DESC:FORM 2

THE PATENTS ACT 1970
(SECTION 39 OF 1970)

&

THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(Section 10 and Rule 13)

SYNERGISTIC HERBICIDAL COMPOSITION OF SULFOSULFURON AND PYROXASULFONE

We, COROMANDEL INTERNATIONAL LIMITED,
an Indian company incorporated under the Companies Act, 1956, and validly existing under the Companies Act, 2013. Having its registered office 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 a synergistic herbicidal composition of Sulfosulfuron and Pyroxasulfone.

Particularly the present invention relates to a synergistic herbicidal composition comprising of Sulfosulfuron and Pyroxasulfone with one or more agrochemical additives in synergistically effective amounts.

More particularly, the present invention relates to a process for preparing the synergistic herbicidal composition of Sulfosulfuron and Pyroxasulfone.

BACKGROUND OF THE INVENTION
Weeds have known to affect human activities including agriculture since longer time. The major contributors of crop loss are weeds, followed by animals and pathogens. Herbicides are used to kill weeds and are still the largest product type accounting for 47.6 % of global pesticide sales. They have been classified in various ways, but classification based on site of action of herbicide is comparatively better as herbicide resistance management can be handled more properly and effectively.

Commonly used herbicides globally are generally broad spectrum and non-selective which restricts their use in arable lands. Thus, there is need to modify the crops genetically so that the crop plants remain unaffected by herbicide application. Different strategies have been used either individually or in combination to develop transgenic plants. Reports suggest that the global area covered by herbicide- resistant transgenic plant outnumbers the area covered by any other genetically modified plants. However, inadvertent use of herbicides has helped in evolution of resistant weeds. This problem is now a subject of discussion worldwide.

Integrated herbicide management is important to avoid selection pressure for the evolution of resistance. Transgenic plants have really helped the mankind in increasing the crop yield, but use of transgenic plant is still a debatable topic which needs meticulous research, observations, and experimentations for a final statement either in favor or against. However, there is always a need for new active ingredients or new combinations of existing active ingredients to overcome the existing problems faced in the agricultural industry.

Compositions comprising a single herbicidally active component suffer from numerous drawbacks such as formation of resistant weeds, requirement of high amount and concentration of the active ingredient, environmental damage, seepage of the active component into ground water, phytotoxicity and harmful effects on the health of animals and humans.

Active compounds having different mechanisms of action are combined to delay the generation of resistance and reduce the amount of application and prevention and treatment costs. Consequently, research is being conducted to produce herbicides and combinations of herbicides that are safer, that have better performance, that require lower dosages, that are easier to use, and that cost less.

Pyroxasulfone is registered to be applied either in the fall, early preplant, or early postemergence, which allows for flexibility in weed control strategy developed by Kumiai Chemical Industry Co., Ltd. It is an isooxazoline, that delivers higher intrinsic activity and a broader spectrum of control of small-seeded broadleaf weeds and grasses. It is a selective herbicide for controlling annual grasses, annual broadleaf weeds, and sedges. This herbicide can only be applied to surface of the agricultural field, and it kills weeds by inhibiting plant shoot growth. Crop maize, wheat, soyabean.

Pyroxasulfone is chemically known as (3-[5-(difluoromethoxy)-1-methyl-3- (trifluoromethyl)pyrazol-4-ylmethylsulfonyl]-4,5-dihydro-5,5-dimethyl-1,2-oxazole). It’s preparation and use are disclosed in US 7,238,689 and has the following chemical structure:

Sulfosulfuron is a novel sulfonylurea herbicide with an imidazo [1, 2-a] pyridine moiety. It shows excellent herbicidal activity pre-emergent or post-emergent form of control on invasive weeds. It was originally created to protect against stubborn weeds growing around crops. Particularly wheat, triticale. Branched chain amino acid synthesis (ALS or AHAS) inhibitor acts by inhibiting biosynthesis of the essential amino acids valine and isoleucine, hence stopping cell division and plant growth. Selectivity derives from rapid metabolism in the crop.

Sulfosulfuron is chemically known as 1-(4,6-dimethoxypyrimidin-2-yl)-3-(2-ethylsulfonylimidazo[1,2-a] pyridin-3-yl)sulfonylurea. It’s preparation and use are disclosed in US 5,017,212 and has the following chemical structure:

WO2009/112454 discloses herbicidal composition comprising Pyroxasulfone in combination with at least one herbicide which is an acetohydroxyacid synthase inhibitors selected from the groups imidazolinone herbicides, sulfonylurea herbicides, triazolopyrimidine herbicides, pyrimidinylbenzoate herbicides and sulfonylaminocarbonyltriazolinone herbicides.

