GB2267644A - Mixed class synergistic fungicide based on pyrimethanil - Google Patents

Abstract

There is provided a fungicidal composition comprising 2-anilino-4, 6-dimethylpyrimidine (pyrimethanil) and a fungicide from a different chemical class. The compositions have synergistic properties.

Description

Title: Fungicidal mixtures Field of the invention This invention relates to compositions with useful fungicidal properties.

In DDR Patent 151 404 there are described a group of anilinopyrimidine compounds having fungicidal activity. We have now found that particularly valuable fungicidal compositions are obtained when one of the compounds disclosed in this patent, namely 2-anilino-4,6-dimethylpyrimidine, having the common name pyrimethanil, is combined with a fungicide from a different chemical class.

The present invention thus provides a fungicidal composition comprising a) 2-anilino-4,6-dimethylpyrimidine, and b) a fungicidal compound from a different chemical class.

Component (b) is generally a compound selected from (i) a conazole steroid demethylation inhibitor, (ii) a steroid reduction inhibitor based on a 1- [3 - (4 -tert-butylphenyl) -2 -methylpropyl group which is attached via the N-atom to piperidine or 2,6-dimethylmorpholine (iii) a dithiocarbamate fungicide (iv) a phthalimide fungicide in which a chloroalkylthio group is attached via the N-atom to the optionally hydrogenated phthalimide group.

(v) an anilide fungicide (vi) an mbc fungicide.

(vii) a carbamate fungicide (viii) a copper compound fungicide (ix) a tin compound fungicide (x) a strobilurine type fungicide, and (xi) a fungicide selected from the group consisting of chlorothalonil, dimethomorph, fenpiclonil, fluazinam, hymexazol, nuarimol, pencycuron, pyrifenox, thicyofen, probenazole, pyroquilon, tricyclazole, quaternary ammonium compounds, fludioxonil, 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one (and mixtures of these two), furmecyclox, 3-iodo-2-propynyl butylcarbamate and sulfur.

Conazoles are defined in ISO standard 257 as compounds based on imidazole or 1,2,4-triazole and containing a halogenated phenyl group Examples include prochloraz (and its metal complexes - especially the manganese or copper complex), propiconazole, flusilazole, hexaconazole, tebuconazole, difenoconazole, bromuconazole, cyproconazole, diniconazole, fenbuconazole, imibenconazole, furconazole, tetraconazole, myclobutanil, penconazole, fluquinconazole, azaconazole, imazalil, triflumizole, epoxiconazole, triticonazole, metconazole and the fungicide having the code No SSF 109.

Examples of type (ii) fungicides include fenpropimorph and fenpropidin.

Examples of type (iii) fungicides include mancozeb and thiram.

Examples of type (iv) fungicides include folpet, captafol and captan.

Examples of type (v) fungicides include a) 3',5'-dichloroanilide fungicides in which the anilino nitrogen comprises a ring carrying two oxo substituents, in positions adjacent the nitrogen, e.g. iprodione, vinclozolin or procymidone, or b) acetanilide fungicides, e.g. metalaxyl or ofurace, c) sulfanilide fungicides, e.g. dichlofluanid, d) benzanilide fungicides, e.g. flutolanil, and e) heteroarylanilide fungicides, e.g. thifluzamide.

Examples of type (vi) fungicides include carbendazim, benomyl and thiophanate-methyl.

Examples of type (vii) fungicides include diethofencarb and propamocarb.

Examples of type (viii) fungicides include Bordeaux mixture, oxine-copper, copper oxychloride and copper naphthenate.

Examples of type (ix) fungicides include tributyltin oxide and tributyltin naphthenate.

Strobilurine type fungicides (type (x) fungicides) are methyl esters of arylacetic acid in which the acetic acid also carries a methoxymethylene or methoxyimino substituent. The aryl group is usually a 2-substituted phenyl group. Examples of such compounds are those disclosed in a wide number of patent applications, including EPs 178826, 203606, 203608, 206523, 229974, 226917, 242070, 242081, 243012, 243014, 251082, 256667, 260794, 260832, 267734, 270252, 273572, 274825, 278595, 291196, 299694, 307101, 307103, 310954, 312221, 312243, 329011 and 336211. Specific compounds are those having the having the code Nos BAS 490F and ICIA 5504.

