CA1052118A - Herbicidal compositions - Google Patents

Abstract

SYNERGISTIC HERBICIDAL
COMPOSITIONS

Abstract of the Disclosure This invention relates to herbicidal compositions comprised of a diphenyl ether herbicide and a paraquat or diquat salt, the weight of the diphenyl ether herbicide to the paraquat or diquat salt ranging from about 1:10 to about 10:1. These compositions exhibit synergistic activity in the control of weeds, and particularly in the control of weeds of the Compositae family, such as the Lactuca and Cirsium species. Preferably the diphenyl ether herbicide is one which has the formula I

wherein X is a hydrogen atom, a halogen atom, a trihalomethyl group, an alkyl group, or a cyano group, Y is a hydrogen atom, a halogen atom, or a trihalomethyl group, and Z is a hydrogen atom, a hydroxy group, an alkoxy group, an alkyl group? a halogen atom, an amino group, an alkylthio group, a cyano group, a carboxy group, a carbalkoxy group, a carboxyalkyl group, a carbalkoxy-alkyl group, an alkanoyloxy group, an alkanoyloxy group, or a carbamoyloxy group.

Description

105~11B
This lnvention relates to novel herbicidal compositions comprised of a diphenyl ether her~icide and a paraquat or diquat salt, and to methods of controlling weeds with these -~
compositions A wide variety of diphenyl ether herbicides can be used in the composi~ions of this invention. Among the preferred classes of diphenyl ether herbicides ara those containing a

2~-dichlorophenyl ring or a 2-chloro-~~trifluoromethylphenyl ring and those containing a ~-nitrophenyl or a 3-subs~uled lO ~-nitrophenyl ring. The most preferred diphenyl ethers are ;~
: those of the formula~
CF3 ~ -.;~ , . .

~'.'' I ``
'''~' ~Z ~ ' . , ' ~ ` N 2 ' ! , ~ ~ ~
~. ., .:
wherein X is a hydrogen atom~ a halogen atom~ a trihalomethyl group, an alkyl group, or a cyano group~
Y is a hydrogen atom~ a halogen atom~ or a tirhalomethyl - group~ and Z is a hydrogen atom~ a hydroxy groUp~ an alkoxy group, -` ; an alkyl group~ a halogen atom~ an amino group~ an `~l alkylthio groupS a cyano group~ a carboxy group~ a -;; 20 carbalkoxy group, a carboxyalkyl group, a carbalkoxy~
alkyl group~ an alkanoyloxy group~ an alkanoyloxy group7 or a carbamoyloxy group. ~-~
, , .
'' , , - ' " ~ ' ' ~ :,' ', ., ~ Among the compounds embraced by Formula I the more : preferred are 2-chloro-4-trifluoromethylphenyl 3-substituted ~:
~-nitrophenyl ethers. All Or the compounds of Formula I are disclosed in co-pending Canadian application number 165,96 of ~o~t o. sayer et al. filed March 13, 1973.
. ~pecific diphenyl ethers which can be used include 2-chloro-4-trifluoromethylphenyl 3-ethoxy-4-nitrophenyl ~
ether, 2-chloro-~-trifluoromethylphenyl 3-carbomethoxy-4- ;
nitrophenyl ether, 2-chloro-4-trifluoromethyl 3-(1-carbethoxy) ~ :
ethoxy-~-nitrophenyl ether~ 2-chloro-4-trifluoromethylphenyl~
4-nitro-3-methoxycarbonylphenyl ether~ and the like. .
.. ..
The preferred compositions of the present in~ention :~
contain 2-chloro-~-trifluoromethylphen~l 3-ethoxy-~-nitrophenyl ;
.....
ether in admixture with a paraquat salt of the formula: : .
. `~

CN3 ~ _CH3.2A ~ -wherein A is an anion~ preferably chloride. ~ ~
In general~ the compositions o~ the present invention . .
,, . . ~.
will contain the active ingredients in a weight ratio of ether to paraquat or diquat salt of from about 1:10 to about 10:1 20more usually about 6:1 to about 1:6, e.g. about 1:1.
The herbicidal compositions Or this invention :.
exhibit synargistic activity in the control Or a broad spectrum :
~' ' ` ' . . ~ . .
., . ~.' ','.

