AU612347B2 - Herbicidal composition and method - Google Patents

Description

Davies Collison, Melbourne and Canberra.

COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION 612347 (Original) FOR OFFICE USE Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: ',PrLiority: Related Art: go I Name of Applicant: Address of Applicant: Actual Inventor(s) Address for Service: RHONE-POULENC AGROCHIMIE 14-20 Rue Pierre Baizet, Lyon 9e,

FRANCE

Jean-Pierre DECOR Guy BORROD Jean-Paul DUFOUR DAVIES COLLISON, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000.

Complete specification for the invention entitled: I V- 1- L- C flTfltflflurx7 flrlflflmrmflmflfl nflt mnn a i_ .l TA The following statement is a full description of this invention, including the best method of performing it known to us 1- BY: Note: [nitial all alterations.

DAVIES COLLISON, MELBOURNE and CANBERRA. WII -la- The present invention relates to herbicidal compositions and products which comprise a picolinic acid or 2-pyridyloxyacetic acid derivative with a phenoxybenzoic acid derivative, to their preparation and to their use in the destruction of weeds and brushwood.

Many derivatives of picolinic acid and 2-pyridyloxyacetic acid are well-known herbicides.

Triclopyr, i.e. 3,5,6-trichloro-2-pyridyloxye a¢ '0:0 acetic acid and picloram, i.e. 4-amino-3,5,6-trichloroo00 .ooo 10 picolinic acid, are described in The Pesticide Manual, 7th 0oo00 °o Ed., The British Crop Protection Council, 1983. Clopyralid, o 0 i.e. 3,6-dichloropicolinic acid is described in The Farm Chemical Handbook, 72nd edition, 1986. Fluoroxypyr, i.e.

o 00 °o o 6-fluoro-4-amino-3,5-dichloro-2-pyridyloxyacetic acid is 0 0o o0 0 15 described in Herbicide Handbook of the Weed Science Society 0 of America, 5th edition, 1983. All of the above mentioned herbicidal compounds are also described in the last Smentioned reference.

The isobutyl and the 2-butoxyethyl esters of triclopyr, the l-methylheptyl ester of fluoroxypyr and the octyl or 2-butoxyethyl ester of clopyralid are also known.

The tri(2-hydroxyethyl) ammonium salt of triclopyr, the potassium or the amine salts of picloram and the 2-hydroxyethylammonium salt of clopyralid are also known.

i B it 000 0 ooo0 0 0 0 .o0 0 0 O0 000 a o 0 a S 0 0 0 40 6d t -2- It is, however, desirable to extend the area of herbicide activities to meet more effectively the needs of farmers. It is also desirable to reduce the doses of these herbicides and still achieve the desired herbicidal effect.

The present invention seeks to reduce the effective amount needed of herbicide, in particular the derivatives of picolinic acid and 2-pyridyloxyacetic acid, or the esters or salts thereof; to provide combinations of herbicides which exhibit an unexpected synergistic effect; 10 or to provide combinations which can be used as total post-emergence herbicides especially against weeds and, in some cases, against brushwood.

The present invention provides a herbicidal composition which comprises a picolinic acid or 2-pyridyloxyacetic acid derivative or a salt or ester thereof, or a mixture thereof, and a phenoxybenzoic acid derivative or a salt or ester thereof, or a mixture thereof, in association with an agriculturally acceptable carrier.

Compounds of group are preferably of formula

X

3 Cl 2

X

i wherein Q is COOR or OCH 2 COOR, wherein R is hydrogen, C 1 to

C

8 alkyl, C 1 to C 8 alkyl substituted with lower alkoxy, alkali metal, alkaline earth metal, or quaternary ammonium which is mono-, di- or tri- substituted with alkyl (preferably lower alkyl) optionally substituted with a hydroxy moiety; X is Cl or F; X 2 is H or Cl; X 3 is H or

NH

2 Preferably, R is H, isobutyl, 2-butoxyethyl, octyl, mono-, di-, or tri- (2-hydroxyethyl) ammonium, potassium or o. sodium.

