DESC:FORM 2

THE PATENTS ACT 1970
(SECTION 39 OF 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(Section 10 and Rule 13)

FUNGICIDAL COMPOSITION COMPRISING FLUXAPYROXAD AND CHLOROTHALONIL

We, COROMANDEL INTERNATIONAL LIMITED,
an Indian company incorporated under the Companies Act, 1956 having its
principal place of business at Coromandel House, Sardar Patel Road,
Secunderabad – 500 003, Telangana, India

The following specification particularly describes the invention and the manner in which it is to be performed.
FIELD OF THE INVENTION
The present invention relates to synergistic fungicidal composition comprising systemic and nonsystemic fungicides. Particularly, the composition comprising systemic fungicide fluxapyroxad and nonsystemic fungicide chlorothalonil with one or more agrochemical auxiliaries in synergistically effective amounts.

More particularly, the present invention relates to synergistic fungicidal water dispersible powder for slurry treatment (WS) composition comprising fluxapyroxad and chlorothalonil and a process thereof.

More particularly, the present invention relates to synergistic fungicidal flowable suspension (FS) composition comprising fluxapyroxad and chlorothalonil and a process thereof.

BACKGROUND OF THE INVENTION
In the field of crop protection, the use of a particular active substance for the control of specific fungi may become increasingly difficult in time, because of the adaptation of the mentioned fungi to the fungicide being used. This leads to the loss of effectiveness in the control of the pathogen and consequently, downfall in crop production and profitability.

A very well-known and widely used form of approaching this problem is by using a combination of different active substances presenting different mechanisms of action.

Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality and profit. Fungicides are used both in agriculture and to fight fungal infections in animals. Although pesticides remain indispensable in agriculture, a great potential still exists to improve their efficiency and thus reduce their input into the environmental and food chain.
Depending on the field of application, the mode of application and depending on physical, chemical and biological parameters, the active substances are employed as active substance formulation in the form of a mixture with customary carriers, adjuvants and additives.

Fluxapyroxad is a broad-spectrum pyrazole-carboxamide fungicide used on a large variety of commercial crops. It stunts fungus growth by inhibiting the succinate dehydrogenase (SQR) enzyme. Fluxapyroxad is a succinate dehydrogenase inhibitor (SDHI). It interferes with several key fungal life functions, including spore germination, germ tube growth, appressoria formation and mycelium growth. It is commonly used as a fungicide for grains, row crops, vegetable crops, and fruit trees (pome and prunus).

Fluxapyroxad chemically known as 3-(Difluoromethyl)-1-methyl-N-(3',4',5'-trifluoro[1,1'-biphenyl]-2-yl)-1H-pyrazole-4-carboxamide. It has the following chemical structure:

Chlorothalonil is a broad-spectrum, nonsystemic fungicide. It is primarily used as a fungicide, bactericide and nematicide and has been reported to be effective on a wide range of vegetables and fruit crops. It is also used as a bactericide, nematocide and mildew-preventing agent in paints. The primary routes of exposure to chlorothalonil are ingestion, inhalation, dermal and ocular. Occupational exposure to chlorothalonil may occur through inhalation of dusts or dermal contact with this compound at workplaces where it is produced or used as a pesticide. The greatest potential for dermal and inhalation exposure to chlorothalonil is expected for pesticide applicators and farm workers who have frequent contact with products containing this compound.

Chlorothalonil is chemically known as 2,4,5,6-Tetrachlorobenzene-1,3-dicarbonitrile and has the following chemical structure:

Chlorothalonil is an organic biocide with very low toxicity to mammals, broad activity against decay fungi and insects, relatively low cost and good stability and leach resistance in wood.

WO2007/017416 A2 BASF, broadly discloses fungicidal mixtures composition comprising fluxapyroxad and at least one active compound selected from the group of azoles, strobilurin, carboxamides, heterocyclic compounds, carbamates and organochlorine compounds.

None of the references disclose any specific combination of systemic and nonsystemic fungicidal mixtures with specific formulations.

The inventors of the present invention surprisingly found that a combination of fluxapyroxad and chlorothalonil water dispersible powder for slurry treatment (WS) composition exhibits a considerable synergistic effect, allowing a higher fungicidal activity to be obtained than that envisaged based on the activities of individual fluxapyroxad and chlorothalonil.

Fluxapyroxad 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.

OBJECT OF THE INVENTION
One object of the present invention is to provide a synergistic fungicidal composition comprising a combination of systemic fungicide and nonsystemic fungicide.

Another object of the present invention is to provide a synergistic fungicidal composition of fluxapyroxad and chlorothalonil with one or more agrochemical auxiliaries.