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:: 3 : -of monoco~yledonou~ and dicotyledonous weeds, and are thus particularly useful as chemical sur~nerfallowing agents. They _ are especially effective against weeds of the Compositae family~ such as Lactuca nulchella ~blue letiuce~ and Cirsium :-~
arvense (Canada thistle). However, they may also ~e used to control weeds of the Ai~oa~e~e~ ~n~ranthaceae~ Carvo~hvllaceae~ l ; Cheno~odi~ceae~ Convolvul~e~e, Cruciferae, Cv~eraceae, ~ -Gramine~e, Leeuminosae, Ma~vace~e, Polv~onaceae, Rubiaceae, ~ ;
Scrophul~riaceae, Solanace~e and Umbelliferae families.
In general~ the compositions are applied post~emergence, ;
that is~ after the weeds have emerged from the growth medium, in a herbicidally effective amount. The compositions will generally be used so as to give an application rate of the ether of from about 0.15 to about 8 lbs./acre~ more usually about 0.25 to about 2 lbs./acre and an application rate of ~ paraquat or diquat salt of about 0~25 to about 2 lbs./acre. ~
., ~ . . .-~` In chemical summer~allow trials 9 treatments of Lactuca ~ulchella and Cirsium arvense with a tank mix combi-nation of 2-chloro-~-trifluoromethylphenyl 3-ethoxy~ nitro-phenyl ether and a paraquat or diquat salt7 produced a synergistic effect in controlling these weed species.
Applications to blue lettuce were made to established plants 0.1 - 0.25 m~ in height and to plants clipped back to a uniform height of 0.1 m. A one-half square meter area was . .
chosen at random in each replication for each treatment. The ~
plants were cut at ground le~el and their fresh weights and ~;
heights were taken~ Tharea~ter~ plants were air-drled and `~
their dry weights were taken.
:
~ .
' : .

;'~ ~":'' ~5~8 Applications to Canada thistle were made at the 2-10 leaf stage. The infestation was natural from stolons already present in the soil. The ten largest Canada thistle plants ;~
were harvested for each treatment and their fresh weights and heights were recorded.
, Table I sets forth the average weights and heights of treated and untreated blue lettuce plants and the average , percent control achieved by the test compounds. The results were the same for the clipped and unclipped plants.
Table II shows a comparison of the actual percent of ,~
- weed control (taken from Table I) with the expected percent ~, control~ as calculated using Colby's method of determini,ng synergism. This method involves the use of the following ' ' --- formula: , ~'~ 15 ' ( 100 ' '~
,,, ' ! wherein A equalsthe percent control by herbicide A at x , -` ~ kg/~a. ' ~;
,, B equals the percent control by herbicide B at y ';
kg/Ha.
'' 20 E equals the expected control by A + B at x + y ' -, ' kg/Ha.
- . .-~able III sets for the percènt control calculated '~
,for weed counts x heights for each treatment of Lacbuca ~
pulchella referred to in Table I. The following formula was " ' , , 25 used to determine the data in Table III. '',~
`'`i ' ' ' '', ';.
'~ , 100 - (weed count per plot x weed height per Plot x 100)' ~weed count in control plot x weed height control plot) ,'~

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The data in Table III was then subjected to Colby's test for determining synergism as shown in Table IV.
Table V shows the average fresh weights and heights of treated and untreated Canada thistle and the average percent ~;
control achieved by the test compounds. The data in Table V
was then subjected to Colby's test for synergism as shown in ~able VI.
In Tables I to VI, Compo~ld I and Compound II are respectively 2-chloro-4-trifluoromethylphenyl 3-ethoxy-4-nitro-phenyl ether and 2-chloro-4-trifluoromethylphenyl 4-nitrophenyl eth~r. The data in these tables demonstrates the unexpected synergistic activity of herbicidal compositions comprising a ;
paraquat or diquat salt and a diphenyl ether herbicide~ when compared to the individual activity of the components of the 15 composition. ` ;

