IL43497A - Herbicidal compositions containing bipyridylium salts together with a cationic additive to increase the herbicidal effect - Google Patents

Abstract

1450531 Herbicidal compositions IMPERIAL CHEMICAL INDUSTRIES Ltd 15 Oct 1973 [27 Oct 1972] 49585/72 Heading A5E Herbicidal compositions comprise an aqueous solution of a salt of a herbicidal bipyridylium diquaternary cation and (A) a cationic additive to increase the herbicidal effect of the bipyridylium salt, which additive is either (a) one or more quaternary ammonium salts of formula:- wherein R<SP>2</SP>, R<SP>3</SP> and R<SP>4</SP> each are an optionally substituted aliphatic radical of. I to 4 carbon atoms, or R 2 is a C 1 -C 4 aliphatic radical while R<SP>2</SP>, R<SP>3</SP> and R<SP>4</SP> together with the N atom represent a pyridinium ring optionally substituted by -a C 1 -C 4 aliphatic radical or fixed to a benzene ring, and wherein R<SP>1</SP> is an aryloxyalkyl radical or an optionally substituted C 3 -C 20 aliphatic radical, and X<SP>-</SP> is an anion, or (b) one or more acid addition salts of an amine of formula:- wherein R<SP>1</SP> is as defined above, R<SP>5</SP> and R<SP>6</SP> are H or C 1 -C 4 aliphatic radicals and X- is an anion, and (B) a non-ionic surfactant. The salt of the bipyridylium diquaternary anion may be a compound of formula:- or of formula:- wherein P and Q are C 1 -C 4 alkyl, optionally substituted by vinyl, OH, halogen, carboxyl, alkoxy, piperidino carbanyl, methyl-substituted morpholino carbanyl, alkylcarbonyl, alkoxycarbonyl, carbamoyl or N-substituted carbamoyl. [X]<SP>n-</SP> is an anion and n is 1 to 4. The cationic additive may be present in an amount of one to thirty parts by weight of ten parts of herbicide. [GB1450531A]

Description

43497/3 liERBICIDAL COMPOSITIONS CONTAINING BIPYRIDYLIUM SALTS, TOGETHER WITH A CATIONIC ADDITIVE TO INCREASE THE HERBICIDAL EFFECT Qisvy ni?oip ni^yan rnsanb ϊΐ ι ύρ η£3θ¾η aj This invention relates to herbicidal compositions comprising a herbicidal bipyridylium quaternary salt together with an additive to increase the herbicidal effect of the latter.

According to the present invention there is provided a herbicidal composition comprising an aqueous solution of a salt of a herbicidal bipyridylium diquaternary cation 10 containing a cationic additive to increase the herbicidal effect of the bipyridylium salt, the said cationic additive comprising either (a) a quaternary ammonium salt of the formula:- R' wWe. » R is an a! 1 ra£ical of £rom 1 t0 carbon atoms and 15 wherein R and R each represent an op iefiell - alkyl s-utrsti-tr ted--a:lip†ra:ti'c radical of from 1 to optionally substituted by a hydroxy group carbon atoms/; or wherein R represents an aliphatic 43497/2 3 4 radical of 1 to 4 carbon atoms while R and R together with the nitrogen atom to which they are attached form a pyrrol -dinium or piperidinium ring; or wherein R 2, R3 md R4 taken together with the attached nitrogen atom represent a pyridinium ring which may optionally b© substituted by an aliphatic radical of 1 to 4 carbon atoms or may b© fused to a benzene ring; and 1 wherein R represents an aryloxyalkyl radical or an alkyl or alkenyi radical of from 6 to 20 carbon atoms which may be optionally substituted by a group wherein R is an alkyl or alkenyi radical of from 6 to 18 carbon atoms and R 8 and R9 are alkyl radical of 1 to 4 carbon atoms, and wherein X" is an anion; or (b) an acid addition salt of an amine having the formula: wherein 1 R has the meaning previously assigned to it and R5 and R^ are each hydrogen atoms or aliphatic radicals, of from 1 to 4 carbon atoms and X° is an anion; tho said herbicidal composition further comprising a non-ionic surface active agent. wherein Π' is an aliphatic radical o-f—from 8 9 6 to l8 oarbon atomn and R—and R are a-l-i-p-h-a-fri-e radicalo o-f from 1 to 4 carbon atomo.-Preferred anions for use as the anion X~ in the foregoing description include bromide and chloride, although any other anion may be used · if desired . The choice of' anion "is a matter" of convenience, depending for example on cost, and is within the competence of a person skilled in the art of formulating herbicides. The additive is preferably present in the compositions of the invention to the extent of from one to thirty parts by weip.ht to ten parts of herbicidal bipyridylium quaternary cation.

