CA2118794C - Synergistic interaction of herbicidal aryloxypropionic acid derivatives and cyclohexanediones - Google Patents

Abstract

A synergistic herbicidal composition comprising: (a) an aryloxypropionic acid derivative of formula (I) and (b) a cyclohex-anedione derivative of formula (II).

Description

SYNERGISTIC INTERACTION OF HERBICIDAL ARYLOXYPROPIONIC

Background of the Invention The p~rotect_ion of crops from weeds and other vegeta-tion which inhibit crop growth is a constantly recurring problem in agriculture. To help combat this problem, re-searchers in th.e field of synthetic chemistry have produced an extensive variety of chemicals and chemical formulations effective in th.e coni:rol of such unwanted growth. Chemical herbicides of many types have been disclosed in the literature and a large number are in commer~;ial use.
In some cares, active herbicides have been shown to be more effective in combination than when applied individu-ally. The result is often termed "synergism", since the combination demonstrates a potency or activity level exceeding that which it should be expected to have, based on a knowledge of the individual potencies of the components. The present invention residles in the discovery that certain aryloxypro-pionic acid derivatives and certain cyclohexanediones, already known individually for their herbicidal potency, display a synergistic effect wizen applied in combination.
Prior Art The t:wo classes of compounds forming the combination which is the subject of the present invention are independently known in the art for their effects on plant growth. Herbicidal aryloxypropionic acid derivatives are disclosed in U.S.
Patents Nos. 4,267,3:36, 4,317,913 and 4,414,391; British tzcv. wv:~;r.~ ~mc~w m we- ~-~:.~ : m:~_>_~ : n:~~.~ ~m i m- T.~.;3 r~;j _:3;3~.n.~~s.--,:" :~
- 21 18 7 9 4 _rR-8659 Patents Noa. 1,595,121 and 2,00Z,368. Also, seo tna 9th ed. , i~ditad by C. R. tiorthing and R. J. Fiance, pp.
400, 401 arid 463.
D~rivati,vea of cyclohexanediones era disclosed as herbicides in U.S. Patent 3,950,420, EPA BC3C1, EP-8-85529.
The effects of mixtures of one cyclohexandione~ ssthoxydim, and one atyloxy prcpionit acid darivat:ve, ~iuazifop, oa annual grass weeds have beer, desczibed by Harker et e1, in Weed Technology, volume 5, 191 issue 2.
DESCHIF'1'ION OF THE INV=VTTON
It has noW been discovered that synergism in the ' control of undesirable vegetation i~ exhibited by compositions comprising:
(a) An aryloxypzopionic acid derivative of the f orntu la CF3 d ~ O- H-CGORl ~J

in which X is hydrogen or halogen;
R1 is hyclrcgen, Cl-C6 alkyl, C1-C6 alkoxyaikyl; and (b~ a cyc~ohaxanediona derivative of the formula HORZ