Yet another object of the present invention is to provide a fungicidal composition comprising fluxapyroxad and chlorothalonil in form of a water dispersible powder for slurry treatment (WS) and a flowable suspension (FS).

SUMMARY OF THE INVENTION
The present disclosure relates to a synergistic fungicidal composition comprising of systemic and nonsystemic fungicides, which exhibits a broad range of fungicide activity against a large number of target pathogens.

One aspect of the present invention is to provide a synergistic fungicidal composition comprising systemic fungicide fluxapyroxad and nonsystemic fungicide chlorothalonil with one or more agrochemical additives.

Another aspect of the present invention is to provide a fungicidal composition comprising of:
a. fluxapyroxad in the range of 2% to 35% (w/w),
b. chlorothalonil in the range of 5% to 65% (w/w), and
c. agrochemical additives in the range of 10 to 90% (w/w).

Yet another aspect of the present invention is to provide a fungicidal composition comprising fluxapyroxad and chlorothalonil in form of a water dispersible powder for slurry treatment (WS), and a flowable suspension (FS).

In yet another aspect of the present invention is to provide a water dispersible powder for slurry treatment (WS) formulation comprising of:
a. fluxapyroxad in the range of 2% to 35% (w/w),
b. chlorothalonil in the range of 5% to 65% (w/w),
c. wetting agent in the range of 0.1% to 5% (w/w),
d. dispersing agent in the range of 0.1% to 6% (w/w),
e. defoamer in the range of 0.1% to 0.5% (w/w),
f. disintegrating agent in the range of 10% to 15% (w/w),
g. pigment in the range of 1% to 2% (w/w), and
h. filler in the range of 5 to 15% (w/w).

In yet another aspect of the present invention is to provide a flowable suspension (FS) formulation comprising of:
a. fluxapyroxad in the range of 2% to 35% (w/w),
b. chlorothalonil in the range of 5% to 65% (w/w),
c. dispersing agent in the range of 1% to 5% (w/w),
d. antifreezing agent in the range of 1% to 5% (w/w),
e. biocide in the range of 1% to 3% (w/w),
f. viscosity modifier in the range of 10% to 15% (w/w),
g. defoamer in the range of 0.1% to 0.5% (w/w),
h. pigment in the range of 1% to 5% (w/w), and
i. base in the range of 50% to 70% (w/w).

In yet another aspect of the present invention is to provide a process for the preparation of a water dispersible powder for slurry treatment (WS) formulation comprising the steps of:
a. weighing and dispensing all the raw materials,
b. mixing weighed materials in a ribbon blender for 20 minutes,
c. milling the obtained mixed materials by passing through air jet milling instrument with an inlet pressure of 2kg/cm2 and grinding pressure of 6 kg/ cm2, and
d. collecting and packaging obtained milled material to get Water dispersible powder for slurry treatment (WS).

In yet another aspect of the present invention is to provide a process for the preparation of a flowable suspension (FS) formulation comprising the steps of:
a. preparing an aqueous slurry by mixing the raw materials,
b. wet milling the slurry, and
c. gelling of wet milling slurry to get a flowable suspension.

Yet another aspect of the present invention is to provide an improved stable and ready to use fungicidal composition, having superior bio-efficacy compared to the individual formulations or mixtures.

DESCRIPTION OF THE INVENTION
The terms "comprise," "comprises," and "comprising" are to be interpreted inclusively rather than exclusively. Likewise, the terms "include," "including" and "or" should all be construed to be inclusive, unless such a construction is clearly prohibited from the context. However, the embodiments provided by the present disclosure may lack any element that is not specifically disclosed herein. Thus, a disclosure of an embodiment defined using the term "comprising" is also a disclosure of embodiments "consisting essentially of” and "consisting of” the disclosed components. Where used herein, the term "example," particularly when followed by a listing of terms, is merely exemplary and illustrative, and should not be deemed to be exclusive or comprehensive. Any embodiment disclosed herein can be combined with any other embodiment disclosed herein unless explicitly indicated otherwise.

It is to be noted that, as used in the specification, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a composition containing “a compound” includes a mixture of two or more compounds. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

As used herein, the terms "crops" and "vegetation" can include, for instance, dormant seeds, germinant seeds, emerging seedlings, plants emerging from vegetative propagules, immature vegetation, and established vegetation.

As used herein, immature vegetation may be understood to include small vegetative plants prior to reproductive stage, and mature vegetation may be understood to include vegetative plants during and after the reproductive stage.

