FIELD OF THE INVENTION

The present invention relates to the field of agrochemicals. In particular, the present invention relates to an herbicidal combination comprising (a) Pendimethalin, a dinitroaniline member, (b) an herbicidal active selected from sulfonylurea class preferably Sulfosulfuron, a composition comprising the combination and agricultural excipients and its application.
BACKGROUND OF THE INVENTION
Different types of herbicides are being used in agriculture for controlling weeds. Although herbicides with different modes of action are available for farmers to control weeds, the problem of weeds in agricultural crops still prevails. The discovery of new herbicides has declined significantly over the past few decades and has only seen a modest upsurge in recent years, thereby the farmers are left to resort to the use of available herbicides. Unfortunately, due to extensive and unsupervised herbicide use, herbicide-tolerant or herbicide-resistant weeds have evolved, rendering the use of existing herbicides ineffective. If herbicides are to remain sustainable, then it is a must that we adopt diversity in crop rotation and herbicide use, as well as, to increase the use of combinations of herbicides to control weeds effectively during crop rotation. Combinations of herbicides are used to control a broader range of weeds. However, the combination of herbicides may not always result in the desired effect. Combination of herbicides may lead to an additive effect or an antagonistic effect. It may also result in phytotoxicity to the crops making it an undesirable combination. Agronomists must therefore carefully select the herbicides that can be combined to offer a synergistic effect that would control weeds while having no phytotoxic effect on the crop and reduce the chances of development of herbicide resistance in weeds.
Pendimethalin is used to control most annual grasses and many annual broad-leaved weeds at 0.4- 2.0 kg a.i./ha in cereals, onions, leeks, garlic, fennel, maize, sorghum, rice, soya beans, peanuts, brassicas, carrots, celery, black salsify, peas, field beans, lupins, evening primrose, tulips, potatoes, cotton, hops, pome fruit, stone fruit, berry fruit (including strawberries), citrus fruit, lettuce, aubergines, capsicums, established turf, and in transplanted tomatoes, sunflowers, and tobacco, applied as pre-plant incorporated, pre-emergence, pre-transplanting, or early post-emergence. Also, Pendimethalin is used for control of suckers in tobacco. Pendimethalin is used by farmers to control a wide variety of weeds. Pendimethalin plays an important role in weed management for numerous major crops such as rice, wheat, maize and soybean as well as minor crops such as fruits and vegetables. Pendimethalin based compositions are registered for commercialization in the country.

However, individual use of Pendimethalin typically leads to resistance, thereby necessitating the increase in dose, and consequently increase in costs to the farmers, phytotoxicity risks to the crop and limits options for herbicide selection, cultivations, and rotations. Further the staining nature of pendimethalin creates a challenge in preparing a composition which minimizes the staining during manufacturing process of the composition as well as during the end use. Hence, pendimethalin is preferably used as a combination.
Indian patent application 2792/CHENP/2006 discloses emulsifiable concentrates comprising an active ingredient being a dinitroaniline compound, preferably selected from the group consisting of pendimethalin, trifluralin and mixtures thereof, an emulsifier or an emulsifier mixture, and a solvent.
Indian patent application 2251 /MUM/2011 describes a capsule suspension composition comprising Pendimethalin in combination with clomazone.
However, the prior arts disclosing combination of pendimethalin suffer from either one or more of the following disadvantages:
• Use of expensive herbicide components or component,
• High dosage of herbicide components and thus possible environmental hazard,
• Risk of Phytotoxicity and thus reduced crop yield,
• Selective on controlling either grassy weeds or sedges or broad-leaf weeds but less
effective/ ineffective in controlling all of them together,
• Incompatibility in synthesis or mixing of the components,
• Lack of synergistic effect
Therefore, there is a need to provide a synergistic herbicidal combination of Pendimethalin, which is chemically compatible, affordable and which can control the weeds including grassy weeds, sedges and broad-leaf weeds present in the Wheat and other crops to improve the growth and grain yield without resulting in any environmental hazard and phytotoxicity.
Object of the Present Invention
An object of the present invention is to provide a novel and synergistic herbicidal combination of Pendimethalin with Sulfosulfuron and a composition comprising the

combination and its utility in controlling different types of weeds and enhancing the yield of food crop.
Summary of the Present Invention
The present invention provides a novel synergistic combination comprising Pendimethalin and a second herbicide Sulfosulfuron belonging to the different class of herbicides. The present application further provides an herbicidal composition comprising the said synergistic combination along with agriculturally acceptable excipient. The present application further discloses the bio-efficacy effect of the disclosed combination in controlling weeds, sedges and BLW's in a Wheat crop and other crops, without any phytotoxic effect on the crop and enhance the food product yield.
The present invention provides a novel synergistic herbicidal combination, comprising:
a. a dinitroaniline compound;
b. an herbicide belonging to the class of sulfonylureas
The present invention discloses a combination comprising pendimethalin in an amount in the range of 20.00 to 35.00% w/w and sulfosulfuron in an amount in the range of 1.00 to 5.00%
w/w.
The present invention also discloses a composition comprising the combination. The combination or the composition of the present invention comprising the combination and agricultural excipients is used for controlling the grassy weeds, sedges and broad-leaf weeds (BLW's) preferably Chenopodium species, Phalaris minor, Melilotus sp., Portulaca oleracea, Convolvulus arvensis, Anagalis arvensis and Avenafatua in a wheat crop.
Detailed Description of the Present Invention
The present invention provides a novel and synergistic combination comprising Pendimethalin, herbicide belonging to class of dinitroaniline and a second herbicide Sulfosulfuron belonging to the class of sulfonylurea.
In an aspect the present invention discloses a novel synergistic herbicidal combination, comprising:
a. a dinitroaniline compound;
b. an herbicide belonging to the class of sulfonylureas;

The dinitro aniline compound of the present invention may be selected from the group comprising benfluralin, butralin, chlornidine, dinitramine, dipropalin, ethalfluralin, fluchloralin, isopropalin, methalpropalin, nitralin, oryzalin, prodiamine, profluralin, and trifluralin, preferably, Pendimethalin.
The second herbicide from the chemical class of the sulfonyl urea is selected from the group comprising amidosulfuron, azimsulfuron, bensulfuron-methyl, chlorsulfuron, cyclosulfamuron, ethametsulfuron-methyl, ethoxysulfuron, flazasulfuron, flucetosulfuron, flupyrsulfuron-methyl sodium, foramsulfuron, imazosulfuron, iofensulfuron, iodosulfuron-methyl sodium, mesosulfuron-methyl, metsulfuron-methyl, nicosulfuron, orthosulfamuron, primisulfuron-methyl, propyrisulfuron, prosulfuron, pyrimisulfan, pyroxasulfone, rimsulfuron, sulfometuron-methyl, sulfosulfuron, thifensulfuron-methyl, triafamone, triasulfuron, tribenuron-methyl or trifloxysulfuron-sodium, or an agriculturally acceptable salt, carboxylic acid, carboxylate salt, or ester thereof of with at least one of the aforementioned compounds. Preferably, the sulfonyl urea is sulfosulfuron.
Without being limited by theory, the present invention discloses that combination of a Sulfosulfuron herbicides with Pendimethalin, is synergistic, enhances the efficacy of the herbicides, reduces the dose as compared to the individual herbicides. The combination does not produce any phytotoxic effect. Further, the said combination of the present invention effectively controls grassy weeds, sedges and broad-leaf weeds (BLW's) in Wheat crop and increases the growth and yield of the Wheat crop.
In another aspect, the present invention discloses the synergistic combination of Pendimethalin and Sulfosulfuron. Pendimethalin may be present in the range of 99-1% by weight, preferably 50 to 1% by weight, more preferably 20.00 to 35.00% by weight and the second herbicide being the Sulphosulfuron is present in the range of 1-99% by weight, preferably 1-50% by weight, more preferably 1.00 to 5.00 % by weight. Preferably the combination comprises Pendimethalin in the range of 20.00 to 35.00% by weight and Sulfosulfuron in the range of 1.0 to 5.0% by weight.
The present invention discloses a novel and synergistic combination comprising the two actives Pendimethalin and Sulfosulfuron in the ratio of 20:1 to 6:1, preferably 19:1 to 8:1.
In yet another embodiment, the combination of the present invention may be administered as a composition. The present invention discloses a composition comprising the herbicidal combination along with agricultural excipients selected from the group consisting of solvents,

