IE66686B1

IE66686B1 - Herbicidal combination comprising 2-chloro-6-nitro-3-phenoxyaniline and at least one herbicide selected from amongst bomoxynil or ioxynil or one of their derivatives

Info

Publication number: IE66686B1
Application number: IE163291A
Authority: IE
Inventors: Thierry Bernard
Original assignee: Rhone Poulenc Agrochimie
Priority date: 1990-05-14
Filing date: 1991-05-13
Publication date: 1996-01-24
Also published as: FR2661800A1; KR100193412B1; FR2661800B1; IE911632A1; BR9102028A; IL98124A; AU641500B2; JPH04226903A; HUT57004A; ATE116803T1; EP0457695A1; HU210430B; DE69106582T2; JP2939002B2; ZA913594B; CN1056395A; ES2066399T3; EG19363A; CN1030637C; DE69106582D1

Abstract

The invention relates to a novel herbicidal association as a result of the combination of a) 2-chloro-6-nitro-3-phenoxyaniline and b) one or more herbicides of the hydroxybenzonitrile type, of which bromoxynil octanoate or bromoxynil heptanoate may be mentioned in particular. The ratio by weight of a/b is preferably between 0.1 and 10. The 2-chloro-6-nitro-3-phenoxyaniline is preferably applied at a dosage rate which has no, or little, herbicidal activity. This association is especially useful for controlling weeds post-emergence in cereal and maize crops.

Description

The present invention relates to a berbicidal product resulting from a combination of a herbicide of the benzonitrile type, selected from amongst bromoxynil or ioxynil or one of their derivatives, with 2-chloro6-nitro-3-phenoxyaniline, which is outstandingly suitable for the selective control of weeds in crops..

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

Prior art: The herbicides of the benzonitrile type, selected from amongst bromoxynil or ioxynil or their derivatives, singly or as a mixture, are used very widely for post emergence control of weeds of the dicotyledon type in cereal fields. In general, these herbicides are called, by the abbreviation HBN"', or hydroxybenzonitrile. From amongst the HBSJs, the following may be mentioned especially: bromoxynil or 3,5~dibromo-4-hydroxybenzonitrile, bromoxynil octanoate or bromoxynil heptanoate, which is the corresponding ester, ioxynil or 4-hydroxy-3,5-diiodobensonitrile, ioxynil octanoate, which is the corresponding ester, or the potassium or sodium salt of ioxynil.

When the HBNs are used early after emergence, they are highly effective against a large number of weeds, even though their activity against certain weeds which are particularly harmful, such as Galium aparin®, Lamium purpurea or Veronica persica, could b® substantially improved.

Moreover, there is known aclonifen, or 2-chloro6-nitro-3~phenoxyaniline, which is a selective herbicide in crops of sunflower and peas, and which is normally used at doses of more than 2 kg/ha.

Object of the invention, or problem to be solved: It is always desirable to improve the action of berbicidal substances as well as their speed of action.

As far as the present invention is concerned, it proposes a novel combination which results from a limited choice from amongst a virtually infinite number ox possibilities and which provides great advantages which will be understood better in the light of what will be described hereinafter.

In this way, it has been found in a completely unexpected manner that the combination improves, in a noticeable and surprising fashion, the respective and isolated action of the two active substances for a certain number of weeds which are particularly harmful in crops, while preserving the selectivity towards the crops. From this follows an improvement of the activity spectrum and the possibility of reducing the respective dose of each active substance used, this latter quality being particularly important for ecological reasons which can be easily understood.

The combination therefore presents 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 ‘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- NEWCG 16:48-53, according to the formula (used by COLBY): XY B « X + Y - --------100 where E is the expected percentage of growth inhibition of 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 3, synergism is present.

Moreover, it has been found in a completely unexpected fashion that aclonifen, when used at a dose which in itself is not herbicidal from the industrial point of view (that Is to say, with an effectiveness which is zero or insufficient), potentiates or increases considerably the herbicidal effect of the HBNs. This is therefore in this case a remarkable innovation as regards its consequences for the application methods of said HBNs.

