DESC:FORM 2

THE PATENTS ACT 1970
(SECTION 39 OF 1970)

&

THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(Section 10 and Rule 13)

HERBICIDAL COMPOSITION OF PENOXSULAM, PROPANIL AND 2, 4-D

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 comprising penoxsulam, propanil and 2, 4-D or its salts, and to methods of using such compositions to prevent and remove most of weeds in a paddy field simultaneously, reinforces preventing effects on barnyard grass, annual chufa, and a plurality of broad-leaf weeds, and has the advantages of being long in effect duration and safe to the environment.

The present invention further relates to a process for preparing such compositions and a method of using such compositions effectively.

BACKGROUND OF THE INVENTION
The crop protection from weeds and other vegetation which inhibit crop growth is a constantly recurring problem in agriculture. Therefore, the control of weeds or unwanted plants is economically important for crop productivity. Researchers in the field of synthetic chemistry have produced an extensive variety of chemicals and chemical formulations as solo or combination of active ingredients for the control of such weeds or unwanted plants. Chemical herbicides of many types have been disclosed in the literature and a large number are in commercial use.

Nowadays, little seed canary grass (Phalaris minor) is a serious weed of irrigated wheat in India that has developed resistance against most of the available herbicidal control measures. To reduce the risk from an increased number of herbicide resistant strains, mixtures of different active compounds are nowadays employed for controlling weeds or unwanted plants. By combining different active compounds having different mechanisms of action, it is possible to ensure efficient and wide spectrum control of weeds over a relatively longer period of time and preventing development of resistance. However, this requires the continued development of an effective composition with different active compounds, to avoid selection to the particular mechanism of action.

Accordingly, there remains a need for a more effective method of controlling or preventing the growth of unwanted vegetation in planting sites by using reduced quantities of herbicidally active substances.

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.

The present invention is based on the discovery that penoxsulam, propanil and 2,4 D or its salts already known individually for their herbicidal efficacy, display a synergistic effect when applied in combination.

Penoxsulam is the active ingredient of Granite (trademark of Dow AgroSciences LLC), an herbicide designed for postemergence control of annual grasses, sedges, and broadleaf weeds in rice culture. Penoxsulam herbicide is to be used as a foliar spray on dry-seeded rice crops, or as either a foliar spray or a granular formulation on water-seeded rice crops to control broadleaf weeds, aquatic plants, and certain grasses.

Penoxsulam is chemically known as 2-(2,2-difluoroethoxy)-N-(5,8-dimethoxy [1,2,4]-triazolo[1,5-c] pyrimidin-2-yl)-6-(trifluoromethyl)benzene sulfonamide, and has the following structure:

Propanil is a widely used contact herbicide. The principal mode of propanil's herbicidal action against weeds is inhibition of their photosynthesis and CO2 fixation. It is a highly selective postemergence herbicide that is used extensively to control barnyard grass (Echinochloa crus-galli) and jungle rice (Echinochloa colona) in several crops, especially rice. Propanil belongs to the class of anilides and is a photosynthetic inhibitor that inhibits the photosystem II (PS II) in chloroplasts.

Propanil is chemically known as N-(3,4-Dichlorophenyl) propenamide, and has the following structure:

2, 4-D is a widely used herbicide that controls broadleaf weeds that has been used as a pesticide since the 1940s. It is used in many places including turf, lawns, rights-of-way, aquatic sites, forestry sites, and a variety of field, fruit, and vegetable crops. It may also be used to regulate the growth of citrus plants. Products are sold in liquid (concentrated or ready-to-use), dust, or granule formulations.

2, 4-D is chemically known as 4-(2,4-dichlorophenoxy)butanoic acid and has the following chemical structure:

The combinations of the present invention have several advantages over solo application of either penoxsulam, propanil and 2, 4-D or its salt.

The combination of the present invention shows enhanced herbicide action in comparison with the herbicide action of solo action of penoxsulam, propanil or 2,4-D or its salt 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.

OBJECT OF THE INVENTION
One object of the present invention is to provide a synergistic herbicidal composition comprising penoxsulam, propanil and 2, 4-D or its salts.

Another object of the present invention is to provide an herbicidal composition comprising penoxsulam, propanil and 2, 4-D or its salts with one or more suitable agrochemical additives.

Yet another object of the present invention is to provide synergistic herbicidal composition that enables efficient and reliable control of grass and broad-leaf weeds.

