WO2015169201A1

WO2015169201A1 - A synergistic fungicidal composition comprising tebuconazole and chlorothalonil

Info

Publication number: WO2015169201A1
Application number: PCT/CN2015/078253
Authority: WO
Inventors: James Timothy Bristow; Yifan Wu
Original assignee: Rotam Agrochem International Company Limited
Priority date: 2014-05-09
Filing date: 2015-05-05
Publication date: 2015-11-12

Abstract

This invention is related to a synergistic fungicidal composition comprising tebuconazole and chlorothalonil for preventing and/or treating fungal infestations in plants and plant parts.

Description

A SYNERGISTIC FUNGICIDAL COMPOSITION COMPRISING TEBUCONAZOLE AND CHLOROTHALONIL

FIELD OF THE INVENTION

The present invention relates to a synergistic fungicidal composition comprising tebuconazole and chlorothalonil for preventing and/or treating fungal infestations in plants and plant parts. The present invention also relates to a method of preventing and/or treating fungal infestations in plants and plant parts comprising (1) preparing a synergistic fungicidal composition comprising tebuconazole and chlorothalonil and (2) applying the synergistic fungicidal composition on the plants or plant parts or on a locus.

BACKGROUND OF THE INVENTION

Fungal infestations cause significant yield reduction. Therefore, preventing and treating fungal infestations of plants and plant parts is crucial to obtain high productivity and is a continual objective in the agricultural field. Particularly, Septoria spp., Puccinia recondite, Puccinia striiformis, Puccinia graminis, Erysiphe graminis, Drechslera maydis, Leveillula taurica, Venturia inequalis are pathogen causing significant yield losses of cereals, vegetables and fruits. We surprisingly found that a combination of tebuconazole and chlorothalonil, characterized by different modes of action, exhibits a considerable synergistic effect, allowing a higher fungicidal activity to be obtained than that envisaged on the basis of the activities of individual tebuconazole and chlorothalonil.

SUMMARY OF THE INVENTION

It has been found that the use of tebuconazole is effective in combatting or preventing fungal diseases.

Tebuconazole is effective in controlling fungal infestations by inhibiting one specific enzyme, C14-demethylase, which plays a role in sterol production. Sterols, such as ergosterol, are needed for membrane structure and function, making them essential for the development of functional cell walls by the fungi. Chlorothalonil is a chloronitrile non-systemic foliar fungicide with protective action. It is a multi-site inhibitor affecting various enzymes and other metabolic processes in fungi. Chlorothalonil inhibits spore germination, and is toxic to fungal cell membranes.

We surprisingly found that a combination of tebuconazole and chlorothalonil, characterized by different modes of action exhibits a considerable synergistic effect. A synergistic fungicidal composition comprising tebuconazole and chlorothalonil is effective in preventing and/or treating fungal infestations caused by, particularly Septoria spp., Puccinia recondite, Puccinia striiformis, Puccinia graminis, Erysiphe graminis, Drechslera maydis, Leveillula taurica and Venturia inequalis.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The use of tebuconazole in combination with chlorothalonil surprisingly and substantially enhances the fungicidal effectiveness of chlorothalonil, and vice versa.

"Plant" as used herein, refers to all plant and plant populations such as desired and undesired wild plants or crop plants.

"Plant parts" as used herein, refers to all parts and organs of plants, such as shoot, leaves, needles, stalks, stems, fruit bodies, fruits, seeds, roots, tubers and rhizomes. Harvested materials, and vegetative and generative propagation materials, for example, cutting, tubers, meristem tissue, rhizomes, offsets, seeds, single and multiple plant cells and any other plant tissues, are also included.

The synergistic fungicidal composition according to the present invention is suitable for plants of the crops: cereals (wheat, barley, rye, oats, corn, rice, sorghum, triticale and related crops) ； fruit, such as pomes, stone fruit and soft fruit, such as apples, pears, plums, peaches, almonds, cherries, and berries, for example grape, strawberries, raspberries and blackberries； leguminous plants (beans, lentils, peas, soybeans) ； oil plants (rape, mustard, sunflowers) ； cucurbitaceae (marrows, cucumbers, melons) ； citrus fruit, such as oranges, lemons, grapefruit and mandarins； and vegetables (spinach, lettuce, asparagus, cabbages, carrots, onions, tomatoes, potatoes, paprika) . Preferably, the composition of the present invention is applied on cereals, vegetables and fruits. More preferably, the composition is applied on wheat, barley, rye, corn, oats, tomato and apple.