Formulation of the present invention also includes water soluble liquid (SL), an emulsifiable concentrate (EC), an emulsion (EW), a microemulsion (ME), a suspension concentrates (SC), an oil-based dispersions (OD), a flowable suspension (FS), water dispersible powder for slurry treatment (WS), water-soluble granule (SG), water dispersible granules (WDG), a water soluble powder (WP), a granule (GR), an encapsulated granule (CG), a fine granule (FG), a macrogranule (GG), an aqueous suspoemulsion (SE), capsule suspension (CS) and a microgranule (MG). Preferably, the fungicidal composition can be formulated as a water dispersible powder for slurry treatment (WS) and a flowable suspension (FS).

One embodiment of the present invention provides a synergistic fungicidal composition comprising systemic fungicide fluxapyroxad and nonsystemic fungicide chlorothalonil with one or more agrochemical additives.

Another embodiment of the present invention is to provide a fungicidal composition comprising of:
a. fluxapyroxad in the range of 2% to 35% (w/w),
b. chlorothalonil in the range of 5% to 65% (w/w), and
c. agrochemical additives in the range of 10 to 90% (w/w).

Yet another embodiment of the present invention is to provide a fungicidal composition comprising fluxapyroxad and chlorothalonil in form of a water dispersible powder for slurry treatment (WS), and a flowable suspension (FS).

In yet another embodiment of the present invention is to provide a water dispersible powder for slurry treatment (WS) formulation comprising of:
a. fluxapyroxad in the range of 2% to 35% (w/w),
b. chlorothalonil in the range of 5% to 65% (w/w),
c. wetting agent in the range of 0.1% to 5% (w/w),
d. dispersing agent in the range of 0.1% to 6% (w/w),
e. defoamer in the range of 0.1% to 0.5% (w/w),
f. disintegrating agent in the range of 10% to 15% (w/w),
g. pigment in the range of 1% to 2% (w/w), and
h. filler in the range of 5 to 15% (w/w).

In yet another embodiment of the present invention is to provide a flowable suspension (FS) formulation comprising of:
a. fluxapyroxad in the range of 2% to 35% (w/w),
b. chlorothalonil in the range of 5% to 65% (w/w),
c. dispersing agent in the range of 1% to 5% (w/w),
d. antifreezing agent in the range of 1% to 5% (w/w),
e. biocide in the range of 1% to 3% (w/w),
f. viscosity modifier in the range of 10% to 15% (w/w),
g. defoamer in the range of 0.1% to 0.5% (w/w),
h. pigment in the range of 1% to 5% (w/w), and
i. base in the range of 50% to 70% (w/w).

According to the present invention, the wetting agent is selected from sodium alkyl naphthalene sulfonate salt such as methyl naphthalene sulfonate salt, ethyl naphthalene sulfonate salt and isopropyl naphthalene sulfonate salt, dialkyl naphthalene sulphonate sodium salt such as dimethyl naphthalene sulphonate sodium salt, methylethyl naphthalene sulphonate sodium salt, diisopropyl naphthalene sulphonate sodium salt, linear alcohol derivative, polyethylene glycol nonylphenol ether ammonium sulphate, polymethyl methacrylate-polyethylene glycol graft copolymer, and polyoxyethylene alkyl ether.

According to the present invention, the dispersing agent is selected from naphthalene sulphonic acid and phenol sulphonic acid condensate, sodium lignosulphonates, sodium lauryl sulphonate, sodium naphthalene sulphonates formaldehyde condensates, sodium salt of methyl naphthalene sulfonate, sodium salt of phenol-sulfonic acid-formaldehyde polycondensate, sodium polycarboxylate, sodium methyl oleoyl Taurate, EO/PO block copolymers, and a combination thereof.

According to the present invention, the defoamer or an anti-foaming agent is a chemical additive that reduces and hinders the formation of foam in industrial process liquids. The defoamer is selected from insoluble oils, polydimethylsiloxanes and other silicones, certain alcohols, stearates, and glycols.

According to the present invention, the rheology modifier is selected from silicon dioxide, xanthan gum, guar gum, and hydroxyethyl cellulose.

According to the present invention, the buffer is selected from oxalic acid, citric acid, and diammonium hydrogen orthophosphate.

According to the present invention, the disintegrating agent is selected from ammonium, sulphate sodium starch glycolate, and polyvinyl pyrrolidine (PVP).

According to the present invention the pigment is selected from naphthol AS pigment (sulfonic acids, C14-17-sec-alkane, sodium salts), 12-Hydroxystearic acid, oligomers, reaction products with stearic acid and 5-Chloro-2-methyl-2,3-dihydroisothiazol-3-one and 2-Methyl-2,3-dihydroisothiazol-3-one (3:1).