Yet another objective of the present invention is to provide an herbicidal composition having persistent herbicidal activity to achieve weed control safe to the environment.
Yet another object of the present invention is to provide a process for the preparation of an herbicidal composition comprising penoxsulam, propanil and 2, 4-D or its salts.

SUMMARY OF THE INVENTION
The present invention provides a synergistic herbicidal composition comprising of (a) penoxsulam, (b) propanil, and (c) 2, 4-D or its salts with suitable agrochemical additives in synergistically effective amounts.

In one aspect of the present invention provides a wettable powder composition comprising:
a) penoxsulam in a range from 0.5% (w/w) to 1.0% (w/w),
b) propanil in a range from 40% (w/w) to 60% (w/w),
c) 2, 4-D amine salt in a range from 20% (w/w) to 30% (w/w),
d) agrochemical additives.

In an aspect of the present invention, the suitable agrochemical additives are selected from a wetting agent, a dispersing agent, a defoamer, an anti-caking agent, a chelating agent, and a filler.

In an aspect of the present invention, the wetting agent is selected from the group comprising an alkyl naphthalene sulfonate, dialkyl naphthalene sulphonate sodium salt, Propol 990N, Jeemol IP, and sodium salt of dibutyl naphthalene sulphonate, present in a range from 1% to 5% (w/w).

In an aspect of the present invention, the dispersing agent is selected from the group comprising of sodium polycarboxylate, blend of dispersing agent (Jeemol DW18), alkyl naphthalene sulfonate condensate, and sodium lignosulfonate, and combination thereof, present in a range from 1% to 10% (w/w).

In an aspect of the present invention, the defoamer is polydimethylsiloxane, present in a range from 0.1% to 1.5% (w/w).

In an aspect of the present invention, the anti-caking agent is silicon dioxide, present in an amount of 1% to 2% (w/w).

In an aspect of the present invention, the chelating agent is citric acid, present in an amount of 0.1% to 0.5% (w/w).

In an aspect of the present invention, the filler is aluminum silicate, present in Q.S.

In another aspect of the present invention is to provide a synergistic herbicidal composition of penoxsulam, propanil and 2, 4-D or its salts with an improved stability and ready to use herbicidal composition, having superior bio-efficacy compared to the individual formulations.
a) weighing the filler, an anticaking agent, a chelating agent, a wetting agent, a dispersing agent, penoxsulam, propanil, 2,4-D amine salt and a defoamer in a pre-blender and mixing it for 1 hour,
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 < 15 micron,
c) collecting the milled material, and post blending the sample for 1 hour,
d) sending the sample to the quality analysis, and
e) packing the formulated material in a suitable package.

Yet another aspect of the present invention is to provide synergistic herbicidal composition that enables efficient and reliable control of grass and broad-leaf weeds.

The present invention relates to herbicidal composition with synergistic activity. The composition contains three components that mutually complement each other when used together and exhibit activity that is greater than the activities of individual components when used alone.
DESCRIPTION OF THE INVENTION
The following detailed description is presented to enable any person skilled in the art to make and use the invention. For purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that these specific details are not required to practice the invention. Descriptions of specific applications are provided only as representative examples. The present application is not intended to be limited to the embodiments shown but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.

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

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

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

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

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, 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. Preferably, the composition of the present invention is formulated as wettable powder (WP).

In one embodiment of the present invention provides a synergistic herbicidal composition comprising of (a) penoxsulam, (b) propanil, and (c) 2, 4-D or its salts with suitable agrochemical additives in synergistically effective amounts.

In another embodiment, the present invention is to provide a wettable powder composition comprising:
a) penoxsulam in a range from 0.5% (w/w) to 1.0% (w/w),
b) propanil in a range from 40% (w/w) to 60% (w/w),
c) 2, 4-D amine salt in a range from 20% (w/w) to 30% (w/w),
d) agrochemical additives.

According to the present invention, the suitable agrochemical additives are selected from a wetting agent, a dispersing agent, a defoamer, an anti-caking agent, a chelating agent, and a filler.

According to the present invention, the wetting agent is selected from an alkyl naphthalene sulfonate, dialkyl naphthalene sulphonate sodium salt, Propol 990N, Jeemol IP, and sodium salt of dibutyl naphthalene sulphonate, present in a range from 1% to 5% (w/w).

According to the present invention, the dispersing agent is selected from sodium polycarboxylate, blend of dispersing agent (Jeemol DW18), alkyl naphthalene sulfonate condensate, and sodium lignosulfonate, and combination thereof, present in a range from 1% to 10% (w/w).

