FIELD OF THE INVENTION
The present invention relates to a hcrbicidal compositions. More particularly, the
present invention relates to a synergistic herbicidal co~nposition comprising
Oxyfluorfen and Clodinafop propargyl and a process for preparing the same.
BACKGROUND OF THE INVENTION
The following discussion of the prior art is provided to place the invention in an
appropriate technical context and enable the advantages of it to be more fully
understood. It should be appreciated, however, that any discussion of the prior art
throughout the specification should not be considered as an express or implied
admission that such prior art is widely known or forms part of common general
knowledge in the field.
As a means of killing or otherwise controlling unwanted plants, e.g., weeds, in
agriculture, it is desirable to treat such plants or the locus thereof with chemical
herbicides. A common method of herbicidal treatment in agricultural practices is
to treat a field to remove or control unwanted vegetation as preparation for
planting a crop plant, a method otherwise known as "bumdown." However, single
herbicides typically lack the weed control spectrum, e.g., the range of weed
species effectively controlled by the herbicide, to fully control the diversity of
weeds in a field. Therefore, it is common to apply two or more herbicides
simultaneously in order to achieve the desired spectrum of control. To facilitate
the simultaneous application of two or more herbicides, it is common to package
the different herbicides separately as concentrate formulations, which can be
admixed with water in a spray tank by the end user, a method also known as tankmixing.
More conveniently. however, the different herbicides can be cofonnulated
in a single concentrate formulation, requiring only dilution in water by
the end user prior to application by spraying. Such a formulatioti is often known
as a package-mix.
Package-mix formulations present numerous challenges to the formulator of
agricultural chemicals such as herbicides. For example, the formulation should
contain the herbicidal active ingredients at as high a total concentration as
possible, for maximum convenience to the end user and to minimize packaging
and shipping costs, while keeping the active ingredients within the desired weight
ratios with respect to each other. Most importantly, the package-mix formulation
must exhibit sufficient physical and chemical stability to have an effective shelf
life of at least a few months, preferably at least a year, and ideally at least two
years. Above all, selection of herbicidal actives so as to produce complementation
of weed control spectrum over the application of individual herbicidal actives.
Unfortunately, most herbicides exhibit phyto-toxicity to the desired crop as well
as to the weeds or grasses sought to be controlled. Phytotoxic means harmful or
lethal to plants. Phytotoxicity is the degree to which a chemical or other
compound is toxic to plants. Phytotoxic effects range from slight burning or
browning of leaves to death of the plant. Damage symptoms vary with the
herbicide and the type of plant that has been affected. High use rates also result in
an accumulation of heavy metals in the soil and surrounding environment.
Clearly, chemical weed control methods are lacking in some respects for the
control of weeds in economically important crops mainly in horticulture crops
which are more vulnerable due to losses resulting froin phyto-toxicity and other
reasons.
The herbicidal active compound oxyfluorfen is known from United States Patcnt
No. US 3,798,276 and is generally used as selective herbicide to control annual
broad leaved weeds and some grasses by pre-emergence or post-emergence
applications in a variety of tropical and sub-trop~cal crops. Oxyfluorfen is
common name for 2-chloro-a,a,a-trifluoro-p-tolyl 3-ethoxy-4-nitrophenyl ether.
Technical oxfluorfen is a red to yellow solid having a melting point of 65-84 "C.
Oxyfluorfen belongs to diphenyl ether family of herbicides having following
structure formula.
Oxyfluorfen is available commercially in both liquid (Emulsifiable concentrate)
and solid (Granular) formulation. Regardless of being a selective herbicide, phytotoxicity
of oxyfluorfen on desired crop is reported in the prior art. Accordingly,
appropriate use instructions for oxyfluorfen is often found on product labels of
commercially available oxfluorfen products and in particular on emulsifiable
concentrate formulations comprising oxfluorfen in order to prevent exposure to
oxfluorfen sensitive plants.
