AU2014100898A4 - A synergistic fungicidal composition - Google Patents

Abstract

A synergistic fungicidal composition for use on plants, parts of plants, seeds or soil comprising as active ingredients pyrimethanil and fluazinam, characterised in that pyrimethanil and fluazinam are present in synergistically effective ratios ranging from about 20:1 to about 1:5 by weight. Methods for preparing the composition and its use in a method for controlling fungal diseases on horticultural crops and vegetables are also disclosed. -- Fluazinam 50 g/l 00 L |ldooi |0 g100 [ 25/01/10 1/02/10 8/02/10 15/02/10 22/02/10 1/03/10 8/03/10 15/03/10 22103/10 29/03/10 5/04/10 12/04/10 Date Fig. 1. Grape bunch area infected with Botrytis cinerea

Description

A SYNERGISTIC FUNGICIDAL COMPOSITION FIELD OF THE INVENTION This invention relates to a synergistic fungicidal composition for the control of fungal diseases on agricultural and horticultural crops, vegetables and turf, to its method of preparation, and its method of use. BACKGROUND OF THE INVENTION Fungal diseases remain a major cause of crop losses in agriculture despite ongoing advances in agricultural practice. Use of synthetic fungicides is the most effective means of combating fungal phytopathogens and boosting productivity but these substances present their own problems for producers. A particular challenge is to balance the risk of non-performance and the need to minimise residues of pesticidal active ingredients in fresh produce and manufactured products such as beverages and frozen or preserved products, etc. Maximum residue limits (MRLs) for pesticides are set by countries and states for individual crops. The MRL determines the timing (and amount) of the last application of pesticide to a crop. This is managed practically by imposing a "withholding period" or "pre-harvest interval", i.e. the minimum interval between the last pesticide application and the time of harvest. A suitable withholding period is determined empirically for each crop and is based on the half-life of the pesticidal active ingredient (or metabolites thereof) on the crop in question. In the case of fungal diseases the grower will spray the last fungicide in the hope that the fungal inoculum is reduced enough to carry the crop through to harvest without unacceptable levels of disease or residues. For control of some diseases other fungicide timings are also important, e.g. control of botrytis spores in grapes at flowering. Advancing technology is enabling analytical laboratories to detect residues in produce at ever decreasing concentrations. This coupled with the belief amongst consumers that residues that are detectable but below the MRL are a health risk is having the effect of driving down MRLs, which in turn is increasing product withholding periods. Therefore there is a need for fungicidal compositions that are increasingly effective throughout the growing period, and especially during 1 the withholding period. Increasingly the crop is required to be free from detectable residues thus placing an even greater demand on the final fungicide spray. Management of fungicide resistance is another ongoing challenge. Fungicides with a site-specific mode of action are more likely to develop resistance, or develop resistance more quickly than those with multi-site modes of action. Resistance also varies based on pathogen, life cycle stages and rates of reproduction. Fungicide resistance in the field is caused or enhanced by a number of factors including overuse of a single fungicide or of fungicides with the same mode of action, fungicide use at times (e.g. post infection rather than pre infection) or under production conditions (e.g. susceptible crop varieties, crop stress) when the number of individuals exposed to selection pressure is high, absence of crop rotation, inadequate spray coverage, suboptimal application rates, etc. The botrytis disease causing organism Botrytis cinerea, for example, has a high propensity for resistance development and has already become resistant to at least three different mode of action chemical groups; benzimidazole, dicarboximide, and anilinopyrimidine. Use of a fungicide combining two (or more) active ingredients may enable one or more of better resistance management, broader spectrum of activity, lowering of application rates, or extension of period of effective control, withholding period or pre-harvest