WO2022190129A1

WO2022190129A1 - Herbicidal compositions comprising of phosphonic acid compound

Info

Publication number: WO2022190129A1
Application number: PCT/IN2022/050214
Authority: WO
Inventors: Parikshit MUNDHRA; Jitendra Mohan
Original assignee: Willowood Chemicals Private Limited
Priority date: 2021-03-09
Filing date: 2022-03-09
Publication date: 2022-09-15
Also published as: AU2022233984A1; BR112023018359A2

Abstract

The present invention provides a synergistic herbicidal composition comprising Glufosinate-ammonium and at least two compounds selected from the group comprising Mesotrione, Oxyfluorfen, Atrazine, 2,4-D and uses thereof.

Description

HERBICIDAL COMPOSITIONS COMPRISING OF PHOSPHONIC ACID

COMPOUND

FIELD OF THE INVENTION

The present invention relates to herbicidal composition comprising Glufosinate-ammonium and at least two compounds selected from Mesotrione, Oxyfluorfen, Atrazine, 2, 4-D and uses thereof.

BACKGROUND OF THE INVENTION

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

Chinese patent application No. 102763676 discloses a binary herbicidal composition containing herbicide A which is glufosinate and herbicide B, wherein herbicide B is one of the following selected from the list: fenoxaprop-ethyl, fenoxaprop-P-ethyl, isoproturon, diclofop- methyl, chlortoluron, methabenzthiazuron, imazamethabenz, tralkoxydim, difenzoquat, flampro, flamprop-M, pendimethalin, nicosulfuron, primisulfuron, 2, 4-D, dicamba, fluroxypyr, ioxynil, brominal, bifenox, fluoroglycofen-ethyl, acifluorfen, lactofen, fomesafen, oxyfluorfen, diflufenican, bentazone, isopropyl methoxalamine, piperazine humulone, atrazine, garagard, alachlor, acetochlor, butachlor, metsulfuron-methyl, tribenur on-methyl, thifensulfuron methyl, cinosulfuron, chlorine sulphur. However, the patent application fails to teach a composition comprising three active ingredients.

PCT publication no. WO/2019/030091 discloses an herbicidal mixture comprising of L- glufosinate and its salts and at least one herbicidal compound. The herbicidal compound is to be selected from a laundry list. All the provided examples are of binary combinations. Currently, in order to reduce the risk from increased number of herbicide resistant varieties, 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 successful control of weeds over a relatively longer period of time and preventing development of resistance. However, this requires continuous development of an effective composition with different active compounds, so as to avoid selection to the particular mechanism of action.

Therefore, there exists a need to develop an herbicidal composition which is stable, synergistic, broad spectrum, environmentally safe and more effective in control of weeds in crops. The herbicidal compositions must show a broader scope of activity to avoid or to control the development of resistant varieties to the active ingredients or to the mixtures of known active ingredients used by farmer while minimising the doses of chemical products sprayed in the agricultural fields.

As a solution to the above mentioned problems, the inventors of the present invention surprisingly found that composition comprising Glufosinate-ammonium and at least two compounds selected from the group comprising of Mesotrione, Oxyfluorfen, Atrazine, 2,4-D provides effective control of wide range of weeds or undesired plants.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a combination comprising of Glufosinate- ammonium and at least two compounds selected from the group comprising of Mesotrione, Oxyfluorfen, Atrazine, 2,4-D.

In an embodiment, the composition of the present invention comprises of Glufosinate- ammonium and at least two compounds selected from the group comprising of Mesotrione, Oxyfluorfen, Atrazine, 2, 4-D and one or more excipients.

In another embodiment, the composition of the present invention comprises of Glufosinate- ammonium, Mesotrione and Atrazine and one or more excipients.

In another embodiment, the composition of the present invention comprises of Glufosinate- ammonium, Oxyfluorfen and 2,4-D and one or more excipients. In an embodiment, Glufosinate-ammonium is present in an amount in the range of 7.5 to 25% w/w; and at least two compound selected from Mesotrione, Oxyfluorfen, Atrazine, 2,4-D present in an amount in the range of 1 to 70% w/w and one or more excipient.

