Description:FORM 2

THE PATENTS ACT 1970
(SECTION 39 OF 1970)

&

THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(Section 10 and Rule 13)

HERBICIDAL COMPOSITION OF PYROXASULFONE, OXYFLUORFEN AND AN ADDITIONAL HERBICIDE

We, COROMANDEL INTERNATIONAL LIMITED,
an Indian company incorporated under Companies Act of 1956,
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 the field of agro-chemicals.
Particularly the present invention relates to a synergistic herbicidal composition comprising Pyroxasulfone, Oxyfluorfen and an additional herbicide selected from Sulfosulfuron and Metribuzin with one or more agrochemical additives.
More particularly, the present invention relates to a process for preparing the synergistic herbicidal composition of Pyroxasulfone, Oxyfluorfen and an additional herbicide is selected from Sulfosulfuron and Metribuzin.

BACKGROUND OF THE INVENTION
Weeds are valueless plants that grow wild on cultivated land that cause injury or have undesirable effects on the plants. There are many ways of controlling weed growth like mechanical, biological, cultural, and chemical. We need one or all these methods for an effective and environmentally friendly weed control system.
Chemical control of weeds has been an essential tool for managing weeds in home landscapes and crops. With modern changes, many herbicides of today are selective and effective. These traits of some new herbicides, if used properly, can be less hazardous to the environment.
Herbicides are a broad class of pesticides that hamper the growth of unwanted plants. They are chemicals that can control or manipulate undesirable vegetation. These are used widely in row-crop farming, where they are either applied before or after planting. Spraying herbicides prevents or minimizes other vegetation, maximizes crop production, and improves harvesting.
In some cases, herbicidal active ingredients have been shown to be more effective in combination than when applied individually and this is referred to as "synergism." As described in the Herbicide Handbook of the Weed Science Society of America, Eighth Edition, 2002, p. 462 "'synergism' [is] an interaction of two or more factors such that the effect when combined is greater than the predicted effect based on the response to each factor applied separately."
IN 202021046329 discloses synergistic and non-phytotoxic herbicidal composition comprising of Pyroxasulfone and at least one sulfonylurea herbicide; and at least one additional herbicide. However, this application does not disclose the herbicidal combinations of Pyroxasulfone with Oxyfluorfen and other herbicides.
It is therefore desired to provide an improved herbicidal composition and convenient method which safely and effectively control weed species in the agricultural crops and therefore, there is a constant need for the development and application of synergistic formulations which are not only effective in weed control, but also help in increasing the yield of crop, having potential to manage the challenges of resistance development, shifting of weed flora.
The present invention is based on the discovery that the combination of Pyroxasulfone, Oxyfluorfen and an additional herbicide selected from Sulfosulfuron or Metribuzin already known individually for their herbicidal efficacy, display a synergistic effect when applied in combination.
The herbicidal compounds forming the synergistic composition of this invention are independently known in the art for their effects on plant growth.
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:

Oxyfluorfen is a selective pre and post-emergent herbicide used to control broadleaf and grassy weeds in a variety of nut, tree fruit, vine, and field crops, especially wine grapes and almonds. It is also used for residential weed control. It is a contact herbicide and light are required for it to affect target plants. It is available in emulsifiable concentrate and granular formulations.
Oxyfluorfen is chemically known as 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene. Its preparation, use is disclosed in US 3,950,435 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 acid’s 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:

Metribuzin is a synthetic organic compound and widely used herbicide applied in pre-emergence and post-emergence in crops including soybean, potatoes, tomatoes, sugar cane and intensive vegetable crops. It is known for its efficiency and relatively low toxicity. Metribuzin has a wide range of uses, including vegetable and field crops, turfgrasses (recreational areas), and other non-crop areas.
Metribuzin is chemically known as (4-amino-6-tert-butyl-3-(methylthio)-1,2,4-triazin-5(4H)-one), and has following chemical structure:

As the 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.

OBJECTIVE OF THE INVENTION
One objective of the present invention is to provide a synergistic herbicidal composition comprising Pyroxasulfone, Oxyfluorfen and an additional herbicide selected from Sulfosulfuron and Metribuzin.
Another objective of the present invention is to provide a synergistic herbicidal composition comprising Pyroxasulfone, Oxyfluorfen and an additional herbicide selected from Sulfosulfuron and Metribuzin with one or more agrochemical additives.
Yet another objective of the present invention is to provide a synergistic composition comprising Pyroxasulfone, Oxyfluorfen and Sulfosulfuron with one or more agrochemical additives.
Yet another objective of the present invention is to provide a synergistic composition comprising Pyroxasulfone, Oxyfluorfen and Metribuzin with one or more agrochemical additives.
Yet another objective of the present invention is to provide a synergistic herbicidal composition comprising Pyroxasulfone, Oxyfluorfen, and an additional herbicide selected from Sulfosulfuron and Metribuzin with one or more agrochemical additives, where in the said composition is in the form of wettable power (WP) and water dispersible granules (WDG).
Yet another objective of the present invention is to provide a process for preparing the synergistic herbicidal composition of Pyroxasulfone, Oxyfluorfen and an additional herbicide selected from Sulfosulfuron and Metribuzin.