interval, thereby reducing individual component residues in crops at harvest. Pyrimethanil is a protectant fungicide with contact, translaminar and vapour phase activity. An anilinopyrimidine fungicide, pyrimethanil is a methionine biosynthesis inhibitor. The cystathionine y synthase (cgs) gene product is the proposed specific target (FRAC Code 9, Mode of Action Code D1) but the precise mode of action is currently unknown. Pyrimethanil is also known to inhibit the secretion of hydrolytic enzymes required for host infection. Pyrimethanil is considered to have a medium risk of developing resistance. Pyrimethanil is relatively long lasting on disease susceptible crop surfaces. Accordingly, for example, the New Zealand MRL for grapes is 5 mg/kg. Fluazinam is a contact fungicide with protectant activity. It is a pyridine fungicide (in particular a 2,6-dinitrophenyl crotonate) targeting respiration, specifically an uncoupler of oxidative phosphorylation (FRAC code 29, Mode of Action Code C5). Fluazinam is considered to have a low risk of developing resistance. Fluazinam is relatively short acting. In New Zealand fluazinam has a MRL of 1 mg/kg on grapes that is achieved with a 28 day withholding period. 2 The applicants have discovered that pyrimethanil and fluazinam interact in a surprising synergistic manner with respect to fungicidal activity. As a result of the unexpected synergy, application rates can be lowered beyond what is possible with an additive interaction enabling the composition to be applied later in the crop production cycle without risk of exceeding MRLs at harvest. This in turn gives the grower greater certainty that the crop will reach maturity beyond the last application with a low risk of infection. Alternatively, in the case of organisms at risk of anilinopyrimidine resistance, the use of full label rates for both active ingredients provides robust resistance management and extended disease control thus enabling nil detectable or MRL-compliant residues at harvest. The net effect is more effective disease control at reduced cost. All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. The applicant makes no admission that any reference constitutes prior art - they are merely assertions by their authors and the applicant reserves the right to contest the accuracy, pertinence and domain of the cited documents. None of the documents or references constitutes an admission that they form part of the common general knowledge in NZ or in any other country. OBJECT OF THE INVENTION It is an object of the invention to provide an improved fungicidal composition and/or preparative method thereof and/or use thereof, or at least to provide the public with a useful choice. SUMMARY OF THE INVENTION In one broad aspect this invention provides a synergistic fungicidal composition suitable for use as an agricultural/horticultural fungicide comprising at least one anilinopyrimidine fungicide and pyridine fungicide as active ingredients. In a first surprising aspect there is provided a synergistic, fungicidal composition comprising as active ingredients: (A) at least one anilinopyrimidine fungicide, and (B) at least one pyridine fungicide and/or salts thereof, and wherein components (A) and (B) are present in synergistic ratios. 3 In a second surprising aspect the invention provides for a synergistic fungicidal composition comprising as active ingredients: (A) pyrimethanil and (B) fluazinam, characterised in that active ingredients (A) and (B) are present in synergistically effective ratios from about 20:1 to about 1:5 by weight. Preferably, the composition is applied at a rate ranging from about 5 gai/ha to about 2,500 gai/ha based on the combined weights of pyrimethanil and fluazinam. In a third aspect the invention provides for a synergistic fungicidal composition comprising as active ingredients: (A) pyrimethanil and (B) fluazinam, to selectively control or suppress fungal growth, the composition being characterised in that active ingredients (A) and (B) are present in synergistically effective ratios from about 20:1 to about 1:5 by weight and whereby the composition is applied at a rate ranging from about 5 gai/ha to about 2,500 gai/ha based on the combined weights of pyrimethanil and fluazinam. Accordingly, in a still further broad aspect this invention provides compositions comprising synergistic, selective fungicidal compositions comprising active ingredients (A) and (B) and, optionally, further comprising a further one or more active ingredient(s) being (C) one or more biocide(s) selected from one or more of the group comprising: fungicides, insecticides, and bactericides. Preferably ingredient (C) is one or more insecticides. In a further aspect the fungicidal composition comprises pyrimethanil and fluazinam as active ingredients in pyrimethanil: fluazinam weight ratios from about 20:1 to about 1:5, sufficient to provide a synergistic fungicidal activity when used against fungal pathogens of plants. 