(R)n in which SU~T~TUTE SHEET
_ z _ WO 93/04581 ~ ~ ~~ ~ ~ ~~ DCT/US92/07709 R is independently hydrogen; halogen; vitro; cyano;
C1-C6 alkyl; C1-C:6 alkyl substituted with a substituent selected from the: group consisting of halogen, vitro, hydroxy, C1-C6 alkoxy and C1-C6 alkylthio; C2-C6 alkenyl; C2-C6 alkynyl;
hydroxy; C1-C6 al.koxy; C1-C6 alkoxy substituted with a sub-stituent selected fram :halogen and C1-C6 alkoxy; C2-C6 alkenyl-oxy; C2-C6 alkynyloxy; C2-C6 alkanoyloxy; (C1-C6 alkoxy)-carbonyl; C1-C6 alkylthio; C1-C6 alkylsulfinyl; C1-C6 alkyl-sulfonyl; sulfamoyl; N-C(1-C6 alkyl)sulfamoyl; N,N-di(C1-C6 alkyl)sulfamoyl; benzyloxy, substituted benzyloxy wherein the benzene ring is substituted with from one to three substi-tuents selected iErom the group consisting of halogen, vitro, C1-C alkyl, C1-~~6 alkoxy and C1-C6 haloalkyl; the group NR9Rg0 wherein R~~ and R.10 are independently selected from the group consisting of hydrogen, C1-C6 alkyl, C2-C6 alkanoyl, benzoyl and benzyl; the groups formyl and C2-C6 alkanoxyl and the oxime, imine and Schiff base derivatives thereof; and at least one of X is not selected from the group consisting of halogen, C1-C6 alkyl and C1-C6 alkoxy;
R2 is C1-C~ alkyl, C2-C6 alkenyl, C2-C6 haloalkenyl, C2-C6 alkynyl, C2-C6 haloalkynyl, a substituted C1-C6 alkyl, substituted with halogen, C1-C6 alkoxy, C1-C6 alkylthio, phenyl, substituted phenyl wherein the phenyl is substituted with halogen, vitro, cyano, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy and C1-C6 alkylthio;
R3 is hydrogen, C1-C6 alkyl, C1-C6 fluoroalkyl, C2-C6 alkenyl, C2-C6 alkynyl and phenyl;
R4 is hydrogen or the keto tautomer; C1-C6 alkyl;
C2-C6 alkenyl; C2-C6 alkynyl; substituted C1-C6 alkyl wherein the alkyl group is substituted with C1-C6 alkoxy, C1-C6 alkylthio, C1-C6 alkoxycarbonyl, phenyl, and substituted phenyl wherein the benzene ring is substituted with 1 to 3 substituents selected from the group consisting of halogen, vitro, cyano, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, and C1-C6 alkylthio; C1-C6(alkyl) sulfonyl; benzene sulfonyl;
substituted benzene su:Lfonyl wherein the benzene ring is substituted with. 1 to :3 substituents selected from the group consisting of halogen, vitro, cyano, C1-C6 alkyl, C1-C6 I - 1 J 'c3.1 l:)-1--~tii, RC? . Wi\ : E:Y~. ''i1 ',CHE:'~,_ (l 1~ _'. .._... . . ',. : .~~; ~'3'.l ~: ~~
:-'- . ~ ;:;.~.~ ~l ti 1 l '- ' ~ ' 21 18 ~ 9 4 PR~8559 haloalkyl, cz-C6 a:Lxoxy and ci-C8 alkylthio; an aayl group and an inorganic or or~~anic cation; and n is an :lntsger chosen from ~ tc 5.
- The term:: "alkyl", ~~alkoxy", ~~al.kenyl", "alkylthio~', and the like era u~ced herein to embrace both 6traiQht-chain and branched-chain radicals.
Examples of aryloxygropionic acid deriYativas useful in the present invention arc:
(D) -butyl, 2-[4-,;5-trifluoromethyl-Z-pyridyloxl~) -phenoxy3-propionate:, (fluazitop-butyl);
' (f3uazffc~Py;
(R)-2-(4-~(5-trifluoromathyi-Z-pyridyloxy)pbenoxy]
propionic acid, (fluazifop-P and fiua~ifop-P-butyl);
(RS)-2-[4-~3-chioro-5-trifluoromethyZ-~-pyridyloxy) phonoxy~propionie acid, (haloxyfop);
haloxyfop-etotyl; haloxytop-methyl.
Thess and other aryioxypropionic acid derivatives within the aavps of the irvantion can be prepared by the procedures dnscribs~d in L?.S. Patants Nos. 4,257,336, x,317,913, 4,414,391; ~P1~ Z37S5; and British Patents Non. 1,599,iZ1 and 2,G02,36g.
Preferred cyclohaxanedionas included in the present invention are those in which tra phenyl grosp is substituted with methyl groups and include:
5-(3-acet~tl-2,x,6-trimsthylphanyl)-Z- ~1-l,ethoxy-imino) -propyl ~ -3-hydroxycyclohox-~-en-1-; -and_ Z-(l-(ethc5xyimino)propyl7-.3-hydroxy-5-(2,4,6-tri-mathyl-3-butyryiphenyl)cyelohex-2-enons.
SUBSTITUTE SHEET

FtCV.~U\:~:F'~ ~Il\CIIE:', UI '.' ~3-J:3 : l-3 '?:3 : l:3~k~~1 4f3111'?- +4;~
ti;-3 '_:.;:3;3~14E::>:N .;
__ __ __ ._.. . .. ~ .~.. _.. . , ~_~.._ .,.

