IE69958B1

IE69958B1 - Herbicidal combination containing aclonifen and at least one substituted urea

Info

Publication number: IE69958B1
Application number: IE91291A
Authority: IE
Inventors: Thierry Bernard; Jean-Claude Millet; Jacques Rognon
Original assignee: Rhone Poulenc Agrochimie
Priority date: 1990-03-20
Filing date: 1991-03-19
Publication date: 1996-10-16
Also published as: UA26974A1; BG61021B1; PT97075A; CS9100725A2; RO111981B1; MA22086A1; YU48391A; TNSN91015A1; BG94080A; DK0449751T3; ATE130491T1; ES2080278T3; PL166329B1; GR3018193T3; AU642986B2; IE910912A1; HU208237B; HUT56698A; FR2659833B1; PL289473A1

Abstract

The invention relates to a novel herbicidal association arising from the combination of a) 2-chloro-6-nitro-3-phenoxyaniline or aclonifen, and b) one of more substituted ureas of formula: of which there may be mentioned, in particular, isoproturon, chlortoluron, dimefuron and methabenzthiazuron. The ratio by weight of a to b is generally between 1/60 and 1.5. This association is especially useful in post-emergence weed control.

Description

The present Invention relates to a herbicidal product which results from the combination of herbicidal substituted ureas, if appropriate as a mixture, with aclonifen, and which is remarkably suitable for the selective control of weeds in crops.

The invention also relates to the use of the novel product as a herbicide, in particular in the form of a composition, and to a method of controlling weeds in crops with the aid of the product or the composition.

Substituted ureas have been used for a long time for weeding crop areas. From amongst these, the following may be mentioned by way of example: - isoproturon, or M,N-dimethyl-N' - (4-isopropylphenyl)urea, for weeding in particular cereal fields, - chlortoluron, or N,N-dimethyl-N'-(3-chloro-4methylpheny1)urea for weeding in particular cereal fields, - dime fur on, or N,N-dimethyl-N* - [3-chloro-4-(5tert-butyl-2-oxo-2,3-dihydro-l, 3,4-oxadiazolyl-3-yl) phenyl]urea, for weeding pea fields and oilseed rape fields.

N-methyl-N-n-butyl-Ν'- (3,4-diweeding in particular cereal - neburon, or chlorophenyl)urea, for fields, - linuron, or N-methyl-N-methoxy-N'- (3,4-dichloropheny 1) urea, for weeding in particular maize and sunflower fields, - methabenzthiazuron, or 1-benzothiazolyl2-yl-l,3-dimethylurea, for weeding in particular cereals, beans and peas.

Moreover, aclonifen or 2-chloro-6-nitro-3phenoxyaniline is known, which is a selective herbicide of sunflower and pea crops, and which is usually used at doses above 2 kg/ha.

European Patent Application EP 163598 describes specific formulations which comprise at least one herbicidal substituted urea and, if appropriate, another herbicide. Aclonifen is cited in a very extensive list of possible herbicidal active substances.

European Patent Application EP 185231 page 17 mentions a product which associates linuron with aclonifen, these 2 active substances being combined in a ratio aclonifen/linuron = 0.4.

European Patent Application EP 7482 mentions a possible combination of aclonifen with another known herbicide and cites linuron.

It is always desirable to improve the action of herbicidal active substances.

The invention for its part therefore proposes a novel combination which results from a limited selection from amongst a virtually infinite number of possibilities and which provides great advantages which will be understood better in the light of what will be described hereinafter.

It has thus been found absolutely unexpectedly that the combination improved in a noteworthy and surprising fashion the respective isolated action of the two active substances for a certain number of weeds which are particularly harmful in crops. In doing this, it retains the selectivity towards the crops. From this follows therefore an improvement of the spectrum of activity and a possibility of reducing the particular dose of each active substance used, this latter quality being especially important for ecological reasons which can be readily understood.

The combination thus shows a remarkable degree of synergism, as defined by PML Tammes, Netherlands Journal of Plant Pathology, 70 (1964), p. 7380, in an article with the title 11 Isoboles, une representation graphique de synergie dans les pesticides [Isoboles, a graphic representation of synergism in pesticides], or as defined by Limpel, L.E., P.H. Schuldt and D. Lamont, 1962, Proc. NEWCC 16: 48-53, according to the formula (used by Colby): XY E = X + Y 100 where E is the expected percentage of growth inhibition by a mixture of the two herbicides at defined doses, X is the observed percentage of growth inhibition of herbicide A at a defined dose, Y is the observed percentage of growth inhibition of herbicide B at a defined dose. If the observed percentage of inhibition of the combination is greater than E, synergism is present.