4 In a further broad aspect this invention provides methods of formulating the synergistic fungicidal compositions comprising pyrimethanil and fluazinam. In a further broad aspect this invention provides a method of controlling fungal diseases, which comprises applying to plants, parts of plants, plant seeds, seedlings, or to soil, fungicidally effective amounts of the fungicidal composition of the invention. DETAILED DESCRIPTION Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The term "fungicidal" encompasses all effects on fungi including but not limited to the destruction or killing of fungi, a defined logarithmic reduction, a partial or complete suppression or inhibition of growth, inhibition of germination, and the like. The term "fungicidally effective amount" indicates the quantity or application rate of a fungicidal composition or of a fungicidal active ingredient which is capable of producing any one or more such effects. The term "synergistic" refers to a particular phenomenon that occurs when the observed fungicidal effect of a mixture of active ingredients is unexpectedly greater than might be expected from the sum of the observed fungicidal effects of the active ingredients administered separately. In contrast an antagonistic effect refers to the situation whereby two or more components produce a combined effect which is less than the sum of their individual parts, and an additive effect refers to the situation where a combined effect is equal to the sum of their individual parts. Synergy may be measured in various ways, generally based on fungicide concentrations that produce a defined end point in measured fungal growth, or in measured or otherwise evaluated effects resulting from the fungal growth including the effects of fungal growth on plants. Examples of such measurements or evaluated effects include colony diameter, percentage germination, growth rate, percentage plant part affected, incidence of effects of plant parts, etc. Any of these and other parameters can be enumerated using an instrument and/or evaluated manually or visually and assigned to linear or non-linear rating scales. 5 Methods that may be used to calculate synergy include those described by Y. Levy, M. Benderly, Y. Cohen, U. Gisi, and D. Bassand ("The Joint Action of Fungicides in Mixtures: Comparison of Two Methods for Synergy Calculation", 1986, Bulletin OEPP, 16, 651-657), by F. C. Kull, P. C. Eisman, H. D. Sylwestrowicz, and R. L. Mayer ("Mixtures of Quaternary Ammonium Compounds and Long-chain Fatty Acids as Antifungal Agents", 1961, Applied Microbiology, 9, 538-541), and by R. S. Colby ("Calculating Synergistic and Antagonistic Responses of Herbicide Combinations", 1967, Weeds 15, 20-22). Colby's publication discloses the formula: E =X+ Y - (XY)/100, in which, X represents the percent inhibition of growth by fungicide A at x grams of active ingredient per hectare (gai/ha), Y represents the percent inhibition of growth by fungicide B at y gai/ha, and E represents the expected percent inhibition of growth by fungicides A + B in combination at x + y gai/ha, respectively. When the observed percent inhibition of growth by fungicides A + B is greater than E (expected), the combination is synergistic. If the observed inhibition is less than expected, the combination is antagonistic, and when observed and expected inhibitions are equal, the combination is additive. Colby also presents alternative methods of calculation for original data expressed as percent-of control values and for three-way synergistic interactions. Pyrimethanil (N-(4,6-dimethylpyrimidin-2-yl)aniline) has the following properties: solubility at 20 0 C in grams/litre: water 0.121 (pH 6.1, 25 0 C), acetone 389, ethyl acetate 617, methanol 176, dichloromethane 1000, n-hexane 23.7, toluene 412; stable in water pH 5 to pH 9 at 22*C, and in water