~t-sass Th3l, most preferred substituents are on the 2- and 6-position of the phsny,l rinr~ and are preferably !selected from halogen, methyl r;~nd msthoxy.
These i~nd other cyclorexanedianes along with their tautomeric forms within the scope of the present invention, can be prepared x~y the procedures described in V.S. Patent 3,9SO,4Z0, E8-7~-0080301 and EP-B-OOS5SZ9.
Ths terms "synergism" and "synergistic" are used hrrein to convey the result observed Whon a combin8tion of herbicides d~amonstrates a potoncy in excoss of that which the combination would ba ~xpected to produce on the basis of Thai potencies of each herbicide applied individually.
The term "herbicide" is used herein to denote a compound which controls or aodifias the gro~rth of plants. The term "herbicidall;y effective amount" is used to indicate the quantity of such ,n compound or combination of such compounds which is capable .of pxoducing a controlling or modifying affect. Controlling or modifying effects include all devia-tions frog natural development, for example: kill, rstar-dat=on, Isaf burn, d~rarfing and the like. Tho term "plant"
refers to all physical parts o! a plant, including leads, seedlings, saplings, roots, tubers, stems, stalks, foliage and fruits.-- ' In the compositions of this invention, the aryloxy~
propionic acid derivactive:cyclohexansdione Weight ratio at Which the herbicidal response is synergistic, lies within the rahgs of 1:5 to about 30: 1, preferably about 1:5 to about .1~:1 and moat preferably about 1:2 to about='8-:~:- - -Applicat:fon rates will depend upon the particular compounds chosen t:or use, the particular plant sp~toies and degree of control desired. In general, th~ compositions of the invention are moat efficiently employed at a rats of o.ooi ~~~TpT1 m.,.~_~

WO 93/04581 '~ ~ ~ PCT/US92/07709 ' to 50 pounds per acre (0.001 to 56 kilograms per hectare), preferably 0.001 to 25 pounds per acre (0.001 to 28 kilograms per hectare).
The following examples provide further illustrations demonstrating the synergistic herbicidal response of the present compositions.
Example I
This example demonstrates the synergistic response of butyl (R)-2-[4-(5-trifluoromethyl-2-pyridyloxy)phenoxy]
propionic acid (fluazifop-P-butyl) and 2-[1-(ethoxyimino)-propyl]-5-(2,4,6-trimethyl-3-butyryl phenyl)-1,3-cyclohexane-dione in combined postemergence application to the plants giant foxtail and shattercane.
Plastic pots were filled with 2 parts sandy loam and 1 part peat moss mixed together containing the commercial fungicide cis-N[(trichloromethyl)thio]-4-cyclohexene-1,2-dicarboximide (Captan~) and 17-17-17 fertilizer (percentages of N-P205-K20 on a weight basis). Each pot was seeded to a single plant species. The plant species included giant foxtail (Setaria faberi) and shattercane (_Sorcrhum vulaare).
The pots were placed in a greenhouse for approximately two weeks where they were watered regularly. The greenhouse temperature was approximately 85° F. day and 80° F. night.
At the end of this period, the foliage on the emerged plants was sprayed with herbicidal emulsions formed by diluting emulsiffable concentrates of test compounds with adjuvants and water. The dilutions were made such that at a total spray volume of 25 gallons per acre, the amount of each test compound applied per pot corresponded to the desired application rate in ounces per acre. In control pots, the test compounds were applied individually at various applica-tion rates, whereas in the test pots, emulsions contained both compounds. Untreated pots were used as standards.

