DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005

and

THE PATENTS RULES, 2003
As amended by the Patents (Amendment) Rules, 2014

COMPLETE SPECIFICATION
(Section 10 and Rule 13)

TITLE OF THE INVENTION
A HERBICIDAL COMPOSITION

APPLICANTS
Godrej Agrovet Limited, an Indian company, having its address at Godrej One, Pirojsaha Nagar, Vikhroli (East), MUMBAI – 400079, Maharashtra, INDIA; an Indian Company.

PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION
[001] The present invention relates to a herbicidal formulation which offers broad-spectrum control of weeds in cotton crop.

BACKGROUND OF INVENTION
[002] Weeds are generally plants that do not have any redeeming value as far as food, nutrition or medicinal values are concerned. Moreover, weeds have an accelerated growth mechanism owing to which they compete with cultivated crop plants for requirement of essential light, nutrients and space. Weed infestation thus, affects the yield and quality of crop species and render them economically unviable.
[003] The agriculture industry uses a wide range of herbicides, primarily to control undesired growth of weeds which interfere with growth, development, yield and quality of agricultural crops. More so, they are used to provide an optimum environment for growth and propagation of plant varieties.
[004] For convenience in production, packaging and handling, herbicides are manufactured in a powder form which is subsequently mixed with water to produce an aqueous solution. Different types of formulations have been prepared like capsule suspension (CS) formulations, soluble concentrate (SL) formulations, emulsifiable concentrate (EC) formulations, suspension concentrate (SC) formulations etc.
[005] 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.
[006] 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.
[007] Hence, there is a need in the market for a formulation which combines a pre-emergent herbicide with early post-emergent herbicide which results a synergistic effect for broad spectrum control of weeds which are not controlled when used in isolation.

SUMMARY OF THE INVENTION
[008] In one aspect, the present invention provides a herbicide formulation comprising pendimethalin and pyrithiobac, wherein the formulation is an ZC formulation.
[009] In another aspect, the present invention provides a method of controlling weed species such as Trianthema sp, Digera sp, Phylanthus sp., Achyranthes sp, Xanthium sp., Cassia sp., Commelina sp., Brachiaria sp., Dactyloctenium sp., Dinebra sp., Digitaria sp., Echinochloa sp., Eleusine sp., Cyprus sp., in cotton crop by applying a herbicide formulation comprising pendimethalin and pyrithiobac, wherein the formulation is a ZC formulation (Mixed formulation of CS and SC).