According to the present invention, the defoamer is polydimethylsiloxane, present in a range from 0.1% to 1.5% (w/w).

According to the present invention, the anti-caking agent is silicon dioxide, present in an amount of 1% to 2% (w/w).

According to the present invention, the chelating agent is citric acid, present in an amount of 0.1% to 0.5% (w/w).

According to the present invention, the filler is aluminum silicate, present in Q.S.

In another embodiment of the present invention provides a process for the preparation of a wettable powder composition comprising of penoxsulam, propanil, and 2,4-D or its salts, wherein the process comprises the following steps:
a) weighing the filler, an anticaking agent, a chelating agent, a wetting agent, a dispersing agent, penoxsulam, propanil, 2,4-D amine salt and a defoamer in a pre-blender and mixing it for 1 hour,
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 < 15 micron,
c) collecting the milled material, and post blending the sample for 1 hour,
d) sending the sample to the quality analysis, and
e) packing the formulated material in a suitable package.

Yet another embodiment of the present invention is to provide a synergistic herbicidal composition of penoxsulam, propanil and 2, 4-D or its salts with an improved stability and ready to use herbicidal composition, having superior bio-efficacy compared to the individual formulations.

Yet another embodiment of the present invention is to provide synergistic herbicidal composition that enables efficient and reliable control of grass and broad-leaf weeds.

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.

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 present invention is further illustrated by the following examples which are provided merely to be exemplary of the inventions and is not intended to limit the scope of the invention. Certain modifications and equivalents will be apparent to those skilled in the art and are intended to be included within the scope of the present invention.

EXAMPLES:

Example-1: The illustrative embodiments show the composition of Penoxsulam 0.75 % + Propanil 50% + 2,4-D amine salt 25% in wettable powder form in different amount as follows:

Table-1:
S. No Compositions Function Charge in (%)
1. Penoxsulam Active ingredient 0.75
2. Propanil Active ingredient 50.0
3. 2,4-D amine salt Active ingredient 25.0
4. Sodium Polycarboxylate Dispersing agent 6.0
5. Blend of dispersing agent
(Jeemol DW18) Dispersing agent 4.0
6. Alkyl naphthalene sulfonate Wetting agent 4.0
7. Polydimethylsiloxane Defoamer 1.0
8. Citric acid chelating agent 0.5
9. Silicon dioxide Anti caking agent 2.0
10. Aluminium silicate (China clay) Filler Q.S.

Process for manufacture of composition is as follows: 0.75 gm of penoxsulam, 50.0 gm of propanil, 25.0 gm of 2,4-D amine salt, 6.0 gm of Sodium polycarboxylate, 4.0 gm of blend of dispersing agent (Jeemol DW18), 4.0 gm of alkyl naphthalene sulfonate, 1.0 gm of polydimethylsiloxane, 0.5 gm of citric acid, 2.0 gm of silicon dioxide, and required quantity of aluminum silicate (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 < 15 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Table 2:
S. No Compositions Function Charge in (%)
1. Penoxsulam Active ingredient 0.75
2. Propanil Active ingredient 50.0
3. 2,4-D amine salt Active ingredient 25.0
4. Alkyl naphthalene sulfonate Wetting agent 2.0
5. Alkyl naphthalene sulfonate condensate Dispersing agent 5.0
6. Polydimethylsiloxane Defoamer 0.2
7. Silicon dioxide Anti caking agent 1.0
8. Citric Acid chelating agent 0.1
9. Aluminium silicate (china clay) Filler Q.S.

Process for manufacture of composition is as follows: 0.75 gm of penoxsulam, 50.0 gm of propanil, 25.0 gm of 2,4-D amine salt, 2.0 gm of alkyl naphthalene sulfonate, 05 gm of Alkyl naphthalene sulfonate condensate, 0.2 gm of polydimethylsiloxane, 0.1 gm of citric acid, 1.0 gm of silicon dioxide, and required quantity of aluminum silicate (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 < 15 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Table 3:
S. No Compositions Function Charge in (%)
1. Penoxsulam Active ingredient 0.75
2. Propanil Active ingredient 50
3. 2,4-D amine salt Active ingredient 25
4. Propol 990 N Wetting agent 5.0
5. Sodium lignosulfonate Dispersing agent 6.0
6. Polydimethylsiloxane Defoamer 1.5
7. Silicon dioxide Anti caking agent 2.0
8. Citric Acid chelating agent 0.5
9. Aluminium silicate (China clay) Filler Q.S.