WO 93/04581 2 1 1 8 7 9 4 P~/US92/07709 Sixteen days after treatment, the control and test pots were compared to the standards and rated visually in terms of percent control ranging from 0% to 100%, with 0%
representing no injury to the plant species and 100% repre-senting complete kill of all plants. All types of plant injury were taken into consideration.
For the plant species, the results of these tests are listed in Table I ~,n the columns headed by the symbol "O"
(indicating the "observed" results), each figure represent the average of three replications of the same test. These results are compared with the expected results, shown in the columns headed by the symbol "l~~", derived from the control data using Limpel's formula. (Limpel et al., 1962, "Weed Control by Dimethylchlorote:rephthalate Alone and in Certain Combinations", Proc. NEWCC., vcrl. 16, pp. 48-53):
1: = X + Y - XY

where X - observed percent injury when one of the herbicides is used alone, and Y - observed percent injury when the other herbicide is used alone.
An asterisk (*) is used to indicate the tests where the results show synergism, i.e., where the observed result exceeds the expected result by at least 10 percent. It is clear from the 'table that synergism was observed at many of the application rates tested.

FABLE I
host emergence Applicationl: Averacte of Three Replications Application Rates 4 Control2 O~Observ ed E~Ex pected lOz/A1 Giant Foxtail Shattercane A B O E O E

Control Data 0.063 -- 0 0 0.125 -- 0 27 0.250 -- 0 82 0.500 -- 7 ' 92 1.000 -- 37 100 -- 0.016 0 0 -- 0.031 0 0 -- 0.063 0 0 -- 0.125 32 43 -- 0.250 100 100 Test Data 0.063 0.016 0 0 0 0 0.063 0.031 0 0 3 0 0.063 0.063 10 0 23* 0 0.063 0.125 75* 32 90* 43 0.063 0.250 100 100 100 100 0.125 0.016 0 0 10 27 0.125 0.031 0 0 33 27 0.125 0.063 13* 0 60* 27 0.125 0.125 75* 32 95* 58 0.125 0.250 100 100 100 100 0.250 0.016 0 0 85 82 0.250 0.031 3 0 85 82 0.250 0.063 13* 0 98* 82 0.250 0.125 80* 32 98 90 0.250 0.250 100 100 100 100 RCV. V!>~\ : 1~:Y1 111. ',C:tiL_ _ U 1 __. .__. , '?'> _, ;~_ ;).') '. , [.f _~~') . ~::i.E.l I t; l l 1_ +.~'-~ ti;i _':3~~~~:-1-fi~~ : it r.

TABLE I (continued) Application Ratss ! Contr o12 O:Obs erved. E:Ex fle (Oz~a1 Giant Foxtail 0.500 0.018 10 '7 92 92 0.500 0.03 13 7 98 92 0.500 0.063 78! 7 100 92 0:30- 0.125 80~ 37 100 100 0.800 0.250 100 100 100 100 1.00C x.016 43 .3? 100 100 1.000 0.031 68* 3? 100 100 1.000 0.063 93* 37 100 100 3.000 0.12b 98* 57 100 100 1.000 0.250 100 100 100 100 -------------------------_--~--iai~-~-.r---_---~--~------_-_---1 - Treatmerta contained 1! Ar'ridtx (registered grade Mar:) Z = 16 days after application * = denotes synergistic effect shown - Fluatifop-P-butyl; butyl (R)-2-t4-(5-trifluotomethyl-Z-pyridyloxy)phsnoxy~propionic acid H~= 2-[1-(ethoxyimino)-propyl~-5-(2,4,6-trimethyl-3-butyry:-phenyl~-1,3-cyclohaxanadions rxamnle II
In this example, the tallowing f oraulations ware prepared from 2-[I-ethoxyimino)propyl~-3-hydroxy-5-(2,4,6-trimothyl-3-butyrylphQ:~yl)'cyelohox-2-rnona (Herbicides A~ , and the D isomer of butyl 2-C4-(5-trifluoromsthyl-Z-pyridyloxy)-phe»oxyZ-propionate (Fisrbicida B) .
Formulation (a): Herbicide (A), 125 g/1;
nonionic emulsifier (methyl capped derivat~.va of Renex 650), 20 g/1; Aerosol OT 100, 30 g/1; and Tar~sco 500/100 to 1 liter. -Fcrmulatir~n (b): Herbicide (B), 1Z5 g/1;
phenyl s;~l:onate C7~L~c,*45 'g/1; Geopori SF_ 3sS. 45 9ynperionie*NPE 1800, 10 gjl and Solvaeso 100*~0 1.0 liter.
*!Regif9tered Trade Mark) Field plots 2m x 2m s~rere seeded vrith oilseed rape (~ ~g=etr~). and the plant spaeisi, perennial ryegrass (Lolium baranna) and annual bluegrass (~o ).. At the .. _ ~ -SU~STIT!~'~~ SH~~T