The inventors of the present invention have surprisingly found that formulation of the two active components Sulfosulfuron and Pyroxasulfone has its own benefits such as it has lower application rate that not only reduces the amount of an active substance required for application, but as a rule, also reduces the amount of formulation auxiliaries required. Both reduce the economic outlay and improve the eco-friendliness of the herbicide treatment.

OBJECT OF THE INVENTION
One object of the present invention is to provide a synergistic herbicidal composition comprising Sulfosulfuron and Pyroxasulfone.

Another object of the present invention is to provide a synergistic composition comprising of Sulfosulfuron and Pyroxasulfone with one or more agrochemical additives.

Another object of the present invention is to provide a synergistic water-dispersible granule (WDG) composition comprising of Sulfosulfuron and Pyroxasulfone with one or more agrochemical additives.

Yet another object of the present invention is to provide a process for preparing the synergistic herbicidal composition of Sulfosulfuron and Pyroxasulfone.

SUMMARY OF THE INVENTION
In one aspect of the present invention provides a synergistic composition comprising Sulfosulfuron and Pyroxasulfone.

In another aspect of the present invention provides a synergistic composition comprising of Sulfosulfuron and Pyroxasulfone with one or more agrochemical additives.

In another aspect of the present invention is to provide a synergistic water-dispersible granule composition comprising of Sulfosulfuron and Pyroxasulfone with one or more agrochemical additives.

In another aspect of the present invention provides a process for the preparation of synergistic composition comprising of Sulfosulfuron and Pyroxasulfone with one or more agricultural additives.

In another aspect of the present invention provides with a synergistic composition comprising of Sulfosulfuron and Pyroxasulfone formulation with an improved stability and ready to use herbicidal composition, having superior bio-efficacy compared to the individual formulations.

In another aspect of the present invention is to provide a synergistic water-dispersible granule (WDG) composition comprising:
a) Sulfosulfuron;
b) Pyroxasulfone;
c) other agrochemical additives in effective amounts.

In another aspect, the present invention provides a synergistic water-dispersible granule (WDG) composition comprising:
a) Sulfosulfuron in a range of 5% to 20 % (w/w),
b) Pyroxasulfone in a range of 25% to 55% (w/w),
c) wetting agent in a range of 1% to 10% (w/w),
d) dispersing agents in a range of 1% to 10% (w/w), and
e) other agrochemical additives in a range of 20% to 80% (w/w).

In another aspect, the present invention provides a synergistic water-dispersible granule (WDG) composition comprising:
a) Sulfosulfuron in a range of 5% to 20% (w/w),
b) Pyroxasulfone in a range of 25% to 55% (w/w),
c) wetting agent in a range of 1% to 10% (w/w),
d) dispersing agents in a range of 1% to 10% (w/w),
e) rheology modifier in a range of 5% to 15% (w/w),
f) disintegrating agent in a range of 5% to 15% (w/w),
g) adjuvant in a range of 0.1% to 5% (w/w),
h) defoamer in a range of 0.1% to 5% (w/w), and
i) filler in a range of 10% to 60% (w/w).

In another aspect, the present invention provides a synergistic water-dispersible granule composition comprising of Sulfosulfuron, Pyroxasulfone, wetting agent, dispersing agent and one or more agrochemical additives, wherein agrochemical additives are selected from rheology modifier, disintegrating agent, adjuvant, defoamer and filler.

In another aspect, the present invention provides a process for the preparation of synergistic composition comprising of Sulfosulfuron and Pyroxasulfone.

In another aspect, the present invention provides a synergistic water-dispersible granule composition comprising of Sulfosulfuron, Pyroxasulfone, wetting agent, dispersing agent and one or more agrochemical additives, wherein agrochemical additives are selected from rheology modifier, disintegrating agent, adjuvant, defoamer and filler.

In yet another aspect, the present invention provides a process for the preparation of synergistic composition comprising of Sulfosulfuron and Pyroxasulfone.

In yet another aspect, the present invention provides a process for preparing a synergistic water dispersible granule composition comprising steps of:
a) weighing all the active ingredients, wetting agent, dispersing agent and other agrochemical additives in a pre-blender, and mixing for 1 hour.
b) milling the mixture through air jet miller instrument (Inlet pressure 2-3 kg/cm2 and grinding pressure 6 kg/cm2) to obtain particles of size D90 < 15µ,
c) collecting the milled material and post blending for 1 hour,
d) preparing the dough with 12% water or solvent and extrusion of the granules through (0.8 to 1.0mm mesh),
e) collecting the granules and drying in fluidized bed dryer (FBD) at 45 oC air flow for 20 min by maintain the moisture content 2%.
f) packing the formulated material in a suitable packaging.