DETAILED DESCRIPTION OF INVENTION
[008] The present invention provides a combination of two herbicides to attain a synergistic mode of action for a broad spectrum control of weeds which are not completely controlled when these herbicides are used in isolation.
[009] The present invention aims to use at least two types of herbicides, of which one is a pre-emergent herbicide whilst the other is an early post-emergent herbicide. A pre-emergent herbicide inhibits the initial growth phase of weed seedlings, whereas an early post-emergent herbicide inhibits actively growing weeds that are already through the soil surface if any. Applying both the herbicides simultaneously offers several advantages including (a) an increase in the spectrum of weeds controlled (b) an extension of weed control over a longer period of time (c) an improvement in crop safety by using reduced doses of both the herbicides in combination rather than a single high dose of one herbicide and (d) a delay in the appearance of resistant weed species to both the herbicides. The formulation, thus developed is stable owing to extensive accelerated stability studies performed.
[010] In one aspect, the present invention relates to a herbicide formulation comprising pendimethalin and pyrithiobac, wherein the formulation is an ZC formulation.
[011] Pendimethilin is a pre-emergent herbicide for inhibiting the growth of weed seedlings, roots and shoots. Pendimethalin is dinitroaniline which prevents cell division and elongation in susceptible weed species. Polymorphic orange macrocrystals and yellow microcrystals present in Pendimethalin are highly flammable in nature. Hence, Pendimethalin formulations often exhibit stability problems and problems related to rapid crystallisation rendering them difficult to be processed and highly unreliable in use. For the aforementioned reasons, it is crucial that a formulation be developed which not only is stable in the presence of Pendimethalin but also has a wide range of weed inhibition.
[012] In another aspect, the present invention uses pyrithiobac, an early post-emergent herbicide along with the aforementioned pre-emergent herbicide which inhibits weeds that are already through the soil surface.The pyrithiobac is the acid itself or an agriculturally acceptable sodium ester. More particularly, but not limited to, the post-emergent herbicide is a commercially available form of sodium 2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio)benzoate, also known as Pyrithiobac sodium.
[013] In another embodiment, the formulation further comprises agriculturally acceptable adjuvant and/or carrier.
[014] It is noted that existing mixed formulations of CS and SC are not stable indefinitely and it is necessary to ensure that, after transportation and storage, the formulation remains suitable for use. The present invention thus envisages a ZC formulation which is stable aqueous suspension of microcapsules and solid fine particles, each of which contains one or more active ingredients. The formulation is intended for dilution into water prior to spray application. Formulating the active ingredients together eliminates the need for tank mixing, which can lead to incompatibility, and facilitates control of a wider range of weeds with single application. Like other aqueous liquid formulations, ZC formulations are easy to handle and measure, dust free, non-flammable and offer good miscibility with water.
[015] One part of the ZC formulation of the present invention is prepared by using a compound selected from, but not limited to, class of compounds of dinitro aniline and pyrimidinylthiobenzoic acid. More specifically, polymethylene polyphenyl polyisocyanate is used. To the aforementioned solution, a solution of Hexamythaldiamine 25% is added at a predetermined temperature ranging from 200C - 950C. The resultant solution is further added with a dispersing agent, a biocide (antifungal), PROXEL-GXL (1,2-benzisothizolin-3-one), Gensil2030 (polydimethylsiloxane) (Defoamer), Xanthum gum 2% solution. (Agrhopol 23W) and demineralized water (1% – 25%).
[016] A second part of the ZC formulation of the present invention is prepared at predetermined temperatures in the range of 150C - 700C by using dispersing and wetting Agent (Rhodasurf 860P +Supragil – LDS), Biocide (antifungal), PROXEL-GXL (1,2-benzisothizolin-3-one), Gensil2030b (polydimethylsiloxane) (Defoamer), Xanthum gum 2% solution. (Agrhopol 23W) and Demineralized water (1% – 25).
[017] Part 1 and Part 2 of the present invention are mixed at a temperature of 100C – 500C in the ratio of, but not limiting to, 85:12 under stirring at 250 – 800 for 12 to 24 hours.
[018] In an embodiment of the invention, the the pendimethalin and pyrithiobac is present in a ratio of from about 1:1 to about 20:1.
[019] In yet another embodiment of the invention, the formulation is used for controlling undesirable weeds in cotton crop by contacting the synergistic herbicidal formulation with foliage or seed or the locus thereof before or after planting or emergence.
[020] The invention thus provides a method of controlling weed species such as Trianthema sp., Digera sp., Phylanthus sp., Achyranthes sp., Xanthium sp., Cassia sp., Commelina sp., Brachiaria sp,, Dactyloctenium sp., Dinebra sp, Digitaria sp., Echinochloa sp., Eleusine sp., Cyprus sp., in cotton crop comprising applying the herbicidal formulation to the cotton field.
[021] The combination of both the herbicides have demonstrated synergy in terms of effective control of more no. of weeds for a longer duration. Since the herbicidal combination demonstrated a potency or activity level exceeding that which it would be expected to have, based on a knowledge of the individual potencies of the herbicides. The synergism for the compositions of this invention was measured in accordance with the following Herbicide interaction responses as described by Colby, 1967:
E = X + Y- (XY)/100
where E = expected response
where X = observed (0) value or percent growth control when the herbicide A is applied singly; and Y = observed (0) value or percent growth control when the herbicide B is applied singly.

[022] A response is synergistic when an observed value is greater than the calculated value. A synergistic response is understood to be one in which the interaction response is greater than the sum of responses from the individual herbicidal treatments. An antagonistic response is the opposite situation.