Moreover, it has been found entirely unexpectedly that, at a dose which as such is not herbicidal from an industrial point of view (that is to say, with an effectiveness which is zero or insufficient), aclonifen considerably increased the strength of, or amplified, the herbicidal effect of substituted ureas. This case therefore concerns a noteworthy innovation as far as its consequences with respect to the application methods of the said ureas are concerned.

The invention relates to a product which results from the combination of: a) alconifen with b) one or more substituted ureas of the formula r4 CH3 \ / N - C ~ N / | \ (I) Ar O R3 Rx being selected from amongst (Cx-C3) alkyl radicals, (Cx-C3) alkoxy radicals, a chlorine atom, a bromine atom, a 5-tert-butyl-2,3-dihydro-2-oxo1,3,4-oxadiazol-3-yl group of the formula (CH3)3 c OO \ / \ // I I N -N \ - 4 R2 being selected froni amongst a hydrogen atom, a chlorine atom, where Ar is a ring •)y R3 is a hydrogen atom, a (C^-C*) alkyl or methoxy radical, R4 is a hydrogen atom or a methyl radical; the ratio a)/b) being between 0.033 and 0.333 (expressed as weight/weight) .

When the alkyl or alkoxy radicals comprise at least three carbon atoms, they can be linear or branched.

From amongst the substituted ureas of the formula (I), the following may be mentioned very specifically: isoproturon, or 3-(4-isopropylphenyl)1,1-dimethylurea, chlortoluron, or 3-(3-chloro-p-tolyl)1,1-dimethylurea, neburon, or 1-butyl-3-(3,4-dichlorophenyl)1-methylurea, diuron, or 3-(3,4-dichlorophenyl)-1,1-dimethylurea, metoxuron, or 3-(3-chloro-4-methoxyphenyl) 1,1-dimethylurea, linuron, or 3-(3,4-dichlorophenyl)-1-methoxy1-methylurea, monolinuron, or 3-(4-chlorophenyl)-1-methoxy1-methylurea, methabenzthiazuron, or l-benzothiazol-2-yl1,3-dimethylurea, metobromuron, or 3-(4-bromophenyl)-1-methoxy1-methylurea, and dimefuron, or 3-[4-(5-tert-butyl-2,3-dihydro-2oxo-1,3,4-oxadiazol-3-yl)-3-chlorophenyl-1,1-dimethylurea.

In a more advantageous manner and taking into account the previously mentioned problems which the invention proposes to solve, the following will be used: isoproturon, or 3-(4-isopropylphenyl)1.1- dimethylurea, chlortoluron, or 3-(3-chloro-p-tolyl)1.1- dimethylurea. methabenzthiazuron, or l-benzothiazolyl-2-yl1,3-dimethylurea, for weeding in particular cereals, beans and peas.

These products can be used as herbicides in the aforementioned range of ratio by weight of aclonifen and urea and depending on the crops treated, the climatic conditions, the nature of the soil, the treatment stage of the principal weeds of the location in question, and even, if appropriate, the wishes of the user, depending on whether he wishes the terrain to be perfectly clean or whether he is happy with a satisfactory, but not total, elimination of weeds.

These products according to the invention are intended for simultaneous or separate use or use staggered over time for herbicidal treatment of undesirable plants, in particular against weeds which are present in crops. The nature of the crops concerned can vary, depending on the urea in question. This point will be taken up again in the following part which is reserved for the treatment method.

In the case of simultaneous use (which is preferred) , ready-to-use products which contain the combination of active substances described above can be used. Products which are prepared just before application can also be used, by mixing the active substances as they are described hereinafter at the appropriate time.

The use can also use the product by treating the crops to be protected in succession with one and then the other of the active substances, aclonifen and ureas, in such a way as to form the product according to the invention'in situ on the plant.

The combinations are most frequently of the binary type, but occasionally ternary or quaternary combinations with one or more Other compatible pesticides (including fungicide or insecticide) can be envisaged.

As has been indicated previously, one of the problems which the applicant company proposes to solve, is to amplify the action of the ureas. In this case, aclonifen plays the role of potentiator, or, in the terminology of the discipline of crop protection, of synergist.