for 14 days at 54 0 C; vapour pressure 2.2 x 10-3 Pa at 25 0 C; Ko, (log P) 2.84; Henry's law constant 3.6 x 10- 3 Pa m 3 mori; pKa 3.52 (20 0 C), weak base. Formulation types for pyrimethanil as a single active ingredient include SL, SC. Fluazinam (3-chloro-N-(3-chloro-5-trifluoromethyl-2-pyridyl)-a,a,a-trifluoro-2,6-dinitro-p-toluidine) has the following properties: solubility at 25 0 C in grams/litre: water 1.35 x 10 4 (pH 7), acetone 853, dichloromethane 675, ethyl acetate 722, ethyl ether 231, n-hexane 8, methanol 192, n-octanol 41, toluene 451; stable to acid, alkali and heat; vapour pressure 7.5 x 10-3 at 25 0 C; Ko, (log P) 4.03; Henry's law constant 0.41 Pa m 3 mor 1 ; pKa 7.34. Formulation types for fluazinam as a single active ingredient include DP, SC and WP. 6 According to the invention, a synergistic combination of pyrimethanil and fluazinam is found when the relative amounts of pyrimethanil and fluazinam expressed as a ratio pyrimethanil : fluazinam are present within the range from about 20:1 to about 1:5 parts by weight. Preferably pyrimethanil and fluazinam are present in a ratio from about 10:1 to about 1 : 5 parts by weight. More preferably pyrimethanil and fluazinam are present in a ratio from about 5:1 to about 1:5 parts by weight. Still more suitably pyrimethanil and fluazinam are present in a ratio from about 3:1 to about 1:3 parts by weight. If the active ingredients in the synergistic composition according to the invention are present in certain weight ratios, the synergistic effect is particularly pronounced. However, the weight ratios of the active ingredients in the synergistic composition can be varied within a relatively wide range. The ratios of pyrimethanil to fluazinam indicated in this disclosure do not in anyway limit the scope of this invention, but rather are mentioned as a guide, a person of ordinary skill in the art being capable of carrying out complementary experiments in order to find other values of the ratios of active ingredients which produce a synergistic effect. In a further aspect, the invention the provides for a synergistic fungicidal concentrate comprising as active ingredients pyrimethanil and fluazinam, characterised in that pyrimethanil and fluazinam are present in synergistically effective ratios ranging from about 5:1 to about 1:5 by weight. Preferably, the synergistic fungicidal concentrate is formulated to be applied, on dilution, at an application rate of ranging from about 10 gai/Ha to about 1,500 gai/Ha. The synergistic fungicidal composition comprising pyrimethanil and fluazinam may be used to control a broad range of fungal pathogens including but not limited to Alternaria solani (early blight), Alternaria alternata (leaf spot) Alternaria dauci (alternaria leaf blight), Alternaria porri (purple blotch), Botryosphaeria dothidia (Botryosphaeria rot), Botrytis allil (neck rot), Botrytis cinerea (gray mould), Botrytis squamosa (leaf blight), Cladosporium spp. (scab), Colletotrichum acutatum (anthracnose), Monilinia laxa and Moni/inia fructicola (brown rot), Peronospora farinose (downy mildew), Phomopsis viticola (dead arm), Phytophthora infestans (late blight), Plasmodiophora brassicae (club root), Sclerotinia sclerotiorum (white mould), Spongospora 7 subterranea (powdery scab), Venturia spp. (scab), and Wilsonomyces carpophilus (shot hole). The composition may also be used to control a number of fungal diseases of turf. The composition may comprise 0.1% to 60% pyrimethanil and 0.1% to 60% fluazinam on a weight/weight basis or a weight/volume basis. The percentages of active ingredients in the composition will depend mainly on the formulation type. Formulation types and methods of manufacture developed for crop protection purposes are generally used for preservatives for timber, wood and other biodegradable products. These are described, for example, in "Chemistry and Technology of Agrochemical Formulations", 1998, D. A. Knowles (editor), Kluwer Academic Publishers, "Pesticide Formulation and Adjuvant Technology", 1966, C. L. Foy (editor), CRC Press, and "Formulation Technology: Emulsions, Suspensions, Solid Forms", 2001, H. Mollet and A. Grubenmann, Wiley-VCH. Suitable formulation types for the fungicidal composition include, but are not limited to, a powder, a granule, a concentrate, a gel, a solution, an emulsion, a dispersion, a suspension, or a controlled release form including a