.o 10 Most preferably, Q is OCH 2 COOR wherein R is H, isobutyl, 2-butoxyethyl or tri- (2-hydroxyethyl) ammonium, 1 2 3 X and X are Cl and X is H.

Triclopyr or an ester or salt of triclopyr as shown in formula V is preferred because the product obtained using this compound has remarkable herbicidal properties.

Cl Cl OCH 2 COOR (V) 1 Compounds of group are preferably of general formula (II) below:

(II)

1 wherein: R 1 is Cl or F;

R

2 is Cl or CF3;

R

3 is H, Cl or F; p is 0 or 1; each of R 4 and R 5 which may be identical or different, is H or CH 3

R

6 is OH; alkoxy (preferably lower alkoxy); OM, M being an alkali metal or alkaline earth metal atom, preferably Na or K; or alkylsulphonamide, preferably lower 10 alklsulphonamide; and c7 i, R is NO 2 or Cl.

The adjective "lower" used herein qualifying an organic radical herein means that the radical contains not more than 6 carbon atoms. The alkyl or alkoxy radicals described herein may be straight-chained or branched. It will be understood that the salts and esters of picolinic acid, 2-pyridyloxyacetic acid and phenoxybenzoic acid derivatives should be agriculturally acceptable.

The derivatives of phenoxybenzoic acids are herbicides which are also well-known in the art. US Patents 3,979,437; 4,164,408; 4,164,409; 4,164,410; 3,784,635; 4,063,929; 4,093,446; 4,358,308; 4,419,122; 4,419,125; 4,419,124 describe such herbicides which may be used in the present invention. The derivatives of phenoxybenzoic acids, wherein R 2 is CF 3 p is 0 and R 7 is NO 2 are preferred.

Acifluorfen or acifluorfen-sodium of formulae (III) and (IV) below are most preferred.

1 COOK cC oNoo (ay CF3 0 NO 2

(I)

SC1 COO";a Cl (IV) 000* 00 a CF 3 0 NO 0 0 0 01 Advantageously, the ratio by weight of is S, from 800:1 to 1:1, preferably from 70:1 to 2.5:1.

The combinations of this invention are generally of the binary type, containing a single compound of and a single compound of However, ternary or quaternary combinations with one or more other pesticides are also within the scope of the invention.

The active substances from group and group according to the present invention may be applied together or separately, or one after another over a period of time for the treatment of weeds, for example as herbicides against brushwood.

The invention provides a method for controlling 1 -6the growth of weeds at a locus which comprises applying thereto a picolinic acid or 2-pyridyloxyacetic acid derivative or a salt or ester thereof or a mixture thereof and a phenoxy-benzoic acid derivative or a salt or ester thereof or a mixture thereof, in a ratio by weight of of from 800:1 to 1:1.

In the case where the combination is applied together, it is advantageous to use a composition which oo o comprises a combination of the active substances described 0000 10 above. The method of the present invention also includes oo o mixing before use the active substances or compositions 0 o0 containing the active substances.

0S0000 The herbicidal combinations may also be applied over a period of time. For example, it is possible to treat 15 the crops to be protected successively, with one of active j 0 substances and followed by the other, so as to form a combination of the two in situ on the plant.

The present invention also provides a product comprising and as hereinbefore defined as a combined preparation for simultaneous, separate or sequential use in controlling the growth of weeds at a locus.

The products according to the invention are useful as herbicides. They are particularly useful as post-emergence herbicides for the destruction of annual, perennial, monocotyledonous or dicotyledonous weeds and brushwoods.

I I I

.I_

-7- The products as mixtures are prepared simply by mixing a compound of group with a compound of group In practice, the herbicidal compounds according to the invention are rarely used alone. Generally, the herbicidal compounds are used in combination with agriculturally acceptable solid or liquid carriers and agriculturally acceptable surfactants. Compositions containing the carriers and surfactants also form part of the invention.