Preferably the additive is present to the extent of at least one part to five parts of herbicidal bipyridylium cation. Particularly preferred compositions contain 1 part of cationic .additive by weight one part of bipyridylium cation.

Preferred salts of herbicidal 4 , 4 ' -bipyridylium cations for use in the compositions of the invention are those of the formula:- or wherein P and Q which may be the same or different stand for alkyl radicals of from 1 to Ί carbon, atoms which may be substituted by hydroxyl, halogen, carboxyl, alkoxy, alkylcarbohyl , alkoxycarbonyl , carbamoyl or — — I n- N-substituted carbamoyl; X represents an anion and n is an integer from 1 to inclusive.

Particularly preferred salts of herbicidal bipyridylium quaternary cations are those listed below : - -dimethyl-4 , A ' -bipyridylium dichloride (paraquat dichloride) l,lLethylene-2, 2' -bipyridylium dibromide (diquat dibromide) -1 ,1 ' -di-2hydroxyethyl- ,4' -bipyridylium dichloride 1,1' -b s-3,5~dimethylmorpholinocarbonylmethyl-4 , ' - bipyridylium dichloride (morfamquat dichloride) 1- (2-hydroxyethyl ) -1 ' -methyl-4 , 4 ' -bipyridylium dichloride 1 ,1 '-di-carbamoylmethyl-4 , 4 ' -bipyridylium dichloride 1,1' -bis-N,N-dimethylcarbamoylmethyl- , ' -bipyridylium dichloride ' 1,1' -bis-N,N-diethylcarbamoylmethyl- ,4 ' -bipyridylium dichloride 1,1' di- (piperid inocarbonylmethy1 ) - , 4 ' -bipyridylium dichloride 1,1' -diacetony1-4 , 4 ' -bipyridylium dichloride 1,1' -diethoxycarbonylmethyl-4 ,4 ' -bipyridylium dibromide 1 , 1 ' -diallyl-4 , ' -bipyridylium dibromide The names in brackets alongside some of the compounds in the above list are the accepted common names .for the cationic portion of these compounds. Thus "paraquat" is the common name for the 1 ,1 ' -dimethyl- 4 , ' -bipyridylium cation. Salts of paraquat are particularly preferred bipyridylium compounds for use in the compositions of the invention.

Since the herbicidal effect of a bipyridylium quaternary cation is independent of the nature of the associated anions the choice of the anion is a matter of convenience, depending, for example, on cost. Preferably the anion is one which gives rise to a. salt of " convenient water solubility. Examples of anions, which may be mono-, or polyvalent , include acetate, benzenesulphonate , benzoate, bromide, chloride, iodide, methyl-sulphate, nitrate, phosphate, succinate, sulphate, thiocyanate, tartrate, and pjtoluene-sulphonate. The salts of the bipyridylium from cation may be formed orm- a number of similar anions or mixtures of different ones. A salt having any particular desired anion may be prepared either by direct synthesis from reactants which include the desired anion or by exchanging the anion of a previously prepared salt for the preferred anion by methods well known in the art, for example by passage of a solution of the previously prepared salt through an ion-exchange resin. For reasons of convenience and economy, the chloride anion is a particularly preferred anion.

Since the characteristic . herbicidal activity of a salt of a herbicidal bipyridylium quaternary cation resides in the cation only, it is customary to quote concentrations of active ingredient and rates of application in terms of the amount of bipyridylium quaternary cation used, thus avoiding the inconvenience of having- to quote different application rates for different salts of the same bipyridylium quaternary cation. . Application rates and concentrations quoted in this specification therefore relate to the amount of bipyridylium quaternary cation, unless otherwi&e stated.

Compositions according to the invention include both concentrated compositions and dilute compositions which are ready for application.

The . amount of herbicidal bipyridylium cation present in. the concentrated compositions is preferably from 1.0 to 3.0 pounds pe|r Imperial gallon, that is to say, from 100 grams to. 300 grams per litre; Compositions containing 150 grams to 250 grams per litre are particularly preferred. The choice of non-ionic surface active agent is not critical in the compositions of the invention. By way of example, however, preferred non-ionic surface-active agents for us in the compositions of the invention include the condensation products of ethylene ! oxide . . with fatty alcohols such as oleyl alcohol and . cetyl alcohol, or with alkyl phenols such as octylphenol, nonylphenol, and octylcresol.

Other non-ionic "agents are the partial esters derived from long chain fatty acids and hexitol anhydrides, for example sorbitan monolaurate ; the condensation products of the said partial esters with ethylene oxide; and the lecithins.