anti- freezing agent, dispersing agent, wetting agent, defoamer, preservative, thickener, surfactants, suspending agent, water and combinations thereof.
Suitable agricultural excipients should not be phytotoxic to valuable crops, particularly at the concentrations employed in applying the compositions for selective weed control in the presence of crops and should not react chemically with herbicidal components or other composition ingredients. Such mixtures can be designed for application directly to weeds or their locus or can be concentrates or compositions that are normally diluted with additional carriers and adjuvants may be added before application.
Solvents that can be employed include water and organic solvents. The organic solvents typically used include, but are not limited to, petroleum fractions or hydrocarbons such as mineral oil, aromatic solvents, paraffinic oils, and the like; vegetable oils such as soybean oil, rapeseed oil, olive oil, castor oil, sunflower seed oil, coconut oil, corn oil, cottonseed oil, linseed oil, palm oil, peanut oil, safflower oil, sesame oil, tung oil and the like; esters of the above vegetable oils; esters of monoalcohols or dihydric, trihydric, or other lower polyalcohols (4-6 hydroxy containing), such as 2-ethyl hexyl stearate, n-butyl oleate, isopropyl myristate, propylene glycol dioleate, di-octyl succinate, di-butyl adipate, di-octyl phthalate and the like; esters of mono, di and polycarboxylic acids and the like. Specific organic solvents include toluene, xylene, petroleum naphtha, crop oil, acetone, methyl ethyl ketone, C9-C11 hydrocarbon, cyclohexanone, trichloroethylene, perchloroethylene, ethyl acetate, amyl acetate, butyl acetate, propylene glycol monomethyl ether and diethylene glycol monomethyl ether, methyl alcohol, ethyl alcohol, isopropyl alcohol, amyl alcohol, ethylene glycol, propylene glycol, glycerine, N-methyl-2-pyrrolidinone, N, N-dimethyl alkylamides, dimethyl sulfoxide, liquid fertilizers and the like. Water is generally the carrier of choice for the dilution of concentrates. In the present invention, deminerahzed water is used to make up to volume. Suitable solvent for the purpose of the present invention is C9-C11 hydrocarbon and present in range of 20-50% w/w, preferably 30% w/w.
In accordance with yet another aspect of the invention, the dispersing agent is selected from group consisting of sodium lignosulphonates, sodium naphthalene sulphonate- formaldehyde condensates, acrylic copolymer, aliphatic alcohol ethoxylates, tristyrylphenol ethoxylates potassium, polyarylphenyl ether sulphate ammonium salt and ethoxylated polyarylphenol phosphate ester and combinations thereof, preferably dispersing agent is acrylic copolymer,

more preferably polyarylphenyl ether sulphate ammonium salt and present in an amount of 2.00-10.00% w/w, preferably 2 to 3 % w/w.
In accordance with yet another aspect of the invention, the anti-freezing agent is selected from the group consisting of propylene glycol, di-ethylene glycol (DEG), mono-ethylene glycol (MEG), glycol and like combinations, preferably anti-freezing agent is Di-ethylene Glycol, and present in a range of 1.00- 8.00% w/w, preferably 5.00% w/w.
It is usually desirable to incorporate one or more surface-active agents into the compositions of the present invention. Such surface-active agents are advantageously employed in both solid and liquid compositions, especially those designed to be diluted with carrier before application. The surface-active agents can be anionic, cationic or non-ionic in character and can be employed as emulsifying agents, wetting agents, suspending agents, or for other purposes. Surfactants or wetting agents conventionally used in the art of composition and which may also be used in the present compositions are described, inter alia, in "McCutcheon's Detergents and Emulsifiers Annual," MC Publishing Corp., Ridgewood, N.J., 1998 and in "Encyclopedia of Surfactants," Vol. I-III, Chemical Publishing Co., N.Y., 1980-81. Typical surface-active agents include salts of alkyl sulfates, such as diethanolammonium lauryl sulfate; alkylarylsulfonate salts, such as calcium dodecylbenzenesulfonate; alkylphenol-alkylene oxide addition products, such as nonylphenol-Cis ethoxylate, Ethoxylated polyarylphenol; alcohol-alkylene oxide addition products, such as tridecyl alcohol-Ci6 ethoxylate; polymers such as Acrylic copolymer; soaps, such as sodium stearate; alkylnaphthalene-sulfonate salts, such as sodium dibutyl-naphthalenesulfonate; dialkyl esters of sulfosuccinate salts, such as Sodium dioctyl sulfosuccinate, Octylphenol Ethoxylates, sodium di(2-ethylhexyl) sulfosuccinate; sorbitol esters, such as sorbitol oleate; quaternary amines, such as lauryl trimethylammonium chloride; polyethylene glycol esters of fatty acids, such as polyethylene glycol stearate; block copolymers of ethylene oxide and propylene oxide; salts of mono- and dialkyl phosphate esters; vegetable or seed oils such as soybean oil, rapeseed/canola oil, olive oil, castor oil, sunflower seed oil, coconut oil, corn oil, cottonseed oil, linseed oil, palm oil, peanut oil, safflower oil, sesame oil, tung oil and the like; and esters of the above vegetable oils, particularly methyl esters. Preferably, the wetting agent is Octylphenol Ethoxylates and Sodium dioctyl sulfosuccinate, more preferably Sodium dioctyl sulfosuccinate and is present in a range of 2.00- 10.00% w/w, preferably 1 to 5% w/w, more preferably 2 to 3 % w/w.

In accordance with yet another aspect of the invention, the thickeners include natural gums, cottonseed hulls, wheat flour, soybean flour, pumice, wood flour, walnut shell flour, lignin, Polysaccharides and the like. Preferably, the thickener is Polysaccharides and present in a range of 0.01-0.50% w/w, preferably 0.08% w/w.
In accordance with yet another aspect of the invention, the antifoaming agent is Silicon emulsion, and present in an amount of 0.01-0.5% w/w, preferably 0.20% w/w.
In accordance with yet another aspect of the invention, the suspending agent is selected from Proxel GXL or formaldehyde, Aluminium magnesium silicate and Silicon dioxide. Preferably the suspending agent is Aluminium magnesium silicate and Silicon dioxide and present in a range of 0.10- 2.5% w/w, preferably 0.5 to 2.0% w/w.
In accordance with yet another aspect of the invention, the preservative is 1,2-Benzisothiazol-3(2H)-one and present in an amount of 0.01-0.50% w/w, preferably 0.2% w/w.
Other adjuvants commonly used in agricultural compositions include compatibility agents, sequestering agents, neutralizing agents and buffers, corrosion inhibitors, dyes, odorants, spreading agents, penetration aids, sticking agents and the like.
In an embodiment of the present invention the composition is in form of a dust, granule, water dispersible granule, wettable powder, emulsifiable concentrate, solution, emulsion, suspension or suspoemulsion (SE), preferably a suspoemulsion (SE).
In an aspect, the combination and the composition containing the present invention is used to control the grassy weeds, sedges and broad-leaf weeds (BLW's) preferably Chenopodium species, Phalaris minor, Melilotus sp., Portulaca oleracea, Convolvulus arvensis, Anagalis arvensis and Avenafatua in a wheat crop.
The compositions may also contain other compatible components, for example, other herbicides, plant growth regulators, fungicides, insecticides, and the like and can be combined with liquid fertilizers or solid, particulate fertilizer carriers such as ammonium nitrate, urea and the like.
The synergistic composition of the present invention can be applied in conjunction with one or more other herbicides to control a wider variety of undesirable vegetation. When used in conjunction with other herbicides, the composition can be formulated with the other herbicide or herbicides, tank mixed with the other herbicide or herbicides or applied sequentially with

the other herbicide or herbicides. The synergistic combination can be applied as a solid combination that can be constituted and applied to the fields or directly as solid mixed with any dispensing agent.
The synergistic composition of the present invention can additionally be employed to control undesirable vegetation in many crops that have been made tolerant to or resistant to them or to other herbicides by genetic manipulation or by mutation and selection.
It is generally preferred to use the synergistic composition of the present invention in combination with herbicides that are selective for the crop being treated and which complement the spectrum of weeds controlled by these compounds at the application rate employed. It is further generally preferred to apply the synergistic composition of the present invention and other complementary herbicides at the same time, either as a combination composition or as a tank mix.
The present compositions can be applied to weeds or their locus by the use of conventional ground or aerial dusters, sprayers, and granule applicators, by addition to irrigation water, and by other conventional means known to those skilled in the art.
The following examples illustrate the basic methodology and versatility of the present invention. The examples are meant for illustrative purposes and should not be construed as limiting.
Example 1
The compositions contemplated by Example 1 that are tabulated in Table 1 are formulated as
a suspo emulsion (SE) composition.
Table 1: Quantities of the active ingredients and excipients charged
Component Function Quantities of materials charged (Kg) (%w/w)

agent
SU^lfrn SC 3.00 1.50 1.20 1.50
a.i.@100% composition

1 2 3 4
Pendimethalin a.i. EC 24 28 30 28
@100% composition

C9-C11 hydrocarbon Aromatic solvent 30 30 30 30
Ethoxylated polyarylphenol Emulsifier 3.00 3.00 3.00 3.00
Octylphenol Ethoxylates wetting cum spreading
a rvotff 3.00 3.00 3.00 3.00