According to the present invention the filler is selected from calcite, talc, China clay, aluminum silicate, lactose, starches, or calcium carbonate.

According to the present invention, the antifreezing agent as used in the present invention is selected from ethylene glycol or propylene glycol.
According to the present invention the biocide is selected from benzothiazolinone or formaldehyde.

According to the present invention the viscosity modifier is selected from xanthan gum or carboxymethyl cellulose.

According to the present invention the base is selected from water or vegetable oil.

Yet another embodiment of the present invention is to provide a process for the preparation of a water dispersible powder for slurry treatment (WS) formulation comprising the steps of:
a. weighing and dispensing all the raw materials,
b. mixing weighed materials in a ribbon blender for 20 minutes,
c. milling the obtained mixed materials by passing through air jet milling instrument with an inlet pressure of 4 kg/cm2 and grinding pressure of 6 kg/ cm2, and
d. collecting and packaging obtained milled material to get a water dispersible powder for slurry treatment (WS) composition.

In yet another embodiment of the present invention is to provide a process for the preparation of a flowable suspension (FS) formulation comprising the steps of:
a. preparing an aqueous slurry by mixing the raw materials,
b. wet milling the slurry, and
c. gelling of wet milling slurry to get a flowable suspension.

The fungicide composition of the present invention exhibits a broad range of fungicide activity against a large number of target pathogens. Non-limiting examples of specific pathogens targeted by the fungicide composition include: Botrytis cinerea (i.e., Botrytis bunch rot, gray mold, Botrytis blight), Phomopsis viticola (i.e., Phomopsis cane and leaf spot), Phomopsis rachis, Phomopsis vaccinii (i.e., Phomopsis twigblight and canker), downy mildew, Sphaerotheca macularis (i.e., powdery mildew), Guignardia bidwellii (i.e., black rot), Monilinia vacinii-cormbosi (i.e., mummy berry), Phragmidium sp. (i.e., yellow rust), Drepanopeziza sp. (i.e., anthracnose), Kuehneola sp. (i.e., cane and leaf rust), Sphaerulina sp. (i.e., orange rust), Arthuriomyces sp. (i.e., powdery mildew), Mycosphaerella sp. (leaf spot), Colletotrichum acutatum (i.e., anthracnose fruit rot), Verticillium albo-atrum (i.e., Verticillium wilt), Phytophthora fragariae (i.e., red stele root rot), Dendrophoma obscurans (i.e., stem end rot, leaf blight), Phytophthora cactorum (i.e., leather rot), Diplocarpon earliana (i.e., leaf scorch), Godronia cassandrac (i.e., fusicoccum canker), Alternaria sp. (i.e., Alternaria fruit rot), Exobasidium vaccinii (i.e., red leaf disease), Microsphaera vaccinii (i.e., powdery mildew), Venturia inaegualis (i.e., apple scab), Gymnosporangium sp. (i.e., apple rust), Podosphaera leucotricha (i.e., apple powdery mildew), black rot of apple, blossom end rot of apple, blue mold of apple, brown rot of stone fruit, Rhizopus sp., Leucostoma cincta or Leucostoma persoonii (i.e., cytospora canker of stone fruits), white rot of apple, Monilinia fructicola (i.e., brown rot of stone fruit), Blumeriella jaapii (i.e., cherry leaf spot of stone fruit), sooty mold of pear, pear leafspot, pear leaf blight and fruit spot, Pythium ultimatum, Phytophthora infestans (late blight, potatoes), Aspergillus sp. (i.e., Aspergillus paraciticus), Apiosporina morbosa (i.e., black knot of stone fruit), Rhizoctonia solani (i.e., black scurf in potatoes, aerial blight, soybeans), Alternaria solani (early blight, potatoes), Sclerotium rolfsii (i.e., Sclerotium rot, sugar beets), Fusarium sp., Septoria sp. and white mold in soybeans and the like.

The fungicidal compositions of the present invention can be diluted with water or water solutions of agronomic compounds before use to produce a sprayable composition which is used in treating plants or increasing plant growth. Dilution in water usually results in suspensions, emulsions, suspoemulsion or solutions of the agrochemical active ingredient at a concentration of at least 0.001 g/l.

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 fluxapyroxad 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 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 describe the nature of the invention which are given only for the purpose of illustrating the present invention in more detail and are not limitative and relate to solutions, which have been particularly effective on bench scale.