EXAMPLES
[023] The following experimental examples are illustrative of the invention but not limitative of the scope thereof:
Formulation Example 1
Charge DM water (QS), Supragil –MNS 90 +Greensperse NA( 6 parts), Polydimethylsiloxane(1 Part) and in SS jacketed vessel in water bath and fitted with Stirrer. Heat the above RM under stirring to 60 – 75OC and continue the heating and stirring till the start of addition of Pendimethalin ( 45 parts). Add monomer 1 (2 parts) and amine solution (2.8 parts) Continue the stirring for 2 hrs. Cool the above reaction mass to 25 - 30OC. CS formulation of Pendimethalin has been prepared(Part – A).
To wet grinder charge Polydimethylsiloxane(1 Part), Rhodasurf 860P +Supragil – LDS (2 parts) , Pyrithiobac Acid sodium ( 30 parts) and water (QS). Continue the wet grinding till the particle size of SC formulation D90 <10 micron. Add Agrhopol 23W 2% solution (10 parts) and 1,2-benzisothizolin-3-one (0.1 parts) to above formulation at RT. Aqueous phase of SC formulation has been prepared(Part – B).
Mix the Part- A into Part - B at room temperature in the ratio of 85: 15 respectively under stirring at 250 – 800 RPM in 15 minute. Continue the stirring of above ZC formulation for 4.0 hrs.

Formulation Example 2
Charge DM water (QS), Supragil –MNS 90 +Supragil – LDS( 6 parts), Polydimethylsiloxane(1 Part) and in SS jacketed vessel in water bath and fitted with Stirrer. Heat the above RM under stirring to 60 – 75OC and continue the heating and stirring till the start of addition of Pendimethalin ( 45 parts). Add monomer 1 (2 parts) and amine solution (2.8 parts) Continue the stirring for 2 hrs. Cool the above reaction mass to 25 -30OC. CS formulation of Pendimethalin has been prepared(Part – A).
To wet grinder charge Polydimethylsiloxane(1 Part), Rhodasurf 860P +Supragil – LDS (2 parts) , Pyrithiobac Acid sodium ( 30 parts) and water (QS). Continue the wet grinding till the particle size of SC formulation D90 <10 micron. Add Agrhopol 23W 2% solution (10 parts) and 1,2-benzisothizolin-3-one (0.1 parts) to above formulation at RT. Aqueous phase of SC formulation has been prepared(Part – B).
Mix the Part- A into Part - B at room temperature in the ratio of 85: 15 respectively under stirring at 250 – 800 RPM in 15 minute. Continue the stirring of above ZC formulation for 4.0 hrs.

Formulation Example 3
Charge DM water (QS), Supragil –MNS 90 + Greensperse NA ( 6 parts), Polydimethylsiloxane(1 Part) and in SS jacketed vessel in water bath and fitted with Stirrer. Heat the above RM under stirring to 60 – 75OC and continue the heating and stirring till the start of addition of Pendimethalin ( 45 parts). Add monomer 1 (2 parts) and amine solution (2.8 parts) Continue the stirring for 2 hrs. Cool the above reaction mass to 25 -30OC. CS formulation of Pendimethalin has been prepared(Part – A).
To wet grinder charge Polydimethylsiloxane(1 Part), Rhodasurf 860P +Supragil – LDS (2 parts) , Pyrithiobac Acid sodium ( 30 parts) and water (QS). Continue the wet grinding till the particle size of SC formulation D90 <10 micron. Add Agrhopol 23W 2% solution (10 parts) and 1,2-benzisothizolin-3-one (0.1 parts) to above formulation at RT. Aqueous phase of SC formulation has been prepared(Part – B).
Mix the Part- A into Part - B at room temperature in the ratio of 85: 15 respectively under stirring at 500 – 1000 RPM in 15 minute. Continue the stirring of above ZC formulation for 4.0 hrs.

