DESC:FIELD OF INVENTION
[001] The present invention relates to a herbicidal composition for a broad-spectrum control of weeds in paddy crop.

BACKGROUND OF INVENTION
[002] Weeds are plants that are considered undesirable, since they are plants which grow out of place and are not intentionally sowed. Weeds generally do not have any redeeming value as far as food, nutrition or medicinal values are concerned.
[003] Weeds have an accelerated growth mechanism. Thus, when weeds undesireably grow around essential crops and plants they interfere with the essential crops by: competing for resources that the essential crop typicaly needs, namely direct sunlight, soil nutrients, water, and space for growth; providing hosts and vectors for plant pathogens, giving them greater opportunity to infect and degrade the quality of the desired crops; providing food or shelter for animal pests such as seed-eating birds; offering irritation to skin and/ or digestive tracts of people/ animals, either physical irritation via thorns, prickles, or burs, or chemical irritation via natural poisons or irritants present in the weeds; causing root damage to engineering works such as drains, road surfaces, and foundations, etc.
[004] Weed control is therefore important in agriculture. Methods for weed control include hand cultivation with hoes, powered cultivation with cultivators, smothering with mulch or soil solarization, lethal wilting with high heat, burning, or chemical attack with herbicides.
[005] Accordingly, agriculture industry uses a wide range of herbicides in order to control weeds which interfere with growth, development, yield and quality of agricultural crops.
[006] For convenience in production, packaging and handling, herbicides are frequenty manufactured in a powder form which is subsequently mixed with water to produce an aqueous solution. Different types of formulations have also been prepared like capsule suspension (CS) formulations, soluble concentrate (SL) formulations, emulsifiable concentrate (EC) formulations, suspension concentrate (SC) formulations etc.
[007] However, making an aqueous solution often meets a plethora of challenges like, immiscibility of the herbicide in water, instability of the aqueous solution, narrow range of action, low efficacy, short duration of action, slow onset of action and immiscibility of aqueous solution in sandy soils which have less moisture holding capacity and subsequently lead to shorter duration of action, to name a few.
[008] More so, a wide range of herbicide formulations contain only a single active ingredient and cannot contain two or more active ingredients due to several reasons like adverse reactions, non-synergistic effects, non-compatibility of intermixed ingredients etc.
[009] Hence, there is a need in the market for a composition which combines desirable herbicides for broad spectrum control of weeds.
SUMMARY OF THE INVENTION
[010] In one aspect, the present invention discloses a herbicidal composition including Bispyribac sodium; Pyrithiobac acid and agrochemically acceptable excipients. The herbicidal composition is used for broad spectrum control of weed species such as Echinochloa colonum, Echinochloa crusgalli, Leptochloa Inflorescence, Laptochloa chinensis, Dectylolactinum, Eclipta alba, Digera muricata, Phyllanthus niruri, Portulaca oleracea, Ludwigia spp, Alternanthera polygonoides, Cyanotis sp., Ammania sp., Digera sp., Parthenium sp., Digera arvensis, Cyprus iria, Cyprus spp, Cyprus diformis.

