 196. Cl N \-CN "N CH IIa 25

H

3 C \CH 30 C 3 Preference is furthermore given to compounds of the formula II in which R 1 and R 2 together with the bridging C=C double bond form a 30 3,4-difluoromethylenedioxyphenyl group. In addition, preference is given to compounds of the formula II in which R 4 is 3,5-dimethylisoxazol-4-yl. 35 Particular preference is given to the compounds of the formula IIb in which X is halogen. F 0 CH 40 0= 0 IIb

H

3 C Halogen denotes fluorine, chlorine, bromine and iodine. 45 Particular preference is given to compounds of the formula IIb in which X is bromine (IIb.1) or chlorine (IIb.2).

3 When preparing the mixtures, it is preferred to employ the pure active compounds I and II, with which further active compounds against harmful fungi or other pests, such as insects, arachnids or nematodes, or else herbicidal or growth-regulating active 5 compounds or fertilizers can be admixed as required. Usually, mixtures of the compound I with an imidazole derivative II are used. However, in certain cases mixtures of the compound I with two or more imidazole derivatives II may be advantageous. 10 The mixtures of the compounds I and II or the simultaneous joint or separate use of the compounds I and II have outstanding action against a wide range of phytopathogenic fungi, in particular from the classes of the Ascomycetes, Deuteromycetes, Oomycetes and 15 Basidiomycetes. They are especially important for controlling a large number of fungi in a variety of crop plants, such as cotton, vegetable species (for example cucumbers, beans and cucurbits), coffee, 20 fruit species, soya, grapevine, ornamentals, and a variety of seeds. They are particularly suitable for controlling the following phytopathogenic fungi: Erysiphe cichoracearum and Sphaerotheca 25 fuliginea in cucurbits, Podosphaera leucotricha in apples, Uncinula necator in grapevines, Ustilago species in cereals and sugarcane, Venturia inaequalis (scab) in apples, Botrytis cinerea (gray mold) in strawberries, vegetables, ornamentals and grapevines, Cercospora arachidicola in groundnuts, Phytophthora 30 infestans in potatoes and tomatoes, Pseudoperonospora species in cucurbits and hops, Plasmopara viticola in grapevines, Alternaria species in vegetables and fruit and Fusarium and Verticillium species. 35 The compounds I and II can be applied simultaneously, that is either together or separately, or in succession, the sequence, in the case of separate application, generally not having any effect on the control results. 40 The compounds I and II are usually applied in a weight ratio of from 100:1 to 1:10, preferably from 10:1 to 1:1, in particular from 5:1 to 1:1. The application rates of the compounds I are generally from 5 to 45 2000 g/ha, preferably from 10 to 1000 g/ha, in particular from 50 to 750 g/ha, and those of the compounds II are generally from 4 5 g/ha to 500 g/ha, preferably from 50 to 500 g/ha, in particular from 50 to 200 g/ha. For seed treatment, the application rates of the mixture are 5 generally from 0.001 to 1 g/kg of seed, preferably from 0.01 to 0.5 g/kg, in particular from 0.01 to 0.1 g/kg. If phytopathogenic harmful fungi are to be controlled, the separate or joint application of the compounds I and II or of the 10 mixtures of the compounds I and II is effected by spraying or dusting the seeds, the plants or the soils before or after sowing, or before or after plant emergence. The following are examples of formulations: 15 1. Products for dilution with water A) Water-soluble concentrates (SL) 20 10 parts by weight of the active compounds are dissolved in water or in a water-soluble solvent. As an alternative, wetters or other auxiliaries are added. The active compound dissolves upon dilution with water. 25 B) Dispersible concentrates (DC) 20 parts by weight of the active compounds are dissolved in cyclohexanone with addition of a dispersant, for example polyvinylpyrrolidone. Dilution with water gives a dispersion. 30 C) Emulsifiable concentrates (EC) 15 parts by weight of the active compounds are dissolved in xylene with addition of calcium dodecylbenzenesulfonate and 35 castor oil ethoxylate (in each case 5% strength). Dilution with water gives an emulsion. D) Emulsions (EW, EO) 40 40 parts by weight of the active compounds are dissolved in xylene with addition of calcium dodecylbenzenesulfonate and castor oil ethoxylate (in each case 5% strength). This mixture is introduced into water by means of an emulsifier machine (Ultraturrax) and made into a homogeneous emulsion. Dilution with 45 water gives an emulsion.