SUMMARY OF THE INVENTION
Accordingly, the present invention provides a synergistic herbicidal composition comprising Pyroxasulfone, Oxyfluorfen and an additional herbicide selected from Sulfosulfuron and Metribuzin.
In one aspect, the present invention provides a synergistic herbicidal composition comprising,
a) Pyroxasulfone,
b) Oxyfluorfen,
c) an additional herbicide selected from Sulfosulfuron and Metribuzin, and
d) one or more agrochemical additives.
In another aspect, the present invention provides a synergistic herbicidal composition comprising Pyroxasulfone, Oxyfluorfen and an additional herbicide selected from Sulfosulfuron and Metribuzin with one or more agrochemical additives, wherein the composition is in the form of wettable powder (WP) or water dispersible granules (WDG).
In another aspect, the present invention provides a wettable powder (WP) formulation comprising Pyroxasulfone, Oxyfluorfen and an additional herbicide selected from Sulfosulfuron and Metribuzin, a wetting agent, a dispersing agent, a rheology modifier, a filler and optionally a buffer.
In another aspect, the present invention provides a wettable powder (WP) formulation comprising:
(a) Pyroxasulfone present in a range from 1% to 35% (w/w),
(b) Oxyfluorfen present in a range from 1% to 30% (w/w),
(c) Sulfosulfuron present in a range from 1% to 30% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 0.1% to 10% (w/w) and
(g) filler present in a range from 10% to 80% (w/w).
In another aspect, the present invention provides a wettable powder (WP) formulation comprising:
(a) Pyroxasulfone present in a range from 1% to 35% (w/w),
(b) Oxyfluorfen present in a range from 1% to 30% (w/w),
(c) Metribuzin present in a range from 10% to 50% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 0.1% to 10% (w/w), and
(g) filler present in a range from 10% to 80% (w/w).
In another aspect, the present invention provides a wettable powder (WP) formulation comprising:
(a) Pyroxasulfone present in an amount of 20% (w/w),
(b) Oxyfluorfen present in an amount of 14.1% (w/w),
(c) Sulfosulfuron present in an amount of 6% (w/w),
(d) alkylnaphthalene sulfonate condensate blend (ANS) present in an amount of 4% (w/w),
(e) phenol sulfonic acid-formaldehyde present in an amount of 2% (w/w),
(f) sodium poly alkyl naphthalene sulphonate present in an amount of 2% (w/w),
(g) silicon dioxide present in an amount of 1.5% (w/w), and
(h) China clay present in an amount of 50.4% (w/w).
In another aspect, the present invention provides a wettable powder (WP) formulation comprising:
(a) Pyroxasulfone present in an amount of 18% (w/w),
(b) Oxyfluorfen present in an amount of 16.45% (w/w),
(c) Metribuzin present in an amount of 37.8% (w/w),
(d) alkylnaphthalene sulfonate condensate blend (ANS) present in an amount of 4% (w/w),
(e) phenol sulfonic acid-formaldehyde present in an amount of 2% (w/w),
(f) sodium poly alkyl naphthalene sulphonate present in an amount of 2% (w/w),
(g) silicon dioxide present in an amount of 1.5% (w/w), and
(h) China clay present in an amount of 18.24% (w/w).
In yet another aspect, the present invention provides a water dispersible granules (WDG) formulation comprising Pyroxasulfone, Oxyfluorfen, and at least one additional herbicide selected from Sulfosulfuron and Metribuzin, a wetting agent, a dispersing agent, a rheology modifier, a filler and optionally a buffer.
In yet another aspect, the present invention provides a water dispersible granules (WDG) formulation comprising:
(a) Pyroxasulfone present in a range from 5% to 30% (w/w),
(b) Oxyfluorfen present in a range from 5% to 25% (w/w),
(c) Sulfosulfuron present in a range from 1% to 25% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 0.1% to 10% (w/w) and
(g) filler present in a range from 10% to 80% (w/w).
In yet another aspect, the present invention provides a water dispersible granules (WDG) formulation comprising:
(a) Pyroxasulfone present in a range from 5% to 30% (w/w),
(b) Oxyfluorfen present in a range from 5% to 25% (w/w),
(c) Metribuzin present in a range from 10% to 50% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 1% to 10% (w/w) and
(g) filler is present a range from 10% to 80% (w/w).
In yet another aspect, the present invention provides a water dispersible granules (WDG) formulation comprising:
(a) Pyroxasulfone present in an amount of 20% (w/w),
(b) Oxyfluorfen present in an amount of 14.1% (w/w),
(c) Sulfosulfuron present in an amount of 6% (w/w),
(d) alkylnaphthalene sulfonate condensate blend (ANS) present in the range of 4% (w/w),
(e) phenol sulfonic acid-formaldehyde present in the range of 2% (w/w),
(f) sodium poly alkyl naphthalene sulphonate present in an amount of 2% (w/w),
(g) silicon dioxide is present in an amount of 1.5% (w/w), and
(h) China clay present in an amount of 50.4% (w/w).
In yet another aspect, the present invention provides a water dispersible granules (WDG) formulation comprising:
(a) Pyroxasulfone present in an amount of 18% (w/w),
(b) Oxyfluorfen present in an amount of 16.45% (w/w),
(c) Metribuzin present in an amount of 37.8% (w/w),
(d) alkylnaphthalene sulfonate condensate blend (ANS) present in an amount of 4% (w/w),
(e) phenol sulfonic acid-formaldehyde present in an amount of 2% (w/w),
(f) sodium poly alkyl naphthalene sulphonate present in an amount of 2% (w/w),
(g) silicon dioxide present in an amount of 1.5% (w/w), and
(h) China clay present in an amount of 18.24% (w/w).
In yet another aspect, the present invention provides a process for the preparation of synergistic herbicidal composition comprising of Pyroxasulfone, Oxyfluorfen and an additional herbicide selected from Sulfosulfuron and Metribuzin with one or more agrochemical additives.
In yet another aspect, the present invention provides a process for preparing a synergistic wettable powder (WP) composition comprising steps of:
a) weighing and pre-blending all the active ingredients, wetting agent, dispersing agent, rheology modifier, filler and optionally buffer in a pre-blender, and mixing for 1 hr.
b) milling the sample through air jet mill instrument at inlet pressure 2-3 kg/cm2, grinding pressure 6 kg/ cm2 and checking for the particle size D90 < 10 micron.
c) collecting the milled material and post blending the sample for 1hr.
d) sending the sample to the Quality analysis.
e) packing the formulated material in a suitable packaging.