DESCRIPTION OF INVENTION
[011] The present invention aims at formulating at least two herbicides to attain a synergistic mode of action for a broad spectrum control of weeds.
[012] The present invention aims at formulating at least two herbicides to attain a synergistic mode of action for a broad spectrum control of weeds which are not completely controlled when one herbicide is used in isolation. The formulation of the invention also effectively controls weed species that have developed some resistance against Bispyribac sodium and its derivatives alone. Bispyribac sodium is recently become poor on: grasses: Leptochloa chinensis, Dactyloctenium aegyptium, Eleusine indica, Eragrotis sp.,Cyprus rotundus. Blw: Digera and no residual control and only growth suppression: Echinochloa polystochya, Alternanthera phyloxeroides, Amaranthus palmeri, Eclipta alba, Ipomea aquatica.
[013] In one aspect, the present invention provides a composition of at least two types of herbicides, of which one is an early post-emergent herbicide whilst the other is a post-emergent herbicide.
[014] Accordingly, the present invention uses at least one early post-emergent herbicide in order to inhibit initial growth phase of broad leaf weeds, i.e. growth inhibition of young weed seedlings, roots and shoots. According to the invention, the early post-emergent herbicide used is Pyrithiobac acid. Further, the Pyrithiobac acid is an agriculturally acceptable sodium ester. In various embodiment of the invention, the early post-emergent herbicides used are selected from, but not limiting to, sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio)benzoate (also known as Pyrithiobac sodium), Cyhalofop Butyl, Quizalofop-P-ethyl, Fenoxaprop-p-ethyl, Penoxsulam, Bensulfuron methyl, Ammonium salt of imazethapyr, Halosulfuron-methyl, Thifensulfuron-methyl, Prosulfuron, Quinclorac, Florpyrauxifen-benzyl, Triclopyr, Propanil, Bentazone, Saflufenacil, Acifluorfen, Anilofos, Orthosulfamuron, Chlorimuron Ethyl, Ammonium salt of imazamox, Imazethapyr, or any combination thereof. In an embodiment of the invention, the herbicidal composition has 4gm to 10 gm of Pyrithiobac acid.
[015] Futher, the present invention uses at least one post-emergent herbicide in order to inhibit actively growing weeds such as grasses, broad leaf weeds & sedges that are already present on the soil surface. According to the invention, the post-emergent herbicide used is Bispyribac sodium. In various embodiments of the invention, the post-emergent herbicide is selected from, but not limiting to sodium 2,6-bis((4,6-dimethoxypyrimidin-2-yl)oxy)benzoate (also known as Bispyribac sodium), Azimsulfuron, Bensulfuron methyl, Chlorimuron-ethyl, 2,4-D ethyl ester, Ethoxysulfuron, Fenoxaprop-P-ethyl, Metsulfuronmethyl, Paraquat, Bentazone, Carfentrazone ethyl, Cyhalofop Butyl, Penoxsulam, Cyhalofop-butyl, Triafamone, Ethoxysulfuron, Metsulfuron, Chlorimuron, or any combination thereof. In an embodiment the herbicidal composition has 1gm to 5gm of Bispyribac sodium. In yet another embodiment the weight ratio of Bispyribac sodium to Pyrithiobac acid is in a range of 1:1 to 1:5. Further, the Pyrithiobac acid sodium is an agriculturally acceptable sodium ester. In yet another embodiment the composition is a suspension concentrate (SC).
[016] The herbicidal composition of the present invention further comprises of agrochemically acceptable excipients. In an embodiment of the invention, the agrochemically acceptable excipients include at least a defoamer. In an embodiment, the defoamer is Polydimethylsiloxane silicone antifoam emulsion. In another embodiment the defoamer is present in the range 0.1gm to 1gm.
[017] Further, the agrochemically acceptable excipients include at least two surfactants. In another embodiment, the at least two surfactants are Synergen W06, and Genepol B.
[018] The agrochemically acceptable excipients further include a wetting agent. In an embodiment, the wetting agent is Fatty alcohol alkoxylate. In another embodiment, the wetting agent is present in the range of 50gm to 70gm.
[019] Additionally, the agrochemically excipients includes a spreader. In an embodiment, the spreader is Resicare PSW. In yet another embodiment, the spreader is present in the range of 0.5gm to 2gm. In the present embodiment, the agrochemically excipients include propylene glycol, and aluminium oxide.