The invention; Herbicidal product resulting from a combination of: a) 2-chloro-6-nitro-3-phenoxyaniline, and 10 b) one or more herbicides of the 3,5-dihalo-4-hydroxybenzonitrile type, or an agriculturally acceptable ester or salt of these compounds, in an amount producing a synergistic herbicidal activity.

The herbicides of the 3,5-dihalo-4-hydroxy15 benzonitrile type according to the invention can exist in phenolic form, as salts of amines, potassium or sodium, or in ester form, especially with an alkanoic acid (preferably an alkanoic acid having 4 to 8 carbon atoms).

Herbicides which are especially mentioned from 20 amongst these are bromoxynil, which is 3,5-dibromo-4hydroxybenzonitrile, or ioxynil, which is 4-hydroxy-3,5diiodobenzonitrile.

As regards bromoxynil, the forms which are mainly used are the ester forms in the case of cereals and maize, and the phenol form in the case of maize. The phenol form is generally used at dosage rates which are substantially higher than the ester form (in general 1.8 times to twice as high), but shows a lower phytotoxicity, which justifies its use under certain conditions.

As regards ioxynil, this substance is currently used in ester form or in the form of potassium or sodium salts, especially in cereal crops, occasionally in sugar cane, rice or onions. The difference in action between the ioxynil ester and the ioxynil salt is smaller than between the bromoxynil ester and bromoxynil in phenolic form (factor 1 and two thirds, approximately)., The form used is preferably the ester of bromoxynil or of ioxynil with an alkanoic acid having 4 to 8 carbon atoms.

Bromoxynil butyrate, heptanoate or octanoate, or a mixture of two or three of these compounds, will advantageously be used.

The most preferred form is bromoxynil heptanoate 5 or octanoate, and still more advantageously: bromoxynil octanoate.

These products can be used by way of herbicides in a very wide range of ratio by weight of 2-chloro~6" nitro-3-phenoxyaniline to HBN, which will partly depend on the crops treated, the climatic conditions, the nature of the soil, the treatment stage of the main weeds at the site in question, and, if desired, even on the wish of the user, depending on whether he wants an area that is perfectly clean or whether he is happy with a satis15 factory, but not total, destruction of weeds.

These products according to the invention are intended for simultaneous or separate use, or use staggered over a period of time, for the herbicidal treatment of undesirable plants, especially against weeds which are present in crops. The nature of the crops in question can. vary depending on the HBN in question™ We shall return to this aspect in the part dealing with the treatment method, below.

In the case of simultaneous use (which is pre25 ferred), re&dy-to-use products can be used which contain the combination of the above-described active substances. Equally, products which have been prepared immediately before application can be used, by mixing the active substances, as they are described hereinafter, as the occasion arises.

Squally, the use can consist in using the product by treating the crops to be protected in succession with one and then the other of the active substances, 2chloro-S-nitro-3-phenoxy and HBN, in such a way as to form the product according to the invention in situ on the plant.

In a preferred variant, the ratio by weight of 2chloro"5-nitro-3-phenoxyaniline/3,5-dihalo-4-hydroxybenzonitrile is between 0.1 and 20, naturally taking into account variations which can exist in this margin, due to the fact that the ester is used rather than the phenol in the case of bromoxynil, ox the ester rather than the salt in the case of ioxynilThus, in th© case of bromoxynil phenol, the ratios will be shifted towards the lower zone of the margin since more of the substance is needed.

The ratio by weight is preferably between 0.2 and 5 in the case of bromoxynil esters or ioxynil esters.

Th® combinations are most frequently of a binary type, but, occasionally, ternary or quaternary combinations with one or more other compatible pesticides (including fungicide or insecticide) can be considered.

As has been indicated above, on© of the problems which the filing company proposes to resolve, is increasing the action of th© HBNs. In this case, 2-ehloro~6~nitro~3"phenoxyanilIne plays the role of potentiator, or, in the technical jargon of crop protection, of synergist".

In this case, the preferred ratios indicated above are equally suitable, but the fact that the dose of 2-chloro-6-nitro-3~phenoxyaniline is weakly or not herbicidal, must be taken into account (see section on method of use hereinafter).

The product is thus defined as a herbicidal product based on HBN and comprising, as amplifier, 2~chloro-6-nitro-3-phenoxyaniline which in itself Is not, or weakly, herbicidal at th© dose in question (g/ha).

