CS237340B2 - Herbicidal agent - Google Patents

Abstract

Herbicidal composition, characterized in that it contains as an active ingredient a combination of a compound of the general formula I in which both symbols R* 1 are the same and represent a methyl or ethyl group and R2 and R3 are the same and represent a fluorine atom, a chlorine atom or a bromine atom, and a second herbicide selected from the group comprising α',«,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine, N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl)-benzenamine and 3,5-dinitro-4-dipropylaminophenylsulfonamide, in a weight ratio of the compound of the general formula I to the second herbicide from 4:1 to 1:3, together with one or more agriculturally usable carriers or diluents.

Description

(54) Herbicide

2

Herbicidal composition, characterized in that it contains as an active ingredient a combination of a compound of the general formula I

in which both symbols R ^{* 1} are the same and represent a methyl or ethyl group and

R ² and R ³ are the same and represent a fluorine atom, a chlorine atom or a bromine atom, and a second herbicide selected from the group consisting of α',«,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine, N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl)benzenamine and 3,5-dinitro-4-dipropylaminophenylsulfonamide, in a weight ratio of the compound of general formula I to the second herbicide from 4:1 to 1:3, together with one or more agriculturally acceptable carriers or diluents.

The invention relates to a group of novel 1-substituted benzoyl-3-substituted phenylureas which have been found to act as herbicides, and to their combinations with known active ingredients.

The use of herbicides to control the growth of unwanted vegetation has been the subject of considerable research effort for many years. This control of unwanted vegetation has in many cases a significant economic effect in agriculture. However, the continuous use of chemical herbicides is associated with a number of problems, including environmental pollution, tolerance of useful plants, weed resistance, as well as economic aspects. Accordingly, the search for new economically acceptable herbicides that would be selectively toxic to unwanted vegetation continues.

1-Benzoyl-1-phenylureas, useful as herbicides, have long been known. Pillon et al. in U.S. Patent No.

No. 384,473 describes the use of various 1-phenyl-1-benzoylureas useful as herbicidal agents. Lehureau et al. in U.S. Patent No. 3,342,586 broadly describe ureas exhibiting herbicidal activity, but only 1-phenyl-1-alkanoylureas are preferred. In U.S. Patent No.

166,124 and in Dutch patent specification No. 7,105,350 various 1-(2,6-dihalobenzoyl]-3-phenylureas exhibiting insecticidal activity are described.

The invention describes compounds of general formula I

in which both symbols R ¹ are the same and represent a methyl or ethyl group and

R ² and R ³ are the same and represent a fluorine atom, a chlorine atom or a bromine atom.

A preferred group of substances according to the invention consists of compounds of general formula I, in which R ¹ represents a methyl group and both symbols R ² and R ³ represent fluorine atoms.

The subject of the invention are combined herbicidal compositions containing the above-mentioned compounds as one component of the active ingredient.

2,6-Dialkoxybenzoylphenylureas of the general formula I are prepared in a manner known per se, for example by reacting a 2,6-dialkoxybenzoyl derivative of the general formula II

is reacted with substituted benzene of general formula III

in which

R ¹ , R ² and R ³ have the above-mentioned meanings and one of the symbols Q ¹ and Q ² represents an amino group and the other an isocyanato group.

In accordance with a preferred method of preparation, the 2,6-dialkoxybenzoyl derivative is reacted with anhydrous ammonia to form the corresponding benzamide, which is reacted with oxalic acid chloride to form the 2,6-dialkoxybenzoyl isocyanate of formula II, in which Q ¹ is an isocyanato group, which is then reacted with the appropriate substituted benzene of formula III, in which Q ² is an amino group, to form the corresponding 1-(2,6-dialkoxybenzoyl)-3-(substituted phenyl)urea of formula I. This procedure is illustrated by the following reaction scheme:

In the formulas shown in this scheme, the symbols R ¹ , R ² and R ³ have the above meaning and X represents a halogen atom, a hydroxy group, an alkoxy group with 1 to 6 carbon atoms or a —O—C-alkyl group,

II about

wherein alkyl contains 1 to 6 carbon atoms.

