BG61021B1 - Herbicide preparation and method for undesirable vegetation control - Google Patents

Abstract

The herbicidal composition is obtained by mixing a) 2-chloro 6-nitro 3-phenoxyaniline or alkonifans b) one or more substituted ureas of the formula in particular isoproturon, chlorotoluron, dimefuron and metabenzthiazuron. The weight ratio of akam b is usually between 1/60 and 1.5. The invention also relates to a method for controlling undesirable vegetation in the post-emergence period in which the agent is used.

Description

The invention relates to a herbicide product resulting from the mixing of urea-substituted herbicides, optionally a mixture thereof and alkoniphan, which will be used for the selective control of undesirable vegetation on crops.

The invention also relates to the application of the new product as a herbicide, in particular in the form of compositions and a method for controlling weeds in crops using a product or composition based thereon.

BACKGROUND OF THE INVENTION

Substituted urea is applied to remove the grass in the crops. These include:

isoproturon or N, N-dimethyl-L- (4-isopropylphenyl) -urea for cereals, chlortoluron or N, N-dimethyl-N '- (3-chloro-4-methylphenyl) -urea for cereals, dimefuron or N , N-fluoro-N'- [3-chloro-4- (5-tertiobutyl-2-oxo-2,3-dihydro-1,3,4-oxadiazolyl-3-yl) phenyl] urea for pea and rapeseed crops, Neuron or N-methyl-N, n-butyl-N (3,4-dichlorophenyl) urea for cereals, linuron or N-MeTra-N-MeTokcH-N '(3,4-dichlorophenyl) urea for cereals maize and sunflower, metabenzthiazuron or 1-benzothiazolyl-

2-yl-1,3-dimethylurea for cereals, beans and rapeseed.

In addition, aclonifan or 2-chloro-6-nitro-3-phenoxyaniline, which is a selective herbicide for sunflower peas, and which is commonly used at doses greater than 2 kg / ha, is known.

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

A herbicidal agent (1) is known comprising from 35-66% by weight of a compound of formula

R, O R, I II I

R, -N-C-N-R ₄ in which R 1 is benzothiazol-2-yl-5-trifluoromethyl-1,3,4-thiazol-2-yl or a phenyl radical of formula

a R, - may be metal.

It is known from (2) -2-chloro-6-nitroaniline herbicide.

It is known from (3) - a herbicide agent in the form of an aqueous emulsion.

SUMMARY OF THE INVENTION

The composition improves the action of two active substances on a significant number of weeds while maintaining crop selectivity. As a consequence, the spectrum of impact and the ability to reduce the corresponding dose of each of the active substances used is improved, with the latter being of particular importance for environmental reasons.

Thus, the composition exhibits a significant degree of synergism defined in (4) or (5) according to the formula used by COLBY

E = X + Y - XY Ί00 in which E denotes the expected percentage inhibition of growth from a mixture of two herbicides at fixed doses, X is the observed percent inhibition of growth by herbicide A at a given dose, Y is the observed percent inhibition of herbicide growth B at a certain dose. When the observed percent inhibition of the composition is greater than E, synergism is observed.

At a dose that by itself is not herbicidal from an industrial point of view (i.e. efficacy 0 or insufficient), alkoniphane has been found to significantly enhance the herbicidal action of substituted urea.

In this case, there is a significant change in the use of urea.

The invention relates to a product obtained by mixing alkoniphan and one or more substituted ureas of the formula ^R 1 / ^{CH 3}

N - C - N

Ar ^X II \ _R ,

O ³ in which Ar is a nucleus of formula

as R 1 is selected from (C 1 -C ₃ ) alkyl, (C 1 -C 6 alkoxy, chlorine atom, bromine atom, 5-tert-butyl-2,3-dihydro-2-oxo 1,3,4-oxadiazole-3- silyl of the formula (CHP3C ^ O ^ O N- in which R ₂ is selected from a hydrogen atom, a chlorine atom, where Ar is a nucleus

R ₃ is a hydrogen atom, a (C 1 -C ₄ ) alkyl radical, methoxy, R ₄ is a hydrogen atom or a methyl radical.