microcapsule. Preferred formulation types are a suspension concentrate, an emulsion, a granule, a powder and a capsule suspension. Advantageously, the formulation is a liquid thus minimising exposure of users to the hazards of powders and dusts. The synergistic fungicidal composition is formulated as a liquid suspension, an emulsion, a granule, a powder or an encapsulated suspension; or as a concentrate. In addition to pyrimethanil and fluazinam, the fungicidal composition may contain 0.1 % to 99% of customary formulation additives. Customary formulation additives and their functions are described in the previously mentioned publications. Such additives may include water, agriculturally suitable surfactants, dispersants, emulsifiers, penetrants, spreaders, wetting agents, soaps, carriers, oils, solvents, diluents, inert ingredients, conditioning agents, colloids, suspending agents, thickeners, thixotropic agents, polymers, emollients, acids, bases, salts, organic and inorganic solid matrices of various kinds, preservatives, anti-foam agents, anti-freeze agents, anti caking agents, lubricants, stickers, binders, glues, resins, complexing agents, chelating agents, crystallization inhibitors, dyes, activators, synergists, safeners, rain proofers, UV protectants, fertilizers, micronutrients, and the like. 8 Further biocidal active ingredients may be combined with the fungicidal active ingredients of the composition including other fungicides, insecticides, bactericides, and the like. Preferably the additional biocidal ingredient is one or more insecticides. Compositions are formulated using known methods by dissolving, dispersing, finely dividing, slurrying, blending, emulsifying, homogenizing, stirring, high-shear mixing, comminuting, milling, stabilising, etc, the active ingredients, and by admixing with appropriate quantities of the one or more previously mentioned customary formulation additives to form the composition of the invention. In addition pyrimethanil and/or fluazinam may be microencapsulated, separately or together, prior to mixing with other formulation additives. Further details of suitable methods of manufacture of the composition are provided in the examples. Where applicable to the compositions formulated using the known methods referred to above and as provided in methods of the examples, the mean particle size as determined for example using a laser diffraction particle size analyser after dilution into water, is from about 0.1 microns to about 50 microns. Preferably the mean particle size is from about 0.1 microns to about 20 microns. Still more preferably the mean particle size is from about 0.2 microns to about 5 microns. Preferably the composition is formulated for selective application to fruit or the fruiting zone of horticultural crops, otherwise known as bunch line application. The invention provides a method of fungal diseases, which comprises applying to plants, parts of plants, plant seeds or to soil, fungicidally effective amounts of the synergistic fungicidal compositions comprising pyrimethanil and fluazinam. The composition may be applied at any stage of the crop cycle excluding the withholding period. In general the composition may be diluted into a carrier and applied by conventional means to plants, parts of plants, plant seeds, seedlings, or to soil. Water is the carrier of choice and the composition may be mixed into water and applied by spraying, sprinkling, irrigating, coating, wicking, etc. In the case of seeds known seed treatment methods are to be used. 9 Other biocidal active ingredients may be combined with the fungicidal composition, and may include other fungicides, bactericides, insecticides, nematicides, and the like. These active ingredients may be added as a "tank mixture". Pyrimethanil and fluazinam may be applied sequentially or, preferably, simultaneously. The active ingredients together with other additives are advantageously pre-formulated as a single mixture. It should be emphasized that pyrimethanil and fluazinam of the composition may also be formulated separately and "tank mixed" prior to application. Various combinations of separately formulated active ingredients and other customary formulation additives, and the mixing thereof, can be envisaged in the tank mixing scenario. A common occurrence may be the addition of one or more surfactants during tank mixing. Pyrimethanil and fluazinam may be