DESCRIPTION OF THE INVENTION
The term "comprising", which is synonymous with "including", "containing", or "characterized by” here is defined as being inclusive or open-ended, and does not exclude additional, unrecited elements or method steps, unless the context clearly requires 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.

As used herein, the terms “herbicide” may be understood as a substance that is toxic to plants, used to destroy unwanted vegetation.

As used herein, the term “synergistic composition” may be understood to include effective combination of more than one agrochemical that allows the application of the said agrochemical in a much lower dosage, which results in a less dosage treatment for the crops.

As used herein, the term “agrochemical additives” may be understood to include a range of surfactants, dispersing agents, pigments, solvents, co-solvents, defoamers, and emulsions, crystallization inhibitors, viscosity modifiers, suspending agents, dyes, antioxidants, , light absorbers, mixing aids, neutralizers or pH adjusting substances and buffers, corrosion inhibitors, fragrances, wetting agents, absorption enhancers, micronutrients, plasticizers, lubricants, thickeners, anti-freezing agents, sterilization agents, biocide, adjuvant among others.

The herbicidal composition of the present invention may be formulated as Capsule suspension (CS), Dispersible concentrate (DC), Dustable powder (DP), Powder for dry seed treatment (DS), Emulsifiable concentrate (EC), Emulsifiable granule (EG), Emulsion water in-oil (EO), Emulsifiable powder (EP), Emulsion for seed treatment (ES), Emulsion oil-in-water (EW), Flowable concentrate for seed treatment (FS), Granules (GR), Micro-emulsion (ME), Oil-dispersion (OD), Oil miscible flowable concentrate (OF), Oil miscible liquid (OL), Oil dispersible powder (OP), Suspension concentrate (SC), Suspension concentrate for direct application (SD), Suspo-emulsion (SE), Water soluble granule (SG), Soluble concentrate (SL), Spreading oil (SO), Water soluble powder (SP), Water soluble tablet (ST), Ultra-low volume (ULV) Tablet (TB), Water dispersible granules (WG or WDG), Wettable powder (WP), Water dispersible powder for slurry seed treatment (WS), Water dispersible tablet (WT), a mixed formulation of CS and SC (ZC), a mixed formulation of CS and SE (ZE), a mixed formulation of CS and EW (ZW) among others.

In one embodiment, the present invention is to provide a synergistic water-dispersible granule (WDG) composition comprising:
a) Sulfosulfuron;
b) Pyroxasulfone;
c) other agrochemical additives in effective amounts.

In another embodiment of the present invention Sulfosulfuron is present in a range of of 5% to 20% (w/w); Pyroxasulfone is present in a range of 25% to 55% (w/w).

In another embodiment of the present invention the agrochemical additives selected from wetting agent, dispersing agent, rheology modifier, disintegrating agent, adjuvant, defoamer and filler.

The wetting agent is a compound that facilitates rapid wetting of the powder when added to the water. The wetting agent employed in the formulation composition is selected from the group consisting of non-ionic surfactants, anionic surfactant and a mixture of anionic and non-ionic surfactant and polymeric surfactant.The suitable wetting agent is selected from sodium alkyl naphthalene sulfonate (Morwet 3028), sodium lauryl sulphate or sodium dodecyl sulfate, dialkyl naphthalene sulphonate sodium salt (Supragil WP), linear alcohol derivative (Geropon L WET), polyethylene glycol nonyl phenyl ether ammonium sulfate (Dispersol PS), Blend of Sodium lauryl sulphate and Sodium dodecyl benzene sulphonate (Jesperse DW 18), tristyrylphenol ethoxylate (Sophrophor BSU), and propylene oxide.

The wetting agent is present in the composition in a range of 1% to 10% (w/w), more preferably 2% to 6% (w/w) of the total weight of the composition.

The suitable dispersing agent is selected from acrylate copolymer (Agrilan 789), blend of sodium lauryl sulphate and alkyl aryl benzene sulphonate (Jesperse D-777), sodium polycarboxylate (Geropon T 36), phenol sulfonic acid-formaldehyde-polycondensation as sodium salt (Dispersol PSR19), sodium lauryl sulphate, sodium naphthalene sulphonates formaldehyde condensates, and sodium lignosulphonates.