In another embodiment, in a composition Glufosinate-ammonium is present in an amount in the a range from 10 to 25 %w/w, preferably in an amount 15 %w/w; Mesotrione is present in an amount in the range from 1 to 10 %w/w preferably in an amount 3.2 %w/w and Atrazine present in an amount in the range from 20 to 50% w/w preferably in an amount 30 %w/w.

In another embodiment, in a composition Glufosinate-ammonium is present in an amount in the range from 7.5 to 10 %w/w, preferably in an amount 10 %w/w; Oxyfluorfen is present in an amount in the range from 1 to 10% w/w preferably in an amount 2 %w/w and 2,4-D present in an amount in the range from of 20 to 70% w/w preferably in an amount 20% w/w.

In yet another embodiment, the composition of the present invention is selected from a group comprising:

• Glufosinate-ammonium present in an amount 15% w/w, Mesotrione present in an amount 3.2% w/w and Atrazine present in an amount 30% w/w and one or more excipients.

• Glufosinate-ammonium present in an amount 10% w/w, Oxyfluorfen present in an amount 2% w/w and 2,4-D present in an amount 20% w/w and one or more excipients.

In another embodiment, the composition of the present invention is 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) suspension, Tablet (TB), Ultra-low volume (ULV) liquid, Water dispersible granules (WG/WDG), Wettable powder (WP), Dry flowable (DF), Water dispersible powder for slurry seed treatment (WS), Water dispersible tablet (WT), a mixed formulation of CS and SC (ZC) or A mixed formulation of CS and SE (ZE), a mixed formulation of CS and EW (ZW). In a preferred embodiment, the composition is formulated as WDG/WG/DF

In an embodiment, the excipient used in the present invention is selected from the group comprising of dispersing agent, wetting agent, disintegrating agent, antifoaming agent, fillers or a combination thereof and other excipients as will be required in a particular type of formulation.

DETAILED DESCRIPTION OF THE INVENTION

The definitions provided herein for the terminologies used in the present disclosure are for illustrative purpose only and in no manner limit, the scope of the present invention disclosed in the present disclosure.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although other methods and materials similar, or equivalent, to those described herein can be used in the practice of the present invention, the preferred materials and methods are described herein.

It is to be noted that, as used in the specification and the appended claims, 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 "comprises", "comprising", "includes", "including", or any other variation thereof, are intended to cover a non-exclusive inclusion, subject to any limitation explicitly indicated. For example, a composition or a method that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, or method.

As used herein, the terms “composition” or "formulation" can be used interchangeably, unless stated otherwise, is meant to encompass, and are not limited to, compositions or formulations containing the combination of Glufosinate-ammonium with at least two compounds selected from the group comprising of Mesotrione, Oxyfluorfen, Atrazine, 2,4-D. The expression of various quantities in terms of “% w/w” or “%” means the percentage by weight, relative to the weight of the total solution or composition unless otherwise specified.

The term “active ingredient” “(a.i.)” or “active agent” used herein refers to that component of the composition responsible for control of weeds or undesired plants.

As used herein, the term "effective amount" means the amount of the active substances in the compositions to achieve an observable effect on growth, including the effects of necrosis, death, retardation, prevention, and removal, destruction, or otherwise diminishing the occurrence and activity of the target weeds. An effective amount of the compositions will also vary according to the prevailing conditions such as desired herbicidal effect and duration, weather, target species, locus, mode of application, and the like.

As used herein, the term “herbicide”, refers to any chemical substance used to destroy/kill, delay, reduce, inhibit or otherwise adversely affect the growth of plants, especially weeds.

As used herein, the term “Glufosinate-ammonium” encompasses its enantiomer(s), or any other modified form of Glufosinate-ammonium. Glufosinate-ammonium belongs to the class of phosphonic acid herbicide. It acts by glutamine synthetase inhibition. It is a non-selective contact herbicide. It is used for post-emergence control of annual and perennial broad-leaved and grass weeds in fruit, vineyards, rubber, oil palms, ornamental trees and bushes, non-crop land and pre-emergence in vegetables.

As used herein, the term “Mesotrione” encompasses Mesotrione or its agrochemically acceptable salt(s), derivative(s) or any other modified form of Mesotrione. Mesotrione belongs to the class of benzoylcyclohexanedione / triketone herbicide. It works by inhibiting enzyme 4-hydroxyphenyl pyruvate dioxygenase (HPPD inhibitor). It is used for pre-emergence and post-emergence control of broad-leaved and some grass weeds in sugarcane and maize.