WO 93/04581 ~ -time of spraying, the oilseed rape was at the 2-true leaf growth stage, the annual bluegrass was at the 3-leaf, 2-tiller stage of growth, and the ryegrass was at the 2-leaf growth stage. Formulations (a) and (b) above were each blended separately with 0.1% by weight of Agral and the resulting solutions were applied sequentially at various rates. Injury ratings were taken by visual determination 87 days after treatment. A scale of 0 to 10 is used where 10 is equivalent to complete kill (or 100 percent control) and 0 indicates no visual injury (or 0 percent control) as compared to untreated control plants.
For the plant species, the results of these tests are listed in Table II in the columns headed by the symbol "O"
(indicating the "observed" results). These results are compared with the expected results, shown in the columns headed by the symbol "E", as determined by the Colby formula.
The Colby formula is utilized to demonstrate the presence or absence of synergism (Colby, R. S., "Calculating Synergistic and Antagonistic Responses of Herbicide Combina-tions", 1967 Weeds, vol. 15, pp. 20-22):
Expected effect - X + (100 - x)y where X = observed effect of A and Y = observed effect of B
The basis of demonstration by comparison with the Colby formula is that Herbicide (A) tested alone will kill a proportion of the target weeds and leave a proportion (a%) as survivors. Similarly, Herbicide (B) tested alone will leave (b%) as survivors. When combined, A + B will, however, if synergy is absent, act independently on the target weed, component A again leaving a% survivors, which survivors will be controlled by component B, with an overall effect of a x b If, in practice, the percent control (degree of kill) is greater than that predicted by the Colby formula, 21 18 7~ g 4 11 :
synergism is provided by the difference between the observed and expected (C~ by determined) results. As can be seen from Table II, synergism is widely evident.
FABLE II

gearee of Kill 1 O:Observed E:Ex pected Rates ti li on ca App (a /hal Rvearass Bluegrass A ~ p ,- E O E

g - 7 4 5 2 g 31 9 8 9 6 g 62.5 10 10 10 9 16 62.5 10 10 10 9 31 31. 10 8 10 7 31 6~:.5 10 10 62.5 6::.5 9 6 9 5 6 2 6:! . 5 10 8 10 8 .

62.5 62.5 10 10 10 9 1 A 2-[1-(ethoxyimino)propyl]-3-hydroxy-5-(2,4,6-trimethyl-=

3-butyrylphenyl)cyclohex-2-enone.

B = D isamer of butyl-2-[4-(5-trifluoromethyl-2-pyridyloxy) phenoxy]p:ropionate 2 where O
=
no :injury = complete kill ~,xamole III
This example demonstrates the synergistic response of Herbicide (B) used in Example I and 5-(3-acetyl-2,4,6-trimethylphenyl)-2-[1-(ethoxyimino)-propyl]-3-hydroxycyclohex-2-en-1-one (Herbicide C).
The following formulations were prepared: Formula-tion (b) included Herbicide (B), 125 g/1; emulsifier 50 g/1;
made up to 1.0 liter with Solvesso 100; and formulation (c) included Herbicide (C), 125 g/1; non-ionic emulsifier, 110 g/1; anisole, 400 g/1 made up to 1.0 liter with Solvesso 150.
Pots in the greenhouse were seeded with large crabgrass (Dicritaria sanctuinalis), barnyardgrass (Echinochloa crusQalli), goosegrass (Eleusine indica), guineagrass (Panicum maximum), and johnsongrass (Sorghum halepense).
At the time of spraying, each plant species had 4 -leaves per plant. The above formulations were blended and the final solution blended with 0.1% by weight of AGRAL 90 and 1.0% by weight of ACTIPON. The final solution was applied through a greenhouse track sprayer at a volume of 200 liters per hectare.
Nineteen days after treatment, the degree of injury was rated visually in terms of percent control ranging from 0 to 100%, with 0% representing no control and 100% representing complete kill of all plants in the pot. The degree of kill was then assessed and compared with the expected kill as determined by the Colby formula presented in Example II. It is clear from Table III that synergism was observed at many of the application rates tested.