The names quoted for these compounds are the nonproprietary common names and the chemical structure can be found for example by reference to the "Pesticide Manual", ninth edition, 1991, published by the British Crop Protection Council. Of those not mentioned in the Pesticide Manual the full chemical names are as follows: bromuconazole - 1-[ [4-bromo-2-(2, 4-dichlorophenyl) - tetrahydro-2-furanyl]methyl] 1H-1,2,4-triazole fluquinconazole - 3-(2, 4-dichlorophenyl) -6-fluoro- 2-(1H-1,2,4-triazol-l-yl)- 4(3H)-quinazolinone epoxiconazole - l-[3-(2-chlorophenyl)-2-(4-fluoro phenyl)oxiran-2-ylmethyl] 1H-1,2,4-triazole triticonazole - 5- (4-chlorophenyl) methylene- 2,2-dimethyl-1-(1H-1,2,4-triazol- l-ylmethyl)cycloheptanol metconazole - 5- (4-chlorobenzyl) -2, 2-dimethyl- 1-(1H-1,2,4-triazol-1-ylmethyl) - cyclopentanol thifluzamide - 2' ,6'dibromo-2-methyl-4'-trifluoro- methoxy-4 -trifluoromethyl- 1,3-thiazole-5-carboxanilide fludioxonil - 4- (2, 2-difluoro-1, 3-benzodioxol- 4-yl)pyrrole-3-carbonitrile, SSF 109 - l-(4-chlorophenyl)-2-(lH-l,2,4- triazol-l-yl)cycloheptanol BAS 490F - methyl (E)-methoximino[a-(o-tolyoxy) o-toly] acetate ICIA 5504 - methyl (E)-2-{2-[6-(2-cyanophenoxy) pyrimidin-4-yloxy] phenyl}-3-methoxy- acrylate We have found that the compositions of the invention have advantageous properties over the individual components and that synergism is often demonstrated, and yield of crop may be increased.

The weight ratio of component (a) to component (b) can vary over wide ranges. Suitable ranges of (a) to (b) are from 25:1 to 1:25, especially 5:1 to 1:5.

In addition, other pesticides may be employed in conjunction with the active ingredients described above providing they do not adversely affect the interaction between the fungicidal components.

The compositions of the invention are active against a wide range of fungi, e.g. powdery mildew (Erysiphe graminis) on cereal crops such as wheat, barley, oats and rye and other foliar diseases such as glume blotch (Septoria nodorum), leaf blotch (Rhynchosporium secalis), eyespot (Pseudocercosporella herpotrichoides) and rusts (e.g. Puccinia graminis). Certain compositions of the present invention can be used to control seed-borne organisms such as bunt (Tilletia caries) on wheat, loose smut (Ustilago nuda and Ustilago hordei) on barley and oats, leaf spot (Pyrenophora avenae) on oats and leaf stripe (Pyrenophora graminis) on barley. The compositions can also be applied to rice for control of rice blast (Pyricularia oryzae), to horticultural crops such as apple trees for the control of apple scab (Venturia inaequalis), roses and other ornamentals for the control of powdery mildew (Sphaerotheca pannosa), rust and black spot, to many crops, for the control of Botrytis cinerea, to turf for the control of dollar spot (Sclerotinia homeocarpa) and to stored produce for the control of storage rot organisms of citrus fruit, potatoes, sugar beet, apples, pears etc., (e.g. Penicillium spp., Aspergillus spp. and Botrytis spp.). Other diseases that may be combatted include Helminthosporium spp. and Cercospora spp.

The compositions of the 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 the ingredients in their commercially available form are mixed together by the user in a quantity of water.

In addition to tank mixing immediately prior to use, the compositions containing 2-anilino-4, 6-dimethylpyrimidine may be formulated into a more concentrated primary composition which is diluted with water or other diluent before use. Such compositions may comprise a surface active agent in addition to the active ingredients and examples of such compositions are as follows.

It can be a dispersible solution which comprises the active ingredients dissolved in a water-miscible solvent with the addition of a dispersing agent. Alternatively it can comprise the ingredients in the form of a finely ground powder in association with a dispersing agent and intimately mixed with water to give a paste or cream which can if desired be added to an emulsion of oil in water to give a dispersion of active ingredients in an aqueous oil emulsion.

An emulsifiable concentrate comprises the active ingredient dissolved in a water-immiscible solvent which is formed into an emulsion with water in the presence of an emulsifying agent.

A granular solid comprises the active ingredients associated with powder diluents such as kaolin, which mixture is granulated by known methods. Alternatively it comprises the active ingredients adsorbed or absorbed on a pre-granular diluent, for example Fuller's earth, attapulgite or limestone grit.

A dispersible or wettable powder usually comprises the active ingredients in admixture with a suitable surfactant and an inert powder diluent such as china clay.

Another suitable concentrate is a flowable suspension concentrate which is formed by grinding the active ingredients with water, a wetting agent and a suspending agent.

In some circumstances it may be desirable to combine two types of formulation e.g. one of the components is present in an emulsifiable concentrate and the second component is dispersed as a powder in this concentrate.

The concentrate of the active ingredients (when used as the sole active components) in a composition for direct application to the crop by conventional ground methods is preferably within the range of 0.001 to 10 per cent by weight of the composition, especially 0.005 to 5 per cent by weight, but more concentrated compositions containing up to 40 per cent may be desirable in the case of aerial sprays.