As used herein, the term “Oxyfluorfen” encompasses Oxyfluorfen or its agrochemically acceptable salt(s), derivative(s) or any other modified form of Oxyfluorfen. Oxyfluorfen belongs to the class of diphenyl ether herbicide. It acts by protoporphyrinogen oxidase (PPO) inhibitor. It is a selective contact herbicide. It is used for pre-emergence and post-emergence control of annual broad leaved and grass weeds in tree fruit, citrus, vines, nuts, cereals, maize, soybeans, peanuts, rice, cotton, bananas, peppermint, onions, garlic, ornamentals and conifer seedbeds.

As used herein, the term “2,4-D” encompasses 2,4-D or its agrochemically acceptable salt(s) such as ammonium (2,4-dichlorophenoxy)acetate, 2-hydroxy-N,N,N-trimethylethanaminium (2,4-dichlorophenoxy)acetate, diethylammonium (2,4-dichlorophenoxy)acetate, dimethylammonium (2,4-dichlorophenoxy)acetate, bis(2-hydroxyethyl)ammonium (2,4- dichlorophenoxy)acetate, dodecylammonium (2,4-dichlorophenoxy)acetate, heptylammonium (2,4-dichlorophenoxy)acetate, isopropylammonium (2,4-dichlorophenoxy)acetate, lithium (2,4-dichlorophenoxy)acetate, methylammonium (2,4-dichlorophenoxy)acetate, tetradecylammonium (2,4-dichlorophenoxy)acetate, triethylammonium (2,4- dichlorophenoxy)acetate, tris(2-hydroxypropyl)ammonium (2,4-dichlorophenoxy)acetate, tris(2-hydroxyethyl)ammonium (2,4-dichlorophenoxy)acetate, potassium (2,4- dichlorophenoxy)acetate, sodium (2,4-dichlorophenoxy)acetate (2,4-D sodium) and esters of 2,4-D such as 2-butoxyethyl (2,4-dichlorophenoxy)acetate, butyl (2,4- dichlorophenoxy)acetate, 2-butoxypropyl (2,4-dichlorophenoxy)acetate, 2-ethylhexyl (2,4- dichlorophenoxy)acetate, ethyl (2,4-dichlorophenoxy)acetate, 2-methylpropyl (2,4- dichlorophenoxy)acetate, isooctyl (2,4-dichlorophenoxy)acetate, isopropyl (2,4- dichlorophenoxy)acetate, 1-methylheptyl (2,4-dichlorophenoxy)acetate, methyl (2,4- dichlorophenoxy)acetate, octyl (2,4-dichlorophenoxy)acetate, pentyl (2,4- dichlorophenoxy)acetate, propyl (2,4-dichlorophenoxy)acetate, tefuryl (2,4- dichlorophenoxy)acetate, 3-butoxypropyl (2,4-dichlorophenoxy)acetate, 1- (dimethoxyphosphinoyl)ethyl (2,4-dichlorophenoxy)acetate, derivative(s) or any other modified form of 2,4-D. 2,4-D belongs to the class of phenoxycarboxylic acid herbicide. It works by mimicking the action of the plant growth hormone auxin, which results in uncontrolled growth and eventually death in susceptible plants. It is a selective systemic herbicide. The salts are readily absorbed by the roots, whilst esters are readily absorbed by the foliage. Translocation occurs, with accumulation principally at the meristematic regions of roots and shoots. It acts as a growth inhibitor. It is used for post-emergence control of annual and perennial broad-leaved weeds in cereals, maize, sorghum, grassland, established turf, grass seed crops, orchards (pome fruit and stone fruit), cranberries, asparagus, sugarcane, rice, forestry, and on non-crop land (including areas adjacent to water for control of broad-leaved aquatic weeds). The isopropyl ester can also be used as a plant growth regulator to prevent premature fruit fall in citrus fruit. As used herein, the term “Atrazine” encompasses Atrazine or its agrochemically acceptable salt(s), derivative(s) or any other modified form of Atrazine. Atrazine belongs to the class of triazine herbicide. It is a photosynthetic electron transport inhibitor at the photosystem II receptor site. It is a selective systemic herbicide, absorbed principally through the roots, but also through the foliage, with translocation acropetally in the xylem and accumulation in the apical meristems and leaves. It is used for pre- and post-emergence control of annual broad leaved weeds and annual grasses in maize, sorghum, sugarcane, pineapples, chemical fallow, grassland, macadamia nuts, conifers and industrial weed control.