TABLE III
gostemeraence Application Application % Control 2 O-Observed- E-Expected Rates Crab- Goose- Guinea- Johnson-_Lq,/ha1 ara~ss _ lMillet crass crass crass C O E _ O ~ O ~ O E O E
1 7 0 32* 7 45* 5 55* 8 10 15 1 - - 52* 17 97 92 48* 24 63 59 1 52* 7 100* 75 95* 78 95* 79 100 97 5 2 50* 3 98* 47 93* 15 85* 57 85* 37 10 2 60* 8 35* 53 97 93 97* 65 100 70 20 2 92* 10 100* 66 98* 80 100* 90 100 98 1 B = Fluazifop-P-butyl; (D) butyl 2-[4(5-trifluoromethyl-2-pyridylo:Ky)phenoxy]-propionate C = 5-(3-acetyl-2,4,6-trimethylphenyl)-2-[1-ethoxyimino)-2 propyl]-:3-hydroxycyclohex-2-en-1-one - 19 days after treatment * - Synergistic effect shown, the observed result exceeded the expected result by at least l0 percent The compositions of this invention are useful <_.~
herbicides demonstrating synergistic activity for the control of undesirable vegetation. The compositions can be formulated in the same manner in which herbicides are generally formu-lated. The compounds may be applied either separately or combined as part of a two-part herbicidal system.
The object of the formulation is to apply the compositions to the locus where control is desired by a convenient method. The "locus" is intended to include soil, seeds, and seedllings, as well as established vegetation.
Formulations will generally contain several addi-tives. Among these are some inert ingredients and diluent carriers such as organic solvents, water, oil and water, water in oil emulsions, carriers of dust and granules, and surface active, wetting, dispersing, and emulsifying agents.

Fertilizers, such as ammonium nitrate, urea, potash and superphosphates may also be added.
Aids i~o rooting and growth, such as compost, manure, humus, sand, etc. may likewise be added.
The formulations are commonly dusts, wettable powders, granuleas, solutions or emulsifiable concentrates.
Dusts are free-flowing powder compositions contain-ing the herbicidal compound impregnated on a particulate carrier. The particle size of the carrier is usually in the approximate range of 30 to 50 microns. Examples of suitable carriers are ta7lc, bentonite, diatomaceous earth, and pyrophyl-lite. Anticaking and antistatic agents can be added, if desired. The composition generally contains up to 50% of active ingredient. Dusts, like liquid compositions, can be applied by spraying from boom sprayers, hand sprayers or airplanes.
Wettable powders are finely divided compositions comprising a particulate carrier impregnated with the herbi-cidal compound wind additionally containing one or more surface active agents. The surface active agent promotes rapid dispersion of the powder in aqueous medium to form stable, sprayable suspensions. A wide variety of surface active agents can be u~;ed, fo:r example, long chain fatty alcohols;
salts of sulfoni.c acid; esters of long chain fatty acids; and polyhydric alcohols, in which the alcohol groups are free, omega-substituted polycethylene glycols of relatively long chain length.
Granules comprise the herbicidal composition impreg-nated on a particulate inert carrier having a particle size of about 1 to 2 millimeters in diameter. The granules can be made by spraying' a solution of the active ingredient in a volatile solvent onto the granular carrier. Suitable carriers in preparation of granules include clay, vermiculite, sawdust, granular carbon, etc.