The product is therefore defined as a urea-based 10 herbicidal product which contains aclonifen as an amplifier which, per ee, is not herbicidal at the dose in question.

Naturally, the variants which are preferred as regards the ureas according to the invention are also valid for the present use. It will also be understood that in the case where aclonifen is the amplifier, chlortoluron and isoproturon will also advantageously be used.

The products. according to the invention are mostly used in the form of a herbicidal composition which comprises one or more agriculturally acceptable carriers and/or one or more surfactants.

In the case of the preparations made at the appropriate time, each active substance can be in the form of a composition. In contrast, in the case of a ready-to-use mixture, it is the combination itself which is in form of a composition.

In the account which will follow, the terms active substance and combination will be used without distinction.

Occasionally, it is possible to have readily available a ready-to-use composition containing the combination, given the formulations available on the market.

Occasionally, an adequate formulation which is within the scope of those skilled in the art will be necessary.

In the general description which will follow, the term composition will thus serve indiscriminately to describe the two compositions * containing the two active substances separately or the composition containing the combination.

These combinations which can be used contain, in addition to the active substance or the combination according to the invention as described above, solid or liquid carriers which are agriculturally acceptable and surfactants which are also agriculturally acceptable. Substances which can be used in particular are customary inert carriers and customary surfactants.

These compositions usually contain between 0.5 and 95% of active substance of combination according to the invention. Unless otherwise indicated the percentages are by weight.

In the present account, the term carrier refers to an organic or inorganic material, natural or synthetic, with which the active substance is combined so as to facilitate application to the plant, the seeds or the soil. This carrier is therefore generally inert and must be agriculturally acceptable, in particular on the treated plant. The carrier can be solid (clays, natural or synthetic silicates, silica, resins, waxes, solid fertilisers, and the like) or liquid (water, alcohols, ketones, petroleum fractions, aromatic or paraffinic hydrocarbons, chlorinated.hydrocarbons, liquefied gases, and the like).

The surfactant can be an emulsifier, dispersant or wetting agent of the ionic type. Examples which may be mentioned are salts of polyacrylic acids, salts of lignosulphonic acids, salts of phenolsulphonic acids or of naphthalenesulphonic acids, polycondensates of ethylene oxide with fatty alcohols or with fatty acids or with fatty amines, substituted phenols (in particular alkylphenols or arylphenols), salts of esters of sulphosuccinic acids, taurine derivatives (in particular alkyl taurides), phosphoric esters of alcohols or of polycondensates of ethylene oxide with phenols. The presence of at least one surfactant is essential since the active substances (aclonifen + urea) are not soluble in water V and the application vehicle ie water.

Types of agricultural compositions which may be mentioned are powders for dusting or dispersion (having a content of active substance or of combination according to the invention which can range up to 100%) and granules, in particular those obtained hy extrusion, by compacting, by impregnating a granulated carrier, by granulation using a powder (the content of active substance or of combination according to the invention in these granules being between 1 and 80% in the latter cases).

Types of liquid compositions, or types which are intended to focm liquid compositions when used, which may be mentioned are emulsifiable concentrates, emulsions, flowables, aerosols, wettable powders (or powders for spraying) and pastes.

The emulsifiable concentrates or soluble concentrates mostly comprise 10 to 80% of active substance, the emulsions, for their part, contain 0.01 to 20% of active substance. The flowables generally contain 10 to 75% of active substance, from 0.5 to 15% of surfactants, from 0.1 to 10% of thixotropic agents and from 0 to 10% of suitable additives such as antifoams, corrosion inhibitors, stabilisers and penetrants.

Moreover, in general, these compositions can also contain a variety of other ingredients such as, for example, thixotropic colloids, penetrants, stabilisers, sequestering agents, and the like, as well as other active substances which are known as having pesticidal properties (in particular insecticides or fungicides) or properties which promote the growth of plants (in particular fertilisers) or plant-growth-regulating properties . More generally, the compounds according to the invention can be combined with all solid or liquid additives which correspond to techniques customary in the art of formulation.

For example, in addition to the solvent, the emulsifiable concentrates can, if necessary, contain 2 to 20% of suitable additives such as stabilisers, surfactants, penetrants, corrosion inhibitors, colorants or the abovementioned adhesives.