10 These compositions may also contain other ingredients, e.g. protective colloids, adhesives, thickeners, thixotropic agents, penetrants, stabilizers and sequestering agents, as well as other known active substances which have plant growth regulating properties or pesticidal properties, such as insecticides, fungicides or id herbicides. More generally, the compounds used in the 1 invention may be combined with solid or liquid additives using customary formulation techniques.

-i -8- The doses of the compounds used in the invention vary within wide limits according to the nature of weeds to be controlled and the degree of infestation.

The products used in the invention are generally combined with carriers and, if necessary, with surfactants.

In general, the compositions useful for the invention contain approximately 0.05 to 95% by weight of the products according to the invention, approximately 1% to by weight of one or more solid or liquid carriers and, if required, approximately 0.01 to 50% by weight, preferably to 40% by weight, of one or more surfactants.

The term "carrier" or "filler" denotes an organic o' or inorganic, natural or synthetic material which is °o combined with the active substances in order to facilitate their application to the plant or soil. The carrier or filler is generally inert, and agriculturally acceptable, P° especially to the plant to be treated.

o As solid carriers, there may be mentioned inorganic or synthetic fillers such as kaolin, attapulgite, montmorillonite, bentonite, talcum, fullers' earth, diatomaceous earth, kieselguhr, calcium and magnesium C carbonates, precipitated synthetic silica, alumina, alkali metal silicates and silicoaluminates, resins, waxes and solid fertilizers. Water-soluble fillers such as sodium or ammonium sulphates and urea may also be used.

As liquid carriers, there may be mentioned water; alcohols, such as butanol; esters, such as methyl glycol acetate; ketones, such as cyclohexanone and 1,5,5-trimethyl-3-cyclohexanone; paraffinic or aromatic hydrocarbons, especially xylenes; aliphatic or aromatic chlorinated hydrocarbons, especially trichloroethane or chlorobenzenes; water-soluble solvents such as dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone.

L -9- The surfactant may be an ionic or nonionic emulsifier, dispersant or wetting agent or a mixture of such surfactants.

As nonionic wetting agents, there may be mentioned polycondensates of ethylene oxide with alkylphenols, such as octyl-, nonyl-, and tributyl phenols containing 6 to 18 ethylene oxide units; polycondensates of ethylene oxide with fatty alcohols, such as C 1 0 to C 18 alcohols, containing 6 to 18 units of ethylene oxide; polycondensates of ethylene oxide with fatty amines, such as tallow oil amine, or tall oil containing 2 to 40 units of ethylene oxide; and polycondensates of ethylene oxide with esters of fatty acids oo. and glycerol or sugar type polyhydric alcohols, such as 0000 oooo sorbitan laurate or stearate, containing 5 to 20 units of .o 15 ethylene oxide.

oooo 0ooo0 As anionic wetting agents, there may be mentioned o0 0 o 0oo alkyl naphthalenesulfonate salts, such as isopropylbutyland sodium or potassium dibutyl naphthalenesulfonate; fatty alcohol sulfate ester salts, such as sodium or potassium lauryl sulfates; salts of fatty alcohol sulfosuccinate esters, such as sodium or potassium dioctyl sulfosuccinates; taurine derivatives, such as alkyltaurates, V 0aryl-N-methyltaurides and sodium oleylmethyltauride.

As nonionic dispersants, there may be mentioned polycondensates of ethylene oxide with arylphenols, such as di- and tri- (phenylethyl)phenols containing 18 to 40 units of ethylene oxide.