When alkyl or alkoxy radicals include at least 3 carbon atoms, they may be linear or branched.

Among the substituted ureas of formula I may be cited:

isoproturon or 3- (4-isopropylphenyl) 1,1-dimethylcarbamide, chlortoluron or 3- (3-chloro-p-tolyl) -1,1-dimethylcarbamide, neburon or 1-butyl-3- (3,4-dichlorophenyl) -1-Methylurea, diuron or 3- (3,4-dichlorophenyl) -1,1-dimethylurea, methoxuron or 3- (3-chloro-4-methoxyphenyl-1,1-dimethylurea, linuuron or 3- (3,4-dichlorophenyl) ) -1-methoxy-1-methylcarbamide, monolinuuron or 3- (4-chlorophenyl) -1methoxy-1-methylcarbamide, metabenzthiazuron or 1-benzothiazol-2 yl-1,3-dimethylurea, metobromuron or 3- (4-bromophenyl) -1methoxy-1-methylurea, dimefuron or 3- [4- (5-tert-butyl-2,3-dihydro-2-oxo-1,3,4-oxides) sol-3-yl) -3-chlorophenyl-1,1-dimethylurea.

It is even better to use isoproturon or 3- (4-isopropylphenyl) -1,1-dimethylcarbamide, chlortoluron or 3- (3-chloro-p-tolyl) -1,1 dimethylcarbamide, metabenzthiazuron or 1-benzothiazol-2yl- 1,3-dimethylurea, for the elimination of unwanted vegetation in cereals, beans and peas.

These products can be used as herbicides in a wide range of alkoniphan-urea weight ratios, depending on the crops cultivated, climatic conditions, soil type, the stage of treatment of the predominant weeds and even the desire to use clear terrain or to satisfactory removal of the grass is achieved.

These products are intended for simultaneous, stand alone or long-term use as herbicides, in particular for weed control in crops. The type of treatment cultures varies depending on the urea used.

In the case of co-administration (preferred), ready-to-use products containing mixtures of the active substances described above may be used. Products prepared immediately before use by mixing the active substances as described below may also be used.

Administration can also be accomplished by using the product, treating the crops sequentially with one and then the other active substance, alkoniphan and urea, so as to form in situ on the plant the product of the invention.

According to one preferred embodiment, the weight ratio of alkonifane / urea is between 6/400 and 2/1, preferably 1/60 and 1.5 / 1, and most preferably 1/30 and 1/1.

The mixtures are most commonly of the biner type, but in some cases triple and quaternary mixtures with one or more other compatible pesticides (fungicide or insecticide) are considered.

As stated above, the object of the invention is to enhance the action of urea.

According to one preferred embodiment, the weight ratio of alkoniphan / urea is between 1/60 and 1.2 / 1, preferably 1/60 and 1/2, and most preferably 1/30 and 1/3.

Thus, the product is defined as a herbicide based on urea containing as an enhancer, alone without or with a low herbicidal action, compared to alkoniphane.

Obviously preferred embodiments of urea according to the invention are also valid in this Annex. Also, as an enhancer, alkoniphane may be used, but also preferably chlortoluron and isoproturon.

The products of the invention are most commonly administered in the form of herbicidal compositions containing one or more agriculturally acceptable carriers and / or one or more surfactants.

In cases where the formulations are prepared immediately before use, any of the active substances may be in the form of a composition. On the contrary, in the case of a ready-to-use mixture, the composition itself is in the form of a composition.

The following section describes the active substances and mixtures. Given the commercially available products, it is easy to prepare a ready-to-use composition containing the mixtures.

Adequate formulation known to those skilled in the art is required.

In the general statement below, the term "composition" is used to describe the two formulations containing the two separate active substances or the composition containing the mixture.