European Patent Application 0448538 and European Patent Application 039421 1,
in Example 12 thereof, disclose a process for the preparation of a solid
formulation coinprising N-phosphonomcthylglycine (glyphosatc) or a watersolublc
salt thereof and oxyfluorfen. According to EP 0 448 538 a liquid premix
comprising oxyfluorfen, at least one surfactant, and water or solvents is prepared
at a temperature of from 50 "C. to 80 OC., thus dissolving oxyfluorfen, and a
second premix comprising N-phosphonomethylglycine or a water soluble salt
thereof, an acid acceptor if appropriate and preground ammonium sulfate is
formed, and both premixes are combined to form an extrudable composition,
which is extruded and optionally dried. Oxyfluorfen can also be tank mixed
preferentially with the following ALS mode of action products for improved weed
control: amidosulfuron, azimsulfuron, bensulfuron- methyl, bispyribac-sodium,
cinosulfuron, cloransulam-methyl, chlorimuron-ethyl, chlorsulfuron, cinosulhron,
cyclosulfamuron, diclosulam, ethametsulfuron-methyl, ethoxysulfuron,
flazasulfuron, florasulam, flucarbazone-sodium, flucetosulfuron, flumetsulam,
flupyrsulfuron-methyl,-sodium, halosulfuron-methyl, imazamethabenz-methyl,
imazamox, imazapic, imazapyr, imazaquin, imazethapyr, imazosulfuron,
mesosulfuron- methyl, metazosulfuron, metsulfuron-methyl, nicosulfuron,
orthosulfamuron, oxasulfuron, primisulfuron, procarbazone-sodium,
propoxycarbazone, propyrisulfuron, prosulfuron, pyriftalid, pyrazosulfuron-ethyl,
pyribenzoxim, pyriminobac-methyl, pyroxsulam, pyrimisulfan, rimsulfuron,
sulfometuron-methyl, triasulfuron, tribenuron-methyl, triflusulfuron-methyl and
tritosulfuron. However none of the prior art solves the problem of phyto-toxicity
and also some of the weeds still remains unaffected requiring the sequential
application of other herbicides.
Therefore. thcrc is a long felt need in the art to provide a stable formulation
coinprisi~ig oxytluorfen that solves the problems mentioned above and solves the
existing problem of phyto-toxicity induced by these oxyfluorfen.
Clodinafop-propargyl is prop-2-ynyl (R)-2-[4-[(5-chloro-Mluoropyridin-2-
yloxy)-phenoxylpropionate, disclosed in EP-A 0248 968 and United States Patent
No. 4713109 belongs to aryloxyphenoxypropionate group of herbicides having
following structure.
Clodinafop-propargyl is a compound possessing reported herbicidal activity
against grassy weeds in different crops. It is known that it belongs to the oxy
phenoxy acid ester group of herbicides which is fatty acid synthesis inhibitor, by
inhibiting the acetyl co-enzyme A carboxylase, which is essential for the
production of lipids or fatty acids needed for plant growth. The selectivity of this
herbicide is based on the difference in the speed of herbicide breakdown in the
crop versus the weeds. Clodinafop-propargyl converts from the ester form to the
active acid and then to biologically inactive compounds. Grass weeds such as wild
oats and wild millet cannot effectively break down clodinafop-propargyl, so they
are controlled as a lethal dose accumulates at the meristematic growing points.
This is a post emergence, selective systemic grass herbicide and is known to
control grasscs such as green foxtail, barnyard grass. Persian darnel and volunteer
canary seed in wheat crops. However, it is known that clodinafop proparyyl is
ineffective against several broadleaved weeds.
US 4 881 966 teaches a composition comprising clodinafop-propargyl and a
safener, which is cloquintocet-mexyl that accelerates the rate of clodinafoppropargyl
break down in wheat, thus preventing the accumulation of a lethal dose.
However, the disclosed composition is still not effective in controlling the growth
of the broadleaved weeds.
Clodinafop-propargyl can be tank mixed preferentially with the PPO's like
sulfonylurea group, acifiuorfen sodium, penoxsulam etc.