5 E) Suspensions (SC, OD) In an agitated ball mill, 20 parts by weight of the active compounds are comminuted with addition of dispersants, wetters 5 and water or an organic solvent to give a fine active compound suspension. Dilution with water gives a stable suspension of the active compound. F) Water-dispersible granules and water-soluble granules (WG, 10 SG) 50 parts by weight of the active compounds are ground finely with addition of dispersants and wetters and made as water-dispersible or water-soluble granules by means of technical appliances (for 15 example extrusion, spray tower, fluidized bed). Dilution with water gives a stable dispersion or solution of the active compound. G) Water-dispersible powders and water-soluble powders (WP, SP) 20 75 parts by weight of the active compounds are ground in a rotor-stator mill with addition of dispersants, wetters and silica gel. Dilution with water gives a stable dispersion or solution of the active compound. 25 2. Products to be applied undiluted H) Dustable powders (DP) 30 5 parts by weight of the active compounds are ground finely and mixed intimately with 95% of finely divided kaolin. This gives a dustable product. I) Granules (GR, FG, GG, MG) 35 0.5 part by weight of the active compounds is ground finely and associated with 95.5% carriers. Current methods are extrusion, spray-drying or the fluidized bed. This gives granules to be applied undiluted. 40 J) ULV solutions (UL) 10 parts by weight of the active compounds are dissolved in an organic solvent, for example xylene. This gives a product to be 45 applied undiluted.

6 The active compounds can be used as such, in the form of their formulations or the use forms prepared therefrom, for example in the form of directly sprayable solutions, powders, suspensions or dispersions, emulsions, oil dispersions, pastes, dustable 5 products, materials for spreading, or granules, by means of spraying, atomizing, dusting, spreading or pouring. The use forms depend entirely on the intended purposes; they are intended to ensure in each case the finest possible distribution of the active compounds according to the invention. 10 Aqueous use forms can be prepared from emulsion concentrates, pastes or wettable powders (sprayable powders, oil dispersions) by adding water. To prepare emulsions, pastes or oil dispersions, the substances, as such or dissolved in an oil or solvent, can be 15 homogenized in water by means of a wetter, tackifier, dispersant or emulsifier. However, it is also possible to prepare concentrates composed of active substance, wetter, tackifier, dispersant or emulsifier and, if appropriate, solvent or oil, and such concentrates are suitable for dilution with water. 20 The active compound concentrations in the ready-to-use preparations can be varied within relatively wide ranges. In general, they are from 0.0001 to 10%, preferably from 0.01 to 1%. 25 The active compounds may also be used successfully in the ultra-low-volume process (ULV), it being possible to apply formulations comprising over 95% by weight of active compound, or even to apply the active compound without additives. 30 Oils of various types, wetters, adjuvants, herbicides, fungicides, other pesticides, or bactericides may be added to the active compounds, even, if appropriate, not until immediately prior to use (tank mix). These agents can be admixed with the compositions according to the invention in a weight ratio from 35 1:10 to 10:1. The fungicidal action of the compounds and of the mixtures can be demonstrated by the following experiments: 40 The active compounds, separately or jointly, were prepared as a stock solution comprising 0.25% by weight of active compound in acetone or DMSO. 1% by weight of the emulsifier Uniperol® EL (wetting agent having emulsifying and dispersant action based on ethoxylated alkylphenols) was added to this solution, and the 45 mixture was diluted with water to the desired concentration.