These applicable mixtures also comprise an active substance or mixture according to the invention, as described, liquid or solid carriers acceptable in agriculture and surfactants also acceptable in agriculture. In particular, inert and conventional carriers and conventional surfactants are applicable.

These compositions typically contain between 0.5 and 95% of the active substance or mixtures according to the invention. Percentage unless explicitly stated to be in weight.

The term " carrier " in this disclosure means an organic or mineral substance, natural or synthetic, with which the active substance is mixed to improve application to plants, seeds and soil. This carrier is generally inert and should be acceptable in agriculture, in particular for cultivated plants. The carrier may be solid (clays, natural or synthetic silicates, solid fertilizers, etc.) or liquid (water, alcohols, ketones, petroleum fractions, aromatic or paraffinic hydrocarbons, chlorinated hydrocarbons, liquefied gases, etc.).

The surfactant may be an ionic type emulsifying, dispersing or wetting agent. For example, the salts of polyacrylic acids, lignosulfonic acids, phenolsulfonic acids or naphthalenesulfonic acids, polycondensation products of ethylene oxide and fatty alcohols or fatty acids or fatty amines, substituted phenols, esters, phenols, phenols of sulfosuccinic acids, taurine derivatives, in particular alkylturates, phosphorous esters of polyethoxylated alcohols or phenols. The presence of at least one surfactant is necessary since the active substances (alkoniphan + urea) are insoluble in water and the carrier for administration is water.

Powders for powdering or dispersing (with a content of the compound of formula I up to 100% and granules, in particular obtained by extrusion, compacting, impregnation of a granular carrier, by granulation, leaving out as a formulation of agricultural compositions, may be cited) powder (the content of the compound of formula I in these granules may be between 1 and 80% in the latter case).

Emulsifiable concentrates, emulsions, concentrated suspensions, aerosols, wettable powders (or spray powders), pasty products may be cited as liquid compositions or compositions intended for the preparation of liquid compositions immediately before use.

Emulsifiable or soluble concentrates usually contain between 10 and 80% of the active substance, and as regards emulsions, they contain 0.01 to 20% of the active substance. Concentrated suspensions generally contain from 10 to 75% of the active substance, from 0.5 to 15% of the surfactant, from 0.1 to 10% of thixotropic agents and from 0 to 10% of suitable additives such as antifoams, corrosion inhibitors, stabilizers, penetration agents. Typically, these compositions may also contain any type of other ingredient, for example thixotropic colloids, penetration agents, stabilizers, complexing agents and others, as well as other active substances known as pesticides, especially insecticides and fungicides or with properties of growth stimulants, in particular fertilizers. , or with the properties of growth regulators. Most commonly, the compounds of the invention may be mixed with any solid or liquid additives suitable for conventional application techniques.

For example, in addition to the solvent, the emulsifiable concentrates may contain 2 to 20% of suitable additives, such as stabilizers, surfactants, penetration agents, corrosion inhibitors, colorants or adhesives, cited above.

The following substances are considered to be active:

alkoniphane is marketed as a concentrated suspension with 600 g / l active substance, isoproturon is marketed as a concentrated suspension between 400 and 500 g / l active substance, chlortoluron is in the form of a concentrated suspension (between 500 and 510 g / 1 active substance) wettable powders, granules, microgranules.

Those skilled in the art can readily administer the composition based on a mixture of these active substances in the form of, for example, a concentrated suspension. This is the preferred form according to the invention.

EXAMPLES FOR THE IMPLEMENTATION OF THE INVENTION

Treatment method

The invention also relates to a method of controlling undesirable vegetation, in particular in places where crops grow or which are intended for planting crops, consisting of administering an effective dose of the product (or composition containing it), described above.

When administered, the dose should be sufficient to control weed growth without causing permanent significant crop damage. Effective dose refers to the dose that allows the result to be obtained.

The agent and method are applied in the period after the emergence of the plants.

The product (or composition) according to the invention is primarily active against weeds after they have emerged, but also before they emerge, i.e. before the plant has left the soil.