The dispersing agent is present in the composition in a range of 1% to 10% (w/w), more preferably 2% to 6% (w/w) of the total weight of the composition.

Rheology modifiers are sometimes referred to as thickeners or viscosity modifiers, but they do much more than just thicken a formulation. A good rheology modifier structures the formulation but when a force is applied it becomes flowable and easily poured. Flowable formulations require a rheology modifier to prevent sedimentation phenomena. Rheology modifiers produce a “three-dimensional” gel network in the continuous phase resulting in a non-Newtonian fluid, which provides stability to the formulation. The rheology modifier must give high viscosity, so the product does not separate during long-term storage but still allow the product to be easily poured from the package.

The suitable rheology modifier of the present invention is selected from hydrophobic and hydrophilic fumed and precipitated silica particles, silicon dioxide and hydrogenated castor oil (trihydroxy stearin) or castor oil organic derivatives.

The Rheology modifier is present in the composition in a range of 5% to 15% (w/w), more preferably 8% to 12% (w/w) of the total weight of the composition.

The suitable disintegrating agent of the present invention is selected from ammonium sulphate, sodium tripolyphosphate, sodium salt of naphthalene sulfonate and sodium polycarboxylate.

The disintegrating agent is present in the composition in a range of 5% to 15% (w/w), more preferably 8% to 12% (w/w) of the total weight of the composition.

The suitable adjuvant of the present invention is selected from siloxane, trisiloxane ethoxylate, neem oil, and amino acids (Dowsil GP 4314).

The adjuvant is present in the composition in a range of 0.1% to 5% (w/w), more preferably 0.5% to 2% (w/w) of the total weight of the composition.

The suitable defoamer of the present invention is polydimethylsiloxane.

The defoamer is present in the composition in a range of 0.1% to 5% (w/w), more preferably 0.5% to 2% (w/w) of the total weight of the composition.

The suitable filler of the present invention is selected from china clay, kaolin, starch, lactose monohydrate, and calcium carbonate.

The filler is present in the composition in a range of 10% to 60% (w/w), more preferably 15% to 45% of the total weight of the composition.

In yet another embodiment of the present invention is to provide a process for preparing a synergistic water dispersible granule composition comprising steps of:
a) weighing all the active ingredients, wetting agent, dispersing agent, disintegrating agent and other agrochemical additives in a pre-blender, and mixing for 1 hour.
b) milling the mixture through air jet miller instrument (Inlet pressure 2-3 kg/cm2 and grinding pressure 6 kg/cm2) to obtain particles of size D90 < 15µ,
c) collecting the milled material and post blending for 1 hour,
d) preparing the dough with 12% water or solvent and extrusion of the granules through (0.8 to 1.0mm mesh),
e) collecting the granules and drying in fluidized bed dryer (FBD) at 45 oC air flow for 20 min by maintain the moisture content 2%.
f) sending the sample to quality analysis,
g) pack the formulated material in a suitable packaging.

The solvent used in the present invention is selected from and not limited to water, isopropyl alcohol, and methanol.

The composition of the present invention and method provided may be utilized to control weeds or battle undesired vegetation in crops or other settings, including but not limited to cereals, such Maize, soyabeans, wheat, triticale, and industrial vegetation management. Preferably, the undesirable vegetation includes species from the families of broadleaved and grass weeds, more preferably from the families of Aeschynomene, Ageratum, Amaranthus, Bidens, Brachiaria, Cenchrus, Cyperus, Digitaria, Echinochloa, Eclipta, Eleusine, Eragrostis Fimbristylis, Galinsoga, Ischaemum, Leptochloa, Monochoria, Panicum, Paspalum, Polygonum, Portulaca, Richardia, Sesbania, Setaria, Sida, Sorghum, most preferably Echinochloa, Leptochloa, Ischaemum, Monochoria, and Cyperus, or combinations thereof. It has been surprisingly found that the novel herbicidal composition of the present invention delays the appearance of the resistant strains of weeds and achieves effective and economical control of undesired weeds.

The composition achieves improved biological activity by enhancing overall control of weeds over a shorter period. Additional benefits of using the herbicidal composition of the present invention includes reduced risk of occupational hazard, lower cost of application, better cost: benefit ratio to the end user, reduced fuel, and labor cost, saving in applicator’s time and loss caused by mechanical damage to the crop and soil.

The present compositions can be applied to the undesirable vegetation and/or weeds or their locus using conventional ground or aerial dusters, sprayers, and granule applicators, by addition to irrigation or paddy water, and by other conventional means known to those skilled in the art.