Each composition of the present invention can be used in the agricultural sector and related fields of use for preventing and/or treating fungal infestations example, but not limited to:

Septoria speckled leaf blotch (Septoria passerinii) , yellow rust (Puccinia striiformis) , stem rust (Puccinia graminis) , powdery mildew (Erysiphe graminis) on barley；

Septoria blotch (Septoria tritici) , stagonospora blotch (Septoria avenae f.sp. triticea) (Septoria nodorum) , brown rust (Puccinia recondita) , yellow rust (Puccinia striiformis) , stem rust (Puccinia graminis) , powdery mildew (Erysiphe graminis) on wheat；

Leaf spots, minor (Septoria zeae) (Septoria zeicola) (Septoria zeina) , southern corn leaf blight (Drechslera maydis) on corn；

Speckled blotch (Septoria blight) (Septoria avenae) , stem rust (Puccinia graminis) , powdery mildew (Erysiphe graminis) on oat；

Septoria leaf blotch (Septoria secalis) , septoria tritici blotch (speckled leaf blotch) (Septoria tritici) , stagonospora blotch (glume blotch) (Septoria nodorum) , brown rust (Puccinia recondita) , yellow rust (Puccinia striiformis) , stem rust (Puccinia graminis) , powdery mildew (Erysiphe graminis) on rye；

Powdery mildew (Leveillula taurica) on tomato； and

Apple scab disease (Venturia inequalis) on apple.

The synergistic fungicidal composition according to this invention is effective in preventing and/or treating fungal infestations caused by, particularly Septoria spp., Puccinia recondite, Puccinia striiformis, Puccinia graminis, Erysiphe graminis, Drechslera maydis, Leveillula taurica, Venturia inequalis, in plants and plant parts, particularly plants and their plant parts of cereals, vegetables and fruits. In some embodiments, the synergistic fungicidal composition according to this invention is effective in preventing and/or treating fungal infestations, particularly Septoria spp., Puccinia recondite, Puccinia striiformis, Puccinia graminis, Erysiphe graminis, Drechslera maydis, Leveillula taurica, Venturia inequalis, in plants and plant parts, particularly plants and their plant parts of wheat, barley, rye, corn, oats, tomato and apple.

The method of the invention is particularly suitable for preventing and/or treating fungal infestations caused by Septoria spp., Puccinia recondite, Puccinia striiformis, Puccinia graminis, Erysiphe graminis, Drechslera maydis, Leveillula taurica, Venturia inequalis, in plants and plant parts, particularly plants and their plant parts of cereals, vegetables and fruits. More particular, the method provided herein is use for preventing and/or treating fungal infestations caused by Septoria spp., Puccinia recondite, Puccinia striiformis, Puccinia graminis, Erysiphe graminis, Drechslera maydis, Leveillula taurica, Venturia inequalis in crops such as wheat, barley, rye, corn, oats, tomato and apple.

Tebuconazole may be present in the synergistic fungicidal composition of the present invention in any suitable amount, and is generally present in an amount of from about 1％to about 60％by weight of the composition, preferably from about 1％to about 30％by weight of the composition, more preferably from 5％to 15％by weight of the composition, most preferably about 12.5％by weight of the composition.

Chlorothalonil may be present in the synergistic fungicidal composition in any suitable amount, and is generally present in an amount of from about 1％to about 70％by weight of the composition, preferably from about 20％to about 50％by weight of the composition, more preferably from about 25％to about 40％by weight of the composition, most preferably about 37.5％by weight of the composition.

Tebuconazole and chlorothalonil may be present in the composition or applied in any amounts relative to each other, to provide the enhanced or synergistic effect of the mixture. Tebuconazole and chlorothalonil may be present in the synergistic fungicidal composition in any suitable amount, and is generally present in an amount of from 1％to 85％by weight of the composition, preferably from 20％to 80％by weight of the composition, more preferably from 30％to 65％by weight of the composition, most preferably 50％by weight of the composition.

In particular, the weight ratio of tebuconazole and chlorothalonil in the composition independently is preferably in the range of from about 25:1 to about 1:25, about 20:1 to about 1:20, or about 15:1 to about 1:15, more preferably from about 10:1 to about 1:10, about 5:1 to about 1:5 or about 3:1 to about 1:3. In some embodiments, the weight ratio of tebuconazole and chlorothalonil in the composition independently is about 1:3.