Of course th© preferred variants as regards the HBNs according to the invention are equally good in th© present use. It will therefore be understood that, still with 2-chloro~S-nitro~3-phenoxyani!ine as th® amplifier, the HBNs In ester form will be used advantageously.

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

In th© case where the preparations are made up as the occasion arises, each active substance can be in the form of a composition.. In contrast, in the case of a ready mix, it is the combination itself which is in the form of a composition.

Sometimes, taking into account the formulations which are available on th® market, it is possible that a ready-for-use composition which contains the composition is readily available. Sometimes, an appropriate formulation which is within the reach of those skilled in the art will be necessary.

Besides the active substance or the combination according to the invention as described above, the compositions contain solid or liquid agriculturally acceptable carriers and those surfactants which ar© equally agriculturally acceptable. The customary inert carriers and the customary surfactants can be used in particular.

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

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

The surfactant can be an ionic emulsifier, dispersant or wetting agent. Examples which may be mentioned are salts of polyacrylic acids, salts of lignosulphonic acids, salts of phenolsulphonic acids, or naphthalenesulphonic acids, or polycondensates of ethylene oxide with fatty alcohols or with fatty acids or with fatty amines, substituted phenols (especially alkylphenols or arylphenols)f salts of esters of sulphosuccinic acids, taurine derivatives (especially alkyltaurates) lf phosphoric esters of alcohols or polycondensates of ethylene oxide with phenols- The presence of at least one surfactant is indispensable since th© active substances in the combination (2-chloro-6-nitro-3-phenoxy + HBN) are not water-soluble, and the vector agent for the application is waterThe following may be mentioned as agricultural forms of compositions; powders for dusting or dispersion (with a content of active substances which can be up to 100%), and granules, especially those obtained by extrusion, by compacting or by impregnation of a granulated carrier, or by granulation of a powder, (the content of active substances in these granules being between 1 and 80% in these last-mentioned cases).

The following may be mentioned as liquid forms of compositions, or forms which are intended to make up liquid compositions at the time of application; emulsifiable concentrates, emulsions, flowables, wettable powders (or powder for spraying) and pastes.

More detailed information on this type of formulation are given hereinafter to illustrate these observations : - the emulsifiable concentrates mostly comprise 10 to 80% of active substance or of combination, 0.5 to 15% of surfactants, 0-1 to 10% of thickeners, and 0 to 10% of suitable additivesp - the wettable powders (or powder for spraying) are usually prepared in such a way that they contain 20 to 95% of active substance, and they usually contain, besides the solid carrier, 0 to 5% of a wetting agent, 3 to 10% of a dispersant and, if necessary, 0 to 10% of one or more suitable additives.

The suspoemulsions mostly comprise 10 to 50% by weight of active substances or combinations, 0.5 to 15% of surfactants, 0-1 to 10% of thickeners, and 0 to 10% of suitable additives The flowables generally contain 10 to 75% of active substances or combinations, 0.5 to 15% of surfactants, 0.1 to 10% of thickeners, and 0 to 10% of suitable additives.

Prom amongst these suitable additives, the following may be mentioned: thixotropic colloids, penetrants, stabilisers, sequestering agents, etc. ...

Moreover, the said compositions can contain other active substances which have pesticidal properties (especially insecticides or fungicides), or properties which favour plant growth (especially fertilisers), orgrowth-regulating properties with the proviso that there is no major incompatibility between all these active substances.

In the case of the BBNs in ester form, it is preferred to produce a suspoemulsion from an emulsifiable HBN concentrate in ester form and the 2-chloro-6-nitro-3phenoxy in the form of a flowable, with the proviso that this is subject to optimisation within the reach of those skilled in the art of the formulation of plant-protection products.

It is known that, in this type of formulation, the 2-chloro-6-nitro-3-phenoxy will be in the form of fine, suspended particles, and the HBN ester in solubilised form, the entire mixture being in the form of a stable emulsion.

In the case where the HBNs are in phenolic form, it is preferable to produce a flowable, naturally still with the same provisos as regards the industrial feasibility which may make adjustments necessary. Special care must be taken to avoid the formation of a eutectic between the two active substances.