7 Use example 1 - activity against late blight on tomatoes caused by Phytophthora infestans Leaves of potted plants of the tomato cultivar "Large Fruited St. 5 Pierre" were sprayed to runoff point with an aqueous suspension having the concentration of active compounds stated below. The next day, the leaves were infected with a cold aqueous zoospore suspension of Phytophthora infestans having a density of 0.25 x 106 spores/ml. The plants were then placed in a 10 water-vapor-saturated chamber at 18 - 20 0 C. After 6 days, the blight on the untreated but infected control plants had developed to such an extent that the infection could be determined visually in %. 15 Evaluation is carried out by determining the infected leaf areas in percent. These percentages are converted into efficacies. The efficacy (E) is calculated as follows using Abbot's formula: 20 E = (1 - a/p)*100 a corresponds to the fungal infection of the treated plants in % and 25 $ corresponds to the fungal infection of the untreated (control) plants in % An efficacy of 0 means that the infection level of the treated plants corresponds to that of the untreated control plants; an 30 efficacy of 100 means that the treated plants were not infected. The expected efficacies of the active compound mixtures are de termined using Colby's formula [R.S. Colby, Weeds 15, 20-22 (1967)] and compared with the observed efficacies. 35 Colby's formula: E = x + y + z - x*y*z/100 40 E expected efficacy, expressed in % of the untreated control, when using the mixture of the active compounds A, B and C at the concentrations a, b and c x efficacy, expressed in % of the untreated control, when using 45 active compound A at a concentration of a 8 y efficacy, expressed in % of the untreated control, when using active compound B at a concentration of b z efficacy, expressed in % of the untreated control, when using 5 active compound C at a concentration of c Table A - Individual active compounds Concentration of Eff active compound icacy in % of 10 Example Active compound in the spray the untreated in the spraycotl control liquor [ppm] Control 1 ntr (90% infection) 0 (untreated) 15 0 15 2 I (dithianon) 7.5 0 3.73 0 6 89 3 78 IIa 3 1.5 67 (cyazofamid) 0.75 56 0.75 56 20 0.375 44 6 20 1.5 33 4 IIb.1 .5 0.75 0 0.375 0 25 Table B - Combinations according to the invention Active compound mixture Observed Calculated Example Concentration efficacy efficacy*) 30 Mixing ratio I + IIa 5 15 + 1.5 ppm 99 67 10 : 1 I + IIa 35 6 7.5 + 0.75 ppm 83 56 10 : 1 I + IIa 7 3.75 + 0.375 ppm 67 44 10 : 1 I + IIa 40 ll 8 3.75 + 3 ppm 100 78 1.25 : 1 I + IIa 9 3.75 + 6 ppm 100 89 1 : 1.6 45 I + IIb.1 10 15 + 1.5 ppm 56 33 10: 1 9 Active compound Example mixture Observed Calculated Concentration efficacy efficacy*) Mixing ratio 5 I + IIb.1 11 7.5 + 0.75 ppm 33 0 10 : 1 I + IIb.1 12 3.75 + 0.375 ppm 22 0 10 : 1 10 I + IIb.1 13 7.5 + 6 ppm 56 20 1.25 : 1 I + IIb.1 14 3.75 + 6 ppm 94 20 15 1 : 1.6 *) efficacy calculated using Colby's formula Use example 2: Activity against peronospora of grape vines caused by Plasmopara viticola 20 Leaves of potted grape vines of the cultivar "MUller-Thurgau" were sprayed to runoff point with an aqueous suspension having the concentration of active compounds stated below. To be able to assess the persistency of the substances, the plants were, after 25 the spray coating had dried on, placed in a greenhouse for 3 days. Only then were the leaves inoculated with an aqueous zoospore suspension of Plasmopara viticola. The grape vines were then initially placed in a water-vapor-saturated chamber at 24oC for 48 hours and then in a greenhouse at temperatures between 20 30 and 30 0 C for 5 days. After this period of time, the plants were, to promote sporangiophore eruption, again placed in a moist chamber for 16 hours. The extent of the development of the infection on the undersides of the leaves was then determined visually. 35 Table C - Individual active compounds Concentration of Eff active compound icacy in % of Example Active compound t e pr the untreated in the spray ~40 liquor [ppm] control Control 15 (untreated) (96% infection) 0 (untreated) 7.5 58 16 I (dithianon) 7.5 58 3.73 48 45 10 6 16 17 IIa 3 16 17 (cyazofamid) 0.75 16 0.375 6 5 6 6 3 0 18 IIb.1 0.75 6 0.375 6 1 Table D - Combinations according to the invention Active compound Example mixture Observed Calculated Concentration efficacy efficacy*) Mixing ratio 15 I + IIa 19 7.5 + 0.75 ppm 79 65 10 : 1 I + IIa 20 3.75 + 0.375 ppm 69 51 10 : 1 20 1 + IIa 21 3.75 + 3 ppm 69 56 1.25 : 1 I + IIa 22 3.75 + 6 ppm 74 56 25 1 : 1.6 I + IIb.1 23 7.5 + 0.75 ppm 74 61 10 1 I + IIb.1 24 3.75 + 0.375 ppm 69 51 30 10 : 1 I + IIb.1 25 7.5 + 6 ppm 79 61 1.25 : 1 I + IIb.1 35 26 3.75 + 3 ppm 69 48 1.25 : 1 I + IIb.1 27 3.75 + 6 ppm 74 51 1 : 1.6 40 *) efficacy calculated using Colby's formula The test results show that, for all mixing ratios, the observed efficacy is higher than that predicted using Colby's formula. 45