Bio-efficacy Studies of the invention
The studies were carried out in farmer fields on cotton crop grown under natural outdoor conditions. The five treatment combinations imposed included herbicidal ZC formulation of the invention at two different doses, recommended dose of pyrithiobac-sodium and Pendimethalin individually alongwith one treatment of untreated control applied as spray on the cotton field within 24 hours of sowing at an application rate of 500 liter water per hectare using knapsack sprayer with flat fan nozzle. The number of individual weed species present in the field was recorded at 15, 21 and 30 days after the application of the ZC formulation in comparison with untreated control. The results were as shown in the following Tables 1 – 6:

Table 1a. Population of dominant broad leaf weeds influenced by various herbicides applied in cotton
Treatment Dose
g a.i./ha Broad leaf weed Density (no./m2)
Trianthema sp Digera sp Phylanthus sp. Achyranthes sp.
15 DAT 21 DAT 30 DAT 15 DAT 21 DAT 30 DAT 15 DAT 21 DAT 30 DAT 15 DAT 21 DAT 30 DAT
Pyrithiobac- sodium
62.50 0.6 1.6 12.0 3.0 3.3 9.6 6.66 12.44 16.00 1.67 2.00 2.00
Pendimethalin
680.75 1.3 10.0 15.0 18.0 20.6 34.0 6.00 11.66 19.67 2.00 2.33 2.67
Treatment 1 of Invention comprising pyrithiobac sodium@ 54.25g a.i./ha + Pendimethalin
@ 595 g a.i. / ha 649.25 1.0 1.3 4.0 2.0 3.3 3.6 1.0 5.66 8.33 0.00 0.67 0.67
Treatment 2 of invention comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 742.00 0.6 1.0 3.3 1.3 1.6 3.0 0.33 5.55 8.33 0.33 0.33 0.67
Control
- 16.6 21.0 51.3 17.6 23.3 44.3 10.22 15.22 27.00 4.00 4.33 4.33
CD (p=0.05)
SE(m) 0.39
0.13
0.54
0.18 0.54
0.18 1.34
0.43
1.04
0.33
0.98
0.32
0.38
0.12
0.98
0.32 0.95
0.30 1.43
0.46 1.03
0.33 0.93
0.30

Table 1b. Population of dominant broad leaf weeds influenced by various herbicides applied in cotton
Treatment Dose
g a.i./ha Broad leaf weed Density (no./m2)
Xanthium sp. Cassia sp Commelina diffusa
15 DAT 21 DAT 30 DAT 15 DAT 21 DAT 30 DAT 15 DAT 21 DAT 30 DAT
Pyrithiobac- sodium
62.50 2.67 2.67 2.67 2.67 3.0 3.0 5.67 6.00 6.00
Pendimethalin
680.75 1.33 2.0 2.67 3.0 3.0 3.33 4.67 5.33 5.33
Treatment 1 of Invention comprising pyrithiobac sodium@ 54.25g a.i./ha + Pendimethalin
@ 595 g a.i. / ha 649.25 0.67 1.0 1.33 0.0 0.67 0.67 3.67 4.00 4.00
Treatment 2 of invention comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 742.00 0.0 1.33 1.33 0.0 0.33 1.0 4.33 4.33 4.67
Control
- 3.0 3.67 4.00 6.0 6.00 6.33 10.00 10.33 11.02
CD (p=0.05)
SE(m)

1.13
0.36 0.97
0.31 1.00
0.32 1.13
0.36 1.51
0.49 1.89
0.68 1.67
0.64
1.95
0.63
1.84
0.59

Table 2a. Population of dominant monocot weeds influenced by various herbicides applied in cotton
Treatment Dose
g a.i./ha Weed density (no./m2)
Brachiaria sp. Dactyloctenium aegypticum Dinebra sp Digitaria sp
15 DAT 21 DAT 30 DAT 15 DAT 21 DAT 30 DAT 15 DAT 21 DAT 30 DAT 15 DAT 21 DAT 30 DAT
Pyrithiobac- sodium
62.50 3.67 4.33 5.67 4.0 7.7 31.7 4.00 4.67 6.33 3.0 9.0 55.0
Pendimethalin
680.75 3.33 3.67 3.67 2.0 11.0 16.0 3.67 4.67 4.67 0.0 4.0 38.0
Treatment 1 of Invention comprising pyrithiobac sodium@ 54.25g a.i./ha + Pendimethalin
@ 595 g a.i. / ha 649.25 0.33 1.33 2.33 3.0 3.3 12.7 1.33 2.33 2.33 0.0 3.0 23.6
Treatment 2 of invention comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 742.00 0.33 1.33 1.67 1.0 1.3 8.3 1.67 2.00 2.33 0.0 1.3 8.3
Control
- 5.00 6.00 7.33 4.0 18.7 42.7 6.0 6.67 8.00 13.0 17.0 72.0
CD (p=0.05)
SE(m)