[020] Accordingly, the herbicidal composition is used to control weed species such as Echinochloa colonum, Echinochloa crusgalli, Leptochloa Inflorescence, Laptochloa chinensis, Dectylolactinum, Eclipta alba, Digera muricata, Phyllanthus niruri, Portulaca oleracea, Ludwigia spp, Alternanthera polygonoides, Cyanotis sp., Ammania sp., Digera sp., Parthenium sp., Digera arvensis, Cyprus iria, Cyprus spp, Cyprus diformis.
[021] Another aspect of the present invention provides a method of preparation of the herbicidal composition. Accordingly, the method begins with grinding a predetermined quantity of Bispyribac sodium and a predetermined quantity of Pyrithiobac acid in order to obtain a mixture.
[022] In an embodiment, at least one early post-emergent herbicide selected from, but not limiting to, sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio)benzoate (also known as Pyrithiobac acid sodium), Cyhalofop Butyl, Quizalofop-P-ethyl, Fenoxaprop-p-ethyl, Penoxsulam, Bensulfuron methyl, Ammonium salt of imazethapyr, Halosulfuron-methyl, Thifensulfuron-methyl, Prosulfuron, Quinclorac, Florpyrauxifen-benzyl, Triclopyr, Propanil, Bentazone, Saflufenacil, Acifluorfen, Anilofos, Orthosulfamuron, Chlorimuron Ethyl, Ammonium salt of imazamox, Imazethapyr, or any combination thereof. In another embodiment, at least one post-emergent herbicide selected from, but not limiting to, sodium 2,6-bis((4,6-dimethoxypyrimidin-2-yl)oxy)benzoate (also known as Bispyribac sodium), Azimsulfuron, Bensulfuron methyl, Chlorimuron-ethyl, 2,4-D ethyl ester, Ethoxysulfuron, Fenoxaprop-P-ethyl, Metsulfuronmethyl, Paraquat, Bentazone, Carfentrazone ethyl, Cyhalofop Butyl, Penoxsulam, Cyhalofop-butyl, Triafamone, Ethoxysulfuron, Metsulfuron, Chlorimuron, or any combination thereof.
[023] In a further embodiment, 1gm to 5gm of Bispyribac sodium is dry grinded with 4gm to 10 gm of Pyrithiobac acid to obtain the mixture. In yet another embodiment, ratio of Bispyribac sodium to Pyrithiobac sodium is in the range of of 1:1 to 1:5.
[024] According to the invention, the method further includes adding a first surfactant, a second surfactant, and a defoamer to propylene glycol to form a solution. In an embodiment, the first surfactant along with the second surfactant and 0.1gm to 1gm of the defoamer are added to 3gm to 8gm of propylene glycol to form the solution. In another embodiment, the at least two surfactants are Synergen W06, and Genepol B. In another embodiment, the defoamer is Polydimethylsiloxane silicone antifoam emulsion.
[025] According to the invention, the method further includes adding a wetting agent along with Propylene Oxide/Ethylene Oxide/Propylene Oxide block polymer to the solution. In an embodiment, the wettin agent is is Fatty alcohol alkoxylate. In a another embodiment, 50gm to 70gm of the wetting agent is mixed with 15gm to 25gm of Propylene Oxide/Ethylene Oxide/Propylene Oxide block polymer and is added to the solution.
[026] In the next step, the method of the present invention involves adding a spreader along with Aluminium Oxide to the solution. In an embodiment, the spreader is Resicare PSW. In yet another embodiment, 0.5gm to 2gm of the spreader is mixed with 1gm to 3gm of Aluminium Oxide and is added to the solution.
[027] The next step of the present method includes adding the mixture to the solution under continuous stirring to maintain a predetermined temperature range to obtain a formulation. In an embodiment, the mixture is added to the solution under continuous stirring and cooled with ice to maintain the temperature range of 20oC - 40oC to obtain the formulation.
[028] According to the invention, the next step includes homogenization and wet grinding the formulation in order to obtain the herbicidal composition of the present invention. In an embodiment, the formulation is homogenized by stirring at 1400 – 2500 RPM for 0.2 hours – 1 hours below 30oC. in yet another embodiment, the homogenized formulation is passed through a dynomill at temperature below 40oC in order for wet grinding. In a further embodiment of the invention, the formulation is a suspension concentrate (SC) formulation.