Claims (8)

1. A fungicidal mixture, comprising 5 A) the compound of the formula I 0 1S CN' 10 S CN and B) at least one imidazole derivative of the formula II 15 R R R2)N II 0 2 -R 4 20 in which R I and R 2 are halogen and phenyl which may be substituted by halogen or Cl-C 4 -alkyl, or R 1 and R 2 together with the bridging C=C double bond form a 3,4-difluoromethylenedioxyphenyl group; 25 R 3 is cyano or halogen, and R 4 is di-(Cl-C 4 -alkyl)amino or isoxazol-4-yl which may carry two C 1 -C 4 -alkyl 30 radicals; in a synergistically effective amount.

2. A fungicidal mixture as claimed in claim 1, comprising, as 35 imidazole derivative II, the compound IIa. Cl1 N \>-CN N CH 3 IIa I4o5h-d ' 40 H 3 C 0 CH 3 45 12

3. A fungicidal mixture as claimed in claim 1, comprising, as imidazole derivative II, a compound of the formula IIb in which X is halogen. 5 F O ~ l F 0N CH 3 0= O IIb H 3 C 10

4. A fungicidal mixture as claimed in any of claims 1 to 3, wherein the weight ratio of the compound I to the compound II is from 100:1 to 1:10. 15

5. A fungicidal composition comprising a solid or liquid carrier and a mixture as claimed in any of claims 1 to 3.

6. A method for controlling harmful fungi, which comprises 20 treating the harmful fungi, their habitat, or the plants, seeds, soils, areas, materials or spaces to be kept free from them with the compound of the formula I, an imidazole derivative of the formula II as set forth in any of claims 1 to 3 and, if appropriate, an active compound III as set forth 25 in claim 4.

7. A method as claimed in claim 7, which comprises treating the harmful fungi, their habitat, or the plants, seeds, soils, areas, materials or spaces to be kept free from them with 30 from 5 to 2000 g/ha of the compound I as set forth in claim 1.

8. A method as claimed in claim 7, which comprises treating the harmful fungi, their habitat, or the plants, seeds, soils, 35 areas, materials or spaces to be kept free from them with from 5 to 500 g/ha of at least one compound II as set forth in any of claims 1 to 3. 40 45 13 Fungicidal mixtures based on dithianon Abstract 5 Fungicidal mixtures, comprising A) the compound of the formula I 10 0 S CN C, S CN 15 and B) at least one imidazole derivative of the formula II 20 R2> N II O 2 -R 4 25 in which R 1 and R 2 are halogen and phenyl which may be substituted by halogen or alkyl or R 1 and R 2 together with the bridging C=C double bond form a 3,4-difluoromethylenedioxyphenyl group; R 3 is cyano or 30 halogen, and R 4 is dialkylamino or isoxazol-4-yl which may carry two alkyl radicals; in a synergistically effective amount, methods for controlling harmful fungi using mixtures of the 35 compounds I and II and the use of the compounds I and II for preparing such mixtures are described. 40 45