In crop protection products, it is always desirable to increase the specific activity
of an active ingredient and the reliability of action. In an aspect of the present
invention, there is provided a mixture which comprises a compound A which is
oxyfluorfen, and the compound B which is clodinafop-propargyl which are
selective in crops to control undesirable harmhl plants.
Hitherto, no attempts have been made to formulate a combination of oxyfluorfen
and clodinafop-propargyl. Surprisingly, it has now been found that combinations
of these active compounds exhibit a synergistic effect when used for the control of
harmful plants. Further it has been found that by combining oxfluorfen with
clodinafop-propargyl the existing problem of phyto-toxicity of oxyfluorfen is
significantly reduced.
The present invention provides such a storage stable agrochemical wettable
powder (WP): emulsifiable concentrate (EC) and dry flowahle (DF) of
oxyfluorfen and clodinafop-propargyl that causes no phytotoxicity.
SUMMARY OF THE INVENTION
The present invention is broadly related to herbicidal compositions. In accordance
with an aspect, there is provided a synergistic herbicidal composition comprising
an agrochemically effective amount of oxyfluorfen; and an agrochemically
effective amount of clodinafop-propargyl, wherein oxyfluorfen and clodinafoppropargyl
are present in a weight ratio of from about 2:l to about 4: 1.
In accordance with another aspect, there is provided a herbicidal formulation,
comprising
a. the synergistic herbicidal composition;
b. a safener; and
c. agriculturally acceptable excipients;
wherein Oxyfluorfen is present in an amount of 10 to 20% w/w.
The herbicidal formulation, comprises clodinafop-propargyl in an amount of 5.0%
w/w.
The herbicidal formulation of the present invention may be formulated as wettable
powder (WP) formulation, emulsifiable concentrate (EC) formulation and dry
flowahle (DF) formulation. Preferably, the herbicidal formulation, is in the form
of wettable powder (WP).
The agriculturally acceptable excipients are selected from the group consisting of
dispersing agent, wetting agent, antifoaming agent and fillers.
The safener is present in all amount of 1.25% wlw and is cloquintocct mexyl.
The herbicidal formulation. comprises the dispersing agent in an amount of 1 to
10% wlw, preferably 7% wlw, and selected from the group consisting of sodium
salt of naphthalene sulfonate condensate, Sulfonated aromatic polymer, sodium
salt, Sodium Polycarboxylate, Ethanesulfonic acid, 2-[methyl[(9Z)-1-0x0-9-
octadecenyl]amino]-, sodium salt, Sodium 2-(methyloe1oyamino)ethane-1-
sulphonate and combinations thereof, preferably selected from sodium salt of
naphthalene sulfonate condensate, Sodium 2-(methyloeloyamino) ethane-lsulphonate
and combinations thereof.
The herbicidal formulation, comprises the wetting agent in an amount of 1 to 15%
wlw, preferably 15% wlw, and is selected from the group consisting of sodium
lauryl sulphate, sodium alkyl naphthalene sulfonate blend, Sodium
alkylnaphthalene sulfonate, Non-ionic derivative and combinations thereof,
preferably non-ionic derivative.
Further, the antifoaming agent is present in an amount of 0.01 to 0.5% wlw,
preferably 0.02% wlw, and is dimethyl polysiloxane emulsion.
Still further, the filler is selected from china clay, silica and combinations thereof.
The herbicidal formulation, of the present invention has good stability, solves the
problem of phytotoxicity of Oxyfluorfen in economically important crops mainly
herbicidal vulnerable horticulture crops, exhibits a broad spectrum of activity in
controlling diversity of weeds present in a crops and also enhances the
vigourlyield of the plant, and complements the performance of both the actives for
enhanced weed control thereby reducing the required sequential application of the
composition to control the weeds in a crop field and also reduce the cnvironmental
load of herbicides.