Such compositions may be produced in conventional manner, for example by mixing tebuconazole with chlorothalonil with appropriate auxiliaries. Suitable auxiliaries which may be comprised in the composition according to the invention are all customary formulation adjuvants or components, such as extender, carriers, solvents, surfactants, stabilizers, anti-foaming agents, anti-freezing agents, preservatives, antioxidants, colorants, thickeners, solid adherents and inert fillers. Such auxiliaries are known in the art and are commercially available. Their use in the formulation of the compositions of the present invention will be apparent to the person skilled in the art. Formulation includes water-soluble concentrate (SL) , an emulstifiable concentrate (EC) , an emulsion (EW) , a micro-emulsion (ME) , a suspension concentrates (SC) , an oil-based suspension concentrates (OD) , a flowable suspension (FS) , a water-dispersible granule (WG) , water-soluble granule (SG) , a water-dispersible powder (WP) , a water soluble powder (SP) , a granule (GR) , an encapsulated granule (CG) , a fine granule (FG) , a macrogranule (GG) , an aqueous suspo-emulsion (SE) , capsule suspension (CS) and a microgranule (MG) . Preferably, the synergistic fungicidal composition can be formulated as suspension concentrates (SC) , water-dispersible powder (WP) or water-dispersible granule (WG) . Most preferably, the synergistic fungicidal composition can be formulated as suspension concentrates (SC) .

The fungicidal composition may comprise one or more inert fillers. Such inert fillers are known in the art and available commercially. Suitable fillers include, for example, natural ground minerals, such as kaolins, aluminas, talc, chalk, quartz, attapulgite, montmorillonite, and diatomaceous earth, or synthetic ground minerals, such as highly dispersed silicic acid, aluminum oxide, silicates, and calcium phosphates and calcium hydrogen phosphates. Suitable inert fillers for granules include, for example, crushed and fractionated natural minerals, such as calcite, marble, pumice, sepiolite, and dolomite, or synthetic granules of inorganic and organic ground materials, as well as granules of organic material, such as sawdust, coconut husks, corn cobs, and tobacco stalks.

The fungicidal composition optionally includes one or more surfactants which are preferably non-ionic, cationic and/or anionic in nature and surfactant mixtures which have good emulsifying, dispersing and wetting properties, depending on the nature of the active compound to be formulated. Suitable surfactants are known in the art and are commercially available. Suitable anionic surfactants can be both so-called water-soluble soaps and water-soluble synthetic surface-active compounds. Soaps which may be used are the alkali metal, alkaline earth metal or substituted or unsubstituted ammonium salts of higher fatty acid (C₁₀-C₂₂) , for example the sodium or potassium salt of oleic or stearic acid, or of natural fatty acid mixtures. The surfactant can be an emulsifier, dispersant or wetting agent of ionic or nonionic type. Examples which may be used are salts of polyacrylic acids, salts of lignosulphonic acid, salts of phenylsulphonic or naphthalenesulphonic acids, polycondensates of ethylene oxide with fatty alcohols or with fatty acids or with fatty amines, substituted phenols, especially alkylphenols, sulphosuccinic ester salts, taurine derivatives, especially alkyltaurates, or phosphoric esters of polyethoxylated phenols or alcohols. The presence of at least one surfactant is generally required when the active compound and/or the inert carrier and/or auxiliary/adjuvant are insoluble in water and the vehicle for the final application of the composition is water.

The fungicidal composition optionally further comprises one or more polymeric stabilizer. The suitable polymeric stabilizers that may be used in the present invention include, but are not limited to, polypropylene, polyisobutylene, polyisoprene, copolymers of monoolefins and diolefins, polyacrylates, polystyrene, polyvinyl acetate, polyurethanes or polyamides. Suitable stabilizers are known in the art and commercially available.

The surfactants and polymeric stabilizers mentioned above are generally believed to impart stability to the composition, in turn allowing the composition to be formulated, stored, transported and applied.

Suitable anti-foams include all substances which can normally be used for this purpose in agrochemical compositions. Suitable anti-foam agents are known in the art and are available commercially. Particularly preferred antifoam agents are mixtures of polydimethylsiloxanes and perfluroalkylphosphonic acids, such as the silicone anti-foam agents available from GE or Compton.