The above and other features and aspects of the present invention will be more clearly described in the complete specification which will be filed pursuant to the present provisional specification.

Examples:

Example-1: Pyroxasulfone 40%+ Sulfosulfuron 12% WDG

S. No. Composition Function Quantity
(in %w/w)
1. Pyroxasulfone @96.0 % (b) 40% Herbicide 41.6
2. Sulfosulfuron @97% (b) 12% Herbicide 12.37
3. Jesperse DW 18 (Blend of Sodium lauryl sulphate and Sodium dodecyl benzene sulphonate) Wetting agent 6.0
4. Jesperse D-777 (Blend of Sodium lauryl sulphate and alkyl aryl benzene sulphonate) Dispersing agent 6.0
5. Dowsil GP 4314 (Amino acids) adjuvant 1.0
6. Ammonium sulphate Disintegrating agent 10.0
7. China clay Filler 23.03
Total 100

Manufacturing Process:
Pyroxasulfone, Sulfosulfuron, Blend of Sodium lauryl sulphate and Sodium dodecyl benzene sulphonate, Blend of Sodium lauryl sulphate and alkyl aryl benzene sulphonate, Amino acids, Ammonium sulphate and China clay were weighed in the pre-blender reactor and start mixing for 1 hour. The mixture was milled through air jet mill instrument (Inlet pressure 2-3 kg/cm2, grinding pressure 6 kg/ cm2) to obtain the desired particle size (D90 < 15 microns). Collecting the milled material and post blend the material for 1 hour. Preparing the dough with 12% water or solvent and extrusion of the granules through (0.8 to 1.0mm mesh). collecting the granules and drying in fluidized bed dryer (FBD) at 45 oC for 20 min by maintain the moisture content 2%. Pack the material in a suitable package.

Example-2: Pyroxasulfone 40%+ Sulfosulfuron 12% WDG

S. No. Composition Function Quantity
(in %w/w)
1. Pyroxasulfone @96.0 % Herbicide 40.0
2. Sulfosulfuron @97% Herbicide 12.0
3. Blend of sodium lauryl sulphate and Sodium dodecyl benzene sulphonate. Wetting agent 6.0
4. Blend of sodium lauryl sulphate and alkyl aryl benzene sulphonate. Dispersing agent 6.0
5. Polydimethylsiloxane Defoamer 1.0
6. Ammonium sulphate Disintegrating agent 10.0
7. China clay Filler 25.0
Total 100

Manufacturing Process:
Pyroxasulfone, Sulfosulfuron, Blend of Sodium lauryl sulphate and Sodium dodecyl benzene sulphonate, Blend of Sodium lauryl sulphate and alkyl aryl benzene sulphonate, Polydimethylsiloxane, Ammonium sulphate and China clay were weighed in the pre-blender reactor and start mixing for 1 hour. The mixture was milled through air jet mill instrument (Inlet pressure 2-3 kg/cm2, grinding pressure 6 kg/ cm2) to obtain the desired particle size (D90 < 15 microns). Collecting the milled material and post blend the material for 1 hour. Preparing the dough with 12% water or solvent and extrusion of the granules through (0.8 to 1.0mm mesh). collecting the granules and drying in fluidized bed dryer (FBD) at 45 oC for 20 min by maintain the moisture content 2%. Pack the material in a suitable package.

Example-3: Pyroxasulfone 30%+ Sulfosulfuron 8% WDG

S. No. Composition Function Quantity
(w/w %)
1. Pyroxasulfone@96.0 % Herbicide 30.0
2. Sulfosulfuron @97% Herbicide 8.0
3. Alkylnaphthalene sulfonate condensate blend Wetting agent 3.0
4. Acrylate copolymer Dispersing agent 5.0
5. Ammonium Sulphate Disintegrating agent 10.0
6. Polydimethylsiloxane Defoamer 1.0
7. Starch Filler 43.0
Total 100

Manufacturing Process:
Pyroxasulfone, Sulfosulfuron, alkylnaphthalene sulfonate condensate blend, acrylate copolymer, polydimethylsiloxane, ammonium sulphate and starch were weighed in the pre-blender reactor and start mixing for 1 hour. The mixture was milled through air jet mill instrument (Inlet pressure 2-3 kg/cm2, grinding pressure 6 kg/ cm2) to obtain the desired particle size (D90 < 15 microns). Collecting the milled material and post blend the material for 1 hour. Preparing the dough with 12% water or solvent and extrusion of the granules through (0.8 to 1.0mm mesh). collecting the granules and drying in fluidized bed dryer (FBD) at 45 oC for 20 min by maintain the moisture content 2%. Pack the material in a suitable package.