applied sequentially, in any order and in any effective timescale, suitably within a one week period, more suitably within a 24 hour period, and, preferably, within one hour. A bunch line application is preferred. Use rates for the composition of the invention vary within the range from about 5 gai/Ha to about 2,500 gai/Ha, depending on the crop and the disease. Preferably the use rates vary within the range from about 10 gai/Ha to about 1,500 gai/Ha. Still more preferably the use rates vary within the range from about 20 gai/Ha to about 1,000 gai/Ha. Still more preferably the use rates vary within the range from about 50 gai/Ha to about 1,000 gai/Ha. 10 EXAMPLES It will be appreciated that the compositions are provided as non-limiting examples only and that other synergistic fungicidal compositions comprising pyrimethanil and fluazinam as active ingredients will also fall within the ambit of the present invention. The Examples are illustrative only and are not meant to restrict the scope of the invention. EXAMPLE 1. Pyrimethanil fluazinam SC Disperse 8 g magnesium aluminium silicate with high shear mixing into about 250 ml of water followed by 0.1 g defoamer, a dispersant comprising 20 g ethoxylated polyarylphenol phosphate potassium salt and 10 g non-ionic wetting agent. Add 165 g technical grade pyrimethanil and 103 g technical grade fluazinam, in turn, to the mixture with vigorous stirring. Pass the resulting fungicide mixture through a Dyno mill or similar bead mill at a rate that results in a particle size less than 5 pm. Disperse 2 g Xanthan gum in 200 ml water, then add the resulting gel to the fungicide mixture along with a preservative comprising 2.5 g 40% formaldehyde. Finally add water to make the volume up to 1000 ml. The resulting suspension concentrate comprises 160 g/L pyrimethanil and 100 g/L fluazinam, and can be diluted with water ready for use. EXAMPLE 2. Pyrimethanil fluazinam WP Blend 330 g pyrimethanil tech, 206 g fluazinam tech, 5 g sodium naphthalene sulfonate, and 20 g sodium polynaphthalene sulfonate, then make up to 1000 g with china clay. Air mill the resulting mixture to approximately 5 pm. The resulting wettable powder containing 320 g/kg pyrimethanil and 200 g/kg fluazinam can be diluted with water ready for use. EXAMPLE 3. Pyrimethanil fluazinam EC Dissolve 103 g pyrimethanil tech and 64 g fluazinam tech in 600 g Aromatic 150 and 75 g methyl pyrrolidone solvents. When fully dissolved add 75 g TENSIOFIX 8426 and 75 g TENSIOFIX 8427, and stir to dissolve. The resulting emulsifiable concentrate formulation comprising 100 g/L pyrimethanil and 62.5 g/L fluazinam may be diluted with water ready for use. 11 In the following examples, the synergistic fungicidal effects of mixtures comprising pyrimethanil and fluazinam as active ingredients are demonstrated in vitro. Synergy was determined by the "Wadley method" for similar joint action as disclosed by Y. Levy, M. Benderly, Y. Cohen, U. Gisi and D. Bassand ("The joint action of fungicides in mixtures: comparison of two methods for synergy calculation", 1986, Bulletin OEPP 16, 651-657), according to the formulae: 1. ED(exp) = (a + <b)/(a/EDA + b/EDB), in which, EDA is the concentration in ppm of (A), acting alone, which produced an end point, EDB is the concentration in ppm of (B), acting alone, which produced an end point, a and b are the proportions of (A) and (B) in the mixture, and ED(exp) is the expected equally effective concentration in ppm of (A) and (B), acting together, in the proportions a and b, and 2. SF = ED(exp)/ED(obs), in which, SF is the synergy factor, and ED(obs) is the observed equally effective concentration in ppm of (A) and (B), acting together, in the proportions a and b. If SF > 1, there is synergistic interaction between the fungicides, if SF < 1, there is antagonistic interaction, and if SF = 1, there is additive action (i.e. similar joint action). The end point used was EC 90 , the concentration producing 90% inhibition of fungal growth. EC values were calculated by regression analysis of dose response data using the GraphPad Prism software. EXAMPLE 4. Botrytis cinerea Pers (Botryotinia fuckeliana (de Bary) Whetzel 1945) was grown on malt extract agar (MEA) plates for 4 days at 250C in the presence of pyrimethanil alone (A), or fluazinam alone (B), and the mixtures shown in Table 1. Synergy was observed at ratios ranging from 10:1 to 1.6:1. 12 Table 1.