0.70
0.23 1.19
0.38 1.08
0.35 0.69
0.28 0.77
0.25 3.63
1.03 1.29
0.42 1.39
0.45 1.19
0.38 1.13
0.36 1.18
0.38 1.54
0.50

Table 2b. Population of dominant monocot weeds and sedges influenced by various herbicides applied in cotton

Treatment Dose
g a.i./ha Grass weed density (no./m2) Density of sedges (no./m2)
Echinochloa
Colona Eleusine sp
. Cyprus sp.
15 DAT 21 DAT 30 DAT 15 DAT 21 DAT 30 DAT 15 DAT 21 DAT 30 DAT
Pyrithiobac- sodium
62.50 0.67 4.3 11.0 1.0 12.33 46.33 4.00 4.67 5.33
Pendimethalin
680.75 1.0 16.7 37.0 0.33 14.33 27.33 3.67 3.67 3.67
Treatment 1 of Invention comprising pyrithiobac sodium@ 54.25g a.i./ha + Pendimethalin
@ 595 g a.i. / ha 649.25 0.0
1.0 2.0 0.33 1.0 7.33 2.67 2.67 3.00
Treatment 2 of Invention comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 742.00 0.33 1.33 2.0 0.33 1.0 4.0 2.67 3.0 3.33
Control - 5.0
43.0
87.0 2.33 27.33 49.00 8.00 8.33 9.33
SEM
CD (p=0.05)
0.57
0.21 2.08
0.89 5.31
1.67 0.39
0.13 6.63
1.36 7.32
2.14 1.99
0.64 1.37
0.44 1.47
0.47

Table 3. Population of total weeds influenced by various herbicides applied in cotton

Treatments Dose/ha Formulation
(a.i.) Total Weed Density/sqm Weeds dry wt/sqm
(g at 30 DAT) %
WCE
(30 DAT)
15DAT 21 DAT 30 DAT Observed
(O) Expected
(E)
Pyrithiobac- sodium
62.50 2.67 14.33 70.33 7.45 83.20
Pendimethalin
680.75 3.67 30.67 54.67 12.28 72.29
Treatment 1 of Invention comprising pyrithiobac sodium@ 54.25g a.i./ha + Pendimethalin
@ 595 g a.i. / ha 649.25 1.67 3.67 10.33 0.49 98.89 95.34
Treatment 2 of Invention comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 742.00 1.33 3.00 7.33 0.40 99.09 95.34
Control - 12.67 58.33 104.00 44.33 0.00
CD (p=0.05)
SE(m) 2.90
0.93
9.81
3.15 10.96
3.52 6.38
1.95 -

The study results in the above Tables 1a – 3 show that the ZC formulation of the invention at lower dosages (lower percentages or concentrations) of the active herbicides in combination is very effective in controlling total weed flora (Monocots and Dicots weeds and Sedges) in cotton crop as compared to Pyrithiobac-sodium and Pendimethalin individually. This also clearly shows the synergistic effect of the ZC formulation of the invention with longer herbicidal effects. This also clearly shows that herbicides applied in combination either pre plant incorporated or pre-emergence or post emergence generally increased thespectrum of weed control and /or the length of residual weed control in a single single application that saves time and labour in a weed management programme. The mixing of 2 compatible herbicides from different chemical families in ZC 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 their individual applications.