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~05~1~B
The compositions of the invention are generally applied to the growth medium or to plants to be treated in a herbicidal formulation which also comprises an agronomically acceptable carrier. By agronomically acceptable carrler i5 meant any substanca which can be used to dissolve, disperse, or diffuse a herbicidal compound in the composition without impair-ing the effectiveness of the herbicidal compound and which by itself has no detrimental effect on the soil, equipment, crops, or agronomic environment. The herbicidal compositions of the invention can be either solid or liquid formulations or solutions.
For example, the compositions can be formulated as we~table ~,o C' powders, emulsifiable concentrates, dusts, granular formulations, ''' aerosols, or flowable emulsion concentrates. In such formula- `' . .
''; tions, the compounds are extended with a liquid or solid carrier and, when desired, suitable surfactants are incorporated. The two components of the compositions can be combined together in '~
a single solution or for~lulation or they can be added as separate 'solutions or formulations to a spray tank prior to application of the mixture. While it is preferred that the two active ingred-ients be applied in admixtura, it is within the scope of the invention that they be applied sequentially to the area where .; , , .
weeds are to be controlled.
Adjuvants, such as wetting agents, spreading agents, dispersing agents, stickers, adhesives, and the like, can also , be advantageously employed in accordance with agricultural ~
' practices. Examples of adjuvants which are commonly used in the ~ ~' .. , .:., , '; art can be found in the John W. McCutcheon, Inc. publication '~ "Detergents and Emulsifiers Annual." ' -' :' ~.: :

-13~

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, The components of the heIbicidal fcompositions of the in~ention can be clissolved in any appropriate sol-vent. Examples of solvents which are use~ul in the practice of this invention include alcohols, ketones, aromatic hydrocarbons, halogenated hydrocarbons~ dimethylformamide~
dioxane', ~imethyl sul~o~ide~ and the like. Mixtures of these solvents can also be used~ The concentration of f !:
the solution can vary from about 2% to about 98~ with a preferred range being about 25% to about 75%0 ~10 - For the preparation of emulsifiable concentrates~
the components of the compositions can be dissolved in organic solvents~ such as benzene~ toluene~ xylene~ methyl-ated naphthalene, corn oil~ pine oil~ o-dichlorobenzene, isophorone, cyclohexanone~ methyl oleate~ and the like~ ;
or'in mixtures'of these solvents~ together with an emul- i~
sifying agent which permits dispersion in water. Suitable . . . .- ' emulsifiers include, for example~ the` ethylene oxide deriv-atives of alkylphenols or long~chain alcohols~ mercaptans~
' carboxylic acids~ and reactive amines and partially ester-ified polyhydric alcohols~ Solvent-soluble sulfates or sulfonates~ such as the alkaline earth salts or ~nine salts of alkylbenzenesulfonates and the fatty alcohol sodium sulfates~ having surface-active properties can be used as i ' emulsifiers either alone or in conjunction with an ethylene ~
oxide reaction pro'duct. Flowable emulsion concentrates . ~' ;
are formulated similarly to the emulsifiable c'oncentrates ~ and include, in addition to the above components~ water '. ' and a stabilizing agent such as a water-soluble cellulose ` ~' derivative or a water-soluble salt of a polyacrylic acidO ' ;~
3 The concentration o~ the active ingredient in emulsifiable `~

'` -:;
-- ::