In yet another aspect, the present invention provides a process for preparing a synergistic water dispersible granule (WDG) composition comprising steps of:
a) weighing and pre-blending all the active ingredients, wetting agent, dispersing agent, rheology modifier, filler and optionally buffer in a pre-blender, and mixing for 1 hr.
b) milling the mixture through air jet mill instrument with an inlet pressure 2-3 kg/cm2 and grinding pressure of 6-6.5 kg/cm2 to obtain particles of size D90 < 10 micron.
c) collecting the milled material and post blending the sample for 1 hr.
d) preparing the dough with 12% water or solvent and extrusion of the granules through 1.0 mm mesh.
e) collecting the granules and drying in fluidized bed dryer at 65C for 20 min.
f) packing the formulated material in a suitable packaging.
In yet another aspect of the present invention is to provide a synergistic herbicidal composition which is more effective against undesirable plants and vegetation.
In yet another aspect of the present invention provides an herbicidal composition with improved stability and ready to use, having superior bio-efficacy compared to the individual formulations.
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 “water dispersible granule” formulation may be understood as a solid, non-dusty granular formulation which disperses or dissolves quickly when added to water in the spray tank to give a fine particle suspension.
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. The preferable formulation of the present invention is wettable powder (WP) and water dispersible granules (WDG) form.
In one embodiment, the present invention provides a synergistic herbicidal composition comprising,
a) Pyroxasulfone,
b) Oxyfluorfen,
c) an additional herbicide selected from Sulfosulfuron and Metribuzin, and
d) one or more agrochemical additives.
In another embodiment, the present invention provides a synergistic herbicidal composition comprising Pyroxasulfone, Oxyfluorfen, and an additional herbicide selected from Sulfosulfuron and Metribuzin with one or more agrochemical additives, wherein the composition is in the form of wettable powder (WP) and water dispersible granules (WDG).
In another embodiment, the present invention provides a wettable powder (WP) formulation comprising Pyroxasulfone, oxyfluorfen, and an additional herbicide selected from sulfosulfuron and metribuzin, and a wetting agent, a dispersing agent, a rheology modifier, a filler and optionally buffer.
In another embodiment, the present invention provides a wettable powder (WP) formulation comprising:
(a) Pyroxasulfone present in a range from 1% to 35% (w/w),
(b) Oxyfluorfen present in a range from 1% to 30% (w/w),
(c) Sulfosulfuron present in a range from 1% to 30% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 0.1% to 10% (w/w) and
(g) filler present in a range from 10% to 80% (w/w).
In another embodiment, the present invention provides a wettable powder (WP) formulation comprising:
(a) Pyroxasulfone present in a range from 1% to 35% (w/w),
(b) Oxyfluorfen present in a range from 1% to 30% (w/w),
(c) Metribuzin present in a range from 10% to 50% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 0.1% to 10% (w/w), and
(g) filler present in a range from 10% to 80% (w/w).
In another embodiment, the present invention provides a wettable powder (WP) formulation comprising:
(a) Pyroxasulfone present in an amount of 20% (w/w),
(b) Oxyfluorfen present in an amount of 14.1% (w/w),
(c) Sulfosulfuron present in an amount of 6% (w/w),
(d) alkylnaphthalene sulfonate condensate blend (ANS) present in an amount of 4% (w/w),
(e) phenol sulfonic acid-formaldehyde present in an amount of 2% (w/w),
(f) sodium poly alkyl naphthalene sulphonate present in an amount of 2% (w/w),
(g) silicon dioxide present in an amount of 1.5% (w/w), and
(h) China clay present in an amount of 50.4% (w/w).
In another embodiment, the present invention provides a wettable powder (WP) formulation comprising:
(a) Pyroxasulfone present in an amount of 18% (w/w),
(b) Oxyfluorfen present in an amount of 16.45% (w/w),
(c) Metribuzin present in an amount of 37.8% (w/w),
(d) alkylnaphthalene sulfonate condensate blend (ANS) present in an amount of 4% (w/w),
(e) phenol sulfonic acid-formaldehyde present in an amount of 2% (w/w),
(f) sodium poly alkyl naphthalene sulphonate present in an amount of 2% (w/w),
(g) silicon dioxide present in an amount of 1.5% (w/w), and
(h) China clay present in an amount of 18.24% (w/w).
In yet another aspect, the present invention provides a water dispersible granules (WDG) formulation comprising Pyroxasulfone, Oxyfluorfen, and at least one additional herbicide selected from Sulfosulfuron and Metribuzin, a wetting agent, a dispersing agent, a rheology modifier, a filler and optionally a buffer.
In another embodiment, the present invention provides a water dispersible granules (WDG) formulation comprising:
(a) Pyroxasulfone present in a range from 5% to 30% (w/w),
(b) Oxyfluorfen present in a range from 5% to 25% (w/w),
(c) Sulfosulfuron present in a range from 1% to 25% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 0.1% to 10% (w/w) and
(g) filler present in a range from 10% to 80% (w/w).
In another embodiment, the present invention provides a water dispersible granules (WDG) formulation comprising:
(a) Pyroxasulfone present in a range from 5% to 30% (w/w),
(b) Oxyfluorfen present in a range from 5% to 25% (w/w),
(c) Metribuzin present in a range from 10% to 50% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 1% to 10% (w/w) and
(g) filler is present a range from 10% to 80% (w/w).
In another embodiment, the present invention provides a water dispersible granules (WDG) formulation comprising:
(a) Pyroxasulfone present in an amount of 20% (w/w),
(b) Oxyfluorfen present in an amount of 14.1% (w/w),
(c) Sulfosulfuron present in an amount of 6% (w/w),
(d) alkylnaphthalene sulfonate condensate blend (ANS) present in the range of 4% (w/w),
(e) phenol sulfonic acid-formaldehyde present in the range of 2% (w/w),
(f) sodium poly alkyl naphthalene sulphonate present in an amount of 2% (w/w),
(g) silicon dioxide is present in an amount of 1.5% (w/w), and
(h) China clay present in an amount of 50.4% (w/w).
In another embodiment, the present invention provides a water dispersible granules (WDG) formulation comprising:
(a) Pyroxasulfone present in an amount of 18% (w/w),
(b) Oxyfluorfen present in an amount of 16.45% (w/w),
(c) Metribuzin present in an amount of 37.8% (w/w),
(d) alkylnaphthalene sulfonate condensate blend (ANS) present in an amount of 4% (w/w),
(e) phenol sulfonic acid-formaldehyde present in an amount of 2% (w/w),
(f) sodium poly alkyl naphthalene sulphonate present in an amount of 2% (w/w),
(g) silicon dioxide present in an amount of 1.5% (w/w), and
(h) China clay present in an amount of 18.24% (w/w).
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 wetting agent is selected from the group comprising of alkylnaphthalene sulfonate condensate (ANS) blend, dialkyl naphthalene sulphonate sodium salt, linear alcohol derivative, and polyethylene glycol nonylphenyl ether ammonium sulfate.
Dispersing agent is a chemical substance, which is typically a surfactant, that is added to a suspension of solid or liquid particles in a liquid (such as a colloid or emulsion) to improve the separation of the particles and to prevent their settling or clumping. They can disperse active ingredients in the formulation and prevent agglomeration after dispersal in water.
The dispersing agent is selected from the group comprising of sodium polyalkyl naphthalene sulphonate, phenol sulfonic acid-formaldehyde, phenol sulfonic acid-formaldehyde polycondensation as sodium salt, acrylic copolymer, sodium salt of methyl naphthalene sulfonate, sodium polycarboxylate, sodium methyl oleoyl taurate, sodium ligno sulphonate and sodium lauryl sulphate or combination thereof.
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 silicon dioxide.
Filler refers to solid chemicals that are added to an herbicide formulation to aid in the delivery of the active ingredient. Filler is selected from the group comprising of, but not limited to, natural minerals such as corn starch, lactose monohydrate, quartz, talc, kaolin, pyrophyllite, montmorillonite, attapulgite, bentonite clay, china clay, kieselguhr, chalk, zeolite, calcite, sericite, acid clay, diatomaceous earth, natural rock, Fuller’s earth, meerschaum, gibbsite, dolomite or pumice; synthetic minerals such as precipitated silica, fumed silica, sodium silicate, alumina, aluminum silicate, aluminum hydroxide; inorganic salts such as calcium carbonate, ammonium sulfate or other ammonium salts, sodium sulfate, potassium chloride. The suitable filler of the present invention is china clay.
Buffering agent or buffer is classified as a utility modifier that widens the range of conditions under which a given herbicide formulation is useful. Thus, a buffering agent increases the dispersion and/or solubility of an herbicide under conditions of extreme acidic or alkaline waters. The suitable buffering agent of the present invention is oxalic acid.
In yet another embodiment, the present invention provides a process for the preparation of synergistic herbicidal composition comprising of Pyroxasulfone, Oxyfluorfen, and an additional herbicide selected from Sulfosulfuron and Metribuzin with one or more agrochemical additives.
In yet another embodiment, the present invention provides a process for preparing a synergistic wettable powder (WP) composition comprising steps of:
a) weighing and pre-blending all the active ingredients, wetting agent, dispersing agent, rheology modifier, filler and optionally buffer in a pre-blender, and mixing for 1 hr.
b) milling the sample through air jet mill instrument at inlet pressure 2-3 kg/cm2, grinding pressure 6 kg/ cm2 and checking for the particle size D90 < 10 micron.
c) collecting the milled material, and post blending the sample for 1hr.
d) sending the sample to the Quality analysis.
e) packing the formulated material in a suitable packaging.
In yet another embodiment, the present invention provides a process for preparing a synergistic water dispersible granule composition comprising steps of:
a) weighing and pre-blending all the active ingredients, wetting agent, dispersing agent, rheology modifier, filler and optionally buffer in a pre-blender, and mixing for 1 hr.
b) milling the mixture through air jet mill instrument with an inlet pressure 2-3 kg/cm2 and grinding pressure of 6-6.5 kg/cm2 to obtain particles of size D90 < 10 micron.
c) collecting the milled material and post blending the sample for 1 hr.
d) preparing the dough with 12% water or solvent and extrusion of the granules through 1.0 mm mesh.
e) collecting the granules and drying in fluidized bed dryer at 65C for 20 min.
f) packing the formulated material in a suitable packaging.
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 combinations of the present invention have several advantages over solo application of either Pyroxasulfone or Oxyfluorfen or Sulfosulfuron or Metribuzin, and, likewise, over any binary combination of these herbicides. The combination of the present invention shows enhanced herbicide action in comparison with the herbicide action of solo action of Pyroxasulfone, Oxyfluorfen, and Sulfosulfuron or Metribuzin against undesirable vegetation. Moreover, the combinations of the invention show a persistent herbicidal activity, even under difficult weathering conditions, and minimize the risk of weeds escaping. The combinations are generally non-toxic or of low toxicity against mammals. Apart from that, the combinations of the present invention show superior crop compatibility with certain conventional crop plants and with herbicide tolerant crop plants, i.e., their use in these crops leads to a reduced damage of the crop plants and/or does not result in increased damage of the crop plants. Thus, the combinations of the invention can also be applied after the emergence of the crop plants. The combinations of the present invention may also show an accelerated action on harmful plants, i.e., they may affect damage of the harmful plants more quickly in comparison with solo or binary applications of the at least three herbicides involved.
From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the scope of the novel concepts of the present invention. It is to be understood that no limitations with respect to the specific embodiments illustrated is intended or should be inferred. All such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims.
The following examples describes 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.