In the case where the HBNs are in salt form, it is possible to produce a flowable in which the HBN salt will be dissolved and the 2-chloro-6-nitro-3-phenoxyaniline will be suspended.

Treatment method according to the invention The invention equally relates to a method of controlling weeds, in particular in an environment in which crops are growing, or where it is intended to grow crops, which consists of applying an effective dosage of the composition, as has just been described above, containing th® product according to the inventionAmongst the crops, the combination of 2-chloro-65 nitro-3-phenoxyaniline/taromoxynil ester (especially heptanoate and/or octanoate) will preferably be used on cereals (wheat, barley, etc..) and maize, the combination 2-chloro-6-nitro-3-phenoxyaniline/bromoxynil in phenol form on maize, and the combination 2"chloro"6-nitro10 3-phenoxyaniline/ioxynil ester (especially heptanoate and/or octanoate) or phenol on cereals, sugar cane, rice and onions.

When applied, the dosage should be sufficiently high for controlling the growth of the weeds without causing substantial permanent damage to said crops.. Effective dosage is understood as meaning, in this context, the dosage which does in fact allow this result to be obtained.

The application is carried out at the post20 emergence stag® of the crops. Post-emergence is understood as meaning application of the product after the cultivated plant has emerged from the soil. The mixture acts on th© leaves of the weeds, but also by application to th® soil and subsequent uptake by the roots25 Above all, th® product according to the invention acts against the weeds after the latter have emerged, even though a pre-emergence action, that is to say when the plant has not yet emerged from the soil, would equally be possible.

The product is leaf-acting and root-acting in proportions which can vary according to the active substances in question and the treated plants.

The product (which can be applied for simultaneous or separate use, or use staggered over a period of time) will usually be applied at a dosage rate from 150 g/ha to 1,100 g/ha, depending on the nature of the 3,5dihalo-4-hydroxybenzonitrile.

Th® following weeds which can be controlled by said product (or said composition) may be mentioned: * From amongst the dicotyledons which are present mainly in cereal fields: Anthemis arvensis, Anthemis cotula, Brassica nigra Capsella bursarPastoris„ Chrysanthemum secretum,. Galium aparine, Lamium amplexicaule, Lamium purpureum, Lapsana communis, Matricaria inodora, Papaver rhoeas, Raphanus raphnistrum, Sinapis arvensis, Stellaria media, Veronica hederifolia, veronica persica, Viola arvensis, Viola tricolor, Sirapis. alba? * From amongst the dicotyledons which axe present mainly in maize fields: Abutilon theophrasti, Amaranthus retroflexus, Atriplex patula, Bidens pilosa, Chenopodium album. Datura stramonium, Ipomea purpurea. Polygonum spp. (for example Polygonum_aviculare, Polygonum convolvulus and Polygonum persicariaU Portulaca oleracea, Solanum miqrum, Xanthium strumarium; * From amongst th® grasses present mainly in cereal fields: Alooecurus mvosuroidas, Aoera spica-venti; * From amongst th® grasses present mainly in maize fields: Digitaria sanquinalis, Echinochlpa crus-galli, Setaria viridis.

Depending on the variants which follows ~ the combination bromoxynil octanoate or heptanoate/2~chloro"6"nitro~3"phenoxyaniline will be applied to cereals such as, especially, wheat or barley, or to maize. The dosage rate per hectare will advantageously be to 500 g/ha of 2-chloro-5-nitro-3-phenoxy,aniline, and 100 to 400 g/ha of bromoxynil ester, very advantageously: 100 to 400 g/ha of 2-chloro-6-nitro"3-phenoxyaniline, and 120 to 300 g/ha of bromoxynil ester? - the combination bromoxynil’-phenol/2-chloro-Snitro-3-phenoxyaniline will be applied to maize, at " 11 dosage per hectare of: to 500 g of 2-chloro-6-nitro-3-phenoxyaniline, and 200 to 800 g of bromoxynil-phenol, preferably: 100 to 400 g of 2~ohloro-6-nitro~3~phenoxvaniline, and 240 to 600 g of bromoxynil-phenol,.

The invention will now be described on the basis of concrete use examples which, it will be clearly understood, are given purely by way of indication and can in no way restrict the scope of the said invention.