EXAMPLES:
Example-1: Fluxapyroxad 10% + Chlorothalonil 60% WS
S. No. Ingredients Function Quantity
(in %w/w)
1. Fluxapyroxad @96% Active Ingredient 10.0
2. Chlorothalonil @98% Active Ingredient 60.0
3. Sodium isopropyl naphthalene sulfonate salt Wetting agent 4.0
4. Naphthalene sulphonic acid and Phenol sulphonic acid condensate Dispersing agent 5.0
5. polydimethylsiloxane Defoamer 0.3
6. Ammonium Sulphate Disintegrating agent 10.0
7. Naphthol AS
(Sulfonic acids, C14-17-sec-alkane, sodium salts) Pigment 1.0
8. China clay Filler 8.07
Total 100

Manufacturing process
All the raw materials were weighed, dispensed and the mixture was mixed in a ribbon blender for 20 minutes. The mixture was passed through air jet milling instrument, inlet pressure - 2kg/cm2 and grinding pressure - 6kg/ cm2 for milling the sample. The milled material was collected and packed.

Example-2: Fluxapyroxad 15% + Chlorothalonil 20% WS
S. No. Ingredients Function Quantity
(in %w/w)
1. Fluxapyroxad @96% Active Ingredient 15.0
2. Chlorothalonil @98% Active Ingredient 20.0
3. Dialkyl naphthalene sulphonate sodium salt Wetting agent 4.5
4. Sodium salt of methyl naphthalene sulfonate Dispersing agent 2.5
5. Phenol sulfonic acid-formaldehyde-polycondensation as sodium salt Dispersing agent 2.5
6. silicon dioxide Rheology modifier 1.8
7. 12-Hydroxystearic acid, oligomers, reaction products with stearic acid Pigment 1.0
8. Oxalic acid buffer 0.02
9. Aluminum silicate Filler 55.18
Total 100

Manufacturing process
All the raw materials were weighed, dispensed and the mixture was mixed in a ribbon blender for 20 minutes. The mixture was passed through air jet milling instrument, inlet pressure - 2kg/cm2 and grinding pressure - 6kg/ cm2 for milling the sample. The milled material was collected and packed.

Example-3: Fluxapyroxad 20 % + Chlorothalonil 30 % WS
S. No. Ingredients Function Quantity
(in %w/w)
1. Fluxapyroxad @96% Active Ingredient 20.0
2. Chlorothalonil @98% Active Ingredient 30.0
3. 12-Hydroxystearic acid, oligomers, reaction products with stearic acid Pigment 1.0
4. Linear Alcohol Derivative Wetting agent 4.5
5. Sodium polycarboxylate Dispersing agent 2.5
6. Sodium Methyl Oleoyl Taurate Dispersing agent 3.0
7. silicon dioxide, Rheology modifier 2.5
8. Oxalic acid buffer 0.02
9. Aluminium silicate Filler 36.48
Total 100

Manufacturing process
All the raw materials were weighed, dispensed and the mixture was mixed in a ribbon blender for 20 minutes. The mixture was passed through air jet milling instrument, inlet pressure - 2kg/cm2 and grinding pressure - 6kg/ cm2 for milling the sample. The milled material was collected and packed.

Example-4: Fluxapyroxad 30% + Chlorothalonil 50% WS
S. No. Ingredients Function Quantity
(in %w/w)
1. Fluxapyroxad @96% Active Ingredient 30.0
2. Chlorothalonil @98% Active Ingredient 50.0
3. Naphthol AS
(Sulfonic acids, C14-17-sec-alkane, sodium salts) Pigment 1.0
4. Polyethylene glycol Nonylphenol ether ammonium sulphate Wetting agent 0.5
5. Sodium Ligno sulphonate Dispersing agent 0.3
6. Sodium lauryl sulphate Dispersing agent 0.1
7. silicon dioxide, Rheology modifier 1.1
8. Aluminium silicate Filler 17
Total 100

Manufacturing process
All the raw materials were weighed, dispensed and the mixture was mixed in a ribbon blender for 20 minutes. The mixture was passed through air jet milling instrument, inlet pressure - 2kg/cm2 and grinding pressure - 6kg/ cm2 for milling the sample. The milled material was collected and packed.