The present invention provides a synergistic compositions of Glufosinate-ammonium with at least two compounds selected from the group comprising of Mesotrione, Oxyfluorfen, Atrazine, 2,4-D and one or more excipients.

It has been surprisingly found that composition comprising Glufosinate-ammonium, and at least two herbicidal compounds selected from Mesotrione, Oxyfluorfen, Atrazine, 2,4-D not only provides effective control of weeds or undesired plants but also such combination is synergistic in nature.

In an embodiment, the synergistic composition of the present invention comprises of Glufosinate-ammonium in an amount in the range from 7.5 to 25% w/w; and at least two compound selected from Mesotrione, Oxyfluorfen, Atrazine, 2,4-D present in an amount in the range of 1 to 70% w/w and one or more excipient. In another embodiment, in a composition Glufosinate-ammonium is present in an amount in the range from 10 to 25 %w/w, preferably in an amount 15%w/w; Mesotrione is present in an amount in the range from 1 tolO %w/w, preferably in an amount 3.2 %w/w and Atrazine present in an amount in a range from of 20 to 50% w/w, preferably in an amount 30 %w/w. In another embodiment, in a composition Glufosinate-ammonium is present in an amount in the range from 7.5 to 10 %w/w, preferably in an amount 10%w/w; Oxyfluorfen is present in an amount in the range from 1 tol0%w/w, preferably in an amount 2 %w/w and 2,4-D present in an amount in the range from 20 to 70% w/w, preferably in an amount 20 % w/w.

In yet another embodiment, the composition of the present invention is selected from a group comprising: • Glufosinate-ammonium present in an amount 15% w/w, Mesotrione present in an amount 3.2% w/w and Atrazine present in an amount 30% w/w and one or more excipients.

In an embodiment, the composition of the present invention comprises one or more excipients selected from dispersing agent, wetting agent, disintegrating agent, antifoaming agent, fillers or a combination thereof and other excipients as will be required in a particular type of formulation.

In another embodiment, the composition of the present invention is 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) suspension, Tablet (TB), Ultra-low volume (ULV) liquid, Water dispersible granules (WG/WDG), Wettable powder (WP), Dry flowable (DF), Water dispersible powder for slurry seed treatment (WS), Water dispersible tablet (WT), a mixed formulation of CS and SC (ZC) or A mixed formulation of CS and SE (ZE), a mixed formulation of CS and EW (ZW). In a preferred embodiment, the composition is formulated as WDG/WG/DF.

It is generally observed that solid particles in a liquid undergo spontaneous aggregation to form lumps. Hence, it is recommended to add a dispersing agent/surf actant which prevents agglomeration of solid particles and keep them suspended in fluid. Accordingly, the composition of the present invention contains dispersing agent such as sodium salt of naphthalene sulphonate condensate, sulfonated aromatic polymer sodium salt, sodium polycarboxylate, ethanesulfonic acid 2-[methyl[(9Z)-l-oxo-9-octadecenyl]amino]-sodium salt, sodium 2-(methyloleoylamino)ethane-l -sulphonate, amine salt of phosphate tristyryl phenol ethoxylated, acrylic copolymer, graft copolymer, salt of naphthalene sulphonate, naphthalene sulfonate formaldehyde condensate, phosphate ester, salt of polycarboxylate, alcohol block copolymer, ethoxylated polyarylphenol phosphate ester. One or more dispersing agents may be used in the synergistic composition of the present invention. The dispersing agent is present in an amount in the range from 1 to 10% w/w.