As anionic dispersants, there may be mentioned salts of polycarboxylic polymers, such as sodium polycarboxylate and polyacrylate; polycondensates of formyl and diphenylsulfonates or alkyl naphthalenesulfonates, in particular sodium methyl naphthalenesulphonate; polycondensates of ethylene oxide with phosphoric acid esters or ester salts of alkyl- or arylphenols, such as phosphoric acid esters of nonylphenols containing 6 to 18 units of ethylene oxide in the form of an acid and a potassium salt, and phosphoric acid esters of di- or tri- (phenylethyl) phenol containing 18 to 40 units of ethylene oxide in the form of an acid or a salt; phosphate treated polycondensates of ethylene oxide with fatty alcohols, such as C11 to C19 fatty alcohols containing 6 to 18 units of ethylene oxide; and alkali metal or alkaline earth metal lignosulfonates.

The compositions according to the invention may be in the form of dry flowables and may contain from 1 to by weight of a natural or synthetic binder.

0, Natural binders, suitable for the present invention a0 include starch and its derivatives, such as carboxymethyl 0000 ao 15 cellulose, hydroxyethyl cellulose, hydroxypropylmethyl 0 0 cellulose; sugars, such as lactose, mannose and sorbose; and 0 00 gums, such as gum arabic and xanthan gums.

.000. Synthetic binders, suitable for the present invention include polymers, such as polyvinyl alcohol, polyvinyl acetate, polyvinylpyrrolidone, alkali metal polyacrylates; polycondensates, such as polyethers and 0 t0 polyglycols; copolycondensates of maleic anhydride, polycondensates of formyl and alkyl naphthalenesulfonates such as the polycondensate of formyl and of sodium methyl naphthalenesulfonate; and alkali metal lignosulfonates.

The presence of at least one surfactant in the compositions according to the invention is generally indispensable when the active substances and/or the inert carrier are(is) insoluble in water and the suitable agent for application is water.

The composition according to the present invention may be applied in fairly diverse forms including relatively dilute solid or liquid forms, whereas the compositions suitable for transport, sale and storage are more likely to I- i -ll-, be concentrated compositions.

When the herbicidal compositions of the present invention are solid compositions, they may be in the form of wettable powders or dusting powders containing up to 100% by weight of the active substances; or in the form of granules, preferably dry flowable granules, made by impregnating a granulated carrier, or by granulating a powder containing each of the active substances of group and group in the range between about 0.5 and 80% by weight.

Liquid forms of the herbicidal composition, or forms designed to be liquid compositions when applied, include solutions, emulsifiable concentrates and flowables ooo aor pastes.

a0 000 00°0 Flowables, which can be applied by spraying, are oooc .000 15 prepared so to be a stable fluid product which does not settle. These can be prepared by grinding the composition o into fine powders which usually contain from about 10 to by weight of active substances, from about 0.5 to 15% by weight of surfactants, from about 0.1 to 10% by weight of thixotropic agents, from about 0 to 10% by weight of a suitable additive such as an antifoam agent, a corrosion *inhibitor, a stabilizer, a penetrant and an adhesive, and a carrier, such as water or an organic liquid in which the active substances are sparingly soluble or insoluble. A solid organic substance or an inorganic salt may be dissolved in the carrier to assist in preventing sedimentation or as an antifreeze when water is used.

A flowable composition is present below in Example 1.

EXAMPLE I combination of active substances of group and group 500 g ethylene oxide/tristyrylphenol phosphate polycondensate 50 g F; X 2 is H or Cl; and X 3 is H or NH 2 or a mixture thereof and acifluorfen or acifluorfen sodium, or a mixture thereof, in association with a herbicidally acceptable carrier.

-12ethylene oxide/alkylphenol polycondensate 50 g sodium polycarboxylate 20 g ethylene glycol (antifreeze) 50 g organopolysiloxane oil (antifoam) 1 g polysaccharide (thickener) 1.5 g water 316.5 g The emulsifiable or soluble herbicidal composition as concentrates generally contain about 10 to 80% by weight of the active substances, and the emulsions or solutions ready for use contain, for their part, 0.001 to 20% by weight of the active substances.

These compositions may in addition contain other ingredient, such as protective colloids, adhesives, thickeners, thixotropic agents, penetrants, stabilizers, 15 sequestering agents, as well as other known active substances with pesticidal properties, particularly insecticidal or fungicidal properties, or properties which encourage plant growth, particularly fertilizers, or plant growth regulating properties. More generally, the compounds according to the invention may be combined with solid or liquid additives using customary formulation techniques.