2~ 1 ~a~ ~ ~ _ Microcapsules and other slow release formulations are advantageous as formulations to deliver and distribute the active ingredients. Mic:rocapsules consist of fully enclosed droplets or granules containing the active materials in which the enclosing material is an inert porous membrane, arranged to allow escape of the enclosed materials to the surrounding medium at controlled rates over a specified period of time.
Encapsulated droplets are typically about 1 to 50 microns in diameter. The enclosed liquid typically constitutes about 50 to 95% of the weight of the entire capsule, and may contain an amount of salvent in addition to the active materials.
Encapsulated granules are characterized by porous membranes sealing the openings of the granule carrier pores, trapping the liquid containing the active components inside for con-trolled release. A typical granule size ranges from 1 milli-meter to 1 centimeter in diameter. In agricultural usage, the granule size is generally about 1 to 2 millimeters in diameter.
Granules formed by extrusion, agglomeration or prilling are useful in the present invention as well as materials in their naturally occurring form. Examples of such carriers are vermiculite, starch sintered clay granules, kaolin, attapul-gite clay, sawdust and granular carbon. Useful encapsulating materials include natural and synthetic rubbers, cellulosic materials, styrene-butadiene copolymers, polyacrylonitriles, polyacrylates, polyesters, polyamides, polyureas, polyurethanes and starch xanth.ates.
The herbicidal compositions can also be applied to the soil in the form of: a solution in a suitable solvent.
Solvents frequer.~tly used in herbicidal formulations include kerosene, fuel oil, xylene, petroleum fractions with boiling ranges above xyl.ene, and aromatic petroleum fractions rich in methylated napht:halenes.
Emulsi.fiable concentrates consist of an oil solution of the herbicidE: along with an emulsifying agent. Prior to use, the concentrate is diluted with water to form a suspended emulsion of oil droplets. The emulsifiers used are usually a mixture of anionic and nonionic surfactants. Other additives such as spreading agents and stickers can be included in the emulsifiable concentrate.
It is not necessary that the compositions be admixed with the soil particles. After application by the above-discussed methods, they may be distributed below the soil surface to a depth of at least one-half inch by conventional means such as discing, dragging, or mixing.

Claims (13)

WHAT IS CLAIMED IS:

1. A synergistic herbicidal composition comprising:
(a) An aryloxypropionic acid derivative of the formula in which X is hydrogen or halogen;
R1 is hydrogen, C1-C6 alkyl, C1-C6 alkoxyalkyl; and (b) a cyclohexanedione derivative of the formula in which R is independently hydrogen; halogen; nitro; cyano;
C1-C6 alkyl; C1-C6 alkyl substituted with a substituent selected from the group consisting of halogen, nitro, hydroxy, C1-C6 alkoxy and C1-C6 alkylthio; C2-C6 alkenyl; C2-C6 alkynyl;
hydroxy; C1-C6 alkoxy; C1-C6 alkoxy substituted with a substi-tuent selected from halogen and C1-C6 alkoxy; C2-C6 alkenyl-oxy; C2-C6 alkynyloxy; C2-C6 alkanoyloxy; (C1-C6 alkoxy)-carbonyl; C1-C6 alkylthio; C1-C6 alkylsulfinyl; C1-C6 alkyl-sulfonyl; sulfamoyl; N-(C1-C6 alkyl) sulfamoyl; N,N-di(C1-C6 alkyl)sulfamoyl; benzyloxy, substituted benzyloxy wherein the benzene ring is substituted with from one to three substi-tuents selected from the group consisting of halogen, nitro, C1-C6 alkyl, C1-C6 alkoxy and C1-C6 haloalkyl; the group NR9R10 wherein R9 and R10 are independently selected from the group consisting of hydrogen; C1-C6 alkyl, C2-C6 alkanoyl, benzoyl and benzyl; the groups formyl and C2-C6 alkanoxyl and the oxime, imine and Schiff base derivatives thereof;
R2 is C1-C6 alkyl, C2-C6 alkenyl, C2-C6 haloalkenyl, C2-C6 alkynyl, C2-C6 haloalkynyl, a substituted C1-C6 alkyl, substituted with halogen, C1-C6 alkoxy, C1-C6 alkylthio, phenyl, substituted phenyl wherein the phenyl is substituted with halogen, nitro, cyano, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy and C1-C6 alkylthio;
R3 is hydrogen, C1-C6 alkyl, C1-C6 fluoroalkyl, C2-C6 alkenyl, C2-C6 alkynyl and phenyl;
R4 is hydrogen or the keto tautomer; C1-C6 alkyl;
C2-C6 alkenyl; C2-C6 alkynyl; substituted C1-C6 alkyl wherein the alkyl group is substituted with C1-C6 alkoxy, C1-C6 alkylthio, C1-C6 alkoxycarbonyl, phenyl, and substituted phenyl wherein the benzene ring is substituted with 1 to 3 substituents selected from the group consisting of halogen, nitro, cyano, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy, and C1-C6 alkylthio; C1-C6(alkyl) sulfonyl; benzene sulfonyl;
substituted benzene sulfonyl wherein the benzene ring is substituted with 1 to 3 substituents selected from the group consisting of halogen, nitro, cyano, C1-C6 alkyl, C1-C6 haloalkyl, C1-C6 alkoxy and C1-C6 alkylthio; an acyl group and an inorganic or organic: cation; and n is an integer chosen from 2 to 5.