Wetting is the first stage of dispersion, in which air surrounding the granular composition is substituted with water. Wetting of the composition with water cannot occur if the surface tension of the liquid is very high. Hence, it is recommended to add a wetting agent to the composition to facilitate the process of dispersion of the granules in the liquid. Non-limiting examples of wetting agents that can be used in the present invention include, but not limited to, sodium lauryl sulphate, sodium alkyl naphthalene sulfonate blend, sodium alkylnaphthalenesulfonate, sodium isopropyl naphthalene sulfonate, sodium dioctylsulfosuccinate, ethoxylated polyarylphenol phosphate ester, dioctyl sulphosuccinate, non-ionic ethoxylate. One or more wetting agents may be used in the synergistic composition of the present invention. The wetting agent is present in an amount in the range from 1 to 10% w/w.

Disintegrating agent is selected from the group comprising of sodium sulphate, ammonium sulphate, sodium bicarbonate, lactose or a combination thereof. The disintegrating agent is present in an amount in the range from 1 to 10% w/w.

An antifoaming agent is generally added to the composition, as foam formation prevents the efficient filling of a container. Suitable defoamer used herein, but not limited to, silicon emulsion, polysiloxane emulsion, dimethylpoly siloxane, organic fluorine compounds or a combination thereof and present in an amount in the range from 0.1 to 5% w/w.

A filler is added to the composition to improve the handling and storage characteristics of the composition. Fillers also add mass and/or volume to the active ingredient in order to facilitate precise measurement of the doses. Suitable fillers that may be used in the composition of the present invention include, but not limited to, bentonite clay, china clay, silica, kaolin and diatomaceous earth. The filler may be used in an amount of quantity sufficient to make 100%w/w formulation.

The composition of the present invention can be applied by any one of the methods selected from atomization, spreading, dusting, spraying, diffusion, immersion, irrigation, injection, mixing, sprinkling (water immersion), foaming, dressing, coating, blasting, fumigation, smoking, smog and painting.

In another embodiment, the present invention provides a process for the preparation of a WDG/WG/DF formulation which comprises of a) mixing of Glufosinate-ammonium, Mesotrione, Atrazine, dispersing agent, disintegrating agent, filler in a blender, b) milling the mixture of step a) using a suitable air-jet mill, c) preparing dough of the milled mixture, d) extruding the dough using suitable extruder, e) drying the extruded granule in suitable dryer.

In another embodiment, the composition of the present invention is effective in the management of post-emergence of monocotyledonous and dicotyledonous weeds. In an embodiment of the present invention, the composition used for the post-emergence control of variety of crops, including but not limited to, in cereals namely wheat, maize, sorghum, rice, barley, oats, triticale etc., soybeans, peanuts, cotton, onions, garlic, asparagus, sugarcane, ornamentals, rubber, as well as protecting crops from herbicidal injury caused by any of the individual components.

The rate of application amount varies depending on, for example, the blending ratio of active ingredients, meteorological condition, dosage form, application time, application method, application place, weed to be controlled, and target crop, in ordinary cases.

The synergistic composition of the present invention provides a number of other advantages:

• Increased efficacy in comparison to the other formulations tested during the trial.

• Economically beneficial to the farmers as it provides better yield of the crop with reduction in the number of sprays.

• Reduced possibility of hazards to the farmers due to occupational exposure because of reduction in the number of sprays.

• Is storage stable.

• Is non-phytotoxic.

• Environmental friendly.

The embodiments of the present invention are more particularly described in the following examples that are intended as illustrations only, since numerous modifications and variations within the scope of the present invention will be apparent to those of skill in the art. Unless otherwise noted, all parts, percentages and ratio reported in the following examples are on a weight basis and all excipients used in the examples were obtained or are available from the chemical suppliers.

EXAMPLES

The synergistic herbicidal composition of the present invention comprising Glufosinate- ammonium and at least two compounds selected from Mesotrione, Oxyfluorfen, Atrazine, 2,4- D in WDG/WG/DF form is provided in example 1 to 9. The unit of each component of the composition are expressed in “% w/w” i.e. the percentage by weight, relative to the weight of the total solution or composition.

Examples 1 to 4

Table 1: Glufosinate-ammonium + Mesotrione + Atrazine WDG/WG/DF

Total 100 100

100 100

Q.S.: quantity sufficient required to make 100% w/w formulation

Process of preparing synergistic water dispersible granule herbicidal composition comprising Glufosinate-ammonium + Mesotrione + Atrazine

Table 2 provides quantities of active ingredients and raw material charged to prepare the synergistic composition of the present invention in WDG/WG/DF form. In table 2, active ingredients Glufosinate-ammonium, Mesotrione, Atrazine are in technical grade with 96%, 97% and 97% purity respectively. Particularly example 1 corresponds to column A in table 2.