To simplify the method, and to arrive at a better base for comparison, - Galium aparine, - Viola tricolor,» - Sinapis_alba, - Lamium_.p.urpureum» - Veronica jaersica„ were selected to demonstrate the activity of the product against wheat weeds and to demonstrate the selectivity of the product in this crop.

General experimental set-up The application is effected after the plant species have emerged.

A number of seeds (the number being determined on the basis of the plant species and th© size of th© seed) are sown in 9x9 x 9 cm pots filled with light agricultural soil.

The seeds are then covered, by a layer of soil about 3 sra thick, and th© seed is allowed to germinate until it gives rise to a plaatlet at the right stage. In the case of the grasses, the treatment stage Is the second leaf being formed stage. In th© case of th© dicotyledons, th© treatment stags is th© "cotyledons unfolded, first true leaf being developed*6 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 bs sprayed.

The mixtures are obtained by diluting the formulated products in waterThe following formulated products were used: - 2~Chlor0-6-nitro-3~phenoxyaniline flowable 600 g/1, 'Challenge 600"*®, ~ Bromoxynil octanoate emulsifiable concentrate 225 g/1, Buctril®. These formulations are properly approved and well known in the art.

The pots are then placed in containers for receiving the irrigation water, by way of subirrigation, and maintained for 24 hours at ambient temperature and 60% relative humidity.

After 24 days, the number of live plants in the pots treated with the mixture containing the active substance under test and the number of live plants in a control pot which has been treated under the same conditions, but using a mixture without active substance, are counted» In this way, the destruction percentage of the treated plants is determined relative to the untreated control. A destruction percentage equal to 100% means that complete destruction of the plant species in ques^ tion has taken place, and the percentage 0% means that the number of live plants in the treated pot is identical to that of the control pot- In the examples which follow, the units of active substances are g/ha.

Example 1: Test showing the nature. of the synergistic biological effect ox the combination __ of broatoxynil. octanoate and 2-chlpro-6-nitro-3~Phenoxyaniline on Sinaois alba; The experiment is carried out having sown Sinapis alba seeds.

The table which follows represents the mean of 1 greenhouse trial. In the case of each dosage rate, this higher value is the value obtained, and the lower value is th® expected value calculated according to Colby.

Bromoxynil octanoate i j | 250 J 1-1 I 93 I 125 2- chloroδ-aitro3- phenoxyaniline i 1 1 52 ! ί 1 -Τ- Ο J 55 40 -ΐ-r- 1 80 1 1 83 1 t I 100 99 1 125 | i - 5 1 90 i i | loo | 100 ! 1 -1 43 1 84 J —1-L_ 99 250 j io j 65 1 100 I 100 1 1 46 1 85 1 99 I-1--1---- ί_ι_I With reference to the formula given at the beginning of the description, the results given in the table which follows demonstrate clearly th® excellent and unexpected degree of synergism obtained with the combination of the invention.

Bxeaipl.e_.2g Test, showing the nature of_ the synergistic biological effect _of the combination _of bromoxynil octanoate and 2-c_hi_or_o_-6nitgo-3-.'pheno3'Eyanilin.e on Galium aparineg The experiment is carried out having sown Galium aparine seeds.

Th® table which follow® represents the mean of 1 greenhouse trial. In the case of each dosage rate, the higher value is the value obtained, and the lower value, is the expected value calculated according to Colby.

Bromoxynil octanoate i —j— r 1 θ 1 1 » 62 1 | 125 1 1 1 [ 250 | 1 I ill i 1 ( I0 1 » 0 10 1 10 1 15 1 2-chloro- r 1 1 1 i S-nitro- | 62 1 0 1 10 1 15 1 25 3-phenoxy- | 1 1 0 1 0 1 5 o ·] ο 1 I 4 1 1 enxixne p I 1 1 1 1 125 1 0 I so 1 55 1 65 1 1 0 0 I 5 I . ! ------1. Γ t 250 1 ! 10 1 ! 60 1 1 50 1 I 55 I L 1 I 1 ! 10 1 1 10 1 1 14 I With reference to the formula given at th beginning of the description, the results given in the table which follows demonstrate clearly the excellent and unexpected degree cf synergism obtained with the combination of the invention.