Examples:

Preparation of Wettable Powder (WP):

The present herbicidal composition of Pyroxasulfone, Oxyfluorfen, Sulfosulfuron and Pyroxasulfone, Oxyfluorfen, Metribuzin in wettable powder form (WP) is prepared by following steps as below:
Step 1: Weighing all the raw materials according to the batch size in a pre-blender and mixing it for 1 hr.
a) filler,
b) Pyroxasulfone,
c) Oxyfluorfen,
d) Sulfosulfuron or Metribuzin,
e) wetting agent,
f) dispersing agent,
g) rheology modifier, and
h) optionally buffer.
Step 2: Milling the sample through air jet mill instrument at inlet pressure 2-3 kg/cm2, grinding pressure 6 kg/ cm2 and checking for the particle size D90< 10 micron.
Step 3: Collecting the Milled material, and post blending the sample for 1hr.
Step 4: Sending the sample to the Quality analysis.
Step 5: Pack the formulated material in a suitable packaging.

The following examples illustrates the herbicidal composition of Pyroxasulfone, Oxyfluorfen, Sulfosulfuron and Pyroxasulfone, Oxyfluorfen, Metribuzin as a wettable powder (WP) form in different amount as follows:

Example 1: Pyroxasulfone 20% + Oxyfluorfen 14.1% + Sulfosulfuron 6% (WP):
S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 20.0
2. Oxyfluorfen Herbicide 14.1
3. Sulfosulfuron Herbicide 6.0
4. Alkylnaphthalene sulfonate (ANS)
condensate blend Wetting agent 4.0
5. phenol sulfonic acid-formaldehyde Dispersing agent 2.0
6. Sodium Polyalkyl naphthalene sulphonate Dispersing agent 2.0
7. Silicon dioxide Rheology modifier 1.5
8. China clay Filler 50.4
Total 100

Manufacturing process:
20.0 gm of Pyroxasulfone, 14.1 gm of Oxyfluorfen, 6.0 gm of Sulfosulfuron, 4.0 gm of Alkylnaphthalene sulfonate condensate blend, 2.0 gm of phenol sulfonic acid-formaldehyde, 2.0 gm of sodium poly alkylnaphthalene sulphonate, 1.5 gm of silicon dioxide, and 50.4 gm of china clay were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Example 2: Pyroxasulfone 5% + Oxyfluorfen 5% + Sulfosulfuron 1% (WP)
S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 5.0
2. Oxyfluorfen Herbicide 5.0
3. Sulfosulfuron Herbicide 1.0
4. Alkylnaphthalene sulfonate (ANS)
condensate blend Wetting agent 5.0
5. phenol sulfonic acid-formaldehyde-polycondensation as sodium salt Dispersing agent 3.0
6. Acrylate copolymer Dispersing agent 1.0
7. Silicon dioxide Rheology modifier 2.0
8. Oxalic acid buffer 0.2
9. China clay Filler 77.8
Total 100

Manufacturing process:
5.0 gm of Pyroxasulfone, 5.0 gm of Oxyfluorfen, 1.0 gm of Sulfosulfuron, 5.0 gm of Alkylnaphthalene sulfonate condensate blend, 3.0 gm of phenol sulfonic acid-formaldehyde-polycondensation as sodium salt, 1.0 gm of acrylate copolymer, 2.0 gm of silicon dioxide, 0.2 gm of oxalic acid and 77.8 gm of china clay were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Example 3: Pyroxasulfone 10% + Oxyfluorfen 10% + Sulfosulfuron 10% (WP):
S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 10.0
2. Oxyfluorfen Herbicide 10.0
3. Sulfosulfuron Herbicide 10.0
4. Dialkyl naphthalene sulphonate sodium salt Wetting agent 4.5
5. Sodium salt of methyl naphthalene sulfonate Dispersing agent 2.5
6. phenol sulfonic acid-formaldehyde-polycondensation as sodium salt Dispersing agent 2.5
7. Silicon dioxide Rheology modifier 1.8
8. Oxalic acid buffer 0.20
9. China clay Filler 58.5
Total 100

Manufacturing process:
10.0 gm of Pyroxasulfone, 10.0 gm of Oxyfluorfen, 10.0 gm of Sulfosulfuron, 4.5 gm of dialkyl naphthalene sulphonate sodium salt, 2.5 gm of Sodium salt of methyl naphthalene sulfonate, 2.5 gm of phenol sulfonic acid-formaldehyde-polycondensation as sodium salt, 2.5 gm of silicon dioxide, 0.20 gm of oxalic acid and 58.5 gm of china clay were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Example 4: Pyroxasulfone 15% + Oxyfluorfen 20% + Sulfosulfuron 15% (WP):
S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 15.0
2. Oxyfluorfen Herbicide 20.0
3. Sulfosulfuron Herbicide 15.0
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 0.20
9. China clay Filler 37.3
Total 100

Manufacturing process:
15.0 gm of Pyroxasulfone, 20.0 gm of Oxyfluorfen, 15.0 gm of Sulfosulfuron, 4.5 gm of linear alcohol derivative, 2.5 gm of sodium polycarboxylate, 3.0 gm of sodium methyl oleoyl taurate, 2.5 gm of silicon dioxide, 0.20 gm of oxalic acid, and 37.3 gm of china clay were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Example 5: Pyroxasulfone 30% + Oxyfluorfen 25% + Sulfosulfuron 25% (WP)

S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 30.0
2. Sulfosulfuron Herbicide 25.0
3. Oxyfluorfen Herbicide 25.0
4. Polyethylene glycol Nonylphenol ether ammonium sulfate Wetting agent 5.0
5. Sodium Ligno sulphonate Dispersing agent 3.0
6. Sodium lauryl sulphate Dispersing agent 1.0
7. Silicon dioxide Rheology modifier 1.0
8. China clay Filler 10.0
Total 100

Manufacturing process:
30.0 gm of Pyroxasulfone, 25.0 gm of Oxyfluorfen, 25.0 gm of Sulfosulfuron, 5.0 gm of Polyethylene glycol nonylphenol ether ammonium sulfate, 3.0 gm of Sodium Ligno sulphonate, 1.0 gm of Sodium lauryl sulphate, 1.0 gm of silicon dioxide, and 10.0 gm of china clay were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Example 6: Pyroxasulfone 18% + Oxyfluorfen 16.45% + Metribuzin 37.8% (WP)
S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 18.0
2. Oxyfluorfen Herbicide 16.45
3. Metribuzin Herbicide 37.8
4. Alkylnaphthalene sulfonate (ANS) condensate blend Wetting agent 4.0
5. phenol sulfonic acid-formaldehyde- Dispersing agent 2.0
6. Sodium Polyalkyl naphthalene sulphonate Dispersing agent 2.0
7. Silicon dioxide Rheology modifier 1.5
8. China clay Filler 18.25
Total 100

Manufacturing process:
18.0 gm of Pyroxasulfone, 16.45 gm of Oxyfluorfen, 37.8 gm of Metribuzin, 4.0 gm of Alkylnaphthalene sulfonate condensate blend, 2.0 gm of phenol sulfonic acid-formaldehyde, 2.0 gm of sodium poly alkylnaphthalene sulphonate, 1.5 gm of silicon dioxide, and 18.25 gm of china clay were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Example 7: Pyroxasulfone 5% + Oxyfluorfen 5% + Metribuzin 15% (WP):
S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 5.0
2. Oxyfluorfen Herbicide 5.0
3. Metribuzin Herbicide 15.0
4. Alkylnaphthalene sulfonate (ANS) condensate blend Wetting agent 5.0
5. phenol sulfonic acid-formaldehyde-polycondensation as sodium salt Dispersing agent 3.0
6. Acrylate copolymer Dispersing agent 1.0
7. Silicon dioxide Rheology modifier 2.0
8. Oxalic acid buffer 0.20
9. China clay Filler 63.8
Total 100