Table 2: Quantities of active ingredients and raw material charged

The ingredients were weighed and taken as per table 2. Sodium salt of naphthalene sulfonate condensate, sodium alkyl naphthalene sulfonate blend, sodium sulphate, dimethyl polysiloxane, china clay were taken and stirred well with high shear mixer. To the mixture, Glufosinate ammonium, Mesotrione, Atrazine were added and mixed in a ribbon blender type mixture. The mixture was milled by air jet mill until a mean particle size of below 10 microns was obtained. A dough was prepared using the milled mixture and 1% to 2% water in suitable dough mixer. The dough was then extruded using proper extruder having 0.8 mm size screen while maintaining the temperature of the screen below 50^°C and RPM of the extruder at about 20 to 25^°C to obtain extruded granules. The extruded granules were dried using a fluid bed dryer. The air flow was kept at 75% to 80% and temperature of the air was maintained at 47°C to obtain the title herbicidal composition in WDG/WG/DF form and sent to check for quality parameters.

Example 5 to 9 Table 3: Glufosinate-ammonium + Oxyfluorfen + 2,4-D Sodium WDG/WG/DF

Q.S.: quantity sufficient required to make 100% w/w formulation

Process of preparing synergistic water dispersible granule herbicidal composition comprising Glufosinate-ammonium + Oxyfluorfen + 2,4-D Sodium

Table 4 provides quantities of active ingredients and raw material charged to prepare the synergistic composition of the present invention in WDG/WG/DF form. In table 4, active ingredients Glufosinate-ammonium, Oxyfluorfen, 2,4-D Sodium are in technical grade with 96%, 96% and 95% purity respectively. Particularly example 7 corresponds to column B in table 4. Table 4: Quantities of active ingredients and raw material charged

The ingredients were weighed and taken as per table 4. Sodium salt of naphthalene sulfonate condensate, sodium alkyl naphthalene sulfonate blend, sodium sulphate, dimethyl polysiloxane, china clay were taken and stirred well with high shear mixer. To the mixture, Glufosinate-ammonium, Oxyfluorfen, 2,4 D Sodium were added and mixed in a ribbon blender type mixture. The mixture was milled by air jet mill until a mean particle size of below 10 microns was obtained. A dough was prepared using the milled mixture and 1% to 2% water in suitable dough mixer. The dough was then extruded using proper extruder having 0.8 mm size screen while maintaining the temperature of the screen below 50^°C and RPM of the extruder at about 20 to 25^°C to obtain extruded granules. The extruded granules were dried using a fluid bed dryer. The air flow was kept at 75% to 80% and temperature of the air was maintained at 47^°C to obtain the title herbicidal composition in WDG/WG/DF form and sent to check for quality parameters.

The rate of application amount varies depending on, for example, the blending ratio of active ingredients, metrological condition, a dosage form, an application time, an application method, an application place, weed to be controlled, and a target crop, in ordinary cases.

Bio-efficacy of the herbicidal composition of the present invention

Glufosinate-ammonium 15% + Mesotrione 3.2% + Atrazine 30% WDG/WG/DF

Experimental trial was conducted to evaluate the herbicidal composition of the present invention in India against major weeds in sugarcane crop with solo formulations, binary formulations and ternary formulations of the present invention as per the details provided in Table 5-9. The experiment was laid out in Randomized Block Design (RBD). The plot size was 10 m x 10 m and the spacing was 90 cm x 60 cm. All the recommended agronomic practices were followed throughout the cropping period. The different formulations were weighed according to the doses and diluted in water and applied using high volume knapsack sprayer fitted with a pressure regulator and a vertical bar with one flat fan nozzle and evaluated for % WCE (weed control efficiency) at 30, 60, 90 and 120 days after herbicide application (DAHA). 600 L/ha of water was used to dilute recommended doses of the formulation in the trial.