The final reaction step is generally carried out in a suitable solvent and under an inert atmosphere, such as nitrogen. The temperature range suitable for adding the reactants may range from 0 to 30°C, with a preferred range of 10 to 25°C when Q ¹ is an isocyanato group, and from 25 to 100°C when Q ¹ is an amino group. Suitable solvents include ethyl acetate, benzene and higher halogenated solvents, preferably methylene chloride, 1,2-dichloroethane and chloroform. After addition of the reactants, the temperature of the reaction mixture is usually raised from about 20°C to 40°C. When Q ¹ is an amino group, a tertiary amine base, such as triethylamine or pyridine, may optionally be present. The reaction mixture is worked up according to standard procedures. Typically, the precipitated solid is either filtered off or the solvent is evaporated off in vacuo. If it is necessary to remove the solvent, the residue is suspended in a suitable solvent, usually alcohol, and the solid product is filtered off. The product obtained can be further purified by recrystallization or column chromatography.

The starting substituted anilines and acid chlorides are either commercially available or can be readily prepared by known methods.

The following examples illustrate typical preparations of starting materials used to produce compounds of the general formula.

2,6-dimethoxybenzamide

To 2.5 liters of diethyl ether is added 200 g

2,6-dimethoxybenzoyl chloride, the solution is cooled to 5°C under nitrogen, then the nitrogen supply is stopped and ammonia gas is introduced into the solution for hours while maintaining the temperature between 5 and 10°C. The reaction mixture is stirred for another 1 hour, while its temperature is allowed to rise to about 25°C. The resulting solution has a pH of 9.0. The solids are filtered off and stirred in 2 liters of water, while the pH of the aqueous suspension is adjusted to 8.0 with ammonium hydroxide. The solid material is filtered off again and, after washing with water, dried. 167 g (92%) of the desired product is obtained, which can be used in the next step.

2.6- Dimethoxybenzoyl isocyanate

167 g of 2,6-dimethoxybenzamide are stirred in 2 liters of toluene under a nitrogen atmosphere and 145 g of oxalic acid chloride are added to the solution over 1 hour. The resulting solution is heated to 60 °C and maintained at this temperature overnight. Hydrogen chloride is allowed to escape, preventing condensation of water and its access to the reaction mixture. The reaction mixture is heated to reflux (approximately 110 °C) for 1.5 hours, while nitrogen is introduced under its surface using a gas introduction device. The mixture is allowed to cool to approximately 30 °C with constant stirring, the resulting solution is filtered through a pad of diatomaceous earth under a nitrogen atmosphere and the solvent is evaporated in vacuo. 185 grams (97%) of an oily product are obtained, which is stored under nitrogen.

Using the respective 2,6-dialkoxybenzoyl isocyanate and substituted aniline, it is possible to prepare compounds of general formula I. The following section presents typical examples of the preparation of these compounds.

Example 1

1-(2,6-dimethoxybenzoyl)-3-(2,6-dichlorophenylurea

In a reaction flask, 16.2 g of 2,6-dichloroaniline are dissolved in 200 ml of 1,2-dichloroethane at a temperature of about 25 °C in a nitrogen atmosphere. 25 g of 2,6-dimethoxybenzoyl isocyanate in 25 ml of 1,2-dichloroethane are added to the solution and the resulting solution is heated at 40 °C for another 2 hours after the addition is complete. Chromatography of a sample of the reaction mixture on a thin layer of silica gel in diethyl ether shows that the mixture no longer contains any 2,6-dichloroaniline. The solvent is evaporated in vacuo, the residue is stirred in methanol, the solid material is filtered off and washed with methanol. 26.5 g (72%) of the desired product is obtained. Analysis:

for C16H14Cl2N2O4 calculated

52.02% C, 3.82% H, 7.59% N; found

51.81% C, 3.69% H, 7.36% N.

NMR:

with signal shape and number of protons group 3.8 s, 6H 2,OCH3 6.7 d, 2H p-H on circles 7.4 m, 4H 4-H in circles 10.1 s, 1H NH 10.9 s, 1H NH

Example 2

1-(2,6-Dimethoxybenzoyl)-3-(2,6-difluorophenyl)urea g of 2,6-difluoroaniline is dissolved in 1500 milliliters of methylene chloride, the solution is cooled to 10°C and 90 g of 2,6-dimethoxybenzoyl isocyanate in 200 ml of methylene chloride are added dropwise under a nitrogen atmosphere. The mixture is stirred at 25°C for 3 