In accordancc with yet another aspect of the invention, there is provided a process
for preparing a herbicidal formulation in the form of wettable powder (WP):
comprising the steps of:
a. melting clodinafop propargyl and cloquintocet mexyl at 50 to 55
"C along with wetting agent and absorbing on tiller;
b. adding and mixing oxyfluorfen, dispersing agent, antifoaming
agent, and filler to the mixture of step a; and
c. blending and grinding the mixture of step b until a mean particle
size of 10 to 20 p is obtained;
wherein the ratio of oxyfluorfen and clodinafop-propargyl ranges from about 2: 1
to about 4: 1.
DETAILED DESCRIPTION OF THE INVENTION
The invention according to its various aspects is particularly pointed out and
distinctly claimed in the appended claims read in view of this specification and
appropriate equivalents.
It is to be noted, as used in the specification and the appended claims, the singular
forms "a", "an", and "the" include plural referents unless the context clearly
dictates otherwise. Thus, for example, reference to a composition containing "a
compound includes a mixture of two or more compounds. It should also be noted
that the term "or" is generally employed in its sense including "andlor" unless the
content clearly dictates otherwise. Thc expression of various quantities in the
tenns of "% wlw" or "%" means the percentage by weight, relative to the weight
of the total composition unless otherwise specified.
As used herein WP formulation, EC formulation and DF formulation are the
international denominations adopted by the FA0 (Food and Agriculture
Organization of the United Nations) to designate wettable powder, emulsifiable
concentrate and dry flowable, respectively.
The term "ago chemically effective amount" is that quantity of active agent,
applied in any amount which will provide the required control of broad leaved
weeds and grasses. The particular amount is dependent upon many factors
including, for example, the crop, weeds sought to be controlled and environmental
conditions. The selection of the proper quantity of active agent to be applied,
however, is within the expertise of one skilled in the art.
Many newer and conventional molecules are in practice in agriculture crops for
different weed management, but the indiscriminate use of these chemicals resulted
in reduced percent control due to build-up of the resistance in targeted weed
population. There are many reports on resistance of different weeds for different
molecules mainly due to either resistance or inactivity due to different reasons. To
overcome these problems grower is frequently prone to use repeated applications
of the herbicide where only one application is necessary. Other option is to either
mix other herbicides as readymade formulation or use different herbicides in
sequence. Second option is more costly as well as not environmental friendly as it
I-equired repeated application and also more active 1s used thereby increasing the
cnvironmental load.
To counter this problem, an aspect of the present investigation relates to an
herbicidal combination comprising oxyfluorfen and clodinafop-propargyl as
active ingredients present in a synergistic ratio for an efficacious weed control and
the methods of preparing the same.
Yet another aspect of the present invention is to provide herbicidal composition
with broad spectrum control of overall weed population in a crop field and also
enhances the vigourlyield of the plant.
Another aspect of the present invention is to provide a non-phytotoxic herbicidal
composition.
Another aspect of the present invention is to provide herbicidal composition
which is having good stability.
Another aspect of the invention is to prepare a formulation comprising
oxfluorfen with clodinafop-propargyl in a weight ratio of from about 2:l to 4:l.
According to another aspect of the present invention oxyfluorfen is present in the
range from 10 to 20% and more preferably 15% wlw.
According to another aspect of the present invention clodinafop-propargyl is
present in an amount of 5% w/w.
According to another aspect of the present invention Cloquintocet -mexyl is
present as safener in an amount of 1.25% wlw.
According to another aspect of the present invention. the synergistic herbicidal
combination further comprises a plurality of different excipients selected from
dispersing agents, wetting agents, anti-foaming agents and fillers.
According to another aspect of the present invention, the dispersing agents
contemplated for the present invention are selected from a group consisting of
sodium salt of naphthalene sulfonate condensate, Sulfonated aromatic polymer,
sodium salt, Sodium Polycarboxylate, Ethanesulfonic acid, 2-[methyl[(9Z)-1-0x0-
9-octadecenyl]amino]-, sodium salt, Sodium 2-(methy1oeloyamino)ethane-1-
sulphonate or a combination thereof and are present in an amount of 1 - 10% wlw
and more preferably 7% wlw. In a preferred embodiment of the invention, the
dispersing agents are preferably sodium salt of naphthalene sulfonate condensate
(5% WIW) and Sodium 2-(methyloeloyamino) ethane-1-sulphonate (2% wlw).