Observations from a composite sample (collected from three different spots in the experimental area) were recorded at 30, 60, 90 and 120 Days after herbicide application (DAHA). On each date of taking observation, weeds were collected from one square meter of each experimental plot and were cleaned. Weeds were then separated species wise and were oven dried and then weight was taken separately. Weed control efficacy for individual species was calculated using the formula:

W.C.E (%) = Weed population in control plot — weed population in treated plot X 100

Weed population in control plot

Yield: Canes from each experimental plot were harvested and weight of canes was taken. Afterwards weight was converted to yield into ton per hectare (t/ha).

Table 5: Treatment Details

Table 6: Effect of treatment on weed control efficiency against Narrow leaved weeds at different days after herbicides application

Table 7: Effect of treatment on weed control efficiency against sedges at different days after herbicides application

Table 8: Effect of treatment on weed control efficiency against Broad leaved weeds at different days after herbicides application

Table 9: Effect of treatments on Cane yield at harvest

SEM- Standard error of mean; CD5%: Critical Difference Phytotoxicity Observations

For phytotoxicity evaluation, following observations were made by observing temporary or long lasting damage to the leaves, if any, viz., leaf injury on tips and leaf surface, wilting, vein clearing, necrosis, epinasty and hyponasty at 30, 60, 90 and 120 DAHA.

Table 10: Phyto-toxicity studies of treatments on Sugarcane crop

0-No Phyto-toxicity 10-Complete kill the plant

Glufosinate-ammonium 10% + Oxyfluorfen 2% + 2.4-D Sodium 20% WDG/WG/DF

Experimental trial was conducted to evaluate the herbicidal composition of the present invention in India against major weeds in Tea crop with solo formulations, binary formulations and ternary formulations of the present invention as per the details provided in Table 11.

The experiment was laid out in Randomized Block Design (RBD). The plot size was 10 m x 10 m and the spacing was 75 cm x 75 cm. All the recommended agronomic practices were followed throughout the cropping period. The different formulations were weighed according to the doses and diluted in water and applied using high volume knapsack sprayer fitted with a pressure regulator and a vertical bar with one flat fan nozzle and evaluated for % WCE (weed control efficiency) at 15, 30, 45 and 60 days after herbicide application (DAHA). 600 L/ha of water was used to dilute recommended doses of the formulation in the trial.

A separate area of 0.5 m x 0.5 m was marked in each plot and the species-wise weed (broad leaved and grassy weeds separately) in each marked quadrant were removed at 15, 30, 45 and 60 days after application of herbicide and oven dried at 80°C for 72 hours and weighed to estimate the dry weight of weeds. Using the species-wise weed dry weight recorded at 15, 30, 45 and 60 days after spray of herbicide under absolute control and the respective treatments, the weed control efficiency (WCE) for each treatment was worked out by using formula given below:

Weed dry weight in the untreated plot-Weed dry weight in the treated plot

WCE (%) Weed dry weight in the untreated plot x 100

Fresh green leaf yield was calculated from each plot for three pickings and converted in green yield per hectare and expressed as kg/ha. Phytotoxic effect was also studied during the trial.

Table 11: Treatment Details

Table 12: Effect of treatment on weed control efficiency against Narrow leaved weeds at different days after herbicides application

Table 13: Effect of treatment on weed control efficiency against Broad leaved weeds at different days after herbicides application

Table 14: Effect of treatments on Green Leaf yield at harvest

SEM- Standard error of mean; CD5%: Critical Difference

Phytotoxicity Observations

For phytotoxicity evaluation, following observations were made by observing temporary or long lasting damage to the leaves if any viz., leaf injury on tips and leaf surface, wilting, vein clearing, necrosis, epinasty and hyponasty at 15, 30, 45, 60 DAHA.

Table 15: Phyto-toxicity study of treatments on Tea crop

0-No Phyto-toxicity 10-Complete kill the plant

Evaluation of synergistic effect

A synergistic effect exists whenever the action of an active ingredient combination is greater than the sum of the actions of the individual components. Synergism was calculated by using Colby’s method, Weeds, vol. 15 No. l(Jan 1967), pp. 20-2.

The synergistic action expected for a given combination of three active components can be calculated as follows:

(XY+YZ+XZ) XYZ

E = (X+Y+Z)

Ϊ00 ⁺ 10000

Where:

E represents expected percentage of control for the combination of the three active ingredients at defined doses (for example equal to x, y and z respectively),

X is the percentage of control observed by the compound (I) at a defined dose (equal to x),

Y is the percentage of control observed by the compound (II) at a defined dose (equal to y),

Z is the percentage of control observed by the compound (III) at a defined dose (equal to z).