Example-5: Fluxapyroxad 5% + Chlorothalonil 10% FS
S. No. Ingredients Function Quantity
(in %w/w)
1. Fluxapyroxad @96% Active Ingredient 5.0
2. Chlorothalonil @98% Active Ingredient 10.0
3. EO/PO Proprietary blend Dispersing agent 3.0
4. Ethylene glycol Antifreezing Agent 3.0
5. benzothiazolinone Biocide 1.0
6. Xanthan Gum Viscosity modifier 10.0
7. Polydimethylsiloxane antifoam emulsion Defoamer 0.5
8. 5-Chloro-2-methyl-2,3-dihydroisothiazol-3-one and 2-Methyl-2,3-dihydroisothiazol-3-one (3:1) Pigment 2.0
9. Water Base 65.5
Total 100

Manufacturing Process:
Step-1: All the raw materials were added in a pre-mixer (vessel No. 1) and the mixture was stirred for homogenization for 1 hour.
Step-2: Wet milling obtained slurry from vessel No. 1 through a Dyno-Mill at a temperature of less than 35°C and collect material in vessel No.2 (post-mixer). Maintaining continuous stirring in both the vessels to avoid sedimentation. (The PSD of the material should be d90 < 5 µ). Pigment and viscosity modifiers were added to this slurry under stirring for 45 mins.
Step-3: Gelling the wet milled slurry obtained in step-2 and stirring the mixture for 3 hours for homogenization. Packing the material in HDPE bottles.

Field Bio-efficacy trials:
Trial 1: Bio-efficacy against collar rot disease in Groundnut:
This disease was first reported from Java in 1926. In India, the disease is prevalent in all groundnut tracts and is usually most severe in light sandy soils. Aspergillus niger Van Tieghem is the causal agent of crown/collar rot. Mycelium is hyaline to sub-hyaline. The conidiophores arise directly from the substrate and are septate, smooth, and thick-walled and hyaline to olive brown in colour. The vesicles are mostly globose and have two rows of hyaline phialides viz., primary, and secondary phialides. The conidial heads are dark brown to black. The conidia are produced in long chains and are globose, spinulose and dark brown on maturity.

The pathogen is carried on the seed surface and in or under the tissues of the testa. The primary sources of inoculum are a) mycelium and spores carried on the seeds. b) plant debris in the soil and c) infected cotyledons or embryos. Seeds become infected during the last days of maturation in the soil and during harvesting, handling and particularly during shelling.

The disease perpetuates through contaminated soil also. Soil infection spreads to cotyledons or directly to hypocotyl. The seedlings become more susceptible when they are injured. The fungus can tolerate low moisture levels and develops well at temperatures between 30° and 35°C. It builds up in soils continuously cropped with ground nuts.

In moist soil, seeds may be attacked immediately after sowing leading to pre-emergence rotting. If the ungerminated seeds are removed from the soil, they are found covered with masses of black conidia which give the seed a sooty appearance. Post-emergence infection often culminates in death and rapid decay of seedlings. The first symptom in emerging seedlings is usually rapid drying of the entire plant. Affected tissues are covered by sporulating fungus at the soil surface.

SYNERGY STUDIES:
After calculating % disease control, the synergism was calculated by below formula:

The synergistic pesticidal action of the inventive mixtures calculated by Colby’s formula as follows:

Appropriate analysis of plant response to fungicide combination is critical in determining the type of activity observed. The most widely used model is the one Gowing* derived and Colby** modified. Gowing described a mathematical formula for calculating the predicting response values for pesticide mixtures. He suggested the expected (E) percent inhibition of growth induced by pesticide A plus pesticide B is as follows, *(Jerry Flint et al, 1988) ***
If A1 = the percent inhibition of growth by pesticide A at given rate
B1 = the percent inhibition of growth by pesticide B at given rate then,
B1 (100 – A1)
E = A1 +
100
When the percentage of pesticidal control observed for the combination is greater than the expected percentage, there is a synergistic effect. (Ratio of O/E > 1, means synergism observed.)

Reference:
*Gowing, D. P. 1960. Comments on tests of fungicide mixtures. Weeds 8:379–391.
**Colby, S. R. 1967. Calculating synergistic and antagonistic responses of fungicide combinations. Weeds 15:20–22
*** Jerry Flint et al, 1988. Analyzing Fungicide Interactions: A Statistical Treatment of Colby's Method. Weed Technology 2: 304-309

The field trial was conducted to evaluate the efficacy of innovative mixtures of Fluxapyroxad and Chlorothalonil against Aspergills Niger fungus in Groundnut crop. The trial was conducted with randomized block design with net plot size of 5m x 6m. Ground nut crops were raised with all standard agronomic practices. Seed treatment was done with slurry method by preparing 10 ml slurry volume of chemical at the time of sowing. The visual observations were recorded for % disease control from fifty plants per plot. The observations were recorded at 7 DAA (Days after application), 14 DAA and 28 DAA.

Table 1: collar rot disease control in groundnut:
Compositions Dose
(g AI/100 kg seed) Percent disease control – collar rot.
14 DAS 28 DAS
Fluxapyroxad 10% + Chlorothalonil 60% WS 140 94 87
Fluxapyroxad 33.3% FS 20 65 50
Chlorothalonil 75% WP 120 75 65
WS water dispersible powder for slurry treatment (WS); FS – flowable suspension; WP – wettable powder, and DAA - Days after application.