In addition to the solvent, the emulsifiable concentrates may contain about 2 to 20% by weight of suitable additives such as stabilizers, surfactants, penetrants, corrosion inhibitors, coloring and adhesives.

The concentrates may be diluted with water to Sobtain emulsions of any desired concentration and are especially suitable for application to weeds.

By way of example, formulations of various emulsifiable concentrates are given below.

i- -13- EXAMPLE 2 active substance 400 g/l alkali metal dodecylbenzenesulfonate 24 g/l ethylene oxide/nonylphenol condensate, with 10 molecules of ethylene oxide 16 g/l cyclohexanone 200 g/l aromatic solvent q.s. 1 Liter EXAMPLE 3 active substance 250 g epoxidized vegetable oil 25 g mixture of alkylarylsulfonate and 0 0 S. polyglycol ether and fatty alcohols 100 g dimethylformamide 50 g xylene 575 g The above concentrates may be diluted with water to any desired concentration, and are especially suitable for application to leaves.

Herbicidal compositions of the present invention in the form of a wettable powder or powder for spraying are usually prepared so as to contain about 20 to 95% by weight of the active substances, and in addition to the active substances and a solid carrier, from about 0 to 5% by weight of a wetting agent, from 3 to 10% by weight of a dispersant and, where necessary, from 0 to 10% by weight of one or more stabilizers and/or other additives such as penetrants, adhesives, anti-caking agents, and colorings.

Formulations of wettable powders or powders for spraying are given below.

1k~A.A~ -14- EXA~MPLE 4 active substance ethylene oxide/fatty alcohol condensate (wetting agent) ethylene oxide/phenylethylphenol condensate (dispersant) chalk (inert carrier) Weight 42.5 EXAMPLE Weight 444; 4 4 4 44 active substance condensate of ethylene oxide with branched C 13 oxo synthetic alcohol, containing 8 to 10 ethylene oxide units (wetting agent) neutral calcium lignosulfonate (dispersant) calcium carbonate (inert filler) q.s.

0.75 12 100 EXAMPLE 6 This wettable powder contains the same ingredients as the previous example, in the following proportions: Weight active substance wetting agents dispersant calcium carbonate (inert filler) 1.50 8 q. s. 100 known.

EXAMPLE 7 Weight active substance ethylene oxide/fatty alcohol condensate (wetting agent) 4 ethylene oxide/phenylethylphenol condensate (dispersant) 6 EXAMPLE 8 o Weight oo~ 10 active substance 00000 mixture of anionic and nonionic 00 0surfactants (wetting agent) 000 osodium lignosulphonate (dispersant) kaolin clay (inert carrier) 42.5 To prepare powders for spraying, wettable powders for spraying or wettable powders, the active substances are 0 intimately mixed in suitable mixers with the additives and the mixtures are ground in mills or other suitable grinders.

Powders for spraying with advantageous wettability and suspendability are prepared by suspending in water, the appropriate powder composition at a desired concentration.

The suspensions can be used very advantageously for application to plant leaves.

Instead of wettable powders, pastes may also be prepared. The conditions and procedures for the preparation and use of these pastes are similar to those for wettable powders or powders for spraying.

As already stated, dispersions and aqueous I i-ii~i -16emulsions, e.g. the compositions obtained by diluting with water a wettable powder or an emulsifiable concentrate according to the invention, are included within the general scope of the present invention. These may be water-in-oil or oil-in-water emulsions, and may have a thick consistency like that of "mayonnaise" The compositions according to the invention may also advantageously be formulated in the form of water-dispersible granules, which are also included within the scope of the invention. These dispersible granules with an apparent specific gravity generally between approximately 0.3 and 0.6, have a particle size between approximately 150 and 2000 microns and preferably between 300 and 1500 O. microns. The amount of active substances in the granular g 15 composition is between approximately 1% and 90% by weight, 0 and preferably between 25% and 90% by weight. The remaining 4 part of the granular composition consists essentially of a solid filler and may include, when required surfactant adjuvants which confer water dispersibility on the granules.