According to one aspect of the present invention, the wetting agents contemplated
for the present invention are selected from a group consisting of sodium lauryl
sulphate, sodium alkyl naphthalene sulfonate blend, Sodium alkylnaphthalene
sulfonate, Non-ionic derivative or a combination thereof and are present in an
amount of 1 - 15% w/w and more preferably 15% w/w. In a preferred embodiment
of the invention, the wetting agent is preferably Non-ionic derivative.
In accordance with yet another embodiment of the invention, the anti-foaming
agent is dimethyl polysiloxane emulsion and present in an amount of 0.01-0.50%
wiw and more preferably 0.02% wlw.
111 accordance with yet another embodirncnt of the invention, the synergistic
insecticidal composition further comprises filler (china claylsilica) to make up to
volume or weight.
In accordance with yet another aspect of the invention, there is provided a method
of preparing a synergistic herbicidal combination comprising oxyfluorfen with
clodinafop-propargyl as a wettable powder (WP) formulation.
According to another aspect of the present invention is to provide an herbicidal
composition which demonstrates a complementation of weed control activity over
the application of individual herbicides separately. Yet another aspect of the
present invention is to provide a synergistic herbicidal combination that negates
the need of the sequential application of herbicides thereby reducing the
environmental load of herbicides and thus are environmentally safe.
The present invention is more particularly described in the following examples
that are intented as illustrations only, since numerous modifications and variations
within the scope of the present invention will be apparent to those skilled in the
art. Unless otherwise noted, all parts, percentages, and ratios reported in the
following examples are on a weight basis and all reagent used in the example were
obtained or are available from the chemical suppliers.
EXAMPLES
The following examples illustrate the basic methodology and versatility of the
present invention.
Examples 1-3
The unit of each value below is "% wlw" i. e. the percentage by weight, relative to
the weight of the total solution or composition unless otherwise specified. The
compositions contemplated by each of the Examples 1-3 that are tabulated in
Table I are formulated as a wettable powder (WP) formulation.
Examples 1-3:
Table 1: Synergistic herbicidal eoniposition
Component Function Examples
Oxyfluorfen
Clodinafop Propargyl
Cloquintocet -mexyl
Sodium salt of naphthalene
sulfonate condensate
Sodiurn 2-(methyloeloyamino)
ethanc- 1 -sulphonate
Non-ionic derivative
Dimethyl Polysiloxane emulsion
China ClayiSilica
**A.I.= Active Ingredient
**A.I
**A,[
Safcner
Dispersing
Agent
Dispersing
Agent
Wetting Agent
Anti-foaming
Agent
Filler
*q.s..= quantity sufficient
The aforementioned herbicidal composition can be formulated as wettable powder
(WP) by the process described in Example 4 below.
Example 4
Process of preparation of herbicidal composition formulated as \bettable
powder (WP)
The herbicidal compositions of Examples 1-3 are prepared by the process
described hereinafter.
All the raw materials were verified for conformance to the laid down individual
specifications. The raw materials required for preparing compositions of examples
I to 3 are illustrated in table 2 under the column headings 1 to 3 respectively.
Entries for oxyfluorfen, clodinafop propargyl and cloquintocet mexyl in table 2
differ from those in table 1 as entries in table 1 are for 100% pure compounds,
whereas those in table 2 are for technical ones, i.e. those containing a certain
percentage of impurities.
The amounts of active ingredients presented in table 2 may be greater than the
values calculated taking into account the percentage purity of the active
ingredients, to compensate for losses of said ingredients during the manufacturing
process. It was observed that following said procedure on industrial scale the final
yield of A.I. will be similar or same as to standardized values.
The required quantities of raw materials as illustrated in Table 2 below were
weighed, transferred through the auto-batching system.