Formulation Example 1
[029] Weighed in a beaker one by one surfactants : Synergen 54.51parts and Genepol 17.17 parts, propylene glycol 5 parts, defoamer 1.5 part and spreader (Resicare PSW) 1.5 part
[030] Placed the beaker under homogenizer and started slow stirring (600 RPM). Added under stirring Aluminium oxide (Alu C ) 1.0 parts slowly to wet it properly.
[031] Added one after another the technical : Bispyribac sodium 8.00 parts and Pyrithiobac sodium 11.32 parts to the above mixture in the beaker under stirring. Cooled the beaker to maintain 35- 40oC.
[032] Stirred the above mixture at 1400 to 1800 RPM for 0.75 hrs maintaining below 30oC.
[033] After homogenizing the mixture is passed through the dynomill maintaining temperature below 35oC for wet grinding. The dynomill pass is repeated until homogeneous mixture with desired particle size (D90=10 µ).

Formulation Example 2
[034] Weighed in a beaker one by one surfactants : Synergen 54.51parts and Genepol 18.17 parts, propylene glycol 5 parts, defoamer 0.5 part and spreader (Resicare PSW) 1.0 part
[035] Placed the beaker under homogenizer and started slow stirring (500 RPM). Added under stirring Aluminium oxide (Alu C ) 1.5 parts slowly to wet it properly.
[036] Added technical : Bispyribac sodium 5.27 parts and Pyrithiobac sodium 14.05 parts to the above mixture in the beaker under stirring. Cooled the beaker to maintain 25 - 30oC.
[037] Stirred the above mixture at 1500 to 2500 RPM for 0.5 hrs maintaining below 30oC.
[038] After homogenizing the mixture is passed through the dynomill maintaining temperature below 35oC for wet grinding. The dynomill pass is repeated until homogeneous mixture with desired particle size (D90=10µ).

Formulation Example 3
[039] Weighed in a beaker one by one surfactants : Synergen 52.51parts and Genepol 18.17 parts, propylene glycol 5 parts, defoamer 0.5 part and spreader (Resicare PSW) 3.0 part
[040] Placed the beaker under homogenizer and started slow stirring (300 RPM). Added under stirring Aluminium oxide (Alu C ) 1.5 parts slowly to wet it properly.
[041] Added technical : Bispyribac sodium 4.01 parts and Pyrithiobac sodium 15.31 parts to the above mixture in the beaker under stirring. Cooled the beaker to maintain 20 - 25oC.
[042] Stirred the above mixture at 1100 to 1500 RPM for 1.0 hrs maintaining below 30oC.
[043] After homogenizing the mixture is passed through the dynomill maintaining temperature below 25oC for wet grinding. The dynomill pass is repeated until homogeneous mixture with desired particle size (D90=10µ).

EXPERIMENTAL DATA
[044] Paddy crops were grown on plots under natural outdoor conditions and herbicidal SC formulations and bispyribac-sodium were individually applied as spray on the paddy field at 10-15 days after sowing in direct seeded rice (DSR) paddy and 10-14 days after transplanting in transplanted paddy at an application rate of 500 liters water per hectare using knapsack sprayer with flat fan nozzle with the following doses of various herbicide formulations in various field experiments:
1. GAVL809K-A (750 ml/ha) – which is 3.33% Bispyribac sodium and 5.83% Pyrithiobac sodium.
2. GAVL809K-B (750 ml/ha) - which is 3.33% Bispyribac sodium and 5% Pyrithiobac sodium.
3. GAVL809K-C (750 ml/ha)- which is 3.33% Bispyribac sodium and 4.20% Pyrithiobac sodium.
4. GAVL809K-A3 (1000 ml/ha)- which is 2.5% Bispyribac sodium and 6.25% Pyrithiobac sodium.
5. GAVL809K- A4 (500 ml/ha)- which is 5.0% Bispyribac sodium and 12.5% Pyrithiobac sodium.
6. GAVL 800K (250 ml/ha) – which is 10% Bispyribac sodium and 0% Pyrithiobac sodium.
[045] Observations on the number of individual weeds present in the field were recorded at 15 and 30 days after the application of the herbicidal formulations in comparison with untreated control for weed control efficiency (WCE). The results were as shown in the following Tables 1 – 12:
[046] Table 1: Population of weeds influenced by various herbicides at 15 days after application in transplanted paddy at Bulandshar, UP during Kharif 2019.