Process for manufacture of composition is as follows: 0.75 gm of penoxsulam, 50.0 gm of propanil, 25.0 gm of 2,4-D amine salt, 5.0 gm of Propol 990 N, 6.0 gm of Sodium lignosulfonate, 1.5 gm of polydimethylsiloxane, 2.0 gm of silicon dioxide, 0.5 gm of citric acid, and required quantity of aluminum silicate (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 < 15 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Table 4:
S. No Compositions Function Charge in (%)
1. Penoxsulam Active ingredient 0.75
2. Propanil Active ingredient 50
3. 2,4-D amine salt Active ingredient 25
4. Jeemol IP Wetting agent 3.0
5. Sodium Polycarboxylate Dispersing agent 10.0
6. Polydimethylsiloxane Defoamer 0.1
7. Silicon dioxide Anti caking agent 1.0
8. Citric acid chelating agent 0.1
9. Aluminium silicate (China clay) Filler Q.S.

Process for manufacture of composition is as follows: 0.75 gm of penoxsulam, 50.0 gm of propanil, 25.0 gm of 2,4-D amine salt, 3.0 gm of Jeemol IP, 10.0 gm of sodium polycarboxylate, 1.0 gm of silicon dioxide, 0.1 gm of citric acid, and required quantity of aluminum silicate (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 < 15 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

Table 5:
S. No Compositions Function Charge in (%)
1. Penoxsulam Active ingredient 0.75
2. Propanil Active ingredient 50
3. 2,4-D amine salt Active ingredient 25
4. Alkyl naphthalene sulfonate Wetting agent 5.0
5. Alkyl naphthalene sulfonate (ANS) condensate Dispersing agent 8.0
6. Polydimethylsiloxane Defoamer 1.2
7. Silicon dioxide Anti caking agent 1.0
8. Citric acid chelating agent 0.5
9. Aluminium silicate (China clay) Filler Q.S.

Process for manufacture of composition is as follows: 0.75 gm of penoxsulam, 50.0 gm of propanil, 25.0 gm of 2,4-D amine salt, 5.0 gm of alkyl naphthalene sulfonate, 8.0 gm of Alkyl naphthalene sulfonate (ANS) condensate, 1.2 gm of polydimethylsiloxane, 0.5 gm of citric acid, 1.0 gm of silicon dioxide, and required quantity of aluminum silicate (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 < 15 microns). Collecting the milled material and post blending the material for 1 hour followed by packing the material in a suitable package.

FIELD AND SYNERGY STUDIES:
Example 2: Efficacy study of penoxsulam 0.75% + propanil 50% + 2,4-D amine salt 25% in wettable powder form:
Weeds were reported to reduce rice yields by 12 to 98%, depending on type method of rice establishment. Rice yield losses due to uncontrolled weed growth and weed competition were least (12%) in transplanted rice and highest in aerobic direct-seeded rice. Traditionally, weed control in India has been largely dependent on manual weeding. However, increased labour scarcity and costs are encouraging farmers to adopt herbicides.

The field studies were conducted to compare the weed controlling activity of the combination of Propanil, Penoxsulam and 2,4-D amine salt. The active ingredient, Propanil belongs to chemical family “Amides” with mode of action PS-II inhibitors (inhibition of Photosystem II), Penoxsulam belongs to chemical family “Triazolopyrimidine sulfonamides” having ALS (inhibition of acetolactate synthase) mode of action and 2,4-D Salt belongs to chemical family Phenoxy-carboxylates with “Synthetic auxin” mode of action. The combination has the potential of controlling the cross-spectrum weeds (broad leaf weeds, grassy weeds, and sedges) in rice. All three molecules are safe to transplant & direct seeded rice when applied in post-emergence (15-20 days after transplanting) application timing.

The weed control activity of the individual herbicides of the invention and their combinations were evaluated on weeds such as Cyperus difformis, Cyperus iria, Echinochloa colonum, Echinochloa crusgalli, Monochoria vaginalis, Ludwigia parviflora & Eclipta alba. Trials were conducted with randomized block design with net plot size of 5m x 6m. Each trial was replicated four times and conducted under GEP guidelines. Spraying was done with manual operated backpack knapsack sprayer with 400 L of water spray volume per hectare at post-emergence (15-20 days after transplanting) 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 the 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 the one Gowing* derived and Colby** modified. Gowing described a mathematical formula for calculating the predicting response values for pesticide mixtures. He suggested the two formulae’s for determining the synergy between 2-way and 3-way combinations, *(Jerry Flint et al, 1988) ***

3-way combination:
(AB + AC + BC) ABC
Expected (E) = A + B + C - +
100 10000
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.