The trial results show excellent efficacy of fluxapyroxad 10% + chlorothalonil 60% WS combinations against collar rot disease of groundnut. The solo application of two active ingredients tested here, were also not able to provide satisfactory control of collar rot disease. The combination of fluxapyroxad 10% + chlorothalonil 60% WS was found to be very promising against groundnut collar rot in terms of efficacy as well as residual control.

Table 2: Percent collar rot disease control at 28 DAA
Compositions Dose
(g or ml/ha) % collar rot disease control @ 28 DAA
Expected Actual
Fluxapyroxad 33.3 FS 20 NA 50
Chlorothalonil 75% WP 120 NA 65
Fluxapyroxad 10% + Chlorothalonil 60% WS 140 82.5 87
Ratio of O/E 1.05
WS water dispersible powder for slurry treatment (WS); FS – flowable suspension; WP – wettable powder, and DAA - Days after application.

The results in table 2 clearly demonstrate synergy between fluxapyroxad and chlorothalonil in controlling groundnut collar rot disease. The large difference between the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination.

Trial 2: Bio-efficacy against wilt disease in chickpea:
Chickpea, also called garbanzo bean or Bengal gram. It is mainly used for human consumption and is an essential constituent of the Mediterranean diet and a basic food in Pakistan and India. The chickpea grain international market is very active due to the crop’s nutritional value. Chickpea is a good and cheap source of protein for people in developing countries (especially in South Asia), who are largely vegetarian, either by choice or because of economic reasons. Chickpea is high in protein, low in fat and sodium, cholesterol free and is an excellent source of both soluble and insoluble fiber, as well as complex carbohydrates, vitamins, folate and minerals, especially calcium, phosphorous, iron, and magnesium.

Chickpea wilt disease occurs in 32 countries across 6 continents. This disease was first reported in India by Butler in 1918, but its etiology was not correctly determined until 1940 by Padwick. According to Haware and Nene, and Halila and Strange, Fusarium wilt epidemics can be devastating to individual crops and cause up to 100% loss under favourable conditions. Fusarium wilt of chickpea is caused by Fusarium oxysporum f. sp. Ciceris Schlechtend: Fr. f Sp. ciceris (Padwick) T. Matuo & K. Satô.

Symptoms of the disease can develop at any stage of plant growth, and affected plants may be grouped in patches or appear spread across a field. The wilt can be observed in susceptible genotypes within 25 days after sowing in the field (designated “early wilt”). However, symptoms are usually more visible in the early stages of flowering, 6 to 8 weeks after sowing and can also appear up to podding stage (“late wilt”). Late wilted plants exhibit drooping of the petioles, rachis, and leaflets, followed by yellowing and necrosis of foliage. Early wilting causes more loss than late wilting. Nevertheless, seeds from late-wilted plants are lighter, rougher, and duller than those from healthy plants.

The pathogen can survive as mycelium and chlamydospores in seed and soil and also on infected crop residues, roots and stem tissue buried in the soil for more than 6 years, even in the absence of the host. Infection of symptomless dicotyledonous weeds can enhance survival of the pathogen in fallow soils. Thus, infested soil is a main source of primary inoculum for the development of Fusarium wilt.

The field trial was conducted to evaluate the efficacy of innovative mixtures of Fluxapyroxad and Chlorothalonil against Fusarium oxysporum fungus in chickpea crop. The trial was conducted with randomized block design with net plot size of 5m x 6m. Chickpea crops were raised with all standard agronomic practices. Seed treatment was done with slurry method by preparing 10 ml slurry volume of chemical for 1 kg seed at the time of sowing. The visual observations were recorded for % disease control from fifty randomly selected plants per plot. The observations were recorded at 14 DAA (Days after application) and 28 DAA.

Table 3: wilt disease control in chickpea:
Compositions Dose
(g AI/100 kg seed) Percent disease control – wilt.
14 DAS 28 DAS
Fluxapyroxad 10% + Chlorothalonil 60% WS 140 90 85
Fluxapyroxad 33.3 FS 20 50 40
Chlorothalonil 75% WP 120 70 60
WS water dispersible powder for slurry treatment (WS); FS – flowable suspension; WP – wettable powder, and DAA - Days after application.