In concrete terms, in the case of the active substances in question: aclonifen is available on the market as a flowable containing 600 g/l active substance, isoproturon is also available on the market as a flowable with between 440 and 500 g/l of active substance, chlortoluron can be found in the form of a flowable (between 500 and 510 g/l active substance), wettable powders, granules and'microgranules.

A person skilled in the art will easily be capable of formulating a composition based on a combi15 nation of these active substances in the form of, for example, a flowable. Moreover, this is the preferred form of .the invention.

Treatment method according to the invention: The invention also relates to a method of con20 trolling weeds, especially in an environment where crops grow, or where it is intended to grow crops, which consists in applying an effective dose of product (or a composition containing it), as has just been described above.

Upon application, the dosage rate should be sufficient for controlling the growth of weeds without causing substantial permanent damage to said crops. Effective dosage rate is understood to mean, only in this context, the dosage rate which allows this result to be obtained.

The application is carried out post-emergence of the crops. Post-emergence is understood to mean application of the product after the plant has emerged from the soil.

The product (or composition) according to the invention is mainly active against weeds after they have emerged, even though a pre-emergence action, that is to say when the plant has not yet emerged from the soil, is also possible.

The action of the prodixct (or composition) takes place via the leaves and roots in proportion which may vary depending on the active substances in question.

The product (which can be applied by simultaneous 5 or separate use or use staggered over time) will normally be applied at a dosage rate ranging from 460 g/ha to 5000 g/ha.

From amongst the weeds which can be controlled by said product (or said composition), the following may be mentioned: Galium aparine, Avena fatua, Lolium multiflorum, Viola tricolor, Sinapis alba, Lamium purpurea, Veronica persica, Agrostis tenuis, Alopecurus myosuroides, Veronica baederefolia.

In the following preferred variants: - The combination isoproturon/aclonifen will be applied to cereals such as, in particular, wheat and barley. The dosage rate per hectare will advantageously be 60 to 600 g/ha aclonifen and 400 to 3600 g/ha isoproturon, very advantageously: 100 to 500 g/ha aclonifen and 500 to 3000 g/ba isoproturon.

- The combination chlortoluron/aclonifen will be applied to cereals such as, in particular, wheat and barley. The dosage rate per hectare will advantageously be: to 600 g/ha aclonifen and 400 to 3600 g/ha chlortoluron, very advantageously: 100 to 500 g/ha aclonifen and 500 to 3000 g/ha chlortoluron.

- The combination dimefuron/aclonifen will be applied to cereals such as, in particular, to peas and oilseed rape. The dosage rate per hectare will be, in particular to 600 g/ha aclonifen and 400 to 3600 g/ha dimefuron. very advantageously: 100 to 500 g/ha aclonifen and 500 to 2000 g/ha dimefuron.

- The combination aclonifen/methabenzthia-zuron 5 will be applied, in particular, to winter wheat and , winter barley.

The dosage rate per hectare will be, in particular, to 1000 g/ha aclonifen and 10 500 to 4000 g/ha methabenzthiazuron and very advantageously: 100 to 500 g/ha aclonifen and 1000 to 3000 g/ha methabenzthiazuron The invention will now be described by way of concrete use examples which are, of course, given only by way of example and can in no way limit the scope of said invention.

So as to simplify the method and arrive at a better base for comparison, the following have been selected: - Galium aparine, - Avena fatua, - Lolium multiflorum, - Viola tricolor, - Sinapis alba, - Lamium purpurea, - Veronica persica - Agrostis tenuis, - Alopecurus myosuroides, - Stellaria media to demonstrate the activity of the product against weeds in wheat and to demonstrate the selectivity of the product in this crop.

General experimental procedure: The application is carried out post-emergence of the plant species.

A number of seeds determined according to the plant species and the size of the seed are sown in 9 x 9 x 9 cm pots filled with light agricultural soil.

The seeds are then cohered with a layer of soil of about 3 mm thickness and the seed is allowed to germinate until it produces a plantlet at a suitable stage. In the case of grasses, the treatment stage is the formation of second leaf" stage. In the case of dicotyledons, the treatment stage is the cotyledons unfolded, first true leaf being developed" stage.

The pots are then treated by spraying them with a mixture in an amount which corresponds to an application rate of 500 1/ha and which contains the active substances to be sprayed.

The mixtures are obtained by diluting the formulated products with water.