The effect of the product (or composition) is on the leaves or roots in a proportion that may vary depending on the active substances used.

Typically, the product, which can be administered simultaneously, sequentially or separately over time, is administered at a dose of 460 g / ha to 200 g / ha.

The weeds that can be controlled by the product (or composition) in question are the following:

Galium aparine, Avena fatua, Lolium multiflorum, Viola tricolor, Sinapis alba, Lamium purpurea, Veronica persica, Agrostis tenuis, Alopecurus myosuroides, Veronica haederefolia.

Preferred options:

The isoproturon-alkoniphane mixture is used in cereals such as wheat, in particular barley. The dosage per hectare is preferably from 60 to 600 g / ha of alconiphan and from 400 to 3600 g / ha of isoproturon, most commonly from 100 to 500 g / ha of alconiphan and from 500 to 3000 g / ha of isoproturon.

The chlortoluron-alkonifane mixture is used in cereals such as wheat, in particular barley. The dosage per hectare is preferably from 60 to 600 g / ha of alkoniphan and from 400 to 3600 g / ha of chlortoluron, and most commonly from 100 to 500 g / ha of alkoniphan and from 500 to 3000 g / ha of chlortoluron.

The dimefuron-alkonifane mixture is used for peas and rapeseed. The dosage per hectare is preferably from 60 to 600 g / ha of alconiphan and from 400 to 3600 g / ha of dimefuron, most commonly from 100 to 500 g / ha of alconiphan and from 500 to 2000 g / ha of dimefuron.

The alkonifan-metabenzthiazuron mixture is used in wheat and barley essences. The dosage per hectare is preferably from 60 to 1000 g / ha of alconiphan and from 500 to 4000 g / ha of metabenzthiazuron, most commonly from 100 to 500 g / ha of alconiphan and from 1000 to 3000 g / ha of metabenzthiazuron.

To simplify the method and to find a better base for comparison, the following weeds are selected: Galium aparine, Avena fatua, Lolium multiflorum, Viola tricolor, Sinapis alba, Lamium purpurea, Veronica persica, Agrostis tenuis, Alopecurus myosuroides, Stellaria media to show the activity of the product on weeds in the wheat and to show the selectivity of the product on these crops.

Common method of experimentation The application is carried out in the period after emergence of the plant species.

In pots measuring 9x9x9 cm full of surface soil, a certain number of seeds are sown, depending on the plant species and size of the seeds.

The seeds are then covered with a layer of soil about 3 cm thick and the seeds allowed to sprout and the plants reach a certain stage. The weed treatment stage is the "second leaf in the process of formation" stage. The two-week treatment stage is the "emergence of cotyledons, the first true leaf in development" stage.

The pots are treated by spraying a paste product in an amount corresponding to a bulk dose of 500 g / ha and containing the active substance.

The leaf product is obtained by diluting the products in water.

Products with the following formulations in g / 1 are used:

600 - Alconiphane Concentrated Suspension "Challenge 600" (R),

500 - Isoproturon Concentrated Suspension "Augur" (R),

500 - Chlortoluron Concentrated Suspension "Dicuran" (R),

400 - Dimefuron Concentrated Surdon Suspension (R).

These compositions are similar and well known in the art.

The pots were placed in containers designed to provide water by subrigation and kept for 24 hours at room temperature and 60% relative humidity.

At 24 hours the number of live plants in pots treated with the paste product containing the active substance to be tested and the number of live plants in the pot used for comparison treated in the same way but with a paste product containing no active substance . This determines the percentage destruction of treated plants in relation to the untreated witness. Percentage destruction 100% indicates that there has been complete destruction of the plant species in question, 0% indicates that the number of living plants in the pot was equal to that in the pot. For examples 1 to 16, the units in the tables are in g / ha (1st row and 1st column).

Example 1. Experiments demonstrating the synergistic biological effect of mixtures of isoproturon and alkoniphan on Lolium multiflorum.

The experiments were conducted with sown seeds of Lolium multiflorum.