2-way combination:

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. Analysing Herbicide Interactions: A Statistical Treatment of Colby's Method. Weed Technology 2: 304-309

The herbicide combinations, application rates, plant species tested, and results are given in the following tables:

Table 6: Demonstrates synergy on weeds using the combination of Propanil, Penoxsulam and 2,4-D amine salt with their two-way and three-way combinations. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 30 days of application. The target weeds were Cyperus iria and Cyperus difformis and the results are recorded in the table below.
Active Dose (GAH) % Weed Control of Cyperus iria % Weed Control of Cyperus difformis
Expected Observed Expected Observed
Propanil 80% DF 1500 50 40
Penoxsulam 21.7% SC 22.5 75 70
2,4-D amine salt 58% SL 750 65 55
Propanil 80% DF + Penoxsulam 21.7% SC 1500 + 22.5 87.5 85 82 80
Ratio of O/E 0.97 0.97
Penoxsulam 21.7% SC + 2 ,4-D amine salt 58% SL 22.5 + 750 91.25 90 86.5 85
Ratio of O/E 0.98 0.98
Propanil 80% DF + 2 ,4-D amine salt 58% SL 1500 + 750 82.5 80 73 70
Ratio of O/E 0.96 0.95
Penoxsulam 0.75 % + Propanil 50% + 2,4-D amine salt 25% WP 22.5 + 1500 + 750 95.6 100 91.9 95
Ratio of O/E 1.04 1.03
DF - Dry flowable; SC – Suspension Concentrate; SL – Soluble liquid; WP – Wettable Powder; GAH – Gram active per hectare.

The results in table 6 clearly demonstrate synergy between the three-way combination of Propanil, Penoxsulam and 2,4-D amine salt against weeds like Cyperus iria and Cyperus difformis. The higher ratio of the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination. However, all two-way combinations showed lower ratio of the observed and the expected efficacy, which clearly showed the no synergistic effect of the combination against weeds like Cyperus iria and Cyperus difformis.

Table 7: Demonstrates synergy on weeds using the combination of Propanil, Penoxsulam and 2,4-D amine salt with their two-way and three-way combinations. The percentage efficacy was calculated after 30 days of application. The target weeds were Echinochloa colonum, Echinochloa colonum and Leptochloa chinensis. The results are recorded in the table below.
Active Dose (GAH) % Weed Control of Echinochloa colonum % Weed Control of Echinochloa crusgalli % Weed Control of Leptochloa chinensis
Expected Observed Expected Observed Expected Observed
Propanil 80% DF 1500 50 40 45
Penoxsulam 21.7% SC 22.5 75 65 50
2,4-D amine salt 58% SL 750 10 5 0
Propanil 80% DF + Penoxsulam 21.7% SC 1500 + 22.5 87.5 85 79 75 72.5 70
Ratio of O/E 0.97 0.94 0.96
Penoxsulam 21.7% SC + 2 ,4-D amine salt 58% SL 22.5 + 750 77.5 75 66.7 65 50 45
Ratio of O/E 0.96 0.97 0.90
Propanil 80% DF + 2 ,4-D amine salt 58% SL 1500 + 750 55 50 43 45 45 40
Ratio of O/E 0.90 0.95 0.88
Penoxsulam 0.75 % + Propanil 50% + 2,4-D amine salt 25% WP 22.5 +1500 + 750 88.7 90 80 85 72.5 75
Ratio of O/E 1.01 1.06 1.03
DF - Dry flowable; SC – Suspension Concentrate; SL – Soluble liquid; WP – Wettable Powder; GAH – Gram active per hectare.

The results in table 7 clearly demonstrate synergy between three-way combination of Propanil, Penoxsulam and 2,4-D amine salt against weeds like Echinochloa colonum, Echinochloa colonum and Leptochloa chinensis. The higher ratio of the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination. However, all two-way combinations showed lower ratio of the observed and the expected efficacy, which clearly showed the no synergistic effect of the combination against weeds like, Echinochloa colonum, Echinochloa colonum and Leptochloa chinensis.