Treatment Density of weeds (No./0.5 m2) Total weed density per 0.5 sq.m. Dry weight of total weeds per 0.5 sq.m. %
WCE
Echinochloa
colonum Echinochloa
crusgalli Leptochloa
Inflorescence Cyperus
iria
Eclipta
alba Digera
muricata Phyllanthus niruri Portulaca oleracea
GAVL809K-A (750 ml/ha) 7 2 1 0 4 0 1 1 16 0.039 99.9
GAVL809K-B (750 ml/ha) 10 4 2 1 11 0 1 2 31 1.34 97.3
GAVL809K-C (750 ml/ha) 11 8 5 2 13 0 1 1 41 1.39 97.2
GAVL 800K
(250 ml/ha) 18 5 5 3 15 4 3 3 56 5.39 89.1
Untreated Control 50 24 11 57 27 10 3 4 186 49.37 0.0

[047] Table 2: Population of weeds influenced by various herbicides at 30 days after application in transplanted paddy at Bulandshar, UP during Kharif 2019.
Treatment Density of weeds (No./0.5 m2) Total weed density per 0.5 sq.m. Dry weight of total weeds per 0.5 sq.m. %
WCE
Echinochloa
colonum Echinochloa
crusgalli Leptochloa
Inflorescence Cyperus
iria
Eclipta
alba Digera
muricata Phyllanthus niruri Portulaca oleracea
GAVL809K-A
(750 ml/ha) 8 2 3 5 9 0 0 1 28 3.32 97.5
GAVL809K-B (750 ml/ha) 10 3 7 6 12 0 0 3 41 7.32 94.4
GAVL809K-C (750 ml/ha) 11 3 4 9 15 0 0 3 45 7.28 94.5
GAVL 800K
(250 ml/ha) 18 6 9 8 26 5 3 4 79 34.12 74.0
Untreated Control 34 9 12 32 36 12 6 8 119 131.28 0.0
[048] Table 3: Population of weeds influenced by various herbicides at 15 days after application in direct seeded rice (DSR) paddy at Kurud, Chhattisgarh, during Kharif 2019.

Treatment Density of weeds (No./0.75 m2) Total weed density per 0.75 m2 Dry weight of total weeds per 0.75m2 % WCE
Laptochloa chinensis Echinochloa crusgalli Ludwigia spp Alternanthera polygonoides Cyperus difformis

GAVL809K-A (750 ml/ha) 0.0 0.00 35.0 0.00 0.00 35.0 0.77 96.9
GAVL809K-B (750 ml/ha) 1.0 0.00 39.0 1.0 0.00 41.0 1.60 93.5
GAVL809K-C (750 ml/ha) 1.0 0.00 53.0 1.0 1.0 56.0 2.90 88.2
GAVL 800K (250 ml/ha) 8.0 5.00 70.0 5.0 4.0 92.0 8.13 66.9
Untreated Control 13.0 7.0 224.00 10.0 24.0 278.0
24.53 0.0

[049] Table 4: Population of weeds influenced by various herbicides at 30 days after application in direct seeded rice (DSR) paddy at Kurud, Chhattisgarh, during Kharif 2019.

Treatment Density of weeds (No./0.75 m2) Total weed density per 0.75 m2 Dry weight of total weeds per
0 .75m2 % WCE Paddy Yield
Per
0.75 m2 (g)
Laptochloa chinensis Echinochloa colona Echinochloa crusgalli Ludwigia spp Alternanthera polygonoides Cyperus difformis

GAVL809K-A (750 ml/ha) 0 0.0 0.0 60.0 0.0 2.0 62.0 2.16 94.0 338.00
GAVL809K-B (750 ml/ha) 1.0 0.0 0.0 101.0 0.0 8.0 110.0 3.82 89.5 335.33
GAVL809K-C (750 ml/ha) 0.0 0.0 1.0 125.0 1.0 10.0 137.0 5.40 85.1 333.00
GAVL 800K (250 ml/ha) 5.0 4.0 8.0 154.0 4.0 31.0 206.0 12.64 65.2 321.33
Untreated Control 13.0 10.0 13.0 342.0 12.0 39.0 429.0
36.29 0.0 268.33

[050] Table 5: Population of weeds influenced by various herbicides at 21 days after application in transplanted paddy at Sonipat, Haryana, during Kharif 2019.
Treatment 21 DAT
Dry biomass of weeds (Echinochloa crussgalli, Laptochloa chinensis
Eclipta alba, Digera arvensis) per sq.m. (g) % WCE
GAVL809K-A (750 ml/ha) 0.855 78.4
GAVL809K-B (750 ml/ha) 1.410 64.3
GAVL809K-C (750 ml/ha) 2.755 30.3
GAVL 800K (250 ml/ha) 2.905 26.5
Untreated Control 3.955 0.0

[051] Table 6: Population of weeds influenced by various herbicides at 30 days after application in transplanted paddy at Trichy, Tamil Nadu, during Kharif 2019.