Example-4: Pyroxasulfone 35%+ Sulfosulfuron 10% WDG

S. No. Composition Function Quantity
(w/w %)
1. Pyroxasulfone@96.0 % Herbicide 35.0
2. Sulfosulfuron @97% Herbicide 10.0
3. Dialkyl naphthalene sulphonate sodium salt Wetting agent 3.0
4. Sodium salt of methyl naphthalene sulfonate Dispersing agent 5.0
5. Ammonium sulfate Disintegrating agent 10.0
6. Polydimethylsiloxane Defoamer 1.0
7. Calcium carbonate Filler 36.0
Total 100

Manufacturing Process:
Pyroxasulfone, Sulfosulfuron, Dialkyl naphthalene sulphonate sodium salt, Sodium salt of methyl naphthalene sulfonate, polydimethylsiloxane, ammonium sulphate and calcium carbonate were weighed in the pre-blender reactor and start mixing for 1 hour. The mixture was milled through air jet mill instrument (Inlet pressure 2-3 kg/cm2, grinding pressure 6 kg/ cm2) to obtain the desired particle size (D90 < 15 microns). Collecting the milled material and post blend the material for 1 hour. Preparing the dough with 12% water or solvent and extrusion of the granules through (0.8 to 1.0mm mesh). collecting the granules and drying in fluidized bed dryer (FBD) at 45 oC for 20 min by maintain the moisture content 2%. Pack the material in a suitable package.

Example-5: Pyroxasulfone 45%+ Sulfosulfuron 13% WDG

S. No. Composition Function Quantity
(w/w %)
1. Pyroxasulfone@96.0 % Herbicide 45.0
2. Sulfosulfuron @97% Herbicide 13.0
3. Sodium lauryl sulphate Wetting agent 4.5
4. Sodium polycarboxylate Dispersing agent 2.5
5. Silicon dioxide Rheology modifier 10.0
6. Polydimethylsiloxane defoamer 1.0
7. China clay Filler 24.0
Total 100

Manufacturing Process:
Pyroxasulfone, Sulfosulfuron, Sodium lauryl sulphate, Sodium polycarboxylate, polydimethylsiloxane, Silicon dioxide and china clay were weighed in the pre-blender reactor and start mixing for 1 hour. The mixture was milled through air jet mill instrument (Inlet pressure 2-3 kg/cm2, grinding pressure 6 kg/ cm2) to obtain the desired particle size (D90 < 15 microns). Collecting the milled material and post blend the material for 1 hour. Preparing the dough with 12% water or solvent and extrusion of the granules through (0.8 to 1.0mm mesh). collecting the granules and drying in fluidized bed dryer (FBD) at 45 oC for 20 min by maintain the moisture content 2%. Pack the material in a suitable package.

Example-6: Pyroxasulfone 50%+ Sulfosulfuron 15% WDG

S. No. Composition Function Quantity
(w/w %)
1. Pyroxasulfone@96.0 % Herbicide 50.0
2. Sulfosulfuron @97% Herbicide 15.0
3. Polyethylene glycol nonyl phenyl ether ammonium sulfate Wetting agent 5.0
4. Sodium Ligno sulphonate Dispersing agent 4.0
5. Silicon dioxide Rheology modifier 10.0
6. Polydimethylsiloxane defoamer 1.0
7. Lactose Monohydrate Filler 15.0
Total 100

Manufacturing Process:
Pyroxasulfone, Sulfosulfuron, polyethylene glycol nonyl phenyl ether ammonium sulfate, sodium ligno sulphonate, polydimethylsiloxane, silicon dioxide and lactose monohydrate were weighed in the pre-blender reactor and start mixing for 1 hour. The mixture was milled through air jet mill instrument (Inlet pressure 2-3 kg/cm2, grinding pressure 6 kg/ cm2) to obtain the desired particle size (D90 < 15 microns). Collecting the milled material and post blend the material for 1 hour. Preparing the dough with 12% water or solvent and extrusion of the granules through (0.8 to 1.0mm mesh). collecting the granules and drying in fluidized bed dryer (FBD) at 45 oC for 20 min by maintain the moisture content 2%. Pack the material in a suitable package.