Table 8: Demonstrates synergy on weeds using the combination Propanil, Penoxsulam and 2,4-D amine salt with their two-way and three-way combinations. The field trials were carried out in India at various locations. The percentage efficacy was calculated after 21 days of application. The target weeds were Monochoria vaginalis, Ludwigia parviflora and Eclipta alba. The results are recorded in the table below.
Active Dose (GAH) % Weed Control of Monochoria vaginalis % Weed Control of Ludwigia parviflora % Weed Control of Eclipta alba
Expected Observed Expected Observed Expected Observed
Propanil 80% DF 1500 25 50 60
Penoxsulam 21.7% SC 22.5 60 65 70
2,4-D amine salt 58% SL 750 80 75 80
Propanil 80% DF + Penoxsulam 21.7% SC 1500 + 30 70 70 82.5 80 88 85
Ratio of O/E 1.00 0.96 0.96
Penoxsulam 21.7% SC + 2 ,4-D amine salt 58% SL 22.5 + 750 92 90 91.2 90 94 92
Ratio of O/E 0.97 0.98 0.97
Propanil 80% DF + 2 ,4-D amine salt 58% SL 1500 + 750 85 85 87.5 85 92 90
Ratio of O/E 1.00 0.97 0.97
Penoxsulam 0.75 % + Propanil 50% + 2,4-D amine salt 25% WP 22.5 +1500 + 750 94 100 95.6 100 97.6 100
Ratio of O/E 1.06 1.04 1.02
DF - Dry flowable; SC – Suspension Concentrate; SL – Soluble liquid; WP – Wettable Powder; GAH – Gram active per hectare.

The results in table 8 clearly demonstrate synergy between a three-way combination of Propanil, Penoxsulam and 2,4-D amine salt against weeds like Monochoria vaginalis, Ludwigia parviflora and Eclipta alba. The higher ratio of the observed and the expected efficacy clearly demonstrates the synergistic effect of the combination. However, all two-way combinations showed lower ratio of the observed and the expected efficacy, which clearly showed the no synergistic effect of the combination against weeds like, Monochoria vaginalis, Ludwigia parviflora and Eclipta alba. ,CLAIMS:WE CLAIM:
1. A synergistic herbicidal composition comprising of (a) penoxsulam, (b) propanil, and (c) 2, 4-D or its salts with suitable agrochemical additives.

2. The composition as claimed in claim 1, wherein the composition is formulated as wettable powder (WP) form.

3. The composition as claimed in claim 2, wherein the composition comprising of:
a) penoxsulam in a range from 0.5% (w/w) to 1.0% (w/w),
b) propanil in a range from 40% (w/w) to 60% (w/w),
c) 2, 4-D amine salt in a range from 20% (w/w) to 30% (w/w),
d) agrochemical additives.

4. The composition as claimed in claim 3, wherein the agrochemical additives are selected from a wetting agent, a dispersing agent, a defoamer, an anti-caking agent, a chelating agent, and a filler.

5. The composition as claimed in claim 4, wherein the wetting agent is selected from an alkyl naphthalene sulfonate, dialkyl naphthalene sulphonate sodium salt, Propol 990N, Jeemol IP, and sodium salt of dibutyl naphthalene sulphonate, present in a range from 1% to 5% (w/w).

6. The composition as claimed in claim 4, wherein the dispersing agent is selected from sodium polycarboxylate, blend of dispersing agent (Jeemol DW18), alkyl naphthalene sulfonate condensate, and sodium lignosulfonate, and combination thereof, present in a range from 1% to 10% (w/w).

7. The composition as claimed in claim 4, wherein the defoamer is polydimethylsiloxane, present in a range from 0.1% to 1.5% (w/w).

8. The composition as claimed in claim 4, wherein the anti-caking agent is silicon dioxide, present in an amount of 1% to 2% (w/w).

9. The composition as claimed in claim 4, wherein the chelating agent is citric acid, present in an amount of 0.1% to 0.5% (w/w) and filler is aluminum silicate, present in Q.S.

10. The process for preparation of a wettable powder composition as claimed in claim 2, wherein the process comprising the steps of:
a. weighing the filler, an anticaking agent, a chelating agent, a wetting agent, a dispersing agent, penoxsulam, propanil, 2,4-D amine salt and a defoamer in a pre-blender and mixing it for 1 hour,
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 < 15 micron,
c. collecting the milled material, and post blending the sample for 1 hour,
d. sending the sample to the quality analysis, and
e. packing the formulated material in a suitable package.

Dated this Sixteenth (16th) day of October, 2023

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