The granules may essentially be of two distinct types depending on whether the filler used is soluble or insoluble in water. When the filler is water-soluble, it may be inorganic, but preferably organic. Excellent results were obtained with urea. In the case of an insoluble 0 25 filler, it is preferably inorganic, such as kaoline or bentonite. It is then advantageously accompanied by surfactants, at a rate of 2 to 20% by weight of the granules. More than half of the surfactants, for example, may consist essentially of at least one anionic dispersant, such as an alkali metal or alkaline earth metal naphthalene polysulfonate or an alkali metal or alkaline earth metal lignosulfonate; the remaining part of the surfactant may consist of nonionic or anionic wetting agents such as an alkali metal or alkaline earth metal alkyl 3 -17naphthalenesulfate.

Moreover, although it is not indispensable, other adjuvants such as antifoams may be added.

ii The granules according to the invention may be prepared by mixing the necessary ingredients followed by granulation according to several known techniques, such as by using a pelletizer, a fluidized bed, an atomizer, an extruder, or the like. The granules are generally crushed followed by sieving to a particle size between about 150 and 14 10 2000 microns.

Preferably, the granules are produced by extrusion.

EXAMPLE 8 S Dispersible granules by weight of active substance and 10% by weight of urea pellets are mixed in a mixer. The mixture is then ground in a toothed roll crusher to form a powder which is moistened with approximately 8% by weight of water. The moist powder is extruded in a perforated rotor extruder into granules, which are dried and then crushed and sieved, so as 20 to retain only the granules with a particle size between 150 and 2000 microns.

EXAMPLE 9 Dispersible granules The following constituents are mixed in a mixer: Weight active substance wetting agent (sodium alkyl naphthalenesulfonate) 2 i -18dispersant (sodium naphthalene polysulfonate) 8 water-insoluble inert filler (kaolin) The mixture is granulated in a fluidized bed in the presence of water and then dried, crushed and sieved to form granules of a size between 0.15 and 0.80 mm.

The granules may be applied alone or in solution or as a dispersion in water in the dose desired. The granules may also be used to prepare combinations with other active substances, particularly fungicides, in the form of wettable powders, granules or aqueous suspensions.

0o The compounds of group may also be used in the o- form of powders for dusting. The powders may contain 50 g of active substances and 950 g of talcum; or 20 g of an 15 active substance, 10 g of finely divided silica and 970 g of t40 0 00 talcum. The ingredients are mixed and ground and the 000.00 mixture is applied by dusting.

Compositions suitable for storage and transport are advantageously prepared to contain from about 0.5 to 95% by weight of an active substance.

Thus, the agricultural compositions according to the invention may contain active substances according to the invention within very wide limits, generally ranging from 0.05% to 95% by weight. The amount of surfactant in the composition is advantageously between 5% and 40% by weight.

A man skilled in the art will be able to select the suitable compositions for each combination.

Active substances in the form of esters, salts or acids are advantageously used in wettable powders.

herbicides against brushwood.

The invention provides a method for controlling -19- Where the two active substances are salts, compositions in the form of solutions will be suitable.

Where the two active substances are in the form of esters or acids, these may also be applied as emulsifiable concentrates, or dispersable granules.

The suitable dose levels of the products according to the invention as herbicides may vary within wide limits, depending on the density of the plants, particularly of the weeds, to be destroyed.

10 The invention also relates to a method for the .oo. destruction of weeds and brushwoods by the application, oo0 0 preferably foliar application, of a product according to the o 0 invention as defined above.

Preferably, the product is applied at a rate of 100 to 800 g/ha for and 1 to 100 g/ha for Spreferably 200 to 700 g/ha for and 10 to 80 g/ha for SThis product is preferably applied by spraying, e.g. in the form of an emulsified concentrate or a solution 20 or a wettable powder.