The table below shows the average values of an experiment conducted in a greenhouse. For each dose, the higher value is the value obtained and the lower value is the expected value calculated according to Colby.

Isoproturon 0 500 1000 2000 0 0 30 65 50 Alconiphan 62 0 60 90 85 30 65 50 125 0 65 90 95 30 65 50 250 0 65 90 98 30 65 50

The results presented in the table above clearly demonstrate the excellent and unexpected synergistic effect obtained with the mixtures according to the invention.

EXAMPLE 2 Experiments Demonstrating the Synergistic Biological Effect of Isoproturon and Alconiphane Mixtures on Alopecura myosuroides.

The experiments were conducted with sown seeds of Alopecurus myosuroides.

The following table shows the mean values of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

The experiments were conducted with sown seeds of Lamium purpurea.

The following table shows the mean values of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

Alconiphan Isoproturon 0 500 1000 2000 0 62 125 250 0 0 0 0 20 30 20 55 20 80 20 50 75 50 65 50 85 50 85 83 85 93 85

Isoproturon 0 500 1000 2000 0 0 0 15 20 Alconiphan 62 0 20 20 25 0 15 20 125 20 40 30 40 20 30 36 250 20 55 50 75 20 32 36

The results presented in the table above clearly demonstrate the excellent and unexpected synergistic effect obtained with the mixtures according to the invention.

Example 3. Experiments demonstrating the synergistic biological effect of mixtures of isoproturon and alkoniphan on Agrostis tenuis.

The experiments were conducted with sown seeds of Agrostis tenuis.

The following table shows the mean values of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

The results presented in the table clearly show the excellent and unexpected synergistic effect obtained with the mixtures according to the invention.

Example 5. Experiments demonstrating the synergistic biological effect of mixtures of isoproturon and alkoniphan on Viola tricolor.

The experiments were conducted with seeded seeds of Viola tricolor.

The following table shows the mean values of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

Alconiphan Isoproturon 0 500 1000 2000 0 62 125 250 0 0 0 0 30 90 30 95 30 100 30 90 100 90 100 90 100 90 95 100 95 100 95 100 95

Isoproturon 0 500 1000 2000 0 0 0 15 20 Alconiphan 62 0 15 25 25 0 15 20 125 0 25 25 30 0 15 20 250 15 30 30 40 15 28 32

The results presented in the table above clearly demonstrate the excellent and unexpected synergistic effect obtained with the mixtures according to the invention.

Example 4. Experiments demonstrating the synergistic biological effect of mixtures of isoproturon and alkoniphan on Lamium purpurea.

The results presented in the table clearly show the excellent and unexpected synergistic effect obtained with the mixtures according to the invention.

EXAMPLE 6 Experiments Demonstrating the Absence of Phytotoxicity of a Mixture of Isoproturon and Alconiphan on Wheat or Triticum aestivum.

The experiment is carried out as described in the previous examples, but after the sowing of the wheat yields the following results:

Isoproturon 0 500 1000 2000 0 0 0 0 0 Alconiphan 62 0 0 0 0 125 0 0 0 0 250 0 0 0 0

It was found that, in addition to increasing the respective activities of the two active substances on the tested weeds, the said mixtures did not show any phytotoxicity on the wheat.

Example 7. Experiments demonstrating the synergistic biological effect of mixtures of chlortoluron and alkonifan on Alopecurus myosuroides.

The experiments were conducted with seeded seeds of Alopecurus myosuroides.

The following table shows the average results of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

The lower value is the expected value and the lower value is calculated according to Colby.

Chlortoluron 0 500 1000 1500 0 0 10 55 93 Alconiphan 62 0 35 75 88 10 55 93 125 0 35 70 88 10 55 93 250 0 50 88 90 10 55 93

The results presented in the table clearly show an excellent and unexpected degree of synergism obtained with the mixtures according to the invention.

Example 9. Experiments demonstrating the synergistic biological effect of mixtures of chlortoluron and alkoniphan on Lolium multiflorum.