sulphate ammonium salt agent 1.10 1.10 1.10 1.10
Acrylic copolymer Dispersing agent 0.50 0.50 0.50 0.50
Aluminium magnesium silicate Suspending agent 1.50 1.50 1.50 1.50
Silicon dioxide Suspending agent 0.50 0.50 0.50 0.50
Sodium dioctyl sulfosuccinate Wetting agent 2.50 2.50 2.50 2.50
Propylene Glycol Antifreezing 5.0 5.0 4.80 5.0
Silicon emulsion Antifoam 0.20 0.20 0.20 0.20
1,2-Benzisothiazol-3(2H)-one Preservative 0.20 0.20 0.20 0.20
Polysaccharides Thickener 0.08 0.08 0.08 0.08
Water Diluent / solvent 31.42 28.92 27.42 28.92
TOTAL 100 100 100 100
Process for preparing synergistic herbicidal composition (Sulfosulfuron 1.5% + Pendimethalin 24% SE) in the form of suspo emulsion (SE) composition.
As per the recipe for 100 kg or Ltr batch
SC Premix
Step 1- 2% Gum Solution: Charge 2 kg Xanthan gum and 2 kg l,2-benzisothiazoline-3-one into 96 kg water and homogenize and should be made 12-18 hour prior to use.
Step 2- Charge 25.92 kg of DM water, 1.1 kg of Polyarylphenyl ether sulphate ammonium salt and 0.5 kg of acrylic copolymer into designated vessel and mix thoroughly.
Step 3- Add 1.5 kg of aluminium magnesium silicate, 0.5 kg of Silicon dioxide and 2.5 kg of Sodium dioctyl sulfosuccinate and 5 kg Propylene Glycol into the vessel having water and homogenise the contents for 45 - 60 minutes using high shear homogeniser at 1000-1200 rpm.
Step 4- Now add 1.50 kg of Sulfosulfuron technical to this premix slowly and homogenised to get uniform slurry ready for grinding.
Step 5- Before grinding, add 0.10 kg of antifoam was added and then material was subjected to grinding in Dyno mill till desired particle size is achieved. (D50<3, D90<10)

Step 6- Add remaining 0.10 kg of Silicon emulsion antifoam after grinding process completes and before sampling for in process analysis.
EC Premix
Step 7- Charge 24 kg of Pendimethalin technical into the vessel having 30 kg Aromatic solvent and 3 kg of Octyl phenol ethoxylate and if required heat the vessel at 60 °C and now add 3 kg of Ethoxylated polyarylphenol and mix properly till it gets clear solution.
SE Composition
Step 8- Now mix EC premix into SC premix under slow stirring into another vessel.
Step 9- Finally add 5 kg of 2% gum solution to this composition and send to QC for quality check.
Evaluation of synergistic effect of herbicidal composition of the present invention
A synergistic effect of two or more products 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. 1 (Jan 1967), pp. 20-2. The synergistic action expected for a given combination of two active components can be calculated as follows:
v XY
Where:
E represents expected percentage of herbicidal control for the combination of the two actives ingredients at defined doses (for example equal to x and y, respectively).
X is the percentage of herbicidal control observed by the compound (Sulfosulfuron) at a defined dose (equal to x).
Y is the percentage of herbicidal control observed by the compound (Pendimethalain) at a defined dose (equal to y).
When the percentage of herbicidal control observed for the combination is greater than the expected percentage, there is a synergism effect.
Observed Control (%)
Ratio = ——-
Expected Control (%)

Ratio of O/E > 1, synergism observed
Example 2:
Field experiment for synergistic activity of Sulfosulfuron and Pendimethalin for the control of weeds in wheat crop was conducted by following the methodology as under:
To evaluate the synergistic effect, wheat crop (local variety) was sown in 5 m x 6 m plots and the treatments were applied @ 2000 ml/ha dose as pre-emergence or post emergence of weeds depending upon the treatments. The treatments with g a.i./ha dose taken were as under:
Tl - Sulfosulfuron (20 g a.i./ha) + Pendimethalin (400 g a.i./ha)
T2 - Sulfosulfuron (20 g a.i./ha) + Pendimethalin (480 g a.i./ha)
T3 - Sulfosulfuron (20 g a.i./ha) + Pendimethalin (560 g a.i./ha)
T4 - Sulfosulfuron (30 g a.i./ha) + Pendimethalin (400 g a.i./ha)
T5 - Sulfosulfuron (30 g a.i./ha) + Pendimethalin (480 g a.i./ha)
T6 - Sulfosulfuron (30 g a.i./ha) + Pendimethalin (560 g a.i./ha)
T7 - Sulfosulfuron (20 g a.i./ha)
T8 - Sulfosulfuron (30 g a.i./ha)
T9 - Pendimethalin (400 g a.i./ha)
T10 - Pendimethalin (480 g a.i./ha)
Til- Pendimethalin (560 g a.i./ha)
T12 - Untreated check
The treatments T9 to Til were applied as pre emergence of weeds (at 2 days after crop
sowing), whereas treatments Tl to T8 as post emergence of weeds (30 days after crop
sowing) by using knapsack sprayer fitted with flat fan nozzle and 500 lit water/ha.
Observations for weed density/m2 (Phalaris minor and Chenopodium album) were recorded
30 days after treatment application with the help of 50 cm x 50 cm quadrant and weed dry
weight g/m2 was also recorded. The weed control efficiency was calculated for each
treatment based on weed dry weight. Based on the weed control efficiency the Expected
control was calculated and compared with Observed control. The results of the trial have
been presented here under:

Weed Species - Phalaris minor

T.
No. Active ingredient/ test product Application rate (g a.i./ha) Observed control
(%) Expected control
(%) Colby Ratio

X Y X Y

Tl Sulfosulfuron Pendimethalin 20 400 67.84 67.13 1 : 1.011
T2 Sulfosulfuron Pendimethalin 20 480 71.73 69.27 1 : 1.036
T3 Sulfosulfuron Pendimethalin 20 560 79.15 74.08 1 : 1.068
T4 Sulfosulfuron Pendimethalin 30 400 80.21 70.82 1 : 1.133
T5 Sulfosulfuron Pendimethalin 30 480 86.93 72.72 1 : 1.195
T6 Sulfosulfuron Pendimethalin 30 560 89.05 76.99 1 : 1.157
T7 Sulfosulfuron - 20 62.19
T8 Sulfosulfuron - 30 66.43
T9 - Pendimethalin 400 13.07
T10 - Pendimethalin 480 18.73
Til - Pendimethalin 560 31.45
T12 Untreated control - - - -
Weed Species - Chenopodium album

T.
No. Active ingredient/ test product Application rate (g a.i./ha) Observed control
(%) Expected control
(%) Colby Ratio

X Y X Y

Tl Sulfosulfuron Pendimethalin 20 400 71.14 66.14 1 : 1.076
T2 Sulfosulfuron Pendimethalin 20 480 74.80 67.12 1 : 1.114
T3 Sulfosulfuron Pendimethalin 20 560 81.30 72.35 1 : 1.124
T4 Sulfosulfuron Pendimethalin 30 400 78.86 68.53 1 : 1.151
T5 Sulfosulfuron Pendimethalin 30 480 82.93 69.44 1 : 1.194
T6 Sulfosulfuron Pendimethalin 30 560 90.65 74.31 1 : 1.220
T7 Sulfosulfuron - 20 59.76
T8 Sulfosulfuron - 30 62.60
T9 - Pendimethalin 400 15.85
T10 - Pendimethalin 480 18.29
Til - Pendimethalin 560 31.30
T12 Untreated control - - - -

The results showed that Sulfosulfuron and Pendimethalain have synergistic effect in each case of application with > 1 Colby's Ratio, However the combination treatments Sulfosulfuron 30 g ai/ha + Pendimethalin 480 g a.i./ha dose and Sulfosulfuron 30 g ai/ha + Pendimethalin 560 g a.i./ha dose showed greater synergistic impact than other combination of the products.
Based on the affirmative results of above experiment towards synergistic effect to control weeds in wheat crop, a field trial was conducted to evaluate the effectiveness of combination formulated product (Sulfosulfuron 1.5% + Pendimethalin 24% SE) @ based on various study parameters.
The synergistic herbicidal composition of the present invention has been tested in the field and the results are presented in the example 3. From the example it can be clearly seen that the combination of the present invention is superior on reducing the count or population of weeds such as Chenopodium species, Phalaris minor, Melilotus sp., Portulaca oleracea, & Avena fatua. at 30, 45, 60 and 75 days after application as compared to the individual herbicide Pendimethalin 30% EC @ 4200 ml/ha, Sulfosulfuron 75% WG @ 33.3 g/ha and other registered product available in the market Carfentrazone ethyl 40% DF @ 50 g/ha. The growth and yield of wheat crop is also improved and almost equivalent to the growth and yield obtained with weed free control. The disclosed combination further showed no phytotoxicity in the Wheat crop even after 35, 40, 50 and 60 days after application.
Example 3: Effect of the combination of the present invention
Product : Sulfosulfuron 1.5% + Pendimethalin 24% SE
Crop : Wheat var. HD-2967
Dateof sowing 25 112020
Date of spraying : 27.11.2020 (2 days after crop sowing - Pendimethalin 30% EC)
26.12.2020 (30 days after crop sowing - Sulfosulfuron 1.5% + Pendimethalin 24% SE, Carfentrazone ethyl 40% DF and Sulfosulfuron 75% WG)
Date of harvesting : 16 04 2021
Objectives:
1. To test bio-efficacy of Sulfosulfuron 1.5% + Pendimethalin 24% SE against weeds based on weed density in wheat crop.