Suitable organic solvents are selected from all customary organic solvents which thoroughly dissolve the active compounds employed. Again, suitable organic solvents for tebuconazole and chlorothalonil are known in the art. The following may be mentioned as being preferred: N-methyl pyrrolidone, N-octyl pyrrolidone, cyclohexyl-1-pyrrolidone； or SOLVESSO^TM200, a mixture of paraffinic, isoparaffinic, cycloparaffinic and aromatic hydrocarbons. Suitable solvents are commercially available.

Suitable preservatives include all substances which can normally be used for this purpose in agrochemical compositions of this type and again are well known in the art. Suitable examples that may be mentioned include

(from Bayer AG) and

(from Bayer AG) .

Suitable antioxidants are all substances which can normally be used for this purpose in agrochemical compositions, as is known in the art. Preference is given to butylated hydroxytoluene.

Suitable thickeners include all substances which can normally be used for this purpose in agrochemical compositions. For example xanthan gum, PVOH, cellulose and its derivatives, clay hydrated silicates, magnesium aluminum silicates or a mixture thereof. Again, such thickeners are known in the art and available commercially.

The fungicidal composition may further comprise one or more solid adherents. Such adherents are known in the art and available commercially. They include organic adhesives, including tackifiers, such as celluloses of substituted celluloses, natural and synthetic polymers in the form of powders, granules, or lattices, and inorganic adhesives such as gypsum, silica, or cement.

In addition, depending upon the formulation, the composition according to the invention may also comprise water.

The formulated composition may for example be applied in spray form, e.g., employing appropriate dilutions.

The rates of application (use) of the composition of the present invention may vary, for example, according to type of use, soil type, season, climate, soil ecology, type of plants, but is such that tebuconazole and chlorothalonil in the combination in an effective amount to provide the desired action. The application rate of the composition for a given set of conditions can readily be determined by trials. The application rate of the total amount of tebuconazole and chlorothalonil in the synergistic fungicidal composition lies in the range of from about 50 to about 150 gram per decare. In general, satisfactory results will be obtained when employing from about 12.5 to about 37.5 gram per decare, e.g., about 25 gram per decare of tebuconazole and from about 37.5 to about 112.5 gram per decare, e.g., about 75 gram per decare, of chlorothalonil.

In general, with a spray volume of from 100 to 800 liters per decare, depending on the growth stage of the crop is used. The spray volume is known in the art. Application rates may also be expressed in terms of concentrations. The concentration is known in the art. Suitable concentration use for, for example, cereals, is 200 mL of the composition or formulation per decare. The spray treatment involves usually foliar application.

The composition of the present invention may contain or be mixed with other pesticides, such as fungicides, insecticides and nematicides, growth factor and fertilizers, to enhance the activity of the association of the invention or to widen its spectrum of activity.

The following examples are given by way of illustration and not by way of limitation of the invention.

FORMULATION EXAMPLES

Example 1

An aqueous suspension concentrate (SC) was prepared having the following composition:

The finely ground tebuconazole was intimately mixed with the adjuvants, giving a suspension concentrate from which suspensions of any desired dilution could be obtained by dilution with water. As an alternative, a suspension of tebuconazole and auxiliaries (including water) were wet milled with a bead-mill to achieve a stable formulation with appropriate treatment characteristics.

Example 2

An aqueous suspension concentrate (SC) was prepared having the followingcomposition：

The finely ground chlorothalonil was intimately mixed with the adjuvants, giving a suspension concentrate from which suspensions of any desired dilution could be obtained by dilution with water. As an alternative, a suspension of chlorothalonil and auxiliaries (including water) were wet milled with a bead-mill to achieve a stable formulation with appropriate treatment characteristics.

Example 3

The finely ground tebuconazole and chlorothalonil were intimately mixed with the adjuvants, giving a suspension concentrate from which suspensions of any desired dilution could be obtained by dilution with water. As an alternative, a suspension of tebuconazole and chlorothalonil and auxiliaries (including water) were wet milled with a bead-mill to achieve a stable formulation with appropriate treatment characteristics.

Example 4

The finely ground tebuconazole and chlorothalonil were intimately mixed with the auxiliaries, giving a suspension concentrate from which suspensions of any desired dilution could be obtained by dilution with water. As an alternative, a suspension of tebuconazole and chlorothalonil and auxiliaries (including water) were wet milled with a bead-mill to achieve a stable formulation and with the appropriate treatment characteristics.