SxamSle„3s Test showing the nature of the svnerqiatic biological effect _of the .c_Qmb.ing.tipo.....®X . -bromoxvnxl octanoate and. 2nchloro-S-pitrQ-3-phenoxva»illn.e_Qp_ Viola tricolor; The experiment is carried out having sown Viola • tricolor seeds.

The table which follows represents the mean of greenhouse trial. In the case of each dosage rate, the higher value is the value obtained, and th® lower value is the expected value calculated according to Colby.

Bromoxynil octanoate 6-nitro3-phenoa aniline 1 1 1 1 1 • 1 0 1 • 62 ι 1 1 125 | 1 t 250 1 1 I 1 1 1 f 1 0 10 1 10 ί 15 I 15 1 — 1— , ! » 1 : Γ 1 1 1 i 1 1 62 10 1 10 ΐ 3θ 1 45 Ϊ τ- ! 1 1 10 1 15 I 15 1 f— 1 1 ... ! . . t I 1 1 —1 1 125 10 1 20 1 30 I 20 1 I 1 1 L 1 1 10 | 15 | 1 1 15 I 1 r } 250 1 1 i 5 1 40 1 1 ί θθ 1 55 1 1 I 1 1 14 1 ιθ 1 19 1 ! L 1 With reference to the formula given at the beginning of the description, the results given in the table which follows demonstrate clearly the excellent and unexpected degree of synergism obtained with the combination of the invention,.

Example,^; Test showing the nature of the svnerqigtic biological effect of the combination of bromoxvnil octanoate and 2-chloro-6-nitro-3-phenoxyaniline _on_Lamium garoarem: The experiment is carried out having sown lamxum purpurea seeds.

The table which follows represents the mean of 1 greenhouse trial. In the case of each dosage rate, the higher value is the value obtained, and the lower value is the expected value calculated according to Colby.

Bromoxynil octanoate I i i i 1 i 2- chloro6-nitro3- phenoxyaniline 125 250 1 - !?!! 0 l 1 -t 0 1 1 0 1 1 1 5 ί 1 . t 35 i 1 1 62 1 1 0 1 1 70 i i 70 I 1 80 1 1 i « 1 1 0 1 » 5 1 35 1 1 125 l 1 20 1 1 75 t 1 95 j 1 100 I 1 1 1 55 1 24 1 48 1 J 1 « ! . ! 250 1 1 50 I 1 100 i 1 100 1 1 100 ί 1 _ I i ! 50 1 ! 52 1 85 1 ! reference to the formula given at the beginning of the description, the results given in the table which follows demonstrate clearly the excellent and unexpected degree of synergism obtained with the combination of the invention.

Example 5s Test showing the nature of the s vner eristic biological .effect of . the combination^ ^of .bromoacynil octanoate and 2-chloro-6-nitro-3-phenoxvaniline _ on Veronica perslca; The experiment is carried out having sown Veronica persica seeds.

Bromoxynil octanoate beginning of the description, the results given in the table which follows demonstrate clearly the excellent and unexpected degree of synergism obtained with the combination of the invention30 Example Ss Test demonstrating· th® absence, of phytotoxicity of the combination of bromoxynil octanoate end 2-chloro6"»nitro-3-phfenoacvanxline to Triticum aestiyum: The experiment was carried out ass above, but after having sown wheat seeds, and gives results shown in the table below.

Bromoxynil octanoate increasing the respective activities of the two active substances against the weeds given by way of example.

Claims

1.) A herbicidal product resulting from a combination of: a) 2-chloro-6-nitro-3-phenoxyanxlxne, and b) on® or more herbicides of the 3,5-dihalo-4-hydroxybenzonitrile type, selected from amongst bromoxynxl, which is 3,5-dibromo-4-hydroxybenzonitrile or an agriculturally acceptable ester or salt thereof, or ioxynil, which is 4-hydroxy-3,5-diiodobenzonxtrile, or an agriculturally acceptable ester or salt thereof

2. ) The product according to claim 1, in which herbicide b) is the ester of bromoxynil or ioxynil with an alkanoic acid having 4 to 8 carbon atoms.

3. ) The product according to claim 2, in which herbicide b) is bromoxynil octanoate or heptanoate, or a mixture of the two.