Treatment Narrow leaf weeds Broad leaf weeds Sedges Dry biomass of total weeds per sq.m. (g) % WCE of total weeds
Dry biomass per sq.m. (g) % WCE Dry biomass per sq.m. (g) % WCE Dry biomass per sq.m. (g) % WCE
GAVL809K-A (750 ml/ha) 4.30 94.56 0.00 100.00 0.00 100.00 4.68 95.19
GAVL809K-B (750 ml/ha) 9.92 87.45 0.06 99.45 0.00 100.00 11.69 87.98
GAVL809K-C (750 ml/ha) 10.20 87.10 0.87 91.64 0.00 100.00 12.02 87.64
GAVL 800K (250 ml/ha) 19.20 75.71 1.55 85.09 1.23 84.28 20.75 78.67
Untreated Control 79.07 0.00 10.37 0.00 7.85 0.00 97.28 0.00

[052] Table 7: Population of weeds influenced by various herbicides at 15 days after application in DSR paddy trial 1 at Dist. Durg, Chhattisgarh, during Kharif 2020.

Treatments Density of weeds/ 0.5 sq.m. Dry wt. of total weeds / 0.75 sq. m. (g) %
WCE
Echinochloa colona Echinochloa crus-galli Alternathera polygonoides Cyprus diformis Total weeds
GAVL809K-A3 (2.5+6.25) (1000 ml/ha) 0.33 0.00 0.67 0.00 1.00 0.63 99.1
GAVL809K A (3.33+5.83)
(750 ml/ha) 3.33 1.00 3.00 0.00 7.33 2.71 96.1
GAVL809K- A4 (5.0+12.5)
(500 ml/ha) 0.00 0.00 0.00 0.00 0.00 0.00 100.0
GAVL 800K (250 ml/ha) 5.33 6.71 8.00 5.67 25.71
8.83 87.2

Untreated Control 15.33 16.33 24.33 50.00 105.99
68.88 0.00

[053] Table 8: Population of weeds influenced by various herbicides at 30 days after application in DSR paddy trial 1 at Dist. Durg, Chhattisgarh, during Kharif 2020.

Treatments Density of weeds/ 0.5 sq.m. Dry wt. of total weeds/ 0.75 sq. m. (g) %
WCE
Echinochloa colona Echinochloa crus-galli Alternathera polygonoides Cyprus diformis Total weeds
GAVL809K-A3 (2.5+6.25) (1000 ml/ha) 0.33 0.00 1.67 0.00 2.00 1.34 98.5
GAVL809K A (3.33+5.83)
(750 ml/ha) 1.00 0.00 2.33 0.67 4.00 1.80 98.0
GAVL809K- A4 (5.0+12.5)
(500 ml/ha) 0.00 0.00 0.00 0.00 0.67 0.00 100.0
GAVL 800K (250 ml/ha) 4.00 2.00 5.67 4.67 16.34 15.54 82.4
Untreated Control 8.33 5.67 21.67 67.67 103.34
88.36 0.00

[054] Table 9: Population of weeds influenced by various herbicides at 15 days after application in DSR paddy trial 2 at Dist. Durg, Chhattisgarh, during Kharif 2020.