The experiments were performed with seeded seeds of Lolium multiflorum.

The following table shows the average results of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

Chlortoluron 0 500 1000 1500 0 0 65 70 80 Alconiphan 62 0 60 97 97 65 70 80 125 10 70 85 99 68 73 82 250 20 70 98 100 72 76 84

Chlortoluron 0 500 1000 1500 Alconiphan 0 62 125 250 0 0 5 10 78 100 78 98 79 93 80 93 100 93 100 93 100 94

The results presented in the table clearly show an excellent and unexpected degree of synergism obtained with the mixtures according to the invention.

Example 8. Experiments demonstrating the synergistic biological effect of mixtures of chlortoluron and alkonifan on Avena fatua.

The experiments were conducted with seeded seeds of Avena fatua.

The following table shows the average results of an experiment conducted in a greenhouse. For each higher dose, the results presented in the table clearly show an excellent and unexpected degree of synergism obtained with the mixtures according to the invention.

EXAMPLE 10 Experiments Demonstrating the Synergistic Biological Effect of Chlortoluron and Alconiphan on Viola tricolor.

The experiments were performed with seeded seeds of Viola tricolor.

The following table shows the average results of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

Chlortoluron 0 500 1000 1500 0 0 0 15 25 Alconiphan 62 0 20 35 60 0 15 25 125 0 30 60 65 0 15 25 250 5 35 70 85 5 19 29

The results presented in the table clearly show an excellent and unexpected degree of synergism obtained with the mixtures according to the invention.

Example 11. Experiments demonstrating the synergistic biological effect of mixtures of chlortoluron and alkoniphan on Galium aparine.

The experiments were performed with seeded seeds of Galium aparine.

The following table shows the average results of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

Chlortoluron 0 500 1000 1500 0 0 15 25 45 Alconiphan 62 0 30 40 65 15 25 45 125 0 45 70 80 15 25 45 250 15 60 70 70 28 36 53

The results presented in the table clearly show an excellent and unexpected degree of synergism obtained with the mixtures according to the invention.

EXAMPLE 12 Experiments Demonstrating the Absence of Phytotoxicity of a Chlortoluron-Alconiphane mixture on Wheat or Triticum aestivum

The experiment is carried out as indicated in the previous examples, but after the sowing of the wheat and produces the following results:

Chlortoluron 0 500 1000 1500 0 0 0 0 0 Alconiphan 62 0 0 0 0 125 0 5 0 0 250 0 5 0 0

It was found that, in addition to increasing the respective activities of the two active substances on the tested weeds, the said mixtures did not show any phytotoxicity on the wheat.

Example 13. Experiments demonstrating the synergistic biological effect of the mixtures of dimefuron and alkonifan on Sinapis alba.

The experiments were performed with seeded seeds of Sinapis alba.

The following table shows the average results of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

Dimefuron 0 500 1000 2000 0 0 10 45 70 Alconiphan 62 0 35 93 100 10 45 70 125 20 80 98 100 28 56 76 250 30 70 100 100 37 61 79

The results presented in the table clearly show an excellent and unexpected degree of synergism obtained with the mixtures according to the invention.

Example 14. Experiments demonstrating the synergistic biological effect of the mixtures of dimefuron and alkonifan on Viola tricolor.

The experiments were performed with seeded seeds of Viola tricolor.

The following table shows the average results of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

Dimefuron 0 500 1000 2000 0 0 25 45 85 Alconiphan 62 0 25 50 95 25 45 85 125 0 30 70 95 25 45 85 250 10 - 83 100 50 86

The results presented in the table clearly show an excellent and unexpected degree of synergism obtained with the mixtures according to the invention.

EXAMPLE 15 Experiments Demonstrating the Synergistic Biological Effect of Dimefuron and Alconiphan on Lolium multiflorum.

The experiments were performed with seeded seeds of Lolium multiflorum.