, I

~ ~(35~3LJ.8 concentrates is ~sually about lO~o to 60% and in flowable emulsion concentrates~ this can be as high as about 75%0 Wettable powders suitable for spraying, can be prepared by admixing the components of the compositions `~
with a ~inely divided solid, such as clays, inorganic silicates and carbonates~ and silicas and incorporating wetting agents, sticking agents~ and/or dispersing agents in such mixtures. The concentration of active ingredients in such ~ormulations is usually in the range of about 20 to 98%, preferably about 40% to 75%. A dispersing agent ~an constitute about 0.5% to about 3% of the composition, and a wetting aOent can constitute from about 0.1% to about 5% of the composition.
Dusts can be prepared by mixing the active com-ponents with finel~ divided inert solids which may be organic or inorganic in nature. Materials useful for this purpose include, for example7 botanical flours, silicas, ., , ~
silicates, carbonates and clays. One convenient method i -o~ preparing a dust is to dilute a wettable powder with a ~;
Xinely divided carrier. Dust concentrates containing about 20% to 80% of the acti~e ingredient are commonly made and are subsequently diluted to about 1% to 10% use concen~
tration.
Granular formulations can be prepared by impreg- `~
`~ 25 nating a solid such as granular fuller's earth~ ~ermiculit;e~ ~ `
~ ground corn cobs, seed hulls, including bran or other grain `~
: ... , , . . ~, hulls~ or similar material. A solution of one or both ~;
active components in a volatile organic solvent can be sprayed or mixed with the granular solid and the solvent ~ -can be sprayed or mixed with the granular solid and the ~15 :1 ~)S~l~&~
solvent then removed by evaporation. The granular material can have any suita~le size, with a ~referable size rangs of 16 to 60 meshO The active ingredient will usually comprise about 2 to 15% of the granular of the granular formulation.
The herbicidal compositions of the invention can also be mixed with fertilizers or fertilizing materials be-fore their applicationO In one type of solid fertilizing composition in which the composition can be used, particles `10 of a fertilizer or fertilizing ingredients~ such as a~onium sulfate, ammonium nitrate, or ammonium phosphate~ can be ~oated with one or more of the ethers. The compositions and solid fertilizing material can also be admixed in : mixing or blending equipment, or they can be incorporated -~
1~ with fertilizers in gra~ular formulations. Any relative ; -proportion of the active ingredients and fertilizer can be used which is su1table for the crops and weeds to be trèated. ;~
~ The total active ingredients will commonly be from about ; 5~ to about 25% of the fertilizing composition. These com~
positions provide fertilizing materials which promote the rapid growth of desired plants, and at the same time con- l~
trol the growth of undesired plants.
The herbicidal compositions of the invention can be applied as herbicidal sprays by methods commonly employed, `~
such as conventional high-gallonage hydraulic sprays, low- ;
gallonage sprays~ airblast spray~ aerial sprays and dusts. j-For low volume applications a solution of the active com~
ponents is usually usedO The dilution and rate of ;. -: .
.

-76- ~ ~

(35~
application will usually depend upon such factors as the t~pe of equipment employed, the method of applicatlon, the area to be treated and the type and stage of development of the weeds.
~he ether and paraquat or diquat salt herbicides of this invention may be used in conjuction with other compatible herbicides such as one or more of -those listed in the Canadian application referred to above and the various individual herbicides listed in the latest editions of (A) Pesticide Manual, British Crop Protection Council, (B) index des produits phytosanitaires, AC~A-FNGPC, (C) Pesticide Handbook - Entoma and (D) Pesticide Index, D.E.H. Frear.
It is to be understood that changes and variations may be made without departing from the spirit and scope of the invention defined by the appended claims.
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Claims (13)

We claim:

1. A synergistic herbicidal composition comprising (a) a diphenyl ether herbicide and (b) a paraquat or diquat salt the weight ratio of (a) to (b) ranging from about 1:10 to about 10:1.

2. The composition of claim 1 wherein the weight ratio of (a) to (b) is about 6:1 to about 1:6.

3. The composition of claim 1 wherein the diphenyl ether herbicide has the formula:

I

wherein X is a hydrogen atom, a halogen atom, a trihalomethyl group, an alkyl group, or a cyano group.
Y is a hydrogen atom, a halogen atom, or a trihalomethyl group, and Z is a hydrogen atom, a hydroxy group, an alkoxy group, an alkyl group, a halogen atom, an amino group, an alkylthio group, a cyano group, a carboxy group, a carbalkoxy group, a carboxyalkyl group, a carbalkoxy-alkyl group, an alkanoyloxy group, or a carbamoyloxy group.

4. The composition of claim 3 wherein the diphenyl ether is a 2-chloro-4-trifluoromethylphenyl 3-substituted 4-nitrophenyl ether.

5. The composition of claim 4 wherein the diphenyl ether is 2-chloro-4-trifluoromethylphenyl 3-ethoxy-4-nitrophenyl ether.

6. The composition of claim 5 wherein the paraquat salt is paraquat dichloride.

7. The composition of claim 1 which additionally comprises an agronomically-acceptable carrier and a surfactant.

8. A method of controlling weeds which comprises applying to the weeds a composition according to claim 1 in a herbicidally effective amount.

9. A method of controlling weeds which comprises applying to the weeds a composition according to claim 6 in a herbicidally effective amount.

10. The method of claim 8 wherein the composition is applied at a rate of about 0.15 to about 8 lbs./acre of the ether and about 0.25 to about 2 lbs./acre of the paraquat or diquat salt.

11. The method of claim 10 wherein the weeds are of the Compositae family.

12. The method of claim 11 wherein the weeds are of the Lactuca species.

13. The method of claim 11 wherein the weeds are of the Cirsium species.