The compositions of the invention are particularly useful for treating seeds, especially cereal seeds, in order to control, particularly, seed-borne diseases. The seeds can be treated in conventional manner using a variety of formulation types, such as dusts, solutions in an organic solvent or aqueous formulations such as flowable suspension concentrates. If cereal grain is to be stored in a store room or container it is sometimes convenient to treat the store room or containers with a composition according to the invention instead of, or in addition to, treatment of the cereal grain itself. A suitable rate of application for a seed dressing is from 0.005 to 5.0 g 2-anilino-4,6-dimethylpyrimidine per kilogram of seed, such as for example from 0.01 to 1.0 g per kilogram of seed.

Alternatively the composition of the invention can be applied directly to plants by, for example, spraying or dusting either at the time which the fungus has begun to appear on the plant or before the appearance of fungus, as a protective measure. In both cases the preferred mode of application is by foliar spray. When the composition of the invention is applied directly to the plant a suitable rate of application is from 0.005 to 2 kilograms per hectare, preferably from 0.1 to 1 kilogram per hectare.

The invention thus includes a method of combating phytopathogenic fungi which comprises applying to the fungus or its locus a mixture according to the invention. The invention is illustrated in the following Example which describe in vitro experiments in which a synergistic effect was observed.

Example 2-Anilino-4,6-dimethylpyrimidine and component (b) fungicides were incorporated into molten agar in amounts to give the required concentration of active ingredient in the agar. The molten agar was then poured into petri dishes and allowed to set. 5 mm mycelial plugs of an agar culture of the specified fungus were transferred to the centre of each plate with the mycelium surface down. The dishes were incubated at 200C. The colony diameters were then measured at various times and the percentage control of growth in comparison with the growth in a dish of agar, used as a standard, which had been similarly inoculated but contained no active ingredient, was calculated.

To indicate the existence of synergism between the active components the results were treated in the manner described by Colby S.R., "Calculating Synergistic and Antagonistic Responses of Herbicide Combinations" in Weeds 1967 15 20-22). In this method the "expected" percent control of growth, E, of the combination compared with untreated control is given by the equation E = A + F - - 100 where A is the % control by 2-anilino-4,6-dimethylpyrimidine, used alone at a given concentration and F is the % control by component (b), used alone at a given concentration. If the observed control of the mixture is greater than E the results indicate synergism. In Table I evidence of synergism is shown at the given rates.