The trial results show excellent efficacy of fluxapyroxad 10% + chlorothalonil 60% WS combinations against wilt disease of chickpea. The solo application of two active ingredients tested here, were also not able to provide satisfactory control of collar rot disease. The combination of fluxapyroxad 10% + chlorothalonil 60% WS was found to be very promising against chickpea wilt in terms of efficacy as well as residual control.

Table 4: Percent Chickpea wilt disease control at 28 DAA
Compositions Dose
(g or ml/ha) % wilt disease control @ 28 DAA
Expected Actual
Fluxapyroxad 33.3% FS 20 NA 40
Chlorothalonil 75% WP 120 NA 60
Fluxapyroxad 10% + Chlorothalonil 60% WS 140 76 85
Ratio of O/E 1.12
WS water dispersible powder for slurry treatment (WS); FS – flowable suspension; WP – wettable powder, and DAA - Days after application.

The results in table 4 clearly demonstrate synergy between fluxapyroxad and chlorothalonil in controlling chickpea wilt disease. The large difference between the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination. ,CLAIMS:WE CLAIM:

1. A synergistic fungicidal composition comprising of systemic fungicide fluxapyroxad and nonsystemic fungicide chlorothalonil with one or more agrochemical additives.

2. The composition as claimed in claim 1, where in the fungicidal composition comprising of:
a. fluxapyroxad in the range of 2% to 35% (w/w),
b. chlorothalonil in the range of 5% to 65% (w/w), and
c. agrochemical additives in the range of 10 to 90% (w/w).

3. The composition as claimed in claim 1, where in the fungicidal composition comprises of fluxapyroxad and chlorothalonil in the form of a water dispersible powder for slurry treatment (WS) and a flowable suspension (FS).

4. The composition as claimed in claim 3, wherein the water dispersible powder for slurry treatment (WS) formulation comprising of:
a. fluxapyroxad in the range of 2% to 35% (w/w),
b. chlorothalonil in the range of 5% to 65% (w/w),
c. wetting agent in the range of 0.1% to 5% (w/w),
d. dispersing agent in the range of 0.1% to 6% (w/w),
e. defoamer in the range of 0.1% to 0.5% (w/w),
f. disintegrating agent in the range of 10% to 15% (w/w),
g. pigment in the range of 1% to 2% (w/w), and
h. filler in the range of 5 to 15% (w/w).

5. The composition as claimed in claim 4, where in the wetting agent is selected from the group consisting of alkyl naphthalene sulfonate salt such as methyl naphthalene sulfonate salt, ethyl naphthalene sulfonate salt and isopropyl naphthalene sulfonate salt, dialkyl naphthalene sulphonate sodium salt such as dimethyl naphthalene sulphonate sodium salt, methylethyl naphthalene sulphonate sodium salt, diisopropyl naphthalene sulphonate sodium salt, linear alcohol derivative, polyethylene glycol nonylphenol ether ammonium sulphate, polymethyl methacrylate-polyethylene glycol graft copolymer, and polyoxyethylene alkyl ether.

6. The composition as claimed in claim 4, where in the dispersing agent is selected from naphthalene sulphonic acid and phenol sulphonic acid condensate, sodium lignosulphonates, sodium lauryl sulphonate, sodium naphthalene sulphonates formaldehyde condensates, sodium salt of methyl naphthalene sulfonate, sodium slat of phenol-sulfonic acid-formaldehyde poly condensate, sodium polycarboxylate, sodium methyl oleoyl Taurate, EO/PO block copolymers, and a combination thereof.

7. The composition as claimed in claim 4, where in the defoamer is selected from polydimethylsiloxanes, and glycols.

8. The composition as claimed in claim 4, where in the pigment is selected from naphthol AS pigment, 12-Hydroxystearic acid, oligomers, reaction products with stearic acid, and 5-Chloro-2-methyl-2,3-dihydroisothiazol-3-one and 2-Methyl-2,3-dihydroisothiazol-3-one (3:1).

9. The composition as claimed in claim 4, where in the filler is selected from calcite, talc, china clay, aluminum silicate, lactose, starches, or calcium carbonate.

10. A process for preparing fungicidal composition as claimed in claim 4, wherein preparing a water dispersible powder for slurry treatment (WS) formulation comprising the steps of:
a. weighing and dispensing all the raw materials,
b. mixing weighed materials in a ribbon blender for 20 minutes,
c. milling the obtained mixed materials by passing through air jet milling instrument with an inlet pressure of 4 kg/cm2 and grinding pressure of 6 kg/ cm2, and
d. collecting and packaging obtained milled material to get a water dispersible powder for slurry treatment (WS) composition.

Dated this Twenty seventh (27th) day of June, 2023

__________________________________
Dr. S. Padmaja
Agent for the Applicant
IN/PA/883