Manufacturing process:
5.0 gm of Pyroxasulfone, 5.0 gm of Oxyfluorfen, 15.0 gm of Metribuzin, 5.0 gm of Alkylnaphthalene sulfonate condensate blend, 3.0 gm of phenol sulfonic acid-formaldehyde-polycondensation as sodium salt, 1.0 gm of acrylate copolymer, 2.0 gm of silicon dioxide, 0.2 gm of oxalic acid and 63.8 gm of china clay were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Example 8: Pyroxasulfone 8% + Oxyfluorfen 10% + Metribuzin 20% (WP)
S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 8.0
2. Oxyfluorfen Herbicide 10.0
3. Metribuzin Herbicide 20.0
4. Dialkyl naphthalene sulphonate sodium salt Wetting agent 4.5
5. Sodium salt of methyl naphthalene sulfonate Dispersing agent 2.5
6. phenol sulfonic acid-formaldehyde-polycondensation as sodium salt Dispersing agent 2.5
7. Silicon dioxide Rheology modifier 1.8
8. Oxalic acid buffer 0.2
9. China clay Filler 50.5
Total 100

Manufacturing process:
8.0 gm of Pyroxasulfone, 10.0 gm of Oxyfluorfen, 20.0 gm of Metribuzin, 4.5 gm of Dialkyl naphthalene sulphonate sodium salt, 2.5 gm of Sodium salt of methyl naphthalene sulfonate, 2.5 gm of phenol sulfonic acid-formaldehyde-polycondensation as sodium salt, 1.8 gm of silicon dioxide, 0.2 gm of oxalic acid and 50.5 gm of china clay were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Example 9: Pyroxasulfone 13% + Oxyfluorfen 15% + Metribuzin 30% (WP)
S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 13.0
2. Oxyfluorfen Herbicide 15.0
3. Metribuzin Herbicide 30.0
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 0.22
9. China clay Filler 29.3
Total 100

Manufacturing process:
13.0 gm of Pyroxasulfone, 15.0 gm of Oxyfluorfen, 30.0 gm of Metribuzin, 4.5 gm of linear alcohol derivative, 2.5 gm of sodium polycarboxylate, 3.0 gm of sodium methyl oleoyl taurate, 2.5 gm of silicon dioxide, 0.22 gm of oxalic acid, and 29.3 gm of china clay were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Example 10: Pyroxasulfone 25% + Oxyfluorfen 20% + Metribuzin 45% (WP)
S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 25.0
2. Oxyfluorfen Herbicide 20.0
3. Metribuzin Herbicide 45.0
4. Polyethylene glycol Nonylphenol ether ammonium sulfate Wetting agent 5.0
5. Sodium Ligno sulphonate Dispersing agent 3.0
6. Sodium lauryl sulphate Dispersing agent 1.0
7. Silicon dioxide Rheology modifier 1.0
Total 100

Manufacturing process:
25.0 gm of Pyroxasulfone, 20.0 gm of Oxyfluorfen, 45.0 gm of Metribuzin, 5.0 gm of Polyethylene glycol Nonylphenol ether ammonium sulfate, 3.0 gm of Sodium Ligno sulphonate, 1.0 gm of sodium lauryl sulphate, 1.0 gm of silicon dioxide were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Preparation of Water Dispersible Granules (WDG):
The present herbicidal composition of Pyroxasulfone, Oxyfluorfen and Sulfosulfuron or Metribuzin in water dispersible granular form (WDG) is prepared by following steps as below:
Step 1: Weighing all the raw materials according to the batch size in a pre-blender and mixing it for 1 hr.
a) filler,
b) Pyroxasulfone,
c) Oxyfluorfen,
d) Sulfosulfuron or Metribuzin,
e) wetting agent,
f) dispersing agent,
g) rheology modifier, and
h) optionally buffer.
Step 2: Milling the sample through air jet mill instrument. Inlet pressure 2-3 kg/cm2, grinding pressure 6 – 6.5 kg/ cm2, and check the particle size D90 < 10 micron.
Step 3: Collecting the milled material, and post blending the sample for 1hr.
Step 4: Preparing dough and 12% water or solvent extruding the granule through 1.0 mm mesh.
Step.5: Collecting the granules and drying in the fluidized bed dryer at 65oC for 20 min. Submitting the sample for analysis by maintaining the moisture 3%.
Step.6: Sending the sample to the Quality analysis.
Step 5: Packing the formulated material in suitable packaging.

The following examples illustrates the herbicidal composition of Pyroxasulfone, Oxyfluorfen, Sulfosulfuron and Pyroxasulfone, Oxyfluorfen, Metribuzin in a water dispersible granules (WDG) form in different amount as follows:

Example 11: Pyroxasulfone 20% + Oxyfluorfen 14.1% + Sulfosulfuron 6% (WDG):
S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 20.0
2. Sulfosulfuron Herbicide 6.0
3. Oxyfluorfen Herbicide 14.1
4. Alkylnaphthalene sulfonate (ANS)
condensate blend Wetting agent 4.0
5. phenol sulfonic acid-formaldehyde Dispersing agent 2.0
6. Sodium Polyalkyl naphthalene sulphonate Dispersing agent 2.0
7. Silicon dioxide Rheology modifier 1.5
8. China clay Filler 50.4
Total 100

Manufacturing process:
20.0 gm of Pyroxasulfone, 14.1 gm of Oxyfluorfen, 6.0 gm of Sulfosulfuron, 4.0 gm of Alkylnaphthalene sulfonate condensate blend, 2.0 gm of phenol sulfonic acid-formaldehyde, 2.0 gm of sodium poly alkylnaphthalene sulphonate, 1.5 gm of silicon dioxide, and 50.4 gm of china clay were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour. Preparing dough and 12% water or solvent extruding the granule through 1.0 mm mesh, collecting the granules, and drying at 65 oC for 30 min followed by packing the material in a suitable package.