Particularly preferred non-ionic surface-active agents are condensates of from 2 to 4 molar proportions of ethylene oxide with primary aliphatic alcohols having from 9 to 15 carbon atoms. Especially preferred non-ionic surface- active agents comprise condensates of from 2 to 3 molar proportions of ethylene oxide with primary . aliphatic alchols having from 9 to 11 carbon atoms inclusive. Examples of this kind of agent include a condensate of 2.5 molar proportions of ethylene oxide with 1 molar proportion of Linevol 911 alcohol, a petroleum derived mixture of aliphatic alcohols containing 20% of C^, ^5% of Cl0, and' 35$ of C-j^ alcohols. A further example comprises Synperonic B 113, which is a condensate of 3 molar proportions of ethylene oxide with' n undecanol.

Condensates of 2 to 3 molar proportions of ethylene oxide with aliphatic primary alcohols having from 9 to 11 carbon atoms inclusive are only slightly watersoluble , but are solubilised in water when in the presence of the cationic additives used in the compositions of the invention.

Preferably the non-ionic surface-active agent is present in a proportion of from 0.2 to 2.0 parts per part by weight of the cationic additive in the composition-.

While the applicants do not wish to be bound by any theory as to the way in which the cationic additives increase the herbicidal effect of bipyridylium quaternary salts, it is believed that a certain , proportion of a herbicidal bipyridylium quaternary salt applied to a plant is inactivated by complexing with plant constituents. It is believed that the cationic additives act to release the bipyridylium quaternary salt from its complexed state, or prevent it from becoming complexed, and so enable a greater proportion of the bipyridylium quaternary salt applied to a plant to exert its toxic effect upon the plant .

Examples of preferred cationic additives for use in the compositions of the invention, include quaternary ammonium salts of the formula :- CH 3 AND + R N — (CH,), N CH 2 Y 3 CH 3 wherein the group R represents an octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, octadecenyl, or octadecadienyl radical and Y represents a bromine or chlorine atom.

Other preferred additives include lauryl isoquinolinium bromide, cetylpyridinium bromide, stearyl dimethylbenzylammonium chloride, and quaternary salts of the formula :- wherein the group Rw represents an octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, or octadecenyl radical.

The cationic additives used in the compositions of the invention may be used singly or a mixture of several additives may be used if desired..