The following formulated products were used; - aclonifen flowable having a content of 600 g/1, Challenge 600®, - isoproturon flowable, with a content of 500 g/1, Augur®, - chlortoluron flowable, with a content of 500 g/1, Dicuran®, - dime fur on flowable, with a content of 400 g/1, Surdone®.

These formulations are duly approved and well known in the art.

The pots are then placed in containers designed for receiving the watering water, in the form of subirrigation, and maintained for 24 days at ambient tenqserature and 60% relative humidity.

After 24 days, the number of live plants in the pots treated with the mixture containing the active substance to be tested is counted and so is the number of live plants in a control pot treated under the same conditions but using a mixture which does not contain active substance. In this way, the percentage destruction of the treated plants is determined in relation to the untreated control. A percentage destruction of 100% means that complete destruction of the plant species in question has taken place, and a percentage of 0% means that the number of live plants in the treated pot is identical to that in the control pot. In'Examples 1 to 16 the units are in g/ha in the tables (1st row and 1st column) .

Example 1: Trial showing the nature of the synergistic biological effect of the combination of isoproturon with aclonifen on Lolium multiflorum.

The experiment is carried out having sown Lolium multiflorum seeds.

The table below shows the average of a greenhouse trial. For each dosage rate, the higher value is the value obtained and the lower value is the expected value using Colby's formula.

Isoproturon Aclonifen 0 500 1 000 2 000 0. 0 30 65 50 62 0 60 30 90 65 85 50 125 0 65 30 90 65 95 50 250 0 65 30 90 65 98 50 With reference to the formula given at the beginning of the description, the results given in the table above clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

Example 2: Trial demonstrating the nature of the synergistic biological effect of the combination of isoproturon with aclonifen on Alopecurus mvosuroides.

The experiment is carried out having sown Alopecurus myosuroides seeds.

* Isoproturon Aclonifen 0 500 1 000 2 000 0 0 20 50 85 62 0 30 20 75 50 - 125 0 55 20 65 50 83 85 250 0 80 20 85 50 93 85 With reference to the formula given at the beginning of the description, the results given in the table below clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

Eyanrole 3: Trial demonstrating the nature of the synergistic biological effect of the combination of iBOProturon with aclonifen on Agrostis tenuis.

The experiment is carried out having sown Agrostis tenuis seeds.

The table below shows the average of a greenhouse trial. For each dosage rate, the higher value ie the value obtained and the lower value is the expected value using Colby's formula.

Isoproturon Aclonifen 0 500 1 000 2 000 0 0 30 90 95 62 0 90 30 100 90 100 95 125 0 95 30 100 90 100 95 250 0 100 30 100 90 ' 100 95 With reference to the formula given at the beginning of the description, the results given in the table below clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

Example 4: Trial demonstrating the nature of the synergistic biological effect of the combination of isoproturon with aclonifen on Lawbiw purpurea.

The experiment is carried out having sown Lam j nm purpurea seeds.

Isoproturon Aclonifen 0 500 1 000 2 000 0 0 0 15 20 62 0 20 0 20 15 25 20 125 20 40 20 30 30 40 36 250 20 55 20 50 32 75 36 With reference to the formula given at the beginning of the description, the results given in the table below clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

Example 5: Trial demonstrating the nature of the synergistic biological effect of the combination of isoproturon with aclonifen on Viola tricolor.

The experiment is carried out having sown Viola tricolor seeds.

Isopjroturon 0 500 1 000 2 000 0 0 0 15 20 62 0 15 0 25 15 25 20 125 0 25 0 25 15 30 20 250 15 30 15 30 28 40 32 * With reference to the formula given at the beginning of the description, the results given in the table below clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

Bacample 6: Trial demonstrating the absence of phvtotoxicitv of the combination of isoproturon with aclonifen on wheat or Triticum aastivum10 The experimental procedure is as above, .but after wheat seeds have been sown, and leads to the result given below: Isoproturon Aclonifen 0 500 1 000 2 000 0 0 0 0 0 62 0 0 0 0 125 0 0 0 0 250 0 0 0 0 r\ It can therefore be said that the abovementioned combination, although increasing the particular activity of the two active substances against the weeds in the exasqple, shows no phytotoxicity whatsoever to wheat. Exastole 7: Trial demonstrating the nature of the synergistic biological effect of the combination of chlortoluron with aclonifen on Alopecurus myosuroides.

The experiment is carried out having sown Alopecurus myosuroides seeds.