The following table shows the average results of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

Dimefuron 0 500 1000 2000 0 0 10 25 60 Alconiphan 62 0 15 35 80 10 25 60 125 0 20 55 65 10 25 60 250 5 20 55 65 14 29 62

The results presented in the table clearly show an excellent and unexpected degree of synergism obtained with the mixtures according to the invention.

Example 16. Experiments demonstrating the synergistic biological effect of the mixtures of dimefuron and alkonifan on Veronica Persica.

The experiments were conducted with seeded seeds of Veronica Persica.

The table below shows the average results of an experiment conducted in a greenhouse. For each dose, a higher value was obtained and a lower value was expected, calculated according to Colby.

Dimefuron 0 500 1000 2000 0 0 55 97 100 Alconiphan 62 0 68 80 100 55 97 100 125 5 100 100 100 57 97 100 250 5 88 94 100 57 97 100

The results presented in the table clearly show an excellent and unexpected degree of synergism obtained with the mixtures according to the invention.

Example 17. Experiments demonstrating the synergistic effect of mixtures of methabenzthiazuron and alkoniphan.

The experiments were conducted outdoors on 2 x 5 m plots in the form of beds planted with two crops and a range of weeds in beds with three replicates of experience. Other weeds are naturally present.

The processing takes place when the crop and the weeds are in the stage of fully developed shoots: three shoots for the monocotyledons and the stage of the developed cotyledons for the bicameral.

The plots are treated with an experienced sprayer mounted on a tractor with a flow rate of 195 l / ha, using, respectively, alkoniphan in the form of a suspension of 600 g / l (CHALLENGE 600), methanbenzthiazuron in the form of liquid 700 g / l (TRIBUNIL), alone or in a mixture .

On day 60, the percentage of weeds available in relation to untreated bystander (0 = no effect, 100 = complete destruction) for Galium aparine, Avena fatua, and wheat and barley essences was visually assessed.

The table below shows the averages obtained from three parallel experiments. For each dose, the result is compared to the expected result using the Colby formula.

Destruction Destruction in% Galium in% Avena aparine fatua Active substance Effectively Expected Effectively Expected gma / ha 250 33 33 Alconiphan 500 45 45 Metabenz- 2000 6 72 thiazuron Alconiphan 250 + 85 37 93 81 Metabenz- 2000 thiazuron Alconiphan 500 + 94 48 94 84 Metabenz- 2000 thiazuron

The table shows the synergistic action of these mixtures.

Claims (22)