Clodinafop propargyl technical and Cloquintocet -mexyl were melted at 50-55 "C
along with wetting agent and absorbed in filler (Silica). Now, the second active
i.e. Oxyfluorfen technical is added along with dispersing agents, antifoaming
agents and china clay in the given proportion, and mixed homogeneously.
The above Inass is mixed in blender and ground by jet milllACM. Grinding is
carried out until a mean particle size of 10-20 microns (D-90) is obtained and
homogeneously inixed in post blender. After homogeneous mixing, the quality of
in-process sample was checked for conformance to the laid out specifications. The
quality approved in-process sample was transferred for packing as per the
requirements.
Table 2: Quantities of the active ingredients and raw materials charged
Quantities of materials
Component Function charged (kg)
1 2 3
Oxyfluorfen (based on 97% wlw Active
10.31 15.47 20.62
minimum purity) Ingredient
Clodanifop-propargyl (based on Active
5.27 5.27 5.27
95% wlw minimum purity) Ingredient
Cloquintocet --n~cxyl( based on
Safener 1.32 1.32 1.32
95% wlw minimum purity)
Sodium salt of naphthalene Dispersing
5.00 5.00 5.00
sulfonate condensate Agent
Sodiurn 2-(methyloeloyamino) Dispersing
2.00 2.00 2.00
ethane- l -sulphonate Agent
Non-ionic derivative Wetting Agent 15.00 15.00 15.00
Anti-foaming
Dimethyl Polysiloxane emulsion 0.02 0.02 0.02
Agent
China ClayISilica Filler 61.08 55.92 50.77
Example 5
Physical and Chemical Properties of herbicidal composition in Wettable
Powder (WP) formulation of present investigation
The Wettablc Powder (WP) synergistic herbicidal compos~tions prepared as per
above examples were tested for different physical and chemical properties.
a) Suspensibility analysis was conducted as per Clause no. 11.2, lndian
Standard (IS): 6940.1982 (Methods of test for pesticides and their
formulations (first revision)). Suspensibility of all the samples was more
than 82%, indicating that Wettable Powder (WP) herbicidal compositions
of Oxyfluorfen and Clodinafop Propargyl will provide a stable spray
suspension in water, thus homogeneous distribution of active ingredient on
target site in agricultural fields will be ensured to achieve effective control
of weeds.
b) The storage stability test at elevated temperature (Accelerated) was
conducted as per method given in, Intemational Collaborative
Intemational Pesticides Analytical Council (CIPAC) Hand book vide
number 46.1. The results shows that all the samples of Wettable Powder
(WP) herbicidal compositions of Oxyfluorfen and Clodinafop Propargyl
were found stable when subjected to accelerated temperature storage at
54°C for 14 days, which is equal to 30 month storage (For 2 years shelf
life) at normal temperature.
Example 6
Evaluation of the synergistic effect for herbicidal combination of Oxfluorfen
and Clodinafop Propargyl
The pcrfi)ri~i~incocf the 1icrbicid;il ci~tnpositiona ccoi-tliiic to thc prcscnt in~ciltioii
((1xylluorii.n and Clodinatop Propargyl) was conip:lr.ed against thc kno~\n
coinlx)sitions of Oxyfluorfcn ?3.5'% EEC (OXYGliARD) and Clodinafop-
Propargyl 15% WI' (WILFOI'). \shich were cvaluatctl against wecd spectrum in
Onion and also the vigouriyield of the crop was tested. Arca for cxperi~nent was
~~iarkefdo r diff'erent plot sizes and application was inade using high volume
knapsack sprayer at 25-35 days after transplanting. Experimental design was in
mdoniized blocks with five replication and each plot was measured an area of 25
sq. mts (5 x 5 nits). Observat~ono n wecd population. dry weight and weed control
efficiency (WCE%) was assessed at 30 days after appl~cation.
Weed control efficiency (WCE%) =
wezd drv wziykt in utltreotrd piot - were Liry we!g"tt in trearec piot
2- 100
weed crs iseight in u~itreatecp icl
Table 3 below summarizes the synergistic effect exists whenever the action of an
active ingredient combination is greater than the sum of the actions of the
individual components i.e. Oxyfluorfen and Clodinafop Propargyl against weed
spectrum at different concentrations.