If observed control of the combination > Expected control, the combination is synergistic If observed control of the combination < Expected control, the combination is antagonistic If observed control of the combination = Expected control, the combination is additive

Table 16: Synergistic effect of Glufosinate-ammonium + Mesotrione + Atrazine against Narrow leaved weeds, Sedges and Broad leaved weeds

Table 17: Synergistic effect of Glufosinate-ammonium + Oxyfluorfen + 2,4-D Sodium against Narrow leaved weeds and Broad leaved weeds

From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and 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. It should be understood that 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.

Claims

We claim:

1. A synergistic herbicidal composition comprising Glufosinate-ammonium and at least two compounds selected from a. Mesotrione; b. Oxyfluorfen; c. Atrazine; d. 2,4-D; and e. one or more excipients.

2. The composition as claimed in claim 1, comprising Glufosinate-ammonium in the range of 7.5 to 25% w/w; and at least two compound selected from Mesotrione, Oxyfluorfen, Atrazine, 2,4-D in the range of 1 to 70% w/w and one or more excipient.

3. The composition as claimed in claim 2, wherein:

Mesotrione is preferably present in an amount 1 tolO % w/w, more preferably in an amount 3.2% w/w;

Oxyfluorfen is preferably present in an amount 1 tolO % w/w, preferably in an amount 2 %w/w;

Atrazine present in an amount of 20 to 50% w/w, preferably in an amount 30 % w/w; and

2,4-D present in an amount of 20 to 70% w/w, preferably in an amount 20% w/w.

4. The composition as claimed in claim 1, wherein the composition is selected from a group comprising:

5. The composition as claimed in claim 1, wherein the composition is 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) suspension, Tablet (TB), Ultra-low volume (ULV) liquid, Water dispersible granules (WDG/WG), Wettable powder (WP), Dry flowable (DF), Water dispersible powder for slurry seed treatment (WS), Water dispersible tablet (WT), a mixed formulation of CS and SC (ZC) or a mixed formulation of CS and SE (ZE), a mixed formulation of CS and EW (ZW).

6. The composition as claimed in claims 1 and 4, wherein the composition is formulated as WDG/WG/DF.

7. The composition as claimed in claim 1, wherein the excipient is selected from the group comprising of:

• dispersing agent present in an amount in the range from 1 to 10% w/w;

• wetting agent present in an amount in the range from 1 to 10% w/w;

• disintegrating agent present in an amount in the range from 1 to 10% w/w;

• antifoaming agent present in an amount in the range from 0.1 to 5% w/w; and

• filler present in an amount quantity sufficient.

8. The composition as claimed in claim 7, wherein:

• dispersing agent is selected from the group comprising sodium salt of naphthalene sulphonate condensate, sulfonated aromatic polymer sodium salt, sodium polycarboxylate, ethanesulfonic acid 2-[methyl[(9Z)-l-oxo-9-octadecenyl]amino]- sodium salt, sodium 2-(methyloleoylamino)ethane-l -sulphonate, amine salt of phosphate tristyryl phenol ethoxylated, acrylic copolymer, graft copolymer, salt of naphthalene sulphonate, naphthalene sulfonate formaldehyde condensate, phosphate ester, salt of polycarboxylate, alcohol block copolymer, ethoxylated polyarylphenol phosphate ester or a combination thereof; • wetting agent is selected from the group comprising sodium lauryl sulphate, sodium alkyl naphthalene sulfonate blend, sodium alkylnaphthalenesulfonate, sodium isopropyl naphthalene sulfonate, sodium dioctylsulfosuccinate, ethoxylated polyarylphenol phosphate ester, dioctyl sulphosuccinate, non-ionic ethoxylate or a combination thereof;

• disintegrating agent is selected from the group comprising sodium sulphate, ammonium sulphate, sodium bicarbonate, lactose or a combination thereof;

• antifoaming agent is selected from the group comprising silicon emulsion, polysiloxane emulsion, dimethylpoly siloxane, organic fluorine compounds or a combination thereof; and

• filler is selected from the group comprising silica, china clay or a combination thereof.