Example 5

Example 6

A water-dispersible granule (WG) was prepared having the following composition:

With the water-dispersible granule, an aqueous suspension of required concentration was obtained through dilution of the water dispersible granule with an appropriate amount of water.

Example 7

A water-dispersible powder (WP) was prepared having the following composition:

Biological Examples

Field Test 1–wheat

Young wheat plants were sprayed with a conidial suspension of Septoria tritici, and incubated at 20℃and 100％relative atmospheric humidity for 48 hours. Then they were sprayed with Formulation Example 1 (tebuconazole 430g/L SC) (with application rate of 1247g AI/decare) , Formulation Example 2 (chlorothalonil 500g/L SC) (with application rate of 16500g AI/decare) and Formulation Examples 3-7 (with application rate of 100g AI/decare) . After staying in a greenhouse at 15℃and 80％relative atmospheric humidity for 15 days, severity was assessed (Table 1) .

Table 1.

Field Test 2–Oat

Young oat plants were sprayed with a conidial suspension of Septoria avenae, and incubated at 20℃and 100％relative atmospheric humidity for 48 hours. Then they were sprayed with Formulation Example 1 (tebuconazole 430g/L SC) (with application rate of 1247g AI/decare) , Formulation Example 2 (chlorothalonil 500g/L SC) (with application rate of 16500g AI/decare) and Formulation Examples 3-7 (with application rate of 100g AI/decare) . After staying in a greenhouse at 15℃and 80％relative atmospheric humidity for 15 days, severity was assessed (Table 2) .

Table 2

Field Test 3–Rye

Young rye plants were sprayed with a conidial suspension of Septoria nodorum, and incubated at 20℃and 100％relative atmospheric humidity for 48 hours. Then they were sprayed with Formulation Example 1 (tebuconazole 430g/L SC) (with application rate of 1247g AI/decare) , Formulation Example 2 (chlorothalonil 500g/L SC) (with application rate of 16500g AI/decare) and Formulation Examples 3-7 (with application rate of 100g AI/decare) . After staying in a greenhouse at 15℃and 80％relative atmospheric humidity for 15 days, severity was assessed (Table 3) .

Table 3

Field Test 4–Barley

Young barley plants were sprayed with a conidial suspension of Puccinia striiformis, and incubated at 20℃and 100％relative atmospheric humidity for 48 hours. Then they were sprayed with Formulation Example 1 (tebuconazole 430g/L SC) (with application rate of 1247g AI/decare) , Formulation Example 2 (chlorothalonil 500g/L SC) (with application rate of 16500g AI/decare) and Formulation Examples 3-7 (with application rate of 100g AI/decare) . After staying in a greenhouse at 15℃and 80％relative atmospheric humidity for 15 days, severity was assessed (Table 4) .

Table 4

Field Test 5–Wheat

Young wheat plants were sprayed with a conidial suspension of Puccinia recondita, and incubated at 20℃and 100％relative atmospheric humidity for 48 hours. Then they were sprayed with Formulation Example 1 (tebuconazole 430g/L SC) (with application rate of 1247g AI/decare) , Formulation Example 2 (chlorothalonil 500g/L SC) (with application rate of 16500g AI/decare) and Formulation Examples 3-7 (with application rate of 100g AI/decare) . The application rate of the Formulations Examples was. After staying in a greenhouse at 15℃and 80％relative atmospheric humidity for 15 days, severity was assessed (Table 5) .

Table 5

Field Test 6–Wheat

Young wheat plants were sprayed with a conidial suspension of Puccinia graminis, and incubated at 20℃and 100％relative atmospheric humidity for 48 hours. Then they were sprayed with Formulation Example 1 (tebuconazole 430g/L SC) (with application rate of 1247g AI/decare) , Formulation Example 2 (chlorothalonil 500g/L SC) (with application rate of 16500g AI/decare) and Formulation Examples 3-7 (with application rate of 100g AI/decare) . The application rate of the Formulations Examples was. After staying in a greenhouse at 15℃and 80％relative atmospheric humidity for 15 days, severity was assessed (Table 6) .