1) Prochloraz a) Pyricularia oryzae Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- prochloraz (%) (E in %) pyrimidine (ppm) (ppm) 0.25 0 3 0.5 0 1 5.0 0 18 0 0.25 85 0 0.05 76 0.25 0.05 88 76.7 0.25 0.25 94 85.5 0.5 0.05 85 76.3 0.5 0.25 88 85.9 5.0 0.05 85 80.3 5.0 0.25 91 87.7 2) Chlorothalonil a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4, 6-dimethyl- chlorothalonil (%) (E in %) pyrimidine (ppm) (ppm) 0.25 0 22 1.25 0 56 0 0.05 1 0 0.25 7 0 1.25 22 0.25 0.05 33 23 0.25 0.25 44 27 0.25 1.25 59 38 1.25 1.25 79 66 3) Fenpropidin a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- fenpropidin (%) (E in %) pyrimidine (ppm) (ppm) 0.25 0 22 0 0.25 9 0 1.25 39 0.25 0.25 31 29 0.25 1.25 77 52 b) Gaeumannomyces graminis Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- fenpropidin (%) (E in t) pyrimidine (ppm) (ppm) 0.25 0 6 0 0.05 11 0 0.25 39 0 1.25 72 0.25 0.05 31 17 0.25 0.25 68 42 0.25 1.25 94 74 4) Proriconazole a) Pseudocercosporella herpotrichoides Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- propiconazole (t) (E in %) pyrimidine (ppm) (ppm) 0.05 0 12 0.25 0 56 0 0.05 4 0.05 0.05 42 16 0.25 0.05 71 58 5) Flusilazole a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- flusilazole (%) (E in %) pyrimidine (ppm) (ppm) 1.25 0 42 0 0.05 38 0 0.25 59 1.25 0.05 84 64 1.25 0.25 95 76 6) Mancozeb a) Pyricularia oryzae Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- mancozeb (%) (E in %) pyrimidine (ppm) (ppm) 0.05 0 1 0.25 0 23 0 0.05 3 0.05 0.05 22 4 0.25 0.05 54 26 7) Thiram a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- thiram (%) (E in t) pyrimidine (ppm) (ppm) 0.05 0 5 0.25 0 24 1.25 0 33 0 1.25 29 0.05 1.25 55 32 0.25 1.25 75 46 1.25 1.25 69 52 8) Iprodione a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- iprodione (%) (E in %) pyrimidine (ppm) (ppm) 0.25 0 44 0 0.05 13 0.25 0.05 76 51 9) Epoxiconazole a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- epoxiconazole (t) (E in t) pyrimidine (ppm) (ppm) 0.05 0 4 0.25 0 17 1.25 0 30 0 1.25 71 0.05 1.25 80 73 0.25 1.25 89 76 1.25 1.25 93 80 10) Bromuconazole a) Sclerotinia sclerotiorum Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- bromuconazole (%) (E in %) pyrimidine (ppm) (ppm) 0.05 0 0 0.25 0 0 0 0.05 22 0.05 0.05 66 22 0.25 0.05 89 22 11) Cyproconazole a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- cyproconazole (t) (E in t) pyrimidine (ppm) (ppm) 0.25 0 11 1.25 0 23 0 1.25 60 0.25 1.25 75 65 1.25 1.25 81 70 b) Sclerotium rolfsii Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- cyproconazole (%) (E in t) pyrimidine (ppm) (ppm) 0.05 0 0 0.25 0 6 0 0.05 29 0.05 0.05 52 29 0.25 0.05 59 33 12) Diniconazole a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- diniconazole (t) (E in t) pyrimidine (ppm) (ppm) 0.25 0 3 1.25 0 18 0 0.05 12 0 0.25 26 0 1.25 41 0.25 0.05 38 14 0.25 0.25 46 27 0.25 1.25 86 43 1.25 0.05 45 28 1.25 0.25 52 39 1.25 1.25 62 52 b) Sclerotinia sclerotiorum Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- diniconazole (%) (E in %) pyrimidine (ppm) (ppm) 0.25 0 1 1.25 0 9 0 0.05 1 0 0.25 2 0.25 0.05 42 2 0.25 0.25 52 3 1.25 0.05 43 10 1.25 0.25 51 11 13) Fluquinconazole a) Fusarium nivale Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- fluquinconazole (%) (E in %) pyrimidine (ppm) (ppm) 0.25 0 12 1.25 0 30 0 0.25 4 0 1.25 25 0.25 0.25 29 16 0.25 1.25 37 34 1.25 0.25 40 33 1.25 1.25 51 47 14) Tebuconazole a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- tebuconazole (%) (E in %) pyrimidine (ppm) (ppm) 1.25 0 48 0 1.25 66 1.25 1.25 93 82 15) Vinclozolin a) Sclerotium rolfsii Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- vinclozolin (%) (E in %) pyrimidine (ppm) (ppm) 0.25 0 6 1.25 0 14 0 0.05 0 0.25 0.05 12 6 1.25 0.05 31 27 16) Benomyl a) Fusarium nivale Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- benomyl (%) (E in %) pyrimidine (ppm) (ppm) 0.25 0 22 0 0.01 0 0.25 0.01 38 22 17) Difenoconazole a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- difenoconazole (%) (E in %) pyrimidine (ppm) (ppm) 1.25 0 30 0 1.25 47 1.25 1.25 72 63 18) Hexaconazole a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- hexaconazole (%) (E in %) pyrimidine (ppm) (ppm) 1.25 0 18 0 0.05 18 0 0.25 41 0 1.25 75 1.25 0.05 38 32 1.25 0.25 55 51 1.25 1.25 88 79 19) Thiophanate-methV1 a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- thiophanate- (t) (E in %) pyrimidine methyl (ppm) (ppm) 1.25 0 8 0 1.25 1 1.25 1.25 24 15 20) Hvmexazol a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6 -dimethyl- hymexazol (%) (E in %) pyrimidine (ppm) (ppm) 0.25 0 26 1.25 0 40 0 1.25 11 0.25 1.25 51 34 1.25 1.25 87 47 21) Ofurace a) Fusarium nivale Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- ofurace (%) (E in %) pyrimidine (ppm) (ppm) 1.25 0 44 0 0.05 2 1.25 0.05 58 46 22) BAS 490F a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- BAS 490F (%) (E in %) pyrimidine (ppm) (ppm) 0.05 0 1 1.25 0 37 0 0.05 23 0 1.25 35 0.05 1.25 46 35 1.25 0.05 65 52 23 ICIA 5504 a) Botrytis cinerea Concentration Concentration Observed Expected of 2-anilino- of control control 4,6-dimethyl- ICIA 5504 (%) (E in %) pyrimidine (ppm) (ppm) 0.05 0 3 0 0.05 12 0.05 0.05 29 15

Claims (2)

1. CLAIMS 1) A fungicidal composition comprising a) 2-anilino-4, 6-dimethylpyrimidine, and b) a fungicidal compound from a different chemical class.
2. 2) A method of combating phytopathogenic fungi which comprises applying to the fungus or its locus a composition as claimed in claim 1.