FIELD AND SYNERGY STUDIES

The field studies were conducted to compare the weed controlling activity of the combination of Pyroxasulfone & Sulfosulfuron. The active ingredient Pyroxasulfone in the combination, belongs to chemical family “Isooxazolines” with mode of action of inhibition of very long chain fatty acids synthesis (VLCFA) inhibitors and Sulfosulfuron belonging to chemical family “Sulfonylureas” with ALS inhibitor (inhibition of acetolactate synthase) mode of action. Combination has the potential of controlling the cross-spectrum weeds (broad leaf weeds & grassy weeds) in wheat at the pre-emergence to extended pre-emergence (0-10 DAS) application timing. Both the molecules are safe to wheat when applied at their recommended dose rate in pre-emergence to extended pre-emergence (0-10 DAS) application timing.

The weed control activity of the individual herbicides of the invention and their combinations were evaluated on weeds such as Phalaris minor, Melilotus alba, Rumex dentatus & Chenopodium album. Trials were conducted with randomized block design with net plot size of 5 m x 6 m. Each trial was replicated four times and conducted under GEP guidelines. Spraying was done with manual operated backpack knapsack sprayer with 300 L of water spray volume per hectare at pre-emergence to extended pre-emergence (0-10 DAS) application timing. Such field trials were carried out at various locations to generate independent data, the locations were chosen randomly across India. Visual observations were recorded on percent weed control for individual weeds on whole plot basis at 15 days after application. These observations are to be taken from entire plot.

Appropriate analysis of plant response to herbicide combination is critical in determining the type of activity observed. The most widely used model is one Gowing* derived and Colby** modified. Gowing described a mathematical formula for calculating the predicting response values for herbicide mixtures. He suggested the expected (E) percent inhibition of growth induced by herbicide A plus herbicide B is as follows, *(Jerry Flint et al, 1988) ***

If A1 = the percent inhibition of growth by herbicide A at given rate
B1 = the percent inhibition of growth by herbicide B at given rate then,
B1 (100 – A1)
E = A1 +
100
Where,
A = observed efficacy of active ingredient A at the same concentration as used in the mixture.
B = observed efficacy of active ingredient B at the same concentration as used in the mixture.
C = observed efficacy of active ingredient C at the same concentration as used in the mixture.

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 herbicide mixtures. Weeds 8:379–391.
**Colby, S. R. 1967. Calculating synergistic and antagonistic responses of herbicide combinations. Weeds 15:20–22
*** Jerry Flint et al, 1988. Analyzing Herbicide Interactions: A Statistical Treatment of Colby's Method. Weed Technology 2: 304-309

Table 1: Table 1 demonstrates synergy on weeds using the combination of Pyroxasulfone & Sulfosulfuron in pre-emergence and extended pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 15 days of application. The target weed was Phalaris minor, and the results are recorded in the table 1 below.

Active
Dose (GAH) Pre-emergence (0 – 3 DAS) Extended pre-emergence (8 – 10 DAS)
% Weed Control of Phalaris minor % Weed Control of Phalaris minor
Pyroxasulfone 120 75 60
Sulfosulfuron 36 30 70
Pyroxasulfone 40% + Sulfosulfuron 12% WDG 120 + 36
90
92
WDG – Water dispersible granules; GAH – Gram active per hectare

The Phalaris minor control results in table 1 clearly demonstrates, synergy between Pyroxasulfone & Sulfosulfuron in pre-emergence and extended pre-emergence application window. The higher ratio of the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination.

Table 2: Table 2 demonstrates synergy on weeds using the combination of Pyroxasulfone & Sulfosulfuron in pre-emergence and extended pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 15 days of application. The target weed was Chenopodium album, and the results are recorded in the table 2 below.

Active
Dose (GAH) Pre-emergence (0 – 3 DAS) Extended pre-emergence (8 – 10 DAS)
% Weed Control of Chenopodium album % Weed Control of Chenopodium album
Pyroxasulfone 120 60 50
Sulfosulfuron 36 60 60
Pyroxasulfone 40% + Sulfosulfuron 12% WDG 120 + 36
90
85
WDG – Water dispersible granules; GAH – Gram active per hectare

The Chenopodium album control results in table 2 clearly demonstrates, synergy between Pyroxasulfone & Sulfosulfuron in pre-emergence and extended pre-emergence application window. The higher ratio of the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination.

Table 3: Table 3 demonstrates synergy on weeds using the combination of Pyroxasulfone & Sulfosulfuron in pre-emergence and extended pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 15 days of application. The target weed was Melilotus alba, and the results are recorded in the table 3 below.