In the field of agriculture, it is often understood that the term "syllergy" is as
defined by Colby S. R. in an article entitled "Calculation of the synergistic and
antagonistic responses of herbicide combinations" published in the jounial Weeds,
1967, 15. p. 20-22. The action expected for a given cotnbination of two active
colnponents can be calculated as follows:
Where,
E = Expected percentage of herbicidal control for the combination for the
combination of the two herbicides at defined doses (for example equal to x and y
respectively),
X = X is the percentage of herbicidal control observed by the compound (I) at a
defined dose (equal to x),
Y = Y is the percentage of herbicidal control observed by the compound (11) 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 synergistic effect,
Table 3: Synergistic impact of separate and combined treatments of
Oxyfluorfen and Clodinafop-Propargyl at different concentrations against
weed spectrum in onion
Compound A.I.(g/ha) WCE Expected Colby's
(%)at 30 Control Ratio
DAA* (Ed (E,+b/Et)
Oxyfluorfen 120 E,I = -
Oxyfluorfen 180 Ea2 =
40.80
Oxyfluorfen
Clodinafop-Propargyl 60 Eb = 56.67
Oxyfluorfen + Clodinafop- 120 +60 E,l+b =
78.33
7 1.07 1.10
Propargyl
Oxyfluorfen + Clodinafop- 180 +60 Ea2+b =
89.20
74.35 1.20
Propargyl
Oxyfluorfen + Clodinafop- 240 +60 Ea3+b =
90.67
76.30 1.19
Propargyl
DAA = Days after applicatton
Ea = % WCE after 30 DAA for Oxyfluotien
Eb = % WCE after 30 DAA far Clodinafop Propargyl
Each = % WCE afier 30 DAA for Onyfluolfen + Clodinafop-propargyl
Et = Expected %WCE afier 30 DAA for Oxyfluorfen and Clodilufap-propargyl in cotnbinatian from alone
It can be seen from the data presented in Table 3, combination of Oxyfluorfen and
Clodinafop-propargyl at all the doses demonstrate synergistic effect against
different weed population.
Example 7: Phytotoxic effect of herbicidal combination of oxyfluorfen and
Clodinafop-propargyl in onion crop
Visual observation on phytotoxicity were recorded for leaf injury on tipisurface,
EpinastyIHyponasty, and wilting, etc. on 0-10 scale (as below) at 1, 3, 7, 14 and
21 days after each application and then average was taken.
SCORE
-
PHYTOTOXICITY (PERCENT)
0
1
No phytotoxicity
1 - 10
Complete destruction
DAA = Days after application
tipisurface
L = Leaf injury to
W = Wilting
Table 4: Effect of new herbicide on the Phytotoxicity in Onion
Phytotoxicity (Days after Application)
Treatments
I @/acre) 1 Dose I 3 7 14 21
DAA DAA DAA DAA DAA
Oxyfluorfen 15% +
Clodinafop-Propargyl 5%
5
6
1600
3200
Oxyfluorfen 20% +
Clodinafop-Propargyl5%
WP
0
3
1600
-
3200
0
1
2
4
0
0
1
2
0
0
0
0
0
0
0
0
0
0
It is evident from Table 4 that Oxyfluorfen and Clodinafop-propargyl WP
formulation did not show any phytotoxicity for any of the selected combination as
per invention for standard dose as well as double the standard dose in onion crop.
From the foregoing it will be observed that numerous modifications and variations
can be effectuated without departing from the true spirit and scope of the novel
concepts of the present investigation. It is to be understood that no limitations with
respect to the specific embodiment illustrated is intended or should be inferred. It
should be understood that all such modifications and improvements have been
deleted herein for the sake of conciseness and readability but are properly within
the scope of the following claims.

We Claim:
1. A synergistic herbicidal composition comprising an agrochernically
effective amount of oxyfluorfen; and an agrochemically effective amount
of clodinafop-propargyl.