It is known that the minimum dose for use for a triclopyr composition containing 90 g/hl of triclopyr at a rate of 1000 1/ha, amounts to approximately 900 g/ha. It is observed that when a combination of triclopyr, or an ester or salt thereof is applied with a derivative of group (B) i brushwoods.

the dose of triclopyr or an ester or salt thereof can be substantially reduced.

The following examples using triclopyr illustrate the invention. A mixture was prepared by mixing 375 ml of the emulsifiable concentrate which contains 240 g per litre of the 2-butoxyethyl ester of triclopyr, and 99.625 litres of water so as to contain triclopyr at a concentration of 90 g/hl (acid equivalent).

A second mixture is prepared by mixing 208 ml of the emulsifiable concentrate containing 240 g/l of the 't 2-butoxyethyl ester of triclopyr and 20.8 ml of a solution containing 240 g/l of acifluorfen-sodium. The mixture is diluted to 1 hl with water. The diluted mixture, therefore, contains 50 g/hl of triclopyr and 5 g/hl of acifluorfen-sodium.

Mixture and mixture are respectively applied by spraying a 10 m 2 (2 x 5 m) experimental plot at a rate of 1000 1/ha dotted with Rubus fruticosus, otherwise known as bramble. A dose of 900 g/ha of triclopyr was therefore applied in the case of mixture and 50 g/ha of acifluorfen and 500 g/ha of triclopyr in the case of mixture The trials were repeated three times and the results are collated in the following Table I.

The table clearly shows a decrease in the dose of the compound needed by mixing it with -21acifluorfen-sodium.

'TABLE I killed TREATMENTS 7 days 14 days 24 days Individual Individual Individual Plots Average Plots Average Plots Average 0 0 0 Untreated 0 0 0 0 0 "0 control 0 0 0 20 50 Mixture 10 16.66 40 46.66 85 88.33 50 70 Mixture (II) 20 20 60 70 90 93.33 20 60 A third mixture was prepared by mixing 400 ml of the emulsifiable concentrate which contains 240 g of the acid in the form of the 2-butoxyethyl ester of triclopyr per litre, and 99.6 litres of water so as to obtain a triclopyr concentration of 96 g/hl.

A fourth mixture is prepared by mixing 200 ml of the emulsifiable concentrate containing 240 g/l of the acid in the form of the 2-butoxyethyl ester of triclopyr and ml of a solution containing 240 g/l of acifluorfensodium. The mixture is diluted to hl with water. The diluted mixture, therefore, contains 48 g/hl of triclopyr and 12 g/hl of acifluorfen-sodium.

and are applied by spraying at a rate of 1000 I/ha to 10 m 2 (2 x 5 m) plots dotted with Rubus spp -22- (blackberry), Rosa canina (dog rose), Equisetum spp, Ailanthus spp. A dose of 960 g/ha of triclopyr was therefore applied in the case of and 120 g/ha of acifluorfen with 480 g/ha of triclopyr in the case of The trials were repeated three times and the results are collated in the following Table.

The Table clearly shows a decrease in the dose of the compound obtained by mixing with acifluorfen-sodium.

II

active dose Rubus Rosa Equisetum Ailanthus matter a.m spp canina spp spp a.m A 960 91 50 97.5 A B 480 120 98 85 100 The formula below also exhibits an excellent herbicidal effect when applied under the same experimental conditions described as above.