Examples of commercially available substances which are useful as additives are listed below: 1. A mixture of quaternary ammonium salts consisting principally of octadienyltrimethylammonium chloride ( 45% ) with smaller amounts of octadecenyl -(35$) and octadecyltrimethylammonium chlorides (10%) as a solution in a mixture of water and isopropanol sold under the Trade Mark Arquad S/50. 2. A mixture of quaternary ammonium salts consisting principally of octadecenyl (48%) and hexadecyl trimethyl ammonium chloride (27%) with a smaller amount of octadecyltrimethylammonium chloride (16%) as a solution in a mixture of water and isopropanol sold under the Trade Mark Arquad T/50. 3. A mixture of quaternary ammonium salts consisting principally of dodecyltrimethylammonium chloride (90%) with a smaller amount of tetradecyltrimethylammonium chloride (9%) as a solution in a mixture of water and isopropanol sold under the Trade Mark Arquad 12/50. 4. A mixture of quaternary ammonium salts consisting principally of hexadecyltrimethylammonium chloride (90%) with small amounts of octadecyl (6%) and octadecenyl trimethyl ammonium chloride and isopropanol sold under the Trade Mark Arquad 16/50. 5. A mixture of quaternary ammonium salts consisting principally of octadecyltrimethylammonium chloride (93%) with a small amount of hexadecyl (6%) and octadecenyl trimethyl ammonium chlorides (1%) as a solution in a mixture of water and isopropanol sold under the Trade Mark Arquad 18/50. 6. A mixture of quaternary salts of the formula :- a ' CH3 wherein the R radical is derived from tallow fatty acids and comprises ^8% octadecenyl , 16% octadecyl, 27% hexadecyl, and >% tetradecyl radicals, sold under the Trade Mark "Duoquad" T. 7. Lauryl isoquinolinium bromide, as a 75% solution sold under the Trade Mark "Isothan" Q 75. 8.. Alkyl dimethyl 1-naphthylmethylammonium chloride sold under the Trade Mark BTC 1100. 9. A mixture of n alkyl (55% C^ ^, 25% C]_2H25» 17% metn l isoquinolinium chlorides sold under the Trade Mark "Ammonyx 78l 10. p_-Tertiary octylphenoxyethyl diethyl benzyl ammonium chloride sold under the Trade Mark "Octaphen" 11. N-lauroylcolaminoformylmethylpyridinium chloride, sold under the Trade Mark "Emcol" E 607 12. Stearyl dimethylbenzylammonium chloride sold under the Trade Mark Triton X-iJOO 13. A mixture of quaternary ammonium salts, consisting principally of dodecyltrimethylammonium chloride (^75 with a smaller amount of tetradecyl trimethyl ammonium chloride (l8#) and lesser amounts of octyl, (8%) decyl (9%) and hexadecyltrimethyl-ammonium chloride (8%) as a solution in aqueous isopropanol sold under the Trade Mark "Arquad" C/50. 14. A mixture of quaternary salts of formula: wherein R is a mixture of aliphatic groups derived from coconut fatty acids, comprising C10H21 (9%) C12H15.(47i) Cl4H29.(l8ji) C-^H^ (8%) Cl8H37 (5¾) and Cl8H35 ^5%) sold under the Trade Mark Ethoquad C/12. 15. Cetyl pyridiniu bromide, sold under the Trade Mark "Fixanol" C. 16. A mixture of amines of general formula RN (CH^)2 prepared from the fatty acids of coconut oil, and wherein the group. R comprises c gH^y (5%), ^ ^oH21 C12H25 i52% Cl4H29 (19%) Cl6H33 9%) Cl8H37 {2%) 8. Alkyl dimethyl 1-naphthylmethylammonium chloride sold under the Trade Mark BTC 1100; 9. A mixture of n alkyl (55% 17% C^gH^ and 3 % C^8H37^ metn :i- isoquinolinium chlorides sold under the Trade Mark "Ammonyx 78l 10. p_-Tertiary octylphenoxyethyl diethyl benzyl ammonium chloride sold under the Trade Mark "Octaphen" 11. N-lauroylcolaminoformylmethylpyridinium chloride sold under the Trade Mark "Emcol" E 607 12. Stearyl dimethylbenzylammonium chloride sold under the Trade Mark Triton X-400 13. A mixture of quaternary ammonium salts, consisting principally of dodecyltrimethylammonium chloride {^1%) with a smaller amount of tetradecyl trimethyl ammonium chloride (18%) and lesser amounts of octyl, (8%) decyl (9%) and hexadecyltrimethyl-ammonium chloride (8%) as a solution in aqueous isopropanol sold under the Trade Mark "Arquad" C/50. -16- octadecenyl (6%) and octadecadienyl (1%) and sold under the Trade. Mark 'Armeen' . This mixture is used in the compositions of the invention not as it stands but in the form of an acid addition salt, for example as its hydrochloride or other salt. 17. A mixture of quaternary alkyl trimethylammonium bromides in which the N-alkyl group comprises 25% C12, 65% and 10$ C g, sold under the Trade Mark "Cetavlon". In another aspect, the. invention provides a process of inhibiting the growth of unwanted .vegetation , ' which comprises applying to the vegetation a composition according to the invention.- Preferred rates' of application correspond to the application of from 0.25 pounds to 1.0 pounds bipyridylium cation per acre (i.e. about Ο.28 to 1.1 kg/hectare) although higher or lower rates of application. may be desirable in some situations; a suitable rate of application for any particular situation is readily ascertainable by one skilled' n the art. 1 The following, list gives details of the chemical composition of various substances referred to in this spec fication by Trade Mark or trade name : - Lisaapol MX: A condensate of from 7 to 8 molar proportions of ethylene oxide with p-nonyl phenol L.ubrol . .

Linevol 911 alcohol: A' petrochemically derived mixture of straight chain aliphatic alcohols containing 20% Cg) ^5% C1Q, and 35% alcohols.

Synperonic B' 113: A condensation product of 3 molar proportions of ethylene oxide with "Synprol" Synperonic B 1125: A condensation product of 2.5 molar proportions of ethylene oxide with "Synprol" Synprol: A petrochemical derived straight chain alcohol containing 8% of undecanol.

Ethylan CD 913. : A condensate of 3 molar proportions of ethylene oxide with 1 molar proportion of Linevol 911 alcohol.

Ethylan CD. 917: As Ethylan CD 913 but with 7 molar proportions of ethylene oxide instead of 3· Ethylan CD 9112 :. As Ethylan CD 913 but with 12 molar proportions of ethylene oxide instead of 3· Ethylan D 253: A condensate of 3 molar proportions of ethylene oxide with a mixture of to C]_cj' straight chain aliphatic alcohols.

Ethylan D 257: As Ethylan D 253 but with 7 molar proportions of ethylene oxide instead of 3· Ethylan D 2512: As Ethylan D 253 but with 12 . molar proportions of ethylene oxide instead of 3.

Lubrol N 13: A condensate of 13 molar proportions of ethylene oxide with p_-nonylphenol .

Ethylan A 2: Polyglycol 200 oleate Ethyland A 3: Polyglycol 300 oleate Ethylan A6: Polyglycol 600 oleate Tween 20: A condensate of 20 molar proportions of ethylene oxide with- sorbitan monolaurate.

Tween 40: A .condensate of 40 'molar proportions of ethylene oxide with sorbitan monolaurate.

Armeen DMCD : Distilled N,N dimethyl coco^amine Cetavlon bromide: A mixture of 72% of dodecy ltrimethyl- ammonium bromide with 28% of tetradecyltrimethyl- ammonium bromide.

The invention is illustrated by the following Examples .

EXAMPLE 1 This Example illustrates the increased herbicidal activity of compositions according to the invention as compared with previously known compositions. Plots of pasture (mainly composed of rye-grass Loliurn pererine) and of harvest stubble infested with grasses (mainly Poa and A rostis species), H metres by 15 metres in dimensions, were sprayed with solutions of compositions according to the invention, and with a known composition for comparison, and the percentage scorch of the grasses assessed after the periods of time shown in the Tables below. The various treatments applied were as follows. All treatments were diluted to a standard volume of 225 litres per hectare for application. 1. On pasture plots this treatment comprised an application of 3 litres per hectare of a solution of paraquat dichloride' containing 20% by weight of paraquat cation. On stubble plots, the treatment was 1.5 litres per hectare of the paraquat solution. In both cases sufficient of a surfactant comprising a 1:4 mixture by weight of "Lissapol N" and "Ethomeen S/25" was added to the spray solution to give a concentration of 0.1% by weight. "Lissapol N" is a Trade Mark for a condensate of from 7 to 8 molar proportions of ethylene oxide with 1 molar proportion of p_- nonyl phenol. "Ethomeen S/25" is a Trade Mark for a condensate of 15 molar proportions of ethylene oxide with one molar proportion of soya amine. Soya amine is a mixture of primary amines prepared from soya bean fatty acids. 2. On' pasture plots, this treatment comprised 3 litres per hectare of 20% paraquat dichloride solution; on stubble plots, 1| litres of the paraquat solution. In both cases, 0. 1$ by weight of an additive comprising a 1:1 mixture by weight of "Arquad" C/50 and a condensate of 3 molar proportions of ethylene oxide with 1 molar proportion of undecanol was included in the spray solution. 3. On pasture plots, this treatment comprised 3 litres per hectare of 20% paraquat dichloride solution; on stubble plots, 1J litres of. the paraquat solution.

In both cases, 0.1$ by weight of an additive comprising a 1:1 mixture by weight of "Cetavlon" bromide and a condensate of 2.5 molecular proportions of ethylene oxide with 1 molar proportion of dodecanol was included in the spray solution. k. On pasture plots, this treatment comprised 6 litres per hectare of 20% paraquat dichloride solution; on stubble plots, 3 litres of the paraquat solution. On pasture plots, the spray solution contained 0. 12% by weight of the "Lisaapol"/ "Ethomeen" mixture described in Treatment 1. On si;ubble plots, the spray solution contained 0.06% of this mixture. 5. This treatment was the same as treatment 4 except that the amount of paraquat and surfactant mixture was half that in Treatment 4.

The results are given in Table I below.

TABLE I Table I continued In the above table, the application rate in Treatment 4 is the rate at which paraquat would normally be used commercially for killing pasture or weed growth in stubble. Treatment 5 shows the reduced herbicidal effect when the application rate of treatment 4 is halved. Treatments 2 and 3 show that by including" a.^cafe onic additive the herbicidal effect of paraquat applied at,.the rate of Treatment can' be increased substantially, in some instances up to the effect of Treatment 4. Treatment 1 is included to show the effect of using the surfactant of Treatment 5 at the same rate (0.1$) as the additive of Treatments 2 and 3.

EXAMPLE 2 This example illustrates the improved herbicidal activity of compositions according to the invention.

Plots of land on which rye-grass (Lolium perenne) was growing were sprayed at 20 gallons per acre (225 litres per hectare) with the treatments listed- below .

Concentration of ingredients are given in terms of weight/ volume percentages; thus 0.25% means 2.5 grams per litre. The concentrations quoted for paraquat dichloride refer to paraquat cation.

Treatments 1. Paraquat dichloride 0.25% plus 0.05% of a mixture of 1 part Lissapol NX with 4 parts of Ethomeen S/25 2. Paraquat dichloride .0.5% plus 0.05% of a mixture of 1 part Lissapol NX with ¾ parts of Ethomeen S/25 3. Paraquat dichloride 0.25% plus 0.1% of a mixture , of equal parts of -G-etavlon bromide and Synperonic B 113· ■ 4. Paraquat dichloride 0.25% plus 0.1% Arquad C/50 5. Paraquat dichloride 0.25% plus 0.1% of Armeen DMCD as its maleate salt. 6. Paraquat dichloride 0.025% plus 0.1% of a mixture of 1 part of Armeen DMCD maleate salt and with 1| parts of Synperonic B 113. 7. Paraquat dichloride 0.25% plus 0.1% of a mixture of 1\ parts of Armeen DC D maleate with 1 part of Synperonic B 113· Damage to the rye grass was assessed 32 days after spraying, on a scale of 0 to 100 where 0 is no effect and 100 is a complete kill. The results are given in Table II below.

; Table II Treatment 1 contains the mixture of Lissapol and Ethomeen wetting agents currently used in commercial formulations of bipyridylium herbicides.

The results for Treatment 2 shows that by doubling the concentration of the paraquat from 0.25% to 0:5%, and keeping the same wetting agent, the' percentage damage is increased from 47. to 83.3. Treatment 3, comprising a composition according to the invention containing the same concentration of paraquat as Treatment 1, gives a percentage damage of 70.0. Thus, by using the additives taught by the invention, the herbicidal activity of paraquat at 0.25% was increased in ■ this test to the extent of approximately 6 >% of the increase in herbicidal effect produced by doubling the concentration of paraquat to 0.5% ' Treatments 4 and 5 show that by using a cationic additive without a non-ionic wetter, some increase in herbicidal activity is produced, but less than in Treatment 3· Treatments 6 and 7 further illustrate the considerable increase in herbicidal activity of compositions according to the invention by comparison with the previously known composition used in Treatment 1.

EXAMPLE 3 This Example illustrates the improved herbicidal activity of compositions according to the invention as compared with a standard commercially used formulution containing a mixture of Lissapol and Ethomeen as a wetting agent. All compositions contained diquat dibromide at a concentration of 1 gram per litre (0.1% w/v) of diquat cation. The compositions were sprayed at the rate of 20 gallons per acre (225 litres per hectare) on to plots of land on which ryegrass (Lolium perenne) was growing. The damage to the rye grass was assessed on a scale of 0 to 100 where 0 is no effect and 100 is complete kill. After 28 days the new growth ("regrowth") from the damaged plants was harvested and its fresh weight measured. Two trials were carried out; the. results are given below:- TRIAL 1 •Treatment Percentage Damage Regrowth X days after (Fresh weight Treatment in grams) 28 days after treatment X = 12 X = 19 Diquat plus L/E 55 48 2010 Diquat plus A/S 65 57 I65O TRIAL 2 Treatment Percentage Damage Regrowth X days after (Fresh weight Treatment in grams) 28 days' after treatment X = 11 X = 28 Diquat plus L/E 53 40 1800 Diquat plus A/S 64 47 1405 In the above tables, L/E stands for a mixture of 1 part of Lissapol NX, with 4 parts of Ethomeen S/25. This mixture was included in the spray at the rate of 1 gram per litre (0.1% w/v). The letters A/S stand for a mixture of equal parts of Arquad C/50 and "Synperonic B 113". It will be seen that the Arquad C/50/Synperonic mixture- gave a higher degree of damage and prevention of regrowth than the Lissapol/Ethomeen mixture.

EXAMPLE 4 This. Example illustrates two concentrated compositions A and B according to the, invention. These contained the following constituents. The quantities specified are grams per litre of the composition .

TABLE III * Where X gives 150 grams per litre of paraquat cation.

These compositions were homogeneous solutions which were readily diluted with water to provide dilute solutions ready for spraying. The concentrated compositions remained homogeneous after prolonged storage at temperatures up to 50°C and did not separate into two layers.

The sodium metaborate and sodium benzoate in the compositions were added as corrosion inhibitors.

Silcolapse 5000 was added to control foam; it comprises an anti-foaming agent based on silicones.

EXAMPLE 5 This Example illustrates the 'improved herbicidal activity of compositions according to the invention as compared with a standard commercially used formulation. All compositions contained paraquat dichloride at a concentration of 1 gram per litre (0.1% w/v) of paraquat cation. The compositions were sprayed at the rate of 20 gallons per acre (225 litres per hectare) on to young pot plants of the species named in the table. After 3 weeks the degree of damage to the plants was assessed on a scale of 0 to 100 wherein 0 represents no effect and 100 represents complete kill. For...comparison s the lower part of the table gives the results obtained with certain non-ionic wetting agents when no cationic additive was present.

TABLE IV NON-IONIC WETTER CATIONIC ADDITIVE AT 0 . 05 $ W/V i 1 Arquad C/ 50 Duoquad C/50 Arraeen DMCD 1 Hydrochloride j Kg Cf Kg Cf ■ j Rg Rg Kg Cf Rg Ethylan CD 913 i 6 3 80 68 ' 60 ' 58 18 60 60 i Ethylan CD 917 ■ 63 70 ' 55 73 1 J 70 50 60 63 r.

Ethylan CD 9112 ; 55 75 50 65 •~ Q 0 0 ■ 60 40 58 50 .

Ethylan D 25 55 73 68 60 63 8* 25 45. 58 Ethylan D 257 68 90 70 3 60 7' ~ ^i 45 40 58 Ethylan D. 2512 43 73 65 60 60 70 33 45 "55 Ethylan A 2 53 80 55 '60 68 Ethylan A3 50 60 58 65 73 Ethylan 6 50 70 65 65 6 3 Lissao-ol NX 65 65 68 53 63 78 ■ Lubrol N13 58 73 73 48 58 70 33 50 50 .

Tween 20 . 53 67 65 6.-3 - 73 Tween 40 58 67 70 6¾ 63 able. IV continued The abbreviations used in Table IV have the following meanings: Kg Knot grass Cf Cocks foot Rg Rye grass The botanical names of the test species are given below :- Knot grass ■ Polygonum aviculare Cocks- foot Dactylis glomerata Rye grass Lolium perenne EXAMPLE 6 This Example further illustrates the improved herbicidal activity of compositions according to the invention, as compared with previous known formulations. The following compositions were tested:- TABLE V Quantities of these compositions were, diluted in water and sprayed on trial plots of ryegrass, in a spray volume of 225 litres per hectare. The damage to the ryegrass was assessed on a percentage scale wherein 0 is no effect and 100 is complete kill. Four i trials were conducted for each rate of application. The percentage damage for each trials was assessed weekly over a period of 5 weeks, and the average percentage damage over this period was calculated. The figure for each application rate was averaged over the four trials. The resulting figures are given in the' table below.

TABLE VI J Treatments 6(a) and 6(b) were two treatments in which compositions No. 6 was applied first before compositions 1 to 5 were i sprayed and then again when the spraying of these compositions was completed. The object of carrying ut these two treatments was to check that there was no significant difference in herbicidal activity of paraquat when applied at different times of the day.

Composition No. 6 is a widely used commercial formulation of paraquat. It will be seen that the compositions of the invention (Nos 1 to 5) containin only 15% of paraquat were as active in this test as composition No. 6 which contained 20% of paraquat .

Claims (6)

43497/2

1. A herbicidal composition, comprising an aqueous solution of a salt of a herbicidal bipyridylium diquatemary cation, containing a cationic additive to increase the herbicidal effect of the bipyridylium quaternary salt, the said cationic additive comprising either (a} a quaternary ammonium salt of the formula:- R< wherein R 2 is an alkyl radical of from 1 to 4 carbon atoms and 3 4 R and R each represent an alkyl radical of from 1 to 4 carbon · * · '· ! ··■ : · · · ·. . · 2 atoms«<.¾pftonal y substituted by a hydroxy group; . or wherein R ' '·'.··'■· ■· . ■ « represents on, aliphatic radical of 1 to 4 carbon atoms while R 4 and R, together with the nitrogen atom to which they are attached ■ ·■' "·· ·, ·.

2. 3 form a pyrrolidinima or piperidinium ring; or wheroin R , and taken together with the attached nitrogen atom represent a pyridiniuro ring which may optionally be substituted by an aliphatic radical of 1 to 4 carbon, atoms.or be fused to a - 59 43497/2 benzene ring and wherein ft1 represents an aryloxyalkyl radical or an alkyl or alkenyl radical of from 6 to 20 carbon atoms optionall substituted by a group is a compound of the formula: - 4Θ - wherein P and Q,which may be the same or different, stand for alkyl radicals of from 1 to 4' carbon atoms, which may be substituted by hydroxyl, halogen, carboxyl, alkoxy, alkylcarbonyl , alkoxycarbonyl , carbamoyl, or N-substituted carbamoyl ; represents an anion, and n is an integer from 1 to 4 inclusive.

3. A composition as claimed in claim 1 or 2 wherein the herbicidal quaternary cation -dimethyl-*) , - bipyridylium cation

4. A herbicidal composition as claimed in any of the preceding claims, which contains from 100 grams to 300 grams per litre of the herbicidal bipyridylium quaternary cation.

5. A herbicidal composition as claimed in any of the preceding claims, which contains from 150 grams to 250 grams per litre of the herbicidal bipyridylium quaternary cation.

6. A herbicidal . composition as claimed in any of the preceding claims, wherein the cationic additive comprises a quaternary ammonium salt of the formula: or wherein the group R represents an octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, octadecenyl, or octadecadienyl radical and Y represents a bromine or chlorine atom.

7. A herbicidal composition as claimed in any of the preceding claims which contains from 0. 1 part to 3 parts by weight of cationic additive per part of bipyridylium cation..

8. A herbicidal composition as claimed in any of the preceding claims, which contains from 0.2 ■ 0. 5 parts by weight of cationic additive per. part of bipyridylium cation.

9. .A' herbicidal composition as claimed in any of the preceding claims wherein the non-ionic surface-active agent comprises a condensate of ethylene oxide with a straight chain aliphatic alcohol, with an alkyl phenol, or with a sorbitan monoester derived from a long chain fatty acid.

10. A herbicidal composition as claimed in any '.V of the preceding claims wherein the non-ionic surface active agent comprises a condensate of from 2 to 4 molar proportions of ethylene oxide with a primary straight chain aliphatic alcohol having from 9 to 15 carbon atoms inclusive.

11. A herbicidal composition; as claimed in. any of the preceding claims wherein the non-ionic surface active- agent comprises a condensate of from 2 to 3 molar proportions of ethylene oxide with n. undecanol. ,

12. A herbicidal composition as claimed in any of the preceding claims wherejin the non-ionic surface active agent is present in the proportion of from 0..2 to 2 parts per part by weight of the cationic additive in the composition.

13. A herbicidal composition 'as claimed in any of the preceding claims wherein the non-ionic surface active agent is present in the proportion of from 0.5 to 1. 5 parts per part of the cationic additive in the composition. ■ V. ' ·■· ' ■ ·

14. An aqueous wetter composition suitable for. admixture With an aqueous solution of a salt of a herbicidal bipyridylium ■ cation to '., provide a composition as claimed in claim 1, which contains a mixture of (A) a cationic additive comprising (a) a quaternary ammonium salt of the formula : - R2 2 wherein R , R"- and R each represent an ■ o^ten-ail - alkyl radical of from 1 to 4 2 carbon atoms; or wherein R represents an aliphatic radical of 1 to ¾ carbon atoms while il R and R together with the nitrogen atom to which they are attached form a pyrrolidiniiim . 3 4 or piperidinium ring; or wherein R , R and R taken together with the. attached nitrogen atom represent a pyridinium ring which may optionally be substituted by an aliphatic radical of 1 to Ί carbon atoms, or may be fused to \ a benzene ring; and wherein R"*" represents an aryloxyalkyl radical or an--o fe£-onally ' alkyl or alkenyl ■&ub-8%-irw e-d---a-tip- a:1?i« radical of from 6 to 20 carbon atoms and wherein X is an anion, or (b) an acid addition salt of an amine having the formula:- wherein R has the meaning . previously assigned ■ ς 6 to it. and R and R each represent a hydrogen atom or an aliphatic radical of 1 to 4 carbon atoms, and X is an anion with (B) a non-ionic surface-active agent, in a ratio of from 0.2 parts to 2 parts of the surface- active agent (B) to., one part by weight of cationic additive (A). 1(5. A wetter .composition as claimed in claim 1*1, wherein the cationic - additive comprises a quaternary ammonium salt of the formula :- wherein the group R represents an octyl, . decyl, dodecyl, tetradecyl, hexadecyl , octadecyl octadecenyl, or octadecadienyl radical and Y represents a bromine or chlorine atom.

16. A wetter composition as claimed in claim 1*1' or claim Ί5· wherein the non-ionic surface active agent comprises a condensate of from 2 to 3 molar proportions of ethylene oxide with a primary aliphatic alcohol having from 9 to 15 carbon atoms.

17. A process of inhibiting the growth of unwanted vegetation, which comprises applying to the vegetation a composition as claimed in any of claims 1 to ΐΊ.

18. A process as claimed in claim 17 wherein the rate of application of the bipyridylium diquaternary cation is from 0.25 pounds to 1.0 pounds per acre.

19. Herb.icidal compositions as claimed in any of claims 1 to 14 and substantially as hereinbefore described , with particular reference to the Examples. -H8-

20. Surfactant compositions as claimed in any of claims 1¾ to 16, and substantially as hereinbefore described.

21. Processes of inhibiting the growth of . vegetation as claimed in claim 17 o.r 18, . and substantially as hereinbefore described, with particular reference to Examples 1 to 3 and 5 and 6. S. HOROWITZ & CO. AGENTS FOR APPLICANTS JED/J L

25. 9..1973.