2. To evaluate the bio-efficacy of Sulfosulfuron 1.5% + Pendimethalin 24% SE against weeds based on weed dry weight in wheat crop.
3. To evaluate the bio-efficacy of Sulfosulfuron 1.5% + Pendimethalin 24% SE against weeds based on per cent weed control efficiency in wheat crop.
4. To evaluate phytotoxicity of Sulfosulfuron 1.5% + Pendimethalin 24% SE on wheat crop.
5. To calculate Cost: Benefit Ratio of treatments.
Design : Randomized Block Design (RBD)
Replications : Three
Treatments : Eight

S.No Treatment Dose g a.i./ha Dose composition (g or ml/ha)
1. Sulfosulfuron 1.5% + Pendimethalin 24% SE 22.5 + 360 1500 ml
2. Sulfosulfuron 1.5% + Pendimethalin 24% SE 30 + 480 2000 ml
3. Sulfosulfuron 1.5% + Pendimethalin 24% SE 37.5 + 600 2500 ml
4. Sulfosulfuron 1.5% + Pendimethalin 24% SE 45 + 720 3000 ml
5. Sulfosulfuron 75% WG + Surfactant (1250 ml/ha) 25 33.3 g
6. Pendimethalin 30% EC 1250 4200 ml
7. Carfentrazone ethyl 40% DF 20 50 g
8. Hand weeding control - -
9. Untreated control - -
10. Sulfosulfuron 1.5% + Pendimethalin 24% SE (For phytotoxicity evaluation only) 90 +1440 6000 ml
Number of Applications : One
Spray Volume : 500 lt/ha
Method of application : pre/post emergent application using knapsack sprayer fitted with
flat fan nozzle Time of application : At 2 and 30 Days after sowing (DAS) Observations Taken:
• Weed density at 30, 45, 60 and 75 days after crop sowing (DAS).
• Weed dry weight at 45, 60 and 75 DAS
• Yield
• Phyto-toxicity at 35, 40, 50 and 60 days after crop sowing

Methodology
The application of Pendimethalin 30% EC was done as pre-emergence (2 days after crop sowing), whereas Sulfosulfuron 1.5% + Pendimethalin 24% SE, Carfentrazone ethyl 40%) DF and Sulfosulfuron 75% WG were applied as post emergence (30 days after crop sowing). Hand weeding was done at 35 and 55 days after crop sowing. The recommended agronomical practices for the area were followed as and when required uniformly in various experimental plots.
The observations for weed density were recorded species wise 30 days after crop sowing (pre spray for post emergence application of treatments) and thereafter at 45, 60 and 75 days after crop sowing. A quadrant of 50 cm x 50 cm (0.25 m2) was used to record weed density by placing at randomly selected four places per plot and data expressed in terms of weeds/m2. To record weed dry weight, weeds collected at 45, 60 and 75 days after crop sowing were dried in open sun for 48 hrs and thereafter in hot air oven at 70 ± 5°C temp for 72 hrs. Based on weed dry weight, per cent weed control efficiency (WCE) was calculated using following formula:
Weed dry weight in weedy check control - weed dry weight in treatment
WCE (%) = x 100
Weed dry weight in weedy check control
The phytotoxicity symptoms were observed visually for leaf injury on tips/ surface, wilting, vein clearing, necrosis, epinasty and hyponasty at 35, 40, 50 and 60 days after crop sowing.
1. Leaf Injury on tips and leaf surface
2. Wilting
3. Vein clearing
4. Necrosis
5. Epinasty
6. Hyponasty
7. Plant Height

To record the observations 1-10 rating scale was used, the details of which are as under:

Rating Crop Injury % Verbal description
0 — No symptoms
1 1-10 Very slight discoloration
2 11-20 More severe, but not lasting
3 21-30 Moderate and more lasting
4 31-40 Medium and lasting
5 41-50 Moderately heavy
6 51-60 Heavy
7 61-70 Very Heavy
8 71-80 Nearly destroyed
9 81-90 Destroyed
10 91-100 Completely destroyed
The yield data were recorded plot wise at harvest and presented in the report in terms of q/ha. Based on yield data, product price, treatment application cost, profit from produce the Cost: Benefit Ratio was calculated. The experimental data were analysed statistically after suitable transformation.
Result:
Weed density:
The major weed species observed in the experimental plots were Phalaris minor,
Chenopodium album, Melilotus alba, Convolvulus arvensis, Portulaca oleracea, Anagalis arvensis and Avena fatua. The mean weed species density recorded 30, 45, 60 and 75 days after crop sowing have been presented in Table 3 to 6. The data recorded at 30 days after crop sowing showed that weeds population in the treatment Pendimethalin 30% EC @ 4200 ml/ha was lowest because this treatment was applied as pre-emergence (2 days after crop sowing). The weed population in other treatments of course were higher and comparable to control (hand weeding) and untreated control, due to application of treatments as post emergence and first hand weeding after 30 days of crop sowing. Hence weed population in post emergence applied treatments to be considered as weed population before application of these treatments.
The weed population recorded at 45, 60 and 75 days after crop sowing, it was observed that all the treatments effectively controlled weeds as compared to weedy check

control. However, weed populations in hand weeding control and Sulfosulfuron 1.5% + Pendimethalin 24% SE @ 3000 ml/ha followed by lower dose @ 2500 ml/ha were low than other treatments. The treatments Sulfosulfuron 1.5% + Pendimethalin 24% SE @ 2000 ml/ha and 1500 ml/ha and Carfentrazone ethyl 40% DF @ 50 g/ha were next in order of effectiveness. The individual constituent products of the combination product (Sulfosulfuron 1.5% + Pendimethalin 24% SE) applied as Pendimethalin 30% EC @ 4200 ml/ha and Sulfosulfuron 75% WG @ 33.3 g/ha were comparatively less effective with higher weed population at each observation time.
Table 3: Bioeffectiveness of Sulfosulfuron 1.5% + Pendimethalin 24% SE to control
weeds in wheat crop at 30 days after crop sowing
Treatment Dose composition Mean weed density 30 days after crop sowin g/m2

Phalaris Chenopodium Melilotus Convolvulus Portulaca Anagalis Avenafatua
(g or ml/ha) minor album alba arvensis oleracea arvensis
Sulfosulfuron
1.5% + 1500 ml 21.67 16.33 12.33 9.67 10.33 7.33 7.67
Pendimethalin
(4.70) (4.10) (3.56) (3.18) (3.28) (2.79) (2.85)
24% SE
Sulfosulfuron
1.5% + 2000 ml 18.33 12.33 11.33 10.67 9.33 8.00 6.67
Pendimethalin
(4.33) (3.58) (3.42) (3.32) (3.12) (2.90) (2.65)
24% SE
Sulfosulfuron
1.5% + 2500 ml 24.00 15.00 14.00 9.33 9.67 8.67 8.67
Pendimethalin
(4.94) (3.93) (3.79) (3.12) (3.18) (3.02) (3.02)
24% SE
Sulfosulfuron
1.5% + 3000 ml 19.67 13.67 14.67 8.67 10.67 8.33 7.33
Pendimethalin
(4.48) (3.74) (3.89) (3.02) (3.34) (2.96) (2.79)
24% SE
Sulfosulfuron
75%WG + 33.3 g 22.00 16.00 13.33 10.00 11.00 9.67 6.67
Surfactant
(4.73) (4.06) (3.71) (3.24) (3.38) (3.19) (2.67)
(1250 ml/ha)
Pendimethalin 4200 ml 8.67 6.33 5.67 3.67 5.33 4.00 1.33
30% EC
(3.02) (2.60) (2.46) (2.02) (2.40) (2.11) (1.29)
Carfentrazon e ethyl 40% DF 50 g 23.67 13.33 12.00 9.67 10.67 9.33 7.67

(4.91) (3.71) (3.53) (3.18) (3.34) (3.13) (2.84)
Hand weeding 22.00 14.33 13.67 9.00 9.67 8.67 8.00
control (4.73) (3.84) (3.76) (3.07) (3.18) (3.02) (2.90)
Untreated 21.33 15.67 13.00 10.33 10.33 9.00 7.33
control (4.66) (4.02) (3.66) (3.28) (3.29) (3.07) (2.79)
SEm(±) - 0.20 0.18 0.21 0.21 0.17 0.17 0.20
CD at 5% - 0.61 0.55 0.64 0.62 0.50 0.51 0.61
Values in parentheses are square root transformed values

Table 4: Bioeffectiveness of Sulfosulfuron 1.5% + Pendimethalin 24% SE to control weeds in wheat crop at 45 days after crop sowing

Treatment Dose composition (g or ml/ha) Mean weed density 45 days after crop sowing/m2

Phalaris minor Chenopodium album Melilotus alba Convolvulus arvensis Portulaca oleracea Anagalis arvensis Avena fatua
Sulfosulfliron 1.5% + Pendimethalin
24% SE 1500 ml 5.67 (2.47) 3.00 (1.84) 1.33 (1.18) 3.33 (1.93) 4.00 (2.11) 1.00 (1.10) 2.33 (1.66)
Sulfosulfliron 1.5% + Pendimethalin
24% SE 2000 ml 4.00 (2.10) 2.33 (1.68) 0.67 (1.00) 2.00 (1.47) 2.33 (1.68) 0.00 (0.71) 1.00 (1.17)
Sulfosulfliron 1.5% + Pendimethalin
24% SE 2500 ml 2.00 (1.56) 1.67 (1.39) 0.00 (0.71) 1.33 (1.27) 1.00 (1.17) 0.00 (0.71) 0.33 (0.88)
Sulfosulfliron 1.5% + Pendimethalin
24% SE 3000 ml 1.67 (1.39) 0.67 (1.00) 0.00 (0.71) 1.67 (1.39) 0.33 (0.88) 0.00 (0.71) 0.00 (0.71)
Sulfosulfliron 75%WG + Surfactant (1250 ml/ha) 33.3 g 6.00
(2.53) 4.33 (2.19) 3.00 (1.86) 4.33 (2.18) 5.67 (2.47) 2.33 (1.57) 2.67 (1.77)
Pendimethalin
30% EC 4200 ml 8.33 (2.96) 8.33 (2.97) 4.67
(2.22) 5.00 (2.34) 6.33 (2.60) 4.67
(2.26) 3.00 (1.86)
Carfentrazone ethyl 40% DF 50 g 5.00 (2.32) 4.00 (2.11) 2.00 (1.47) 4.33 (2.18) 5.33 (2.39) 2.00 (1.47) 2.00 (1.56)
Hand weeding control - 0.00 (0.71) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71)
Untreated control - 26.00 (5.14) 23.33 (4.87) 15.33 (3.97) 15.67 (4.01) 17.00 (4.17) 14.33 (3.84) 11.33 (3.43)
SEm(±) - 0.21 0.20 0.29 0.26 0.18 0.26 0.17
CD at 5% - 0.64 0.61 0.86 0.78 0.55 0.79 0.51
Values in parentheses are square root transformed values
Table 5: Bioeffectiveness of Sulfosulfuron 1.5% + Pendimethalin 24% SE to control
weeds in wheat crop at 60 days after crop sowing

Anagalis arvensis
Treatment
Sulfosulfuron 1.5% +
Pendimethalin 24% SE
Sulfosulfuron
1.5% +

Dose composition (g or ml/ha)
1500 ml
2000 ml

Phalaris
minor
7.33 (2.78)
4.67
(2.26)

Mean weed density 60 days after crop sowing/m2
Melilotus alba
Portulaca oleracea
Convolvulus
arvensis
Chenopodium album
5.00 (2.34)
0.67 (1.00)
2.67 (1.77)
2.67 (1.76)
0.00 (0.71)
1.67 (1.46)
0.00 (0.71)
0.67 (1.00)
1.33 (1.29)
0.00 (0.71)

Pendimethalin 24% SE
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2500 ml 3.33 (1.93) 1.33 (1.29) 0.00 (0.71) 0.33 (0.88) 0.33 (0.88) 0.00 (0.71) 0.00 (0.71)
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 3000 ml 2.00 (1.47) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71)
Sulfosulfuron 75%WG + Surfactant (1250 ml/ha) 33.3 g 7.33 (2.79) 5.33 (2.39) 3.67 (2.03) 5.00 (2.32) 3.67 (2.04) 3.00 (1.86) 4.00 (2.11)
Pendimethalin 30% EC 4200 ml 9.33 (3.13) 9.67 (3.17) 5.33 (2.41) 6.33 (2.58) 7.67 (2.85) 6.33 (2.60) 6.67 (2.67)
Carfentrazone ethyl 40% DF 50 g 5.67 (2.46) 7.00 (2.73) 2.67 (1.77) 3.67 (2.02) 3.00 (1.86) 1.00 (1.17) 1.67 (1.46)
Hand weeding control - 0.00 (0.71) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71) 0.00 (0.71)
Untreated control - 31.00 (5.61) 25.33 (5.08) 24.67 (5.01) 18.33 (4.33) 25.33 (5.07) 18.00 (4.29) 14.67 (3.89)
S Em (±) - 0.22 0.18 0.13 0.20 0.18 0.13 0.16
CD at 5% - 0.66 0.54 0.38 0.59 0.53 0.40 0.48
Values in parentheses are square root transformed values

Table 6: B weeds in w ioeffectiveness of Sulfosulfuron 1.5% + Pendimethalin 24% 5 leat crop at 75 days after crop sowing 3E to control
Treatment Dose composition (g or ml/ha) Mean weed density 75 days after crop sowing/m2

Phalaris minor Chenopodium album Melilotus alba Convolvulus arvensis Portulaca oleracea Anagalis arvensis Avena fatua
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 1500 ml 10.00
(3.22) 9.67 (3.18) 3.00 (1.86) 5.33 (2.41) 6.33 (2.56) 2.00 (1.47) 2.67 (1.77)
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2000 ml 8.67 (3.03) 5.67 (2.47) 1.67 (1.39) 3.33 (1.95) 3.33 (1.93) 0.67 (1.00) 1.67 (1.39)
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2500 ml 5.67 (2.47) 4.00 (2.10) 0.67 (1.00) 2.00 (1.56) 2.00 (1.47) 0.00 (0.71) 0.67 (1.00)
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 3000 ml 4.33 (2.19) 3.33 (1.93) 1.00 (1.17) 1.33 (1.29) 1.00 (1.17) 0.00 (0.71) 0.33 (0.88)
Sulfosulfuron 75%WG + Surfactant 33.3 g 11.33 (3.43) 10.00 (3.24) 7.33 (2.79) 7.67 (2.85) 7.33 (2.79) 6.33 (2.61) 7.33 (2.79)

(1250 ml/ha)
Pendimethalin 30% EC 4200 ml 14.67 (3.87) 15.67 (4.02) 9.67 (3.18) 9.00 (3.07) 12.00
(3.53) 9.00 (3.07) 9.33 (3.12)
Carfentrazone ethyl 40% DF 50 g 9.33 (3.12) 9.00 (3.08) 5.33 (2.40) 5.67 (2.45) 6.33 (2.60) 2.33 (1.68) 4.33 (2.18)
Hand weeding control - 1.33 (1.29) 1.67 (1.39) 0.00 (0.71) 0.67 (1.00) 0.67 (1.05) 0.00 (0.71) 1.67 (1.39)
Untreated control - 36.00 (6.04) 31.33 (5.64) 36.33 (6.06) 25.00 (5.04) 33.33 (5.78) 24.67 (5.01) 21.00 (4.63)
S Em (±) - 0.23 0.18 0.22 0.21 0.30 0.20 0.25
CD at 5% - 0.68 0.54 0.67 0.63 0.89 0.59 0.74
Values in parentheses are square root transformed values
Weed dry weight:
The weed dry weight recorded at 45, 60 and 75 days after crop sowing have been
presented in Tables 7 to 9. It was observed that all the treatments effectively controlled weeds growth and development as compared to untreated control. However, hand weeding control followed by Sulfosulfuron 1.5% + Pendimethalin 24% SE @ 3000 ml/ha and 2500 ml/ha were most effective with low weed dry weight at each observation time. Next in order of effectiveness were Sulfosulfuron 1.5% + Pendimethalin 24% SE @ 2000 ml/ha and 1500 ml/ha and Carfentrazone ethyl 40% DF @ 50 g/ha. Based on weed dry weight also the individual constituent products of the combination product (Sulfosulfuron 1.5% + Pendimethalin 24% SE) applied as Pendimethalin 30% EC @ 4200 ml/ha and Sulfosulfuron 75%) WG @ 33.3 g/ha were comparatively less effective with higher weed dry weight at each observation time. Weed dry weight of each weed species in untreated control remained highest. Table 7: Bioeffectiveness of Sulfosulfuron 1.5% + Pendimethalin 24% SE to control
weeds in wheat crop at 45 days after crop sowing

Treatment Dose composition (g or ml/ha) Mean weed dry weight 45 days after crop sowing g/m2

Phalaris minor ChenopocRum album Melilotus alba Convolvulus arvensis Portulaca oleracea AnagaUs arvensis Avena fatua
Sulfosulfuron 1.5% + Pendimethalin
24% SE 1500 ml 3.63 (1.92) 1.63 (1.29) 0.73 (0.65) 2.23 (1.50) 1.40 (1.20) 0.30 (0.47) 1.47 (1.23)
Sulfosulfuron 1.5% + Pendimethalin
24% SE 2000 ml 2.73 (1.67) 1.57 (1.25) 0.40 (0.52) 1.63 (1.13) 0.97 (1.00) 0.00 (0.22) 1.17 (0.97)
Sulfosulfuron 1.5% + Pendimethalin
24% SE 2500 ml 2.13 (1.47) 1.00 (0.90) 0.00 (0.22) 0.97 (0.89) 0.37 (0.59) 0.00 (0.22) 0.17 (0.40)

Sulfosulfuron 1.5% + Pendimethalin
24% SE 3000 ml 1.43 (1.06) 0.43 (0.54) 0.00 (0.22) 0.67 (0.74) 0.13 (0.37) 0.00 (0.22) 0.00 (0.22)
Sulfosulfuron 75%WG + Surfactant (1250 ml/ha) 33.3 g 4.10 (2.03) 2.43 (1.57) 0.67 (0.84) 2.57 (1.60) 1.47 (1.23) 0.53 (0.67) 1.70 (1.31)
Pendimethalin
30% EC 4200 ml 4.60 (2.15) 3.80 (1.96) 0.83 (0.91) 3.27 (1.82) 2.00 (1.43) 0.97 (1.00) 2.77 (1.67)
Carfentrazone ethyl 40% DF 50 g 3.43 (1.86) 2.73 1.66) 0.67 (0.75) 2.03 (1.44) 1.60 (1.27) 0.37 (0.59) 1.33 (1.16)
Hand weeding control - 0.00 (0.22) 0.00 (0.22) 0.00 (0.22) 0.00 (0.22) 0.00 (0.22) 0.00 (0.22) 0.00 (0.22)
Untreated control - 11.10 (3.34) 11.10
(3.33) 5.33 2.32) 9.63 (3.11) 10.27 (3.21) 4.97
(2.23) 6.97 (2.64)
SEm(±) - 0.16 0.19 0.21 0.23 0.11 0.15 0.16
CD at 5% - 0.47 0.56 0.62 0.70 0.34 0.45 0.48
Values in parentheses are square root transformed values
Table 8: Bioeffectiveness of Sulfosulfuron 1.5% + Pendimethalin 24% SE to control
weeds in wheat crop at 60 days after crop sowing

Treatment Dose composition (g or ml/ha) Mean weed dry weight 60 days after crop sowing g/m2

Phalaris minor Chenopodium album Melilotus alba Convolvulus arvensis Portulaca oleracea Anagalis arvensis Avena fatua
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 1500 ml 5.60 (2.36) 2.60 (1.63) 0.47 (0.55) 1.90 (1.39) 1.97 (1.41) 0.00 (0.22) 1.37 (1.03)
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2000 ml 3.67 (1.93) 1.73 (1.33) 0.00 (0.22) 0.77 (0.66) 1.30 (1.02) 0.00 (0.22) 0.37 (0.51)
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2500 ml 2.73 (1.66) 0.87 (0.85) 0.00 (0.22) 0.27 (0.46) 0.23 (0.44) 0.00 (0.22) 0.00 (0.22)
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 3000 ml 1.67 (1.14) 0.00 (0.22) 0.00 (0.22) 0.00 (0.22) 0.00 (0.22) 0.00 0.22) 0.00 (0.22)
Sulfosulfuron 75%WG + Surfactant (1250 ml/ha) 33.3 g 6.10 (2.47) 3.03 (1.75) 2.33 (1.54) 2.77 (1.67) 2.77 (1.68) 1.37 (1.17) 2.57 (1.62)
Pendimethalin 30% EC 4200 ml 7.37 (2.72) 5.43 (2.34) 2.87 (1.70) 3.90 (1.98) 4.47 (2.11) 2.50 (1.59) 4.80 (2.20)
Carfentrazone 50 g 4.90 4.53 1.70 2.13 2.27 0.97 1.77

ethyl 40% DF (2.21) (2.14) (1.32) (1.47) (1.51) (0.89) (1.34)
Hand weeding control - 0.00 0.22) 0.00 (0.22) 0.00 (0.22) 0.00 (0.22) 0.00 (0.22) 0.00 (0.22) 0.00 0.22)
Untreated control - 18.97 (4.35) 16.13 (4.02) 12.93 (3.60) 14.00 (3.74) 17.03 (4.13) 9.17 (3.03) 9.53 (3.09)
S Em (±) - 0.20 0.13 0.12 0.19 0.16 0.13 0.18
CD at 5% - 0.60 0.40 0.37 0.56 0.48 0.38 0.55
Values in parentheses are square root transformed values
Table 9: Bioeffectiveness of Sulfosulfuron 1.5% + Pendimethalin 24% SE to control
weeds in wheat crop at 75 days after crop sowing

Treatment Dose composition (g or ml/ha) Mean weed dry weight 75 days after crop sowing g/m2

Phalaris minor Chenopodium album Melilotus alba Convolvulus arvensis Portulaca oleracea Anagalis arvensis Avena fatua
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 1500 ml 7.63 (2.76) 5.20 (2.29) 2.10 (1.46) 3.03 (1.75) 3.40 (1.85) 0.97 (0.89) 2.67 (1.65)
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2000 ml 5.07 (2.26) 3.87 (1.98) 1.37 (1.02) 2.50 (1.59) 3.17 (1.79) 0.87 (0.69) 1.33 (1.02)
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2500 ml 3.77 (1.95) 2.80 (1.68) 0.47 (0.55) 1.57 (1.27) 1.37 (1.04) 0.00 (0.22) 0.60 (0.60)
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 3000 ml 2.73 (1.66) 2.03 (1.44) 0.37 (0.57) 1.07 (0.93) 1.07 (0.93) 0.00 (0.22) 0.23 (0.44)
Sulfosulfuron 75%WG + Surfactant (1250 ml/ha) 33.3 g 8.80 (2.97) 5.70 (2.40) 4.20 (2.06) 4.43 (2.11) 4.93
(2.23) 3.03 (1.75) 3.90 (1.99)
Pendimethalin 30% EC 4200 ml 14.87 (3.86) 9.40 (3.07) 4.97 (2.24) 7.83 (2.80) 8.57 (2.93) 3.87 (1.98) 5.63 (2.38)
Carfentrazone ethyl 40% DF 50 g 6.50 (2.54) 6.63
(2.58) 3.33 (1.84) 3.27 (1.82) 4.40 (2.10) 2.53 (1.61) 2.83 (1.69)
Hand weeding control - 1.37 (1.04) 1.30 (1.01) 0.00 (0.22) 0.50 (0.56) 0.73 (0.78) 0.00 (0.22) 0.17 (0.44)
Untreated control - 29.70 (5.45) 22.70 (4.77) 17.63 (4.20) 16.73 (4.09) 21.00 (4.58) 15.27 (3.91) 11.87 (3.45)
S Em (±) - 0.19 0.15 0.22 0.20 0.24 0.21 0.21
CD at 5% - 0.58 0.44 0.65 0.60 0.72 0.63 0.64
Values in parentheses are square root transformed values

Percent weed control efficiency:
The percent weed control efficiency calculated based on weed dry weight in untreated
control at 45, 60 and 75 days after crop sowing have been presented in Tables 10 to 12. It was observed that hand weeding control and Sulfosulfuron 1.5% + Pendimethalin 24% SE) @
3000 ml/ha and 2500 ml/ha were most effective with high weed control efficiency at each observation time. The treatments Sulfosulfuron 1.5% + Pendimethalin 24% SE @ 2000 ml/ha and 1500 ml/ha and Carfentrazone ethyl 40% DF @ 50 g/ha were next in order of effectiveness. The individual constituent products of the combination product (Sulfosulfuron 1.5% + Pendimethalin 24% SE) applied as Pendimethalin 30% EC @ 4200 ml/ha and
Sulfosulfuron 75% WG @ 33.3 g/ha were comparatively less effective with low weed control efficiency at each observation time. Thus, it showed that there was a synergistic impact of the combination product Sulfosulfuron 1.5% + Pendimethalin 24% SE for the weeds control in wheat crop.
Table 10: Per cent weed control efficiency of Sulfosulfuron 1.5% + Pendimethalin 24% 5 SE based on weed dry weight in wheat crop at 45 days after crop sowing

Treatment Dose composition (g or ml/ha) Percent weed control efficiency 45 days after crop sowing

Phalaris minor Chenopodium album Melilotus alba Convolvulus arvensis Portulaca oleracea Anagalis arvensis Avena fatua
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 1500 ml 67.27 85.29 86.25 76.82 86.36 93.96 78.95
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2000 ml 75.38 85.89 92.50 83.04 90.58 100.00 83.25
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2500 ml 80.78 90.99 100.00 89.97 96.43 100.00 97.61
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 3000 ml 87.09 96.10 100.00 93.08 98.70 100.00 100.00
Sulfosulfuron 75%WG + Surfactant (1250 ml/ha) 33.3 g 63.06 78.08 87.50 73.36 85.71 89.26 75.60
Pendimethalin 30% EC 4200 ml 58.56 65.77 84.38 66.09 80.52 80.54 60.29
Carfentrazone 50 g 69.07 75.38 87.50 78.89 84.42 92.62 80.86

ethyl 40% DF
Hand
weeding
control - 100.00 100.00 100.00 100.00 100.00 100.00 100.00
Untreated control - - - - - - - -
Table 11: Per cent weed control efficiency of Sulfosulfuron 1.5% + Pendimethalin 24% SE based on weed dry weight in wheat crop at 60 days after crop sowing

Treatment Dose composition (g or ml/ha) Percent weed control efficiency 60 days after crop sowing

Phalaris minor Chenopodium album Melilotus alba Convolvulus arvensis Portulaca oleracea Anagalis arvensis Avena fatua
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 1500 ml 70.47 83.88 96.39 86.43 88.45 100.00 85.66
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2000 ml 80.67 89.26 100.00 94.52 92.37 100.00 96.15
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2500 ml 85.59 94.63 100.00 98.10 98.63 100.00 100.00
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 3000 ml 91.21 100.00 100.00 100.00 100.00 100.00 100.00
Sulfosulfuron 75%WG + Surfactant (1250 ml/ha) 33.3 g 67.84 81.20 81.96 80.24 83.76 85.09 73.08
Pendimethalin 30% EC 4200 ml 61.16 66.32 77.84 72.14 73.78 72.73 49.65
Carfentrazone ethyl 40% DF 50 g 74.17 83.88 86.86 84.76 86.69 89.45 81.47
Hand weeding control - 100.00 100.00 100.00 100.00 100.00 100.00 100.00
Untreated control - - - - - - - -

Table 12: Per cent weed control efficiency of Sulfosulfuron 1.5% + Pendimethalin 24%
SE based on weed dry weight in wheat crop at 75 days after crop sowing

Treatment Dose composition (g or ml/ha) Percent weed control efficiency 75 days after crop sowing

Phalaris minor Chenopodium album Melilotus alba Convolvulus arvensis Portulaca oleracea Anagalis arvensis Avena fatua
Sulfosulfiiron 1.5% +
Pendimethalin 24% SE 1500 ml 74.30 77.09 88.09 81.87 83.81 93.67 77.53
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2000 ml 82.94 82.97 92.25 85.06 84.92 94.32 88.76
Sulfosulfiiron 1.5% +
Pendimethalin 24% SE 2500 ml 87.32 87.67 97.35 90.64 93.49 100.00 94.94
Sulfosulfiiron 1.5% +
Pendimethalin 24% SE 3000 ml 90.80 91.04 97.92 93.63 94.92 100.00 98.03
Sulfosulfiiron 75%WG + Surfactant (1250 ml/ha) 33.3 g 70.37 74.89 76.18 73.51 76.51 80.13 67.13
Pendimethalin 30% EC 4200 ml 49.94 58.59 71.83 53.19 59.21 74.67 52.53
Carfentrazone ethyl 40% DF 50 g 78.11 70.78 81.10 80.48 79.05 83.41 76.12
Hand weeding control - 95.40 94.27 100.00 97.01 96.51 100.00 98.60
Untreated control - - - - - - - -
Effect on yield and Cost Benefit Ratio:
The wheat grain yields recorded for different treatments at crop harvest and Cost:
Benefit ratio calculated have been presented in Table 13. The data revealed that yields in hand weeding control (38.82 q/ha) and Sulfosulfuron 1.5% + Pendimethalin 24% SE @ 3000 ml/ha (37.04 q/ha) and 2500 ml/ha (36.87 q/ha) were higher than other treatments. The Cost: Benefit ratio also showed that Sulfosulfuron 1.5% + Pendimethalin 24% SE @ 2500 ml/ha
(1: 4.20) and 3000 ml/ha (1: 3.79) were most economical as compared to other treatments. The least economical treatment was Pendimethalin 30% EC @ 4200 ml/ha (1: 0.55). Hence

Sulfosulfuron 1.5% + Pendimethalin 24% SE @ 2500 and 3000 ml/ha was not only effective to control weeds in wheat crop, it also increased the grain yield and resulted to be economical.

Table 13: Yield and Cost application in wheat crop : Benefit Ratio of Sulfosulfuron 1.5% + Pendimethalin 24% SE
Treatment Dose composition (g or ml/ha) Yield (q/ha) Market
rate of
product
(Rs/litor
kg) Product
application
cost
(Rs/ha)+ Profit
from
produce
(Rs/ha)* Additional
profit from
produce over
control
(Rs/ha) Net profit
from produce (Rs/ha) Cost:
Benefit
Ratio
Sulfosulfuron 1.5% + Pendimethalin
24% SE 1500 ml 31.33 (5.60) 1000 4000 62667 14911 10911 1 :2.73
Sulfosulfuron 1.5% + Pendimethalin
24% SE 2000 ml 32.94 (5.74) 1000 4500 65889 18133 13633 1 :3.03
Sulfosulfuron 1.5% + Pendimethalin
24% SE 2500 ml 36.87 (6.08) 1000 5000 73733 25978 20978 1 :4.20
Sulfosulfuron 1.5% + Pendimethalin
24% SE 3000 ml 37.04 (6.09) 1000 5500 74089 26333 20833 1 :3.79
Sulfosulfuron 75%WG + Surfactant (1250 ml/ha) 33.3 g 29.61 (5.45) 21000 3199 59222 11467 8267 1 :2.58
Pendimethalin
30% EC 4200 ml 27.29 (5.23) 450 4390 54578 6822 2432 1 :0.55
Carfentrazone ethyl 40% DF 50 g 30.47 (5.52) 10000 3050 60933 13178 10128 1 :3.32
Hand weeding control - 38.82 (6.23) - - 77644 29889 29889 -
Untreated control - 23.88 (4.89) - - 47756 - - -
SEm(±) 0.07
CD at 5% 0.20
+Treatment application cost Rs 2500/ha
Values in parentheses are square root transformed values *Wheat grain market price Rs 2000 per quintal

Phytotoxicity evaluation on wheat crop:
The phytotoxicity observations recorded at 35, 40, 50 and 60 days after crop sowing have been presented in Table 14. No phytotoxic symptoms like leaf injury on tips/ surface, necrosis, wilting, vein clearing, epinasty and hyponasty have been noticed on wheat crop in 5 various treatments. Thus Sulfosulfuron 1.5% + Pendimethalin 24% SE @ 1500, 2000, 2500, 3000 and 6000 ml/ha and other treatments were not phytotoxic to the wheat crop. Table 14: Phytotoxicity evaluation of Sulfosulfuron 1.5% + Pendimethalin 24% SE on wheat crop

Treatment Dose composition (g or ml/ha) Phytotoxicity symptoms observed*
(Mean data recorded at 35, 40, 50 and 60 days after crop
sowing)

Leaf injury on
tips/ surface Vein clearing Wilting Necrosis Epinasty Hyponasty
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 1500 ml 1 1 1 1 1 1
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2000 ml 1 1 1 1 1 1
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 2500 ml 1 1 1 1 1 1
Sulfosulfuron 1.5% +
Pendimethalin 24% SE 3000 ml 1 1 1 1 1 1
Sulfosulfuron 75% WG + Surfactant (1250 ml/ha) 33.3 g 1 1 1 1 1 1
Pendimethalin 30% EC 4200 ml 1 1 1 1 1 1
Carfentrazone ethyl 40% DF 50 g 1 1 1 1 1 1
Hand weeding control - 1 1 1 1 1 1

Untreated control - 1 1 1 1 1 1
Sulfosulfuron
1.5% + Pendimethalin 6000 ml 1 1 1 1 1 1
24% SE
* Based on 1-10 scale: 1=0-10%, 2=11-20%, 3=21-30%, 4=31-40%, 5=41-50%, 6=51-60%, 7=61-70%, 8=71-80%, 9=81-90%, 10=91-100%
Table 15: Storage stability-Pendimethalin + Sulfosulfuron SE

Laboratory
Parameters Specification (in house) Initial Room temperature storage

storage for 14 days

54±2 0±2 1 6 12 15 18 24
°C °C month months months months months months
Pendimethalin
content percent by 22.8-25.2 24.25 23.93 24.17 24.25 24.2 24.1 24 23.98 23.95
mass
Sulfosulfuron
content percent by 1.425 to 1.65 1.51 1.48 1.5 1.51 1.5 1.495 1.49 1.485 1.48
mass
Pendimethalin
suspensibility 80 96.15 95.1 94.9 95.25 95.4 95.1 94.9 94.8 94.25
percent min. Sulfosulfuron

suspensibility 80 95.65 95.36 95.32 95.45 95.25 95.13 95.11 95.08 95.05
percent min.
pH range (1%
aq. 5.0to8.0 6.65 6.65 6.5 6.65 6.6 6.58 6.54 6.52 6.5
Suspension)
Pourability 95% min. 98.7 98.5 98.45 98.5 98.3 98.25 98.2 98.14 98.05
Viscosity at
spindle no. 62, 350-800 cps 550 655 700 555 580 585 610 630 650
20rpm
Particle size (micron) D50<3, 2.2 2.5 2.4 2.2 2.2 2.3 2.4 2.5 2.6

D90<11 5.6 7.8 5.8 5.6 5.7 6.3 6.8 7.2 7.4
Persistent
foam ml (after 1 minute) 60 nil 4 Nil nil Nil nil Nil 2 3
max.

Conclusion:
> The field trial was conducted for bioefficacy evaluation of a combination product Sulfosulfuron 1.5% + Pendimethalin 24% SE in comparison to individual components of this combination product for the control of weeds in wheat crop. The results showed that Sulfosulfuron 1.5% + Pendimethalin 24% SE @ 2000-3000 ml/ha was most effective to control weeds in wheat crop and subsequently increasing the grain yield. The combination product was found non phytotoxic and economical on application in wheat crop. Based on overall results, it is concluded that Sulfosulfuron 1.5% + Pendimethalin 24% SE @ 2000-2500 ml/ha was the best treatment for the control of weeds in wheat crop. The combination product was tested for stability as per CIPAC guidelines on different parameters and presented no stability concerns on prolong storage.
Advantages of the Present Invention:
1. The synergistic combination of the present invention resulted in significantly lower count of grassy weeds, sedges and broad-leaf weeds (BLW's) such as Phalaris minor, Chenopodium album, Melilotus alba, Convolvulus arvensis, Portulaca oleracea, Anagalis arvensis and Avenafatua as compared to the untreated check.
2. The synergistic combination of the present invention is significantly superior from its individual herbicide available in market in reducing the population of grassy weeds, sedges and broad-leaf weeds (BLW's) at 30, 45, 60 and 75 days after application.
3. The dosage of herbicides used in the combination is less than the dosage of alone herbicide available in the market and thus safeguard the environment.
4. The synergistic combination shows no phytotoxicity effect in wheat crop.
5. The synergistic combination of the present invention provides improved yield as compared to the untreated check and the yield is higher than the individual herbicides applied in the crop.
6. The synergistic combination of the present invention is a stable combination without any decrease or decomposition of the actives on prolong storage.

7. The results of experiments indicate that the synergistic combination is highly effective in controlling weeds and increasing production of wheat at lower doses of combination, thus the invention will assist in food security.

claim:

1. A novel synergistic herbicidal combination, comprising:
a. a dinitroaniline compound;
b. an herbicide belonging to the class of sulfonylureas
2. The synergistic herbicidal combination, as claimed in claim 1, wherein the dinitroaniline compound is selected from the group comprising trifluralin, pendimethalin, benefin, dinitramine, fluchloralin, profluralin, preferably, Pendimethalin.
3. The synergistic herbicidal combination, as claimed in claim 1, wherein the sulfonyl urea is selected from the group comprising amidosulfuron, azimsulfuron, bensulfuron-methyl, chlorsulfuron, cyclosulfamuron, ethametsulfuron-methyl, ethoxysulfuron, flazasulfuron, flucetosulfuron, flupyrsulfuron-methyl sodium, foramsulfuron, imazosulfuron, iofensulfuron, iodosulfuron-methyl sodium, mesosulfuron-methyl, metsulfuron-methyl, nicosulfuron, orthosulfamuron, primisulfuron-methyl, propyri sulfur on, prosulfuron, pyrimisulfan, pyroxasulfone, rimsulfuron, sulfometuron-methyl, sulfosulfuron, thifensulfuron-methyl, triafamone, triasulfuron, tribenuron-methyl or trifloxysulfuron-sodium, or an agriculturally acceptable salt, carboxylic acid, carboxylate salt, or ester thereof, preferably, Sulfosulfuron.
4. The synergistic herbicidal combination, as claimed in claims 1 to 3, containing Pendimethalin and Sulfosulfuron.
5. The synergistic herbicidal combination, as claimed in claims 4, wherein pendimethalin is present in an amount of 20.00 to 35.00% w/w and wherein sulfosulfuron is present in an amount of 1.00 to 5.00% w/w.
6. The synergistic herbicidal combination, as claimed in claim 4, wherein, the said combination is pendimethalin and sulphonyl urea in the ratio of 20:1 to 6:1, preferably 19:1 to 8:1.

7. A composition comprising the herbicidal combination as claimed in claim 1 along with agricultural excipients selected from the group consisting of solvents, anti-freezing agent, dispersing agent, wetting cum spreading agent, defoamer, preservative, thickener, surfactants, suspending agent, water and combinations thereof.
8. The synergistic herbicidal composition as claimed in claim 7, wherein, solvent is preferably C9-C11 hydrocarbon and present in an amount of 20-50% w/w, preferably
30% w/w.
9. The synergistic herbicidal composition as claimed in claim 7, wherein the dispersing agent is selected from group consisting of sodium lignosulphonates, sodium naphthalene sulphonate- formaldehyde condensates, acrylic copolymer, aliphatic alcohol ethoxylates, tristyrylphenol ethoxylates potassium, polyarylphenyl ether sulphate ammonium salt and ethoxylated polyarylphenol phosphate ester and combinations thereof, preferably dispersing agent is acrylic copolymer, more preferably polyarylphenyl ether sulphate ammonium salt and present in an amount of 2.00-10.00% w/w, preferably 2 to 3 % w/w.
10. The synergistic herbicidal composition as claimed in claim 7, wherein the anti-freezing agent is selected from the group consisting of propylene glycol, di-ethylene glycol (DEG), mono-ethylene glycol (MEG) and combinations thereof, preferably anti-freezing agent is Propylene Glycol and present in an amount of 1.00- 8.00% w/w, preferably 5.00% w/w.
11. The synergistic herbicidal composition as claimed in claim 7, wherein the wetting agent is selected from the group consisting of mixture of non-ionic surfactants and amine salt of phosphate tristyryl phenol ethylated, acrylic copolymer, ethoxylated polyarylphenol phosphate ester and combinations thereof, preferably wetting agent is Octylphenol Ethoxylates, more preferably Sodium dioctyl sulfosuccinate and is present in an amount of 2.00- 10.00% w/w, preferably 1 to 5% w/w, more preferably 2 to 3 % w/w.

12. The synergistic herbicidal composition as claimed in claim 7, wherein thickener is selected from the groups consisting of gums or Polysaccharides and present in an amount of 0.01-0.50% w/w, preferably 0.08% w/w.
13. The synergistic herbicidal composition as claimed in claim 7, wherein the defoamer is Silicon emulsion and present in an amount of 0.01-0.5% w/w, preferably 0.20% w/w.
14. The synergistic herbicidal composition as claimed in claim 7, wherein the Suspending agent is Aluminium magnesium silicate and Silicon dioxide and present in an amount of 0.10- 2.5% w/w, preferably 0.5 to 2.0% w/w.
15. The synergistic herbicidal composition as claimed in claim 7, wherein the preservative is l,2-Benzisothiazol-3(2H)-one and present in an amount of 0.01-0.50% w/w, preferably 0.2% w/w.
16. The synergistic herbicidal composition as claimed in claim 7, wherein the composition is in form of a dust, granule, water dispersible granule, wettable powder, emulsifiable concentrate, solution, emulsion, suspension or suspoemulsion (SE), preferably a suspoemulsion (SE).
17. The synergistic herbicidal combination as claimed in claim 1 and a composition comprising the combination as claimed in claim 7 for its use in controlling the grassy weeds, sedges and broad-leaf weeds (BLW's) preferably Chenopodium species, Phalaris minor, Melilotus sp., Portulaca oleracea, and Avena fatua in a wheat crop.