EXAMPLE EMULSIFIABLE CONCENTRATE 24 g of acifluorfen is added to an emulsifiable concentrate containing 240 g of 2-butoxyethyl ester of triclopyr.

t=!jbtLLj UL. e~iieL saiuts oz aityi- or aryipnenois, sucn as 4 -23- EXAMPLE 11 Wettable Powder for 100 g Triclopyr (2-butoxyethyl) Sodium Calcium Alkylnaphthalene Sulfonate Na Lignosulfonate Antifoam Kaolin in weight 27.8 2.12 29.08 00 0 0000 0000 00 0 0 a0 000000 0 0 000 00 IS 00

Claims (14)

1. A herbicidal composition which comprises a picolinic acid or 2-pyridyloxyacetic acid derivative of formula X 3 Cl X2 X ."p 0 wherein Q is COOR or OCH 2 COOR, R is H, C 1 to C, alkyl, CI no to C 8 alkyl substituted with lower alkoxy, alkali metal, °ooo alkaline earth metal or a quaternary ammonium which is o mono-, di-, or tri- substituted with lower alkyl 0 0 Soptionally substituted with a hydroxy moiety; X 1 is Cl or oFo-. F; X 2 is H or Cl; and X 3 is H or NH 2 or a mixture thereof and acifluorfen or acifluorfen sodium, or a mixture thereof, in association with a herbicidally acceptable carrier. ,o 2. A composition according to claim 1 wherein R is H; isobutyl; 2-butoxyethyl; octyl; mono-, di-, or tri-(2- hydroxyethyl)ammonium; potassium or sodium. 9

3. A composition according to claim 1 wherein Q is u OCH 2 COOR wherein R is H, isobutyl, 2-butoxyethyl or tri- (2-hydroxyethyl)ammonium, X 1 and X 2 are Cl, and X 3 is H.

4. A composition according to any one of the Spreceding claims, wherein the ratio by weight of is from 800:1 to 1:1. A composition according to claim 4 wherein the ratio by weight of is from 70:1 to 2.5:1. i,

6. A composition according to any one of the preceding claims which comprises an agriculturally acceptable surfactant. i 7. A composition according to any one of the preceding claims which comprises from 0.05% to 95% by J weight of and

8. A herbicidal composition according to claim 1 substantially as hereinbefore described in any one of Examples 1 to 11.

9. A method for controlling the growth of weeds at a locus which comprises applying thereto a picolinic acid or 2-pyridyloxyacetic acid derivative of formula X2 N X wherein Q is COOR or OCH 2 COOR, R is hydrogen, C, to C S alkyl, C- to C, alkyl substituted with lower alkoxy, alkali metal, alkaline earth metal or a quaternary ammonium which is mono-, di-, or tri- substituted with lower alkyl optionally substituted with a hydroxy moiety; X 1 is Cl or F; X 2 is H or Cl; X 3 is H or NH 2 or a mixture thereof and acifluorfen or acifluorfen sodium, or a mixture thereof, in a ratio by weight of of from 800:1 to 1:1. A method according to claim 9, wherein R is H; isobutyl; 2-butoxyethyl; octyl; mono-, di-, or tri-(2- hydroxyethyl)ammonium; potassium or sodium. 26

11. A method according to claim 9, wherein Q is OCH 2 COOR wherein R is H, isobutyl, or tri(2-hydroxyethyl)- ammonium, X 1 and X 2 are Cl, and X 3 is H.

12. A method according to any one of claims 9 to 11 wherein the ratio by weight of is from 70:1 to 2.5:1.

13. A method according to any one of claims 9 to 12 for the post-emergence herbicidal treatment of weeds.

14. A method according to any one of claims 9 to 13 wherein and are applied simultaneously. A method according to any one of claims 9 to 14 wherein and are applied one after another over a period of time.

16. A method according to any one of claims 9 to for the destruction of weeds and brushwood by folior application at a rate of about 100 to 800 g/ha of and about 1 to 100 g/ha of

17. A method according to claim 16 wherein the rate of application is about 200 to 700 g/ha of and about to 80 g/ha of

18. A method according to claim 16 or 17 wherein the composition is applied by spraying.

19. A method according to claim 9 substantially as hereinbefore described with reference to the Examples. Dated this 13th day of November, 1990. RHONE-POULENC AGROCHIMIE, We By its Patent Attorneys, ZTiSN DAVIES COLLISON