Treatments Density of weeds/ 0.5 sq.m. Dry wt. of total weeds / 0.75 sq. m. (g) %WCE
Echinochloa colona Alternathera polygonoides Cyprus diformis Total weeds
GAVL 809 K A4 ( 500 ml/ha} 25.78
0.00
2.56
28.34 4.19
85.83

GAVL 800K (250 ml/ha) 35.78
4.22
18.00
58.00 10.87
51.16

Control 144.22
16.7
86.78
247.7
39.64
0.00

[055] Table 10: Population of weeds influenced by various herbicides at 30 days after application in DSR paddy trial 2 at Dist. Durg, Chhattisgarh, during Kharif 2020.

Treatments Density of weeds/ 0.5 sq.m. Dry wt. of total weeds/ 0.75 sq. m. (g) %WCE
Echinochloa colona Alternathera polygonoides Cyprus diformis Total weeds
GAVL 809 K A4 (500 ml/ha) 29.44
0.00
5.78
35.22 6.64
91.27

GAVL 800K (250 ml/ha) 44.44
6.22
40.00
90.66
24.35
67.83

Control 159.22
21.1
162.67
342.99
87.82
0.00

[056] Table 11: Population of weeds influenced by various herbicides at 15 days after application in transplanted paddy at Dist. Kanpur, UP during Kharif 2020.

Treatments Density of weeds/ 0.5 sq.m. % weed control
NLW BLW Sedges Total weeds
Echinochloa colona Ammania baccifera Phyllanthus
niruri Digera
arvensis Cyperus
iria Cyperus rotundus
GAVL 809 K A4
(500 ml/ha) 0.00
1.83
0.00
0.00
0.00
2.08
3.91 98.6

GAVL 800K
(250 ml/ha) 5.75
23.00
6.25
6.00
2.33
4.17
47.5
82.9
Control 13.83
204.50
18.33
16.42
15.50
9.50
278.08
0.0

[057] Table 12: Population of weeds influenced by various herbicides at 30 days after application in transplanted paddy at Dist. Kanpur, UP during Kharif 2020.

Treatments Density of weeds/ 0.5 sq.m. (30 DAS) Dry wt. of total weeds/ 0.75 sq. m. (g) %WCE
NLW BLW Sedges Total weeds
Echinochloa colona Ammania baccifera Phyllanthus
niruri Digera
arvensis Cyperus
iria Cyperus rotundus
GAVL 809 K A4
(500 ml/ha) 0.67
4.00
0.33
0.25
0.17
1.17
6.59 0.637
99.6
GAVL 800K
(250 ml/ha) 8.01
22.08
5.08
10.0
5.00
5.83
56.00 24.57
84.2
Control 19.00
237.25
16.67
19.25
21.83
29.42
343.42 155.55
0.00

[058] The study results in the above Tables 1 – 12 show that the SC formulation of the invention is very effective in controlling total weed flora (Narrow and broad leaves weeds and Sedges) in both transplanted & DSR paddy crops as compared to Bispyribac-sodium individually.
[059] This also clearly shows the synergistic effect of the SC formulation of the invention with longer herbicidal effects.
[060] This also clearly shows that herbicides applied in combination generally increased the spectrum of weed control and /or the length of residual weed control in a single application that saves time and labour in a weed management programme.
[061] The mixing of 2 compatible herbicides in SC formulation of the present invention have also shown synergistic effects that improved the control spectrum of specific weed populations for a longer period of time as compared to individual application of Bispyribac sodium.

Phytotoxicity and Crop Compatibility Studies
[062] After spraying the SC formulation of the invention and Bispyritbac-sodium individually on paddy crops as explained above, the paddy crops were continuously monitored and evaluated for phytotoxicity symptoms and crop health on a scale of 0 – 10 as shown in the following Table 13:
Table 13. Scale
Effect
Rate Crop description and condition
None 0 No injury, normal
Slight 1 Slight stunting, injury discoloration
2 Some stand loss, stunting or discoloration
3 Injury more pronounced but not persistent
Moderate 4 Moderate injury, recovery possible
5 Injury more persistent, recovery doubtful
6 Near severe injury, no recovery possible
Severe 7 Severe injury, stand loss surviving
8 Almost destroyed, a few plants surviving
9 Very few plants alive
Complete 10 Complete destruction

[063] Table 14 shows that there is zero effect of the herbicides on the crop plants either as SC formulation or individually thereby indicating that the SC formulation of the invention is safe to the paddy crops.