EC

9 o(obs) ECoo(exp) SF Pyrimethanil 231 10:1 Ratio 0.584 1.601 2.744 5:1 Ratio 0.636 0.876 1.378 3:1 Ratio 0.360 0.585 1.624 1.6:1 Ratio 0.254 0.381 1.500 Fluazinam 0.147 EXAMPLE 5. In a separate experiment Botrytis was grown on MEA plates for 4 days at 250C in the presence of pyrimethanil alone (A), or fluazinam alone (B), and the mixtures shown in Table 2. Synergy was observed at the 1:1, 1:3, 1:5 ratios but the mixture was antagonistic at the 1:10 ratio. Table 2.

EC

90 (obs) ECo(exp) SF Pyrimethanil 184 1:1 Ratio 0.176 0.242 1.376 1:3 Ratio 0.149 0.161 1.081 1:5 Ratio 0.131 0.145 1.113 1:10 Ratio 0.137 0.133 0.971 Fluazinam 0.121 EXAMPLE 6. Botrytis control in the field was evaluated on S6millon grape vines (Vitis vinifera) located in Hawkes Bay, New Zealand. All vines had earlier been treated (at 80% capfall) with an industry standard cyprodinil fludioxonil mixture, which was also used for comparison during the trial period as shown in Figures 1 and 2. Four replications of plots measuring 3.5 m x 10 m, and containing five vines each, were sprayed at the bunch line (500 Litres/Ha) on 26-Jan-2010 and 10-Mar-2010 (indicated by arrows in the figures). Eight bunches per vine were assessed for Botrytis. As seen 13 in the untreated control an infection in February declined naturally with dry weather resulting in the shrivelling and abscission of infected berries. This was followed by a typical late season infection. Pyrimethanil alone and fluazinam alone, each at full label rates, produced a measure of control. The mixture of pyrimethanil and fluazinam, each at half label rates, produced the greatest level of control in both infection periods, demonstrating the high level of disease control produced by the synergistic interaction of the present invention. MODIFICATIONS AND VARIATIONS Having generally described this invention, including the best mode thereof, those skilled in the art will appreciate that the present invention contemplates the embodiments of this invention as defined in the following claims, and equivalents thereof. However, those skilled in the art will appreciate that the scope of this invention should not be measured merely by the specific embodiments exemplified herein. Those skilled in the art will also appreciate that more sophisticated technological advances will likely appear subsequent to the filing of this document with the Patent Office. To the extent that these later developed improvements embody the operative principles at the heart of the present disclosure, those improvements are likewise considered to come within the ambit of the following claims. The Invention may also broadly be said to consist in the parts, elements and features referred or indicated in the specification, individually or collectively, and any or all combinations of any of two or more parts, elements, members or features and where specific integers are mentioned herein which have known equivalents such equivalents are deemed to be incorporated herein as if individually set forth. Throughout the description and claims of the specification the word "comprise" or variations thereof are not intended to exclude other additives, components or steps. 14 Kit of Parts It will also be understood that where a product, method or process as herein described or claimed and that is sold incomplete, as individual components, or as a "Kit of Parts", that such exploitation will also fall within the ambit of the invention. In a preferred embodiment the invention includes within its scope a kit of parts, the kit of parts providing for an improved fungicidal composition comprising components (A) pyrimethanil and (B) fluazinam to achieve synergistic ratios of from about 20:1 to 1:5 and optionally (C) one or more biocides in separate containers or, as separate compartments, within the same container. 15

Claims (5)

1. A synergistic fungicidal composition for use on plants, parts of plants, seeds or soil comprising as active ingredients pyrimethanil and fluazinam, characterised in that pyrimethanil and fluazinam are present in synergistically effective ratios ranging from about 20:1 to about 1:5 by weight, the composition being further characterised in that it is formulated for application at a rate ranging from about 5 gai/Ha to about 2,500 gai/Ha based on the combined weights of pyrimethanil and fluazinam.

2. The synergistic fungicidal composition according to claim 1 wherein the ratio of pyrimethanil to fluazinam is from about 10:1 to about 1:3 by weight, preferably from about 3:1 to about 1:3 by weight.

3. The synergistic fungicidal composition according to claim I or claim 2 whereby the composition is formulated for selective application to fruit or the fruiting zone of horticultural crops.

4. A method for controlling fungal diseases on plants or plant parts which comprises applying to the bunch line of plants or parts of plants a fungicidally effective amount of a synergistic fungicidal composition according to any one of the preceding claims characterised in that pyrimethanil and fluazinam are present in synergistically effective ratios ranging from about 20:1 to about 1:5 by weight and whereby the composition is applied to plants, parts of plants, plant seeds or to soil at a rate ranging from about 5 gai/Ha to about 2,500 gai/Ha based on the combined weights of pyrimethanil and fluazinam.

5. The method according to claim 3 whereby the synergistic fungicidal composition is selectively applied to fruit or the fruiting zone of horticultural crops. PIPERS, Patent Attorneys for Zelam Limited 16