Phytotoxicity and Crop Compatibility Studies
After spraying the ZC formulation of the invention and Pyrithiobac-sodium and Pendimethalin individually on cotton crops as explained above, the cotton crops were continuously monitored and evaluated for phytotoxicity symptoms and crop health on a scale of 0 – 10 as shown in the following Table 4:
Table 4. 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

The results were as shown in the following Table 5 :
TABLE 5
Treatment Dose
g a.i./ha Phytotoxicity
Yellowing Necrosis Epinasty/
Hyponasty Vein
Clearing Scorching Wilting
Pyrithiobac- sodium
62.50 0 0 0 0 0 0
Pendimethalin
680.75 0 0 0 0 0 0
Treatment 1 of Invention comprising pyrithiobac sodium@ 54.25g a.i./ha + Pendimethalin
@ 595 g a.i. / ha 649.25 0 0 0 0 0 0
Treatment 2 of Invention comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 742.00 0 0 0 0 0 0
Control
- 0 0 0 0 0 0

Mean observation recorded after 1,3,5,10,15 and 30 days after application
Table 5 shows that there is zero effect of the herbicides on the crop plants either as ZC formulation or individually thereby indicating that the ZC formulation of the invention is safe to the cotton crops.

Comparative efficacy Studies of EC, SC and ZC formulations
Cotton crop was grown on plots under natural outdoor conditions and herbicidal formulations viz. EC, SC and ZC of the invention at the same doses were individually applied as spray on the cotton field within 24 hours of the sowing at an application rate of 500 liters water per hectare using knapsack sprayer with flat fan nozzle. The number of individual weeds present in the field was recorded at 15 and 30 days after the application of the EC, SC and ZC formulations in comparison with untreated control. The results were as shown in the following Tables 5a &5b:

Table 6a Population of dominant broad leaf weeds influenced by various formulations of herbicide applied in cotton.
Treatment Weed Density (No./m2 )
Commelina diffusa Digera arvensis Phylanthus niruri
15 DAT 30 DAT 15 DAT 30 DAT 15 DAT 30 DAT
T1- ZC Formulation comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 9.00 12.00 1.33 8.00 1.66 8.00
T2- EC Formulation comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 10.33 15.00
4.66 9.00 2.00 11.00
T3- SC Formulation comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 17.00 19.00 8.66 18.00 5.00 18.00
T4- Control 24.00 27.00 13.66 24.00 17.66 34.00

Table 6b. Population of dominant monocot weeds and sedges influenced by various formulations of inventive herbicide applied in cotton

Treatment Narrow leaf weed density (No./m2 ) Density of sedges (No./m2 )

Digitaria
sanguinalis Dactyloctenium aegyptium Cyprus
15 DAT 30 DAT 15 DAT 30 DAT 15 DAT 30 DAT
T1- ZC Formulation comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 0.66 3.00 0.00 2.00 3.00 5.00
T2- EC Formulation comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 0.66 5.00 0.33 2.00 4.33 13.00
T3- SC Formulation comprising pyrithiobac sodium@ 62.0g a.i./ha + Pendimethalin
@ 680.0 g a.i. / ha 1.00 5.00 1.66 5.00 7.33 17.00

T4- Control 3.00 7.00 2.00 5.00 11.00 24.00

Table 6a and 6b show that the ZC formulation of the invention was highly effective as compared to their EC and SC formulations in controlling of the weed flora of cotton.
[024] 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 herbicide formulation comprising pendimethalin and pyrithiobac, wherein the formulation is an ZC formulation.

2. The herbicidal formulation as claimed in claim 1, wherein the pendimethalin and pyrithiobac is present in a ratio of from about 1:1 to about 20:1.

3. The herbicidal formulation as claimed in claim 1, wherein pyrithiobac is the acid itself or an agriculturally acceptable sodium ester.

4. The herbicidal formulation as claimed in claim 1, wherein the formulation further comprises agriculturally acceptable adjuvant and/or carrier.

5. The herbicidal formulation as claimed in claim 1, wherein the formulation is used for controlling undesirable weeds in cotton crop by contacting the synergistic herbicidal mixture as claimed in Claim 1 with foliage or seed or the locus thereof before or after planting or emergence.

6. An effective method of controlling weed species such as Trianthema sp., Digera sp., Phylanthus sp., Achyranthes sp., Xanthium sp., Cassia sp, Commelina sp., Brachiaria sp,, Dactyloctenium sp., Dinebra sp, Digitaria sp, Echinochloa sp., Eleusine sp., Cyprus sp. in cotton crop comprising applying to cotton field the herbicidal formulation as claimed in claim 1.

Dated this 6th day of December 2019

(Nisha Austine)
of Khaitan & Co
Agent for the Applicant
Reg No IN/PA-1390