Table 14. Mean observation recorded after 1,3,5,10,15 and 30 days after application
Treatment Phytotoxicity
Yellowing Necrosis Epinasty/
Hyponasty Vein
Clearing Scorching Wilting
GAVL809K-A
(750 ml/ha) 0 0 0 0 0 0
GAVL809K-B
(750 ml/ha) 0 0 0 0 0 0
GAVL809K-C
(750 ml/ha) 0 0 0 0 0 0
GAVL809K-A3 (2.5+6.25) (1000 ml/ha) 0 0 0 0 0 0
GAVL809K- A4 (5.0+12.5) (500 ml/ha) 0 0 0 0 0 0
GAVL 800K (250 ml/ha) 0 0 0 0 0 0
Untreated Control 0 0 0 0 0 0

[064] As seen in the above table, all values are zero denoting that no phytotoxic effects have been noted for all treatments including control on paddy crop plants.
[065] Advantageously, the mixture formulation of the invention effectively controls Echinochloa species that have been developed some resistance against Bispyribac sodium alone due its synergistic effects. The mixture formulation of the invention also found to be highly effective against a grassy weed such as Laptochloa sp. which has been an emerging weed of paddy & is poorly or not controlled by Bispyribac sodium alone. Further, the herbicidal composition has shown synergistic effects that improved the control spectrum of specific weed populations for a longer period of time as compared to individual application of Bispyribac sodium.
[066] The mixture formulation of the invention was also effectively control some broad leaf weeds viz., Trianthema Spp, , Digera Spp, Ammania baccifera, Phyllanthus niruri, Alternathera sp., Ludwigia spp, Eclipta alba & Portulaca sp. that are the most common weeds in direct seeded rice and/or upland rice as compared to Bispyribac sodium alone application.
[067] The mixture formulation of the invention was also effectively control sedge viz., Cyprus diformis and Cyperus iria as compared to Bispyribac sodium alone application.
[068] Excellent weed control with minimum weed density and dry biomass of individual & total weeds at 15 & 30 DAT and maximum yield of paddy was recorded in the mixture formulation of the invention as compared to individual application of Bispyribac sodium.
[069] Efficacy of SC formulation of the invention on weed control was long lasted up to 30 days after application whereas efficacy of individual application of the Bispyribac sodium broken down within 18-21 days
[070] The species spectrum of the compound of the synergistc mixture of the invention i.e. the weed species which the respective compounds control are particularly useful for the control of key weeds e.g. Echinochloa colonum, Echinochloa crusgalli, Leptochloa Inflorescence, Laptochloa chinensis, Dectylolactinum, Eclipta alba, Digera muricata, Phyllanthus niruri, Portulaca oleracea, Ludwigia spp, Alternanthera polygonoides, Ammania sp., Digera sp., Parthenium sp., Digera arvensis, Cyprus iria, Cyprus spp, Cyprus diformis, at application rate equal to the rate of individual compound (Bispyribac sodium)
[071] The synergistic mixture of herbicides of the invention improved the spectrum of weeds controlled in a single application which saves time and labour in a weed management programme.
[072] The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since the modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to the person skilled in the art, the invention should be construed to include everything within the scope of the disclosure. ,CLAIMS:WE CLAIM:
1. A herbicidal composition comprising: Bispyribac sodium; and Pyrithiobac acid.

2. The herbicidal composition as claimed in claim 1, wherein weight ratio of Bispyribac sodium to Pyrithiobac acid is in a range of 1:1 to 1:5.

3. The herbicidal composition as claimed in claim 1, wherein the Pyrithiobac acid is an agriculturally acceptable sodium ester.

4. The herbicidal composition as claimed in claim 1, comprises agrochemically acceptable excipients.

5. A method of controlling weeds which comprises the step of application to the weeds a herbicidal composition comprising Bispyribac sodium; and Pyrithiobac acid in a weight ratio from about 1:1 to 1:5.

Dated this 21st Day of May 2021
Godrej Agrovet Limited
By their Agent & Attorney

(Nisha Austine)
of Khaitan & Co
Reg No IN-PA-1390