A herbicidal agent resulting from the mixing of 2-chloro 6-nitro 3-phenoxy aniline (alkoniphan) and one or more substituted ureas of formula R, is selected from (C, C ₃ ) alkyl, (C ₍ -C ₃ ) alkoxy, chlorine atom, bromine atom, 5-tert-butyl-2,3-dihydro-2-oxo 1,3,4-oxadiazol-3-yl group of the formula <CH, The N-such as R ₂ is selected from a hydrogen atom, a chlorine atom, where Ar is a nucleus R ₃ is a hydrogen atom, a (C 1 -C ₄ ) alkyl radical, methoxy, R ₄ is a hydrogen atom or a methyl 3θ hunting radical. A herbicidal agent according to claim 1, characterized in that the substituted ureas are selected from isoproturon or 3- (4-isopropylphenyl) 35 1,1-dimethylurea, chlortoluron or 3- (3-chloro-p-tolyl) -1 , 1-dimethylurea, neuron or 1-butyl-3- (3,4-dichlorophenyl) -1-methylurea, 4θ diuron or 3- (3,4-dichlorophenyl) -1,1-dimethyl urea, methoxyuron or 3- (3-chloro-4-methoxyphenyl-1,1-dimethylcarbamide, linuron or 3- (3,4-dichlorophenyl) -1 -me45 toxi-1-methylcarbamide, monolinuron or 3- (4-chlorophenyl) -1-methoxy-1-methylcarbamide, metabenzthiazuron or 1-benzothiazol-2yl-1, 3-dimethyl urea, 5θ metobromuron or 3- (4-bromophenyl) -1methoxy-1-methylurea, dimefuron or 3- [4- (5-tert-butyl-2,3-dihydro-2-oxo-1,3,4-oxadiazol-3- yl) -3-chlorophenyl-1,1-dimethylurea. A herbicidal agent according to claim 2, characterized in that the urea is 3- (4-isopropylphenyl) -1,1-dimethylurea (or isoproturon) or 3- (3-chloro-p-tolyl) 1,1-dimethylurea , (or chlortoluron). The herbicidal agent according to claim 1, characterized in that it is applied simultaneously, sequentially or separately at the time of treatment of unwanted vegetation or weeds in the crops. A herbicidal agent according to claim 1, characterized in that the weight ratio of the alkoniphane and the substituted urea is between 6/400 and 2/1. The herbicidal agent according to claim 5, characterized in that the weight ratio of the alkoniphane and the substituted urea is between 1/60 and 1.5 / 1 and preferably between 1/30 and 1/1. A herbicidal agent according to claim 1, characterized in that it contains a dose of alkoniphan which has no or little herbicidal action. The herbicidal agent according to claim 7, characterized in that the weight ratio of the alkoniphane and the substituted urea is between 1/60 and 1/2. A method of administering alkoniphane as a potentiator of urea activity in the herbicide agent according to claims 7 or 8. A herbicidal composition comprising a product according to any one of claims 1 to 8, at least one inert carrier and / or one surfactant. A herbicidal composition according to claim 10, characterized in that it contains between 0.5 and 95% of the product according to any one of claims 1 to 8. A method for controlling undesirable vegetation in the post-emergence period of crops, characterized in that an effective dose of the product is applied in place according to any one of claims 1 to 8. 13. The control method of claim 12, wherein the controlled weeds are the following: Galium aparine, Avena fatua, Lolium multiflorum, Viola tricolor, Sinapis alba, Lamium purpurea, Veronica persica, Agrostis tenuis, Alopecurus myosuroides, Veronica haederefolia. Control method according to claim 12, characterized in that the product is applied in an amount of 460 to 4200 g / ha. 15. The control method of claim 12, wherein a mixture of 3- (4-isopropylphenyl) -1,1-dimethylcarbamide or isoproturon and alkoniphane in an amount of 60 to 600 g / ha of alkoniphan and from 400 to 3600 g / ha isoproturon, with the crops being cereal. Control method according to claim 15, characterized in that from 100 to 500 g / ha of alkoniphan and from 500 to 3000 g / ha isoproturon are administered. A control method according to claim 12, characterized in that a mixture of chlortoluron or 3- (3-chloro-phtolyl) -1,1-dimethylcarbamide and alkoniphane in amounts of 60 to 600 g / ha of alkoniphan and from 400 to 3600 g / ha of isoproturon, with the crops being cereal. 18. The control method of claim 17, wherein the mixture is administered in an amount of 100 to 500 g / ha of alkoniphan and 500 to 3000 g / ha of chlortoluron. A control method according to claim 12, characterized in that a mixture of dimefuron or N, N-dimethyl N '- [3-chloro-4- (5-tert-butyl-oxo-2,3-dihydro-1, 3,4-Oxadiazolyl-3-yl) phenyl] urea and alkoniphan in an amount of 60 to 600 g / ha alkoniphan and 400 to 3600 g / ha dimefuron, and that the crops are rapeseed and peas. 20. The control method of claim 19, wherein the mixture is administered in an amount of 100 to 500 g / ha of alkoniphan and 500 to 2000 g / ha of dimefuron. Control method according to one of Claims 12 to 14, characterized in that a mixture of 60 to 1000 g / ha of alkoniphan and 500 to 4000 g / ha of metabenzathiazuron is applied. 22. The control method of claim 21, wherein the mixture is administered in an amount of 100 to 500 g / ha of alkoniphan and 1000 to 3000 g / ha of metabenzthiazuron.