4. ) The product according to claim 1, for simultaneous or separate use, or use staggered over a period of time, for the treatment of undesirable plants or weeds in crops.

5. ) The product according to claim 1, in which the ratio by weight of 2-chloro-6-nitro-3-phenoxyaniline to HBN is between 0.1 and 10. δ) The product according to claim 2 or 3, In which the ratio by weight of 2-chloro-δ-nitro-3-phenoxyaniline or bromoxynil or ioxynil ester is between 0.2 and 5.

6. 7) The product according to one of claims 1 to δ, which comprises a non-herbicidal or weakly herbicidal dosage of 2-chloro-5-nitro-3-phenoxyaniliae.

7. 8) Use of 2-chloro-6-nxtro-3-phenoxyaniline by way of amplifier of the EBN activity in a product according to claim 7.

8. 9) A herbicidal composition which contains a product according to one of claims 1 to 7, at least one inert carrier, and at least one surfactant.

9. 10) The herbicidal composition according to claim 9, which contains between 0.5 and 95% of product according to one of claims 1 to 7.

10. 11) A method of controlling weeds after emergence of the crops, in which an effective dosage of a composition according to one of claims 9 or 10 is applied to the site where said crop is growing. 5

11. 12) The control method according to claim 11, in which the weeds controlled are: * From amongst the dicotyledons which are present mainly in cereal fields: Anthemis arvensis, Anthemis eotula, Brassica nigra,,. 10 Capsella bursa-pastoris, Chrysanthemum segetum, GaliumaparineLaminin amolexlccurle, Lamium purpuream, . Lapsana communis, Matricari inodora, Papaver_ rhoeas,. Raohanus raphnistrum, Sinapis arvensis,. Stellania. media, Veronica hederifolia, Veronica persica, Viola arvensis; 15 * From amongst the dicotyledons which are present mainly in maize fields: Abuticlon theophrasti, Amaranthus, retroflexus, Atriplex patula, Bidens pilosa, Chenopodium album. Datura stramonium, Ipomea purpurea, .Polygonum spp. (for example 20 Polygonum aviculare, Polygonum convolvulus and Polygonum persicaria), Portulaca oleracea, Solanum_migrum, Xanthium strumarium; * From amongst the grasses present mainly in cereal fields: 25 Alopecurus mvosuroides, Apera spica-venti; * From amongst the grasses present mainly in maize fields: Digitaria sanguiwalis,, Echinochloa crus-galli,...Setaria viridis. 30

12. 13) The control method according to claim 11, in which the crops are the cereals (wheat, barley, etc.) and maize in the case of the combination of 2-chloro5- nitro-3-phenoxyaniline/bromoxynil ester, maize in the case of the combination 2-chloro-S-nitro-3-phenoxy35 aniline/hromoxynil-phenoi, and the cereals, sugar cane, rice and onions in the case of the combination 2-ehloro6- nitro-3-phenoxyaniline/ioxynil ester or phenol..

13. 14) The control method according to claim 11, which comprises application of the product according to claim 2 to cereals (such as wheat or barley) or maize at a rate of: 50 to 500 g/ha of 2-chloro-5-nitro-3-phenoxyaniliae, and 100 to 400 g/ha of bromoxynil ester.

14. 15) A method according to claim 14, in which the product is applied at a rate of: 100 to 400 g/ha of 2-chloro·-S-nitro-3-phenoxyaniline, and 120 to 300 g/ha of bromoxynil ester. 15) A control method according to claim 11, which comprises applying the combination bromoxynilphenol/2-chlorO“6-nitro-3-phenoxyaniline, ? according to claim 1, is applied to maize in a dosage per hectare of: 50 to 500 g of 2-chioro-5~nitro-3-phenoxy&niline, and 200 to 800 g of bromoxynil phenol.

15. 17) A method according to claim 16, in which the product Is applied at a rate of: 100 to 400 g/ha of 2-chloro-5-nitro-3-phenoxyaniline, and 240 to 500 g/ha of bromoxynil phenol.

16. 18) A herbicidal product according to claim 1, substantially as hereinbefore described.

17. 19) A herbicidal composition according to claim 9, substantially as hereinbefore described.

18. 20) A method according to claim 11, substantially as hereinbefore described and exemplified.