2. A synergistic herbicidal composition comprising:
(a) An aryloxypropionic acid derivative of the formula in which X is hydrogen or halogen;
R1 is hydrogen, C1-C6 alkyl, C1-C6 alkoxyalkyl; and (b) a cyclohexanedione of the formula in which R is formyl or C2-C6 alkanoxyl;
R2 is C1-C6 alkyl;
R3 is C1-C6 alkyl;
R4 is hydrogen or the keto tautomer at a weight ratio of (a) to (b) of from about 1:5 to about 15:1.

3. A composition according to Claim 2 further comprising adjuvants.

4. A composition according to Claim 2 in which (a) is the D isomer of butyl 2-[4-(5-trifluoromethyl-2-pyridyloxy)-phenoxy)-propionate.

5. A composition according to Claim 4 in which (b) is 2-[1-(ethoxyimino)propyl]-3-hydroxy-5-(2,4,6-trimethyl-3-butyrylphenyl)cyclohex-2-enone or the keto tautomer.

6. A composition according to Claim 4 in which (b) is 2-[1-(ethoxyimino)propyl]-3-hydroxy-5-(2,4,6-trimethyl-3-acetylphenyl)cyclohex-2-enone.

7. A composition according to Claim 2 in which X is hydrogen or chlorine and R1 is hydrogen.

8. A composition according to Claim 7 in which R is acetyl or butyryl; R2 and R3 are ethyl; R4 is hydrogen or the keto tautomer.

9. A composition according to Claim 8 in which the weight ratio of (a) to (b) is from about 1:2 to about 8:1.

10. A composition according to Claim 9 further comprising adjuvants.

11. A synergistic herbicidal composition comprising:
(a) A 5-trifluoro-substituted-2-pyridyloxy phenoxy propionic acid derivative optionally substituted at the 3-position with halogen; and (b) a tetrasubstituted 5-phenyl-[2-(1-alkoxy-iminoalkyl) cyclohexanedione derivative at a weight ratio of (a) to (b) of about 1:2 to about 8:1.

12. A method of controlling undesirable vegetation which comprises applying to the locus where control is desired an herbicidal composition comprising a mixture of:
(a) An aryloxypropionic acid derivative of the formula in which X is hydrogen or halogen;
R1 is hydrogen, C1-C6 alkyl, C1-C6 alkoxyalkyl; and (b) a cyclohexanedione of the formula in which R is formyl or C2-C6 alkanoxyl;
R2 is C1-C6 alkyl;
R3 is C1-C6 alkyl;
R4 is hydrogen or the keto tautomer at a weight ratio of (a) to (b) of from about 1:5 to about 15:1.

13. A method according to Claim 12 wherein (a) is the D isomer of butyl 2-(4-(5-trifluoromethyl-2-pyridyloxy)-phenoxy]-propionate and (b) is 2-[1-(ethoxyimino)propyl)-3-hydroxy-5-(2,4,6-trimethyl-3-butyrylphenyl)cyclohex-2-enone or the keto tautomer.