Active
Dose (GAH) Pre-emergence (0 – 3 DAS) Extended pre-emergence (8 – 10 DAS)
% Weed Control of Melilotus alba % Weed Control of Melilotus alba
Pyroxasulfone 120 40 35
Sulfosulfuron 36 50 60
Pyroxasulfone 40% + Sulfosulfuron 12% WDG 120 + 36
80
80
WDG – Water dispersible granules; GAH – Gram active per hectare

The Melilotus alba control results in table 3 clearly demonstrates, synergy between Pyroxasulfone & Sulfosulfuron in pre-emergence and extended pre-emergence application window. The higher ratio of the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination.

Table 4: Table 4 demonstrates synergy on weeds using the combination of Pyroxasulfone & Sulfosulfuron in pre-emergence and extended pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 15 days of application. The target weed was Rumex dentatus, and the results are recorded in the table 4 below.

Active
Dose (GAH) Pre-emergence (0 – 3 DAS) Extended pre-emergence (8 – 10 DAS)
% Weed Control of Rumex dentatus % Weed Control of Rumex dentatus
Pyroxasulfone 120 30 30
Sulfosulfuron 36 60 55
Pyroxasulfone 40% + Sulfosulfuron 12% WDG 120 + 36
78
75
WDG – Water dispersible granules; GAH – Gram active per

The Rumex dentatus control results in table 4 clearly demonstrates, synergy between Pyroxasulfone & Sulfosulfuron in pre-emergence and extended pre-emergence application window. The higher ratio of the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination.

The composition of the present invention has the below advantages
? The present invention provides a synergistic herbicidal composition with broad spectrum activity and can delay the onset of herbicidal resistance.
? The present invention provides an herbicidal composition that can be applied in a single shot reducing the burden on farmers.
? The present invention provides an herbicidal composition which increases shoot and tiller counts which directly contribute to the crop yield.
? The present invention provides an herbicidal composition that shows effective treatment and prevention of growth or germination of weeds.
? The present invention provides an herbicidal composition that is non phyto-toxic to crop plants. ,CLAIMS:WE CLAIM:

1. A synergistic composition comprising Sulfosulfuron and Pyroxasulfone with one or more agrochemical additives.

2. The composition as claimed in claim 1, wherein the composition is formulated as water dispersible granules (WDG).

3. The composition as claimed in claim 1, wherein Sulfosulfuron is present in the range of 5% to 20% (w/w) and Pyroxasulfone is present in the range of 25% to 55 % (w/w).

4. The composition as claimed in claim 1, wherein the agrochemical additives are selected from wetting agent, dispersing agent, rheology modifier, disintegrating agent, adjuvant, defoamer and filler.

5. The composition as claimed in claim 4, wherein the wetting agent is selected from sodium alkyl naphthalene sulfonate, dialkyl naphthalene sulphonate sodium salt, linear alcohol derivative, polyethylene glycol nonyl phenyl ether ammonium sulfate, blend of sodium lauryl sulphate and sodium dodecyl benzene sulphonate, tristyrylphenol ethoxylate, and propylene oxide and present in a range of 1% to 10% (w/w).

6. The composition as claimed in claim 4, wherein the dispersing agent is selected from acrylate copolymer, blend of sodium lauryl sulphate and alkyl aryl benzene sulphonate, sodium polycarboxylate, phenol sulfonic acid-formaldehyde-polycondensation as sodium salt, sodium lauryl sulphate, sodium naphthalene sulphonates formaldehyde condensates, and sodium lignosulphonates, present in a range of 1% to 10% (w/w).

7. The composition as claimed in claim 4, wherein the rheology modifier is silicon dioxide, present in a range of 5 to 15% (w/w).

8. The composition as claimed in claim 4, wherein the disintegrating agent is ammonium sulphate, present in a range of 5% to 15% (w/w).

9. The composition as claimed in claim 4, wherein the adjuvant is selected from siloxane, trisiloxane ethoxylate, neem oil, and amino acids, present in a range of 0.1% to 5% (w/w).

10. The process for the preparation of composition as claimed in claims 1-11, wherein said process comprising steps of:
a) weighing all the active ingredients, wetting agent, dispersing agent, disintegrating agent and other agrochemical additives in a pre-blender, and mixing for 1 hour.
b) milling the mixture through air jet miller instrument (Inlet pressure 2-3 kg/cm2 and grinding pressure 6 kg/cm2) to obtain particles of size D90 < 15µ,
c) collecting the milled material and post blending for 1 hour,
d) preparing the dough with 12% water or solvent and extrusion of the granules through (0.8 to 1.0mm mesh),
e) collecting the granules and drying in fluidized bed dryer (FBD) at 45 oC air flow for 20 min by maintain the moisture content 2%,
f) pack the formulated material in a suitable packaging.

Dated this Eleventh (11th) day of November, 2022

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