The table below shows the average of a greenhouse trial. For each dosage rate, the higher value is the 10 value obtained and the lower value is the expected value using Colby's formula.

Chlortoluron Aclonifen 0 500 1 000 1 500 0 0 65 70 . 80 62 0 60 65 97 70 97 80 125 10 70 68 85 73 99 82 250 20 70 72 98 76 100 84 With reference to the formula given at the beginning of the description, the results given in the table below clearly demonstrate the excellent and unex15 pected degree of synergism obtained with the combination of the invention.

Examnle 8: Trial demonstrating the nature of the synergistic biological effect of the combination of chlortoluron with aclonifen on Avena fatua.

The experiment is carried out having sown Avena fatua seeds.

Chlortoluron Aclonifen 0 500 1 000 1 500 0 0 10 55 93 62 O' 35 10 75 55 88 93 125 0 35 10 70 55 88 93 250 0 50 10 88 55 90 93 With reference to the formula given at the beginning of the description, the results given in the table below clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

Example 9: Trial demonstrating the nature of the synergistic biological effect of the combination of chlortoluron with aclonifen on Lnlium multiflorum.

The experiment is carried out having sown Lolium multiflorum seeds.

The table below shows the average of a greenhouse trial. For each dosage rate, the higher value is the value obtained and the lower value is the expected value using Colby's formula. .

Chlortoluron 0 500 1 000 1 500 0 0 78 93 62 0 100 78 100 93 125 5 98 79 100 93 250 10 93 80 100 94 Aclonifen With reference to the formula given at the beginning of the description, the results given in the table below clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

·* Example 10; Trial demonstrating the nature of the synergistic biological effect of the combination of chlortoluron with aclonifen on Viola tricolor.

The experiment is carried out having sown Viola tricolor seeds.

Chlortoluron Aclonifen 0 500 1 000 1 500 0 0 0 - 15 25 62 0 20 0 35 15 60 25 125 0 30 0 60 15 65 25 250 5 35 5 70 19 85 29 ‘ With reference to the formula given at the. beginning of the description, the results given in the table below clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

Example 11: Trial demonstrating the nature of the synergistic biological effect of the combination of chlortoluron with aclonifen on Galium aparine.

The experiment is carried out having sown Galium aparine seeds.

Chlortoluron Aclonifen 0 500 1 000 1 500 0 0 15 25 45 62 0 30 15 40 25 65 45 125 0 45 15 70 25 80 45 250 15 60 28 70 36 70 · 53 With reference to the formula given at the beginning of the description, the results given in the table below clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

Example 12: Trial demonstrating the absence of phvtotoxicitv of the combination of chlortoluron with aclonifen on wheat or Tritlcum aeativumThe experimental procedure is as above, but after wheat seeds have been sown, and leads to the result given below: Chlortoluron 0 500 1 000 1 500 0 0 0 0 0 62 0 0 0 0 125 0 5 0 0 250 0 0 0 0 · Aclonifen Λ' te * Zt can therefore be said that the abovementioned combination, although increasing the particular activity of the two active* substances against the weeds in the example, shows no phytotoxicity whatsoever to wheat.

Example 13: Trial demonstrating the nature of the synergistic biological effect of the combination of dimefuron with aclonifen on Sinapis alba.

The experiment is carried out having sown Sinapis 10 alba seeds.

The table below shows the average of a greenhouse trial. For each dosage rate, the higher value is the value obtained and the lower value is the expected value using Colby's formula. Dimefuron Aclonifen 0 500 1 000 2 000 0 · 0 10 45 70 62 0 35 10 93 45 100 70 125 20 80 28 98 56 100 76 250 30 70 37 100 61 100 79 j With reference to the formula given at the beginning of the description, the results given in the table below clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

Example 14; Trial demonstrating the nature of the synergistic biological effect of the combination of dimefuron with aclonifen on Viola tricolor.

The experiment is carried out having sown Viola tricolor seeds.

The table below shows the average of a greenhouse trial. For each dosage rate, the higher value is the value obtained and the lower value is the expected value using Colby's formula. 1 Dimefuron Aclonifen 0' 500 1 000 2 000 0 . 0 25 45 85 62 0 . 25 25 50 45 95 85 125 0 30 25 70 45 95 85 250 10 - 83 50 100 86 With reference to the formula given at the beginning of the description, the results given in the table below clearly demonstrate the excellent and unex5 pected degree of synergism obtained with the combination of the invention.