Example 12: Pyroxasulfone 18% + Oxyfluorfen 16.45% + Metribuzin 37.8% (WDG)
S. No Composition Function % (w/w)
1. Pyroxasulfone Herbicide 18.0
2. Oxyfluorfen Herbicide 16.45
3. Metribuzin Herbicide 37.8
4. Alkylnaphthalene sulfonate (ANS) condensate blend Wetting agent 4.0
5. phenol sulfonic acid-formaldehyde- Dispersing agent 2.0
6. Sodium Polyalkyl naphthalene sulphonate Dispersing agent 2.0
7. Silicon dioxide Rheology modifier 1.5
8. China clay Filler 18.25
Total 100

Manufacturing process:
18.0 gm of Pyroxasulfone, 16.45 gm of Oxyfluorfen, 37.8 gm of Metribuzin, 4.0 gm of Alkylnaphthalene sulfonate condensate blend, 2.0 gm of phenol sulfonic acid-formaldehyde, 2.0 gm of sodium poly alkylnaphthalene sulphonate, 1.5 gm of silicon dioxide, and 18.25 gm of china clay were weighed in the pre-blender reactor and mixed 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 < 10 microns). Collecting the milled material and post blending the material for 1 hour. Preparing dough and 12% water or solvent extruding the granule through 1.0 mm mesh, collecting the granules, and drying at 65 oC for 30 min followed by packing the material in a suitable package.

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 pesticide 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 pesticide mixtures. He suggested the expected (E) percent inhibition of growth induced by pesticide A plus pesticide B and plus pesticide C is as follows, *(Jerry Flint et al, 1988) ***

In which, E = Expected percentage of Insecticidal or fungicidal control for the combination of three active ingredient,
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. Analysing Herbicide Interactions: A Statistical Treatment of Colby's Method. Weed Technology 2: 304-309

FIELD TRIALS:

Field experiments were carried out to study the bio efficacy, phytotoxicity and synergism of the formulations as per the present disclosure.
Wheat is the main cereal crop in India. In India, it is grown on an area of 31.6 million hectare with an annual production of 106.84 million tons. Successful weed control is most important factor for fruitful wheat production because losses due weeds have been one of the major limiting factors in wheat production. Weeds compete with crop for light moisture and nutrients. It was concluded that weeds exhibit the economic yield losses to the wheat crop, which may range from 24-39.95% and these must be controlled during the full growing season of the crop for achieving satisfactory crop yields. Traditionally, weed control in India has been largely dependent on manual weeding. However, increased labour scarcity and costs are encouraging farmers to adopt to use herbicides.
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 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 30 days after application. These observations are to be taken from entire plot.

Synergistic study for combination of Pyroxasulfone, Oxyfluorfen and Sulfosulfuron in wettable powder (WP) and water dispersible granule (WDG) formulations:
Table 1: Table 1 demonstrates synergy on weeds using the combination of Pyroxasulfone, Sulfosulfuron & Oxyfluorfen in pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 30 days of application. The target weed was Phalaris minor, and the results are recorded in the table below.

Active Dose (GAH) Pre-emergence (0 – 3 DAS)
% Weed Control of Phalaris minor
Pyroxasulfone 100 60
Sulfosulfuron 30 30
Oxyfluorfen 70.5 55
Pyroxasulfone 20% + Oxyfluorfen 14.1 % + Sulfosulfuron 6% 100 + 30 + 70.5 90
Ratio of O/E 1.02
GAH – Gram active per hectare.
The Phalaris minor control results in table 1 clearly demonstrates, synergy between Pyroxasulfone, Oxyfluorfen and Sulfosulfuron in pre-emergence. 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, Oxyfluorfen and Sulfosulfuron in pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 30 days of application. The target weed was Chenopodium album, and the results are recorded in the table below.

Active Dose (GAH) Pre-emergence (0 – 3 DAS)
% Weed Control of
Chenopodium album
Pyroxasulfone 100 55
Sulfosulfuron 30 55
Oxyfluorfen 70.5 75
Pyroxasulfone 20% + Oxyfluorfen 14.1 % + Sulfosulfuron 6% 100 + 30 + 70.5 98
Ratio of O/E 1.03
GAH – Gram active per hectare.
The Chenopodium album control results in table 2 clearly demonstrates, synergy between Pyroxasulfone, Oxyfluorfen and Sulfosulfuron in 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, Oxyfluorfen and Sulfosulfuron in pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 30 days of application. The target weed was Melilotus alba, and the results are recorded in the table below.

Active Dose (GAH) Pre-emergence (0 – 3 DAS)
% Weed Control of
Melilotus alba
Pyroxasulfone 100 30
Sulfosulfuron 30 50
Oxyfluorfen 70.5 55
Pyroxasulfone 20% + Oxyfluorfen 14.1 % + Sulfosulfuron 6% 100 + 30 + 70.5 88
Ratio of O/E 1.04
GAH – Gram active per hectare.
The Melilotus alba control results in table 3 clearly demonstrates, synergy between Pyroxasulfone, Oxyfluorfen and Sulfosulfuron in 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, Oxyfluorfen and Sulfosulfuron in pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 30 days of application. The target weed was Rumex dentatus, and the results are recorded in the table below.

Active
Dose (GAH) Pre-emergence (0 – 3 DAS)
% Weed Control of Rumex dentatus
Pyroxasulfone 100 30
Sulfosulfuron 30 40
Oxyfluorfen 70.5 50
Pyroxasulfone 20% + Oxyfluorfen 14.1 % + Sulfosulfuron 6% 100 + 30 + 70.5 85
Ratio of O/E 1.07
GAH – Gram active per hectare.
The Rumex dentatus control results in table 4 clearly demonstrates, synergy between Pyroxasulfone, Oxyfluorfen and Sulfosulfuron in pre-emergence application window. The higher ratio of the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination.
Synergistic study for combination of Pyroxasulfone, Oxyfluorfen, and Metribuzin in wettable powder (WP) and water dispersible granule (WDG) formulations:

Table 5: Table 5 demonstrates synergy on weeds using the combination of Pyroxasulfone, Oxyfluorfen and Metribuzin in pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 30 days of application. The target weed was Phalaris minor, and the results are recorded in the table below.