Table 6

Field Test 7–Rye

Young rye plants were sprayed with a conidial suspension of Erysiphe graminis, and incubated at 20℃and 100％relative atmospheric humidity for 48 hours. Then they were sprayed with Formulation Example 1 (tebuconazole 430g/L SC) (with application rate of 1247g AI/decare) , Formulation Example 2 (chlorothalonil 500g/L SC) (with application rate of 16500g AI/decare) and Formulation Examples 3-7 (with application rate of 100g AI/decare) . The application rate of the Formulations Examples was. After staying in a greenhouse at 15℃and 80％relative atmospheric humidity for 15 days, severity was assessed (Table 7) .

Table 7

Field Test 8–Tomato

Young tomato plants were sprayed with a conidial suspension of Leveillula taurica, and incubated at 20℃and 100％relative atmospheric humidity for 48 hours. Then they were sprayed with Formulation Example 1 (tebuconazole 430g/L SC) (with application rate of 1247g AI/decare) , Formulation Example 2 (chlorothalonil 500g/L SC) (with application rate of 16500g AI/decare) and Formulation Examples 3-7 (with application rate of 100g AI/decare) . The application rate of the Formulations Examples was. After staying in a greenhouse at 15℃and 80％relative atmospheric humidity for 15 days, severity was assessed (Table 8) .

Table 8

Field Test 9–Apple

Young rye plants were sprayed with a conidial suspension of Venturia inequalis, and incubated at 20℃and 100％relative atmospheric humidity for 48 hours. Then they were sprayed with Formulation Example 1 (tebuconazole 430g/L SC) (with application rate of 1247g AI/decare) , Formulation Example 2 (chlorothalonil 500g/L SC) (with application rate of 16500g AI/decare) and Formulation Examples 3-7 (with application rate of 100g AI/decare) . The application rate of the Formulations Examples was. After staying in a greenhouse at 15℃and 80％relative atmospheric humidity for 15 days, severity was assessed (Table 9) .

Table 9

Claims

A synergistic fungicidal composition comprising tebuconazole and chlorothalonil for preventing and/or treating fungal infestations in plants and plant parts.
The synergistic fungicidal composition according to claim 1, the weight ratio of tebuconazole and chlorothalonil in the composition independently is in the range of from about 25: 1 to about 1: 25, preferably the weight ratio is about 1: 3.
The synergistic fungicidal composition according to claim 1, wherein tebuconazole is present in an amount of from about 1％ to about 60％ by weight of the composition, preferably from about 1％ to about 30％ by weight of the composition, more preferably from about 5％ to about 15％ by weight of the composition, most preferably about 12.5％ by weight of the composition.
The synergistic fungicidal composition according to claim 1, wherein chlorothalonil is present in an amount of from about 1％ to about 70％ by weight of the composition, preferably from about 20％ to about 50％ by weight of the composition, more preferably from about 25％ to about 40％ by weight of the composition, most preferably about 37.5％ by weight of the composition.
The synergistic fungicidal composition according to any of the preceding claims, wherein the application rate of the total amount of tebuconazole and chlorothalonil is from about 50 to about 150 gram per decare.
The synergistic fungicidal composition according to any of the preceding claims, wherein the application rate of tebuconazole is from about 12.5 to about 37.5 gram per decare and the application rate of chlorothalonil is from about 37.5 to about 112.5 gram per decare.
The synergistic fungicidal composition according to any of the preceding claims, the composition is in a form of suspension concentrates (SC) , water-dispersible granules (WG) or water-dispersible powders (WP) .
The synergistic fungicidal composition according to any of the preceding claims, the composition is applied to plants, plant parts and/or surrounding.
The fungicidal composition according to claim 8, the plants are cereals, vegetables and fruits.
The synergistic fungicidal composition according to any of the preceding claims, the composition is used for treating and/or preventing fungal diseases caused by Septoria spp. , Puccinia recondite, Puccinia striiformis, Puccinia graminis, Erysiphe graminis, Drechslera maydis, Leveillula taurica and Venturia inequalis.
The use of the composition of any of the preceding claims to prevent and/or treat fungal infestations in plants and plant parts.
A synergistic fungicidal composition comprising tebuconazole and chlorothalonil, wherein the weight ratio of tebuconazole and chlorothalonil in the composition is 1: 3； and wherein the composition is used for preventing and/or treating Septoria spp. , Puccinia recondite, Puccinia striiformis, Puccinia graminis, Erysiphe graminis, Drechslera maydis, Leveillula taurica and Venturia inequalis in cereals, vegetables and fruits plants and their plant parts.