Bacewnle 15: Trial demonstrating the nature of the synergistic biological effect of the combination of dimefuron with aclonifen on Lolium multiflorum.

The experiment is carried out having sown Lolium multiflorum seeds.

The table below shows the average of a greenhouse trial. For each dosage rate, the higher value is the value obtained and the lower value is the expected value using Colby's formula. Dimefuron 0 500 1 000 2 000 0 0 10 25 60 62 0 15 10 35 25 80 60 125 0 20 10 55 25 65 60 250 5 20 14 55 29 65 62 Aclonifen v With reference to the formula given at the beginning of the description, the results given in the table below, clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

Example 16: Trial demonstrating the nature of the synergistic biological effect of the combination of dimefuron with aclonifen on Veronica Persica.

The experiment is carried out having sown Veronica Persica seeds.

The table below shows the average of a greenhouse trial. For each dosage rate, the higher value is the value obtained and the lower value is the expected value using Colby's formula. Dimefuron 0 500 1 000 2 000 0 0 55 97 .100 62 0 68 55 80 97 100 100 125 5 100 57 100 97 100 100 250 5 88 57 94 97 100 100 With reference to the formula given at the beginning of the description, the results given in the table below clearly demonstrate the excellent and unexpected degree of synergism obtained with the combination of the invention.

Example 17; Trial demonstrating the nature of the synergistic . effect of the combination of aclonifen with methabenzthiazuron.

The trial is conducted in the field on 2 x 5 m plots in the form of bands and sown with two crops and a range of weeds in bands, with three replications per trial. Other weeds are present naturally.

The treatment is carried out when the crop and the weeds are at the stage where one sucker is developed completely, three suckers in the case of the monocotyledons and from the cotyledon stage to the plantlet stage in the case of the dicotyledons.

The plots are treated with a test sprayer mounted on a tractor and with an output of 195 1/ha, using respectively aclonifen in the form of a suspension with a content of 600 g/l (CHALLENGE 600), methabenzthiazuron in liquid form with a content of 700 g/l (TRIBUNAL), in each case on their own and as a mixture.

After 60 days, the percentage of weeds present is scored visually by comparison with an untreated control (O = no effect, 100 = complete destruction) on Galium aparine and Avena fatua. and on winter wheat and winter barley.

The table below shows the average of the results from three replications per trial. The result is given for each dosage rate, observed by comparison with the result expected by applying Colby's formula.

Destruction in % Galuia aparine Destruction in % Avena fatua Active substance in g.a.s./ha Found Expected Found Expected 250 Aclonifen 500 Me tbabenz thiazuron 2000 33 45 6 33 45 72 Aclonifen 250 + Me thabenz thi azuron 2000 85 37 93 81 Aclonifen 500 + Methabenzthiazuron 2000 94 48 94 84 This table clearly demonstrates the unexpected synergistic behaviour of the above combination.

Claims

1. ) Herbicidal product which results from the synergistic combination of a) 2-chloro-6-nitro-3phenoxyaniline, whose official common name is aclonifen. 5 and b) one or more substituted ureas of the formula: R 4 CH 3 \ / N - C ~ N / | \ < z > Ar 0 R 3 in which Ar is a ring of the formula R x being selected from amongst (C x -C 3 ) alkyl radicals, (C x -C 3 ) alkoxy radicals, a chlorine atom, a 10 bromine atom, a 5-tert-butyl-2,3-dihydro-2-oxo1,3,4-oxadiazol-3-yl group of the formula (CH 3 ) 3 C 0 0 \ / \ // II M -N \ R 2 being selected from amongst a hydrogen atom, a chlorine atom, where Ar is a ring 15 R 3 is a hydrogen atom, a (C 1 -C 4 ) alkyl or methoxy radical, R 4 is a hydrogen atom or a methyl radical, characterized in that the ratio by weight of aclonifen to substituted urea is between 0.033 and 0.333. 1-butyl-3-(3,4-dichlorophenyl) 3- ( 3,4-dichlorophenyl) 3 -(3-chioro-4-methoxyphenyl)

2. ) Product according to claim 1, characterized in that the substituted ureas are selected from amongst: isoproturon, or 3-(4-isopropylphenyl)1,1-dimethylurea, 5 chlortoluron, or 3-(3-chloro-p-totyl)1,1-dimethylurea, neburon, or 1-methylurea, diuron, or 10 1,1-dimethylurea, metoxuron, or 1.1- dimethylurea, linuron, or 3-(3,4-dichlorophenyl)-1-methoxy1-methylurea, 15 monolinuron, or 3- (4-chlorophenyl) -1-methoxy1-methylurea, methabenzthiazuron, or l-benzothiazol-2-yl1,3-dimethylurea, metobromuron,· or 3-(4-bromophenyl)-1-methoxy20 1-methylurea, and dimefuron, or 3-(4-(5-tert-butyl-2,3-dihydro-2oxo-1,3,4-oxadiazol-3-yl)-3-chlorophenyl1.1- dimethylurea.