Active
Dose (GAH) Pre-emergence (0 – 3 DAS)
% Weed Control of
Phalaris minor
Pyroxasulfone 90 35
Metribuzin 189 45
Oxyfluorfen 82.25 65
Pyroxasulfone 18% + Oxyfluorfen 16.45% + Metribuzin 37.8% 90 + 189 + 82.25 90
Ratio of O/E 1.02
GAH – Gram active per hectare.

The Phalaris minor control results in table 5 clearly demonstrates, synergy between Pyroxasulfone, Oxyfluorfen and Metribuzin in pre-emergence. The higher ratio of the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination.

Table 6: Table 6 demonstrates synergy on weeds using the combination of Pyroxasulfone, Oxyfluorfen and Metribuzin in pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 30 days of application. The target weed was Chenopodium album, and the results are recorded in the table below.

Active
Dose (GAH) Pre-emergence (0 – 3 DAS)
% Weed Control of
Chenopodium album
Pyroxasulfone 90 40
Metribuzin 189 60
Oxyfluorfen 82.25 75
Pyroxasulfone 18% + Oxyfluorfen 16.45% + Metribuzin 37.8% 90 + 189 + 82.25 100
Ratio of O/E 1.06
GAH – Gram active per hectare.

The Chenopodium album control results in table 6 clearly demonstrates, synergy between Pyroxasulfone, Oxyfluorfen and Metribuzin in pre-emergence application window. The higher ratio of the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination.

Table 7: Table 7 demonstrates synergy on weeds using the combination of Pyroxasulfone, Oxyfluorfen and Metribuzin in pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 30 days of application. The target weed was Melilotus alba, and the results are recorded in the table below.

Active Dose (GAH) Pre-emergence (0 – 3 DAS)
% Weed Control of
Melilotus alba
Pyroxasulfone 90 30
Metribuzin 189 45
Oxyfluorfen 82.25 60
Pyroxasulfone 18% + Oxyfluorfen 16.45% + Metribuzin 37.8% 90 + 189 + 82.25 92
Ratio of O/E 1.08
GAH – Gram active per hectare.

The Melilotus alba control results in table 7 clearly demonstrates, synergy between Pyroxasulfone, Oxyfluorfen and Metribuzin in pre-emergence application window. The higher ratio of the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination.

Table 8: Table 8 demonstrates synergy on weeds using the combination of Pyroxasulfone, Oxyfluorfen and Metribuzin in pre-emergence application window. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 30 days of application. The target weed was Rumex dentatus, and the results are recorded in the table below.

Active Dose (GAH) Pre-emergence (0 – 3 DAS)
% Weed Control of
Rumex dentatus
Pyroxasulfone 90 20
Metribuzin 189 30
Oxyfluorfen 82.25 55
Pyroxasulfone 18% + Oxyfluorfen 16.45% + Metribuzin 37.8% 90 + 189 + 82.25 85
Ratio of O/E 1.13
GAH – Gram active per hectare.

The Rumex dentatus control results in table 8 clearly demonstrates, synergy between Pyroxasulfone, Oxyfluorfen and Metribuzin in 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.
 This combination provides consisting efficacy in wettable powder (WP) and water dispersible granules (WDG) formulation with same AI input percentages. , Claims:WE CLAIM:
1. A herbicidal composition comprising:
a) Pyroxasulfone,
b) Oxyfluorfen,
c) an additional herbicide selected from Sulfosulfuron and Metribuzin, and
d) one or more agrochemical additives.
2. The composition as claimed in claim 1, wherein the composition is formulated as wettable powder (WP) and water dispersible granules (WDG).
3. The composition as claimed in claim 1, wherein the agrochemical additives are selected from wetting agent, dispersing agent, rheology modifier, filler and buffer.
4. The composition as claimed in claim 3, wherein the wetting agent is selected from the alkylnaphthalene sulfonate condensate (ANS) blend, dialkyl naphthalene sulphonate sodium salt, linear alcohol derivative, and polyethylene glycol nonyl phenyl ether ammonium sulfate.
5. The composition as claimed in claim 3, wherein the dispersing agent is selected from sodium Polyalkyl naphthalene sulphonate, phenol sulfonic acid-formaldehyde, phenol sulfonic acid-formaldehyde polycondensation as sodium salt, acrylic copolymer, sodium salt of methyl naphthalene sulfonate, sodium polycarboxylate, sodium methyl oleoyl taurate, sodium ligno sulphonate, and sodium lauryl sulphate or combination thereof.
6. The composition as claimed in claim 3, wherein the rheology modifier is silicon dioxide, filler is china clay and buffer is oxalic acid.
7. The composition as claimed in claims 1-6, the wettable powder formulation comprising:
(a) Pyroxasulfone present in a range from 1% to 35% (w/w),
(b) Oxyfluorfen present in a range from 1% to 30% (w/w),
(c) Sulfosulfuron present in a range from 1% to 30% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 0.1% to 10% (w/w) and
(g) filler present in a range from 10% to 80% (w/w).
8. The composition as claimed in claims 1-6, the wettable powder formulation comprising:
(a) Pyroxasulfone present in a range from 1% to 35% (w/w),
(b) Oxyfluorfen present in a range from 1% to 30% (w/w),
(c) Metribuzin present in a range from 10% to 50% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 0.1% to 10% (w/w), and
(g) filler present in a range from 10% to 80% (w/w).
9. The composition as claimed in claims 1-6, the water dispersible granules (WDG) formulation comprising:
(a) Pyroxasulfone present in a range from 5% to 30% (w/w),
(b) Oxyfluorfen present in a range from 5% to 25% (w/w),
(c) Sulfosulfuron present in a range from 1% to 25% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 0.1% to 10% (w/w) and
(g) filler present in a range from 10% to 80% (w/w).
10. The composition as claimed in claims 1-6, the water dispersible granules (WDG) formulation comprising:
(a) Pyroxasulfone present in a range from 5% to 30% (w/w),
(b) Oxyfluorfen present in a range from 5% to 25% (w/w),
(c) Metribuzin present in a range from 10% to 50% (w/w),
(d) wetting agent present in a range from 1% to 10% (w/w),
(e) dispersing agent present in a range from 1% to 10% (w/w),
(f) rheology modifier present in a range from 1% to 10% (w/w) and
(g) filler is present a range from 10% to 80% (w/w).

Dated this Third (3rd) day of March, 2023

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