2. The synergistic herbicidal composition, as claimed in claim 1, wherein
oxyfluorfen and clodinafop-propargyl are present in a weight ratio of from
about 2: 1 to about 4.1.
3. A herbicidal formulation, comprising:
a. the synergistic herbicidal composition as claimed in claims 1 and 2;
b. a safener; and
c. agriculturally acceptable excipients;
wherein Oxyfluorfen is present in an amount of 10 to 20% w/w.
4. The herbicidal formulation, as claimed in claim 3, wherein clodinafoppropargyl
is present in an amount of 5.0% wiw.
5. The herbicidal formulation, as claimed in any of the claims 3 or 4,
formulated as wettable powder (WP) formulation, emulsifiable concentrate
(EC) formulation and dry flowable (DF) formulation.
6. The herbicidal formulation, as claimed in claim 5, wherein the formulation
is in the form of wettable powder (WP).
7. The herbicidal formulation, as claimed in any of the claims 3 to 6, wherein
the agriculturally acceptable excipients are selected from the group
consisting of dispersing agent, wetting agent, antifoaming agent and filler.
8. The herbicidal formulation, as claimed in any of the claims 3 to 7, wherein
the safener is present in an amount of 1.25% wlw and is cloquintocet
mexyl.
9. The herbicidal fonnulation, as claimed in claim 7, wherein the dispersing
agent is present in an amount of 1 to 10% wlw, preferably 7% wiw, and
selected from the group consisting of sodium salt of naphthalene sulfonate
condensate, Sulfonated aromatic polymer, sodium salt, Sodium
Polycarboxylate, Ethanesulfonic acid, 2-[methyl[(9Z)-1-0x0-9-
octadecenyl]amino]-, sodium salt, Sodium 2-(methyloe1oyamino)ethane-Isulphonate
and combinations thereof, preferably selected from sodium salt
of naphthalene sulfonate condensate, Sodium 2-(methyloeloyamino)
ethane- l -sulphonate and combinations thereof.
10. The herbicidal formulation, as claimed in claim 7, wherein the wetting
agent is present in an amount of 1 to 15% w/w, preferably 15% wlw, and
is selected from the group consisting of sodium lauryl sulphate, sodium
alkyl naphthalene sulfonate blend, Sodium alkylnaphthalene sulfonate,
Non-ionic derivative and combinations thereof, preferably non-ionic
derivative.
11. The herbicidal formulation, as claimed in claim 7, wherein the antifoaming
agent is present in an amount of 0.01 to 0.5% wlw, preferably 0.02% wlw
and is dimethyl polysiloxane emulsion.
12. The herbicidal formulation. as claimed in claim 7. wherein the tiller is
selected from china clay, silica and combinations thereof.
13. The herbicidal formulation. as claimed in any of the claims 3 to 12,
wherein the herbicidal formulation has good stability.
14. The herbicidal formulation, as claimed in any of the claims 3 to 12, which
solves the problem of phytotoxicity of Oxyfluorfen in economically
important crops mainly herbicidal vulnerable horticulture crops.
15. The herbicidal formulation, as claimed in any of the claims 3 to 12,
exhibiting a broad spectrum of activity in controlling diversity of weeds
present in a crops and also enhances the vigouriyield of the plant.
16. The herbicidal formulation, as claimed in any of the claims 3 to 12, that
complements the performance of both the actives for enhanced weed
control thereby reducing the required sequential application of the
composition to control the weeds in a crop field and also reduce the
environmental load of herbicides.
17. A process for preparing a herbicidal formulation in the form of wettable
powder (WP), comprising the steps of:
a. melting clodinafop propargyl and cloquintocet mexyl at 50 to 55
OC along with wetting agent and absorbing on filler;
b. adding and mixing oxyfluorfen, dispersing agent, antifoaming
agent, and filler to the mixture of step a; and
c. blending and grinding the mixture of step b until a mean particle
size of 10 to 20 N is obtained;
wherein the ratio of oxyfluorfen and clodinafop-propargyl ranges from
about 2: 1 to about 4: 1