3. ) Product according to claim 2, characterized in 25 that the urea is 3- (4-isopropylphenyl) -1,1-dime thylurea (or isoproturon) or 3- (3-chloro-p-totyl) -1,1-dime thylurea (or chlortoluron) .

4. ) Product according to claim 1, for simultaneous or separate use or use staggered over time, for treating 30 undesirable plants or weeds in crops.

5. ) Product according to claim 1, characterized in that it comprises a dosage rate of aclonifen which is not herbicidal.

6. ) Use of aclonifen as amplifier of the activity of 35 the urea in a product according to claim 5.

7. ) Herbicidal composition, comprising a product according to one of claims 1 to 5, at least one inert carrier and/or at least one surfactant.

8. ) Herbicidal composition according to claim 7, characterized in that it comprises between 0.5 and 95% of product according to one of claims 1 to 5.

9. ) Method of controlling weeds post-emergence of the crops, characterized in that an effective dose of a product according to one of claims 1 to 5 is applied to the location.

10. ) Control method according to claim 9, characterized in that the weeds controlled are: Galium apaarine, Avena fatua, Lolium multiflorum, Viola tricolor, Sinapis alba, Lolium purpurea, Veronica persica, Agrostis tennis, Alopecurus myosuroides.

11. ) Control method according to claim 9, characterized in that the product is applied at a rate of 460 to 5000 g/ha.

12. ) Control method according to claim 9, characterized in that the combination of 3-(4-isopropylphenyl)-1,1-dime thylurea, or isoproturon, with aclonifen is applied at a rate of: 60 to 600 g/ha aclonifen, 400 to 3600 g/ha isoproturon, and in that the crops are cereals.

13. ) Control method according to claim 12, characterized in that 100 to 500 g/ha aclonifen, 500 to 3000 g/ha isoproturon are applied.

14. ) Control method according to claim 9, characterized in that the combination of chlortoluron, or 3-(3-chloro-p-tolyl)-1,1-dimethylurea, with aclonifen is applied at a rate of: 60 to 600 g/ha aclonifen, 400 to 3600 g/ha chlortoluron, and in that the crops are cereals.

15. ) Control method according to claim 14, characterized in that the combination is applied at a rate of: 100 to 500 g/ha aclonifen, 500 to 3000 g/ha chlortoluron. Control method according to

16. ) claim 9, ·' I - 28 characterized in that the combination of dimefuron, or N,N-dimethyl-N'-(3-chloro-4-(5 - tert-butyl-2-oxo2,3 - dihydro -1,3,4 - oxadiazoly 1 - 3 - y 1) phenyl ] urea, wi th aclonifen is applied at a rate of: 5 60 to 600 g/ha aclonifen, 400 to 3600 g/ha dimefuron, and in that the crops are oilseed rape or peas.

17. ) Control method according to claim 16, characterized in that the combination is applied at a 10 rate of: 100 to 500 g/ha aclonifen, 500 to 2000 g/ha dimefuron. 18} Control method according to one of claims 9 to 11, characterized in that the combination is applied at 15 a rate of: 60 to 1000 g/ha aclonifen, 500 to 4000 g/ha of methabenzthiazuron.

18. 19) Control method according to claim 18, characterized in that the combination is applied at a 20 rate of: 100 to 500 g/ha aclonifen, 1000 to 3000 g/ha methabenzthiazuron.

19. 20) A herbicidal product according to claim 1, substantially as hereinbefore described and exemplified. 25

20. 21) Use according to claim 6, substantially as hereinbefore described and exemplified.

21. 22) a herbicidal composition according to claim 7, substantially as hereinbefore described and exemplified.

22. 23) A method according to claim 9. of controlling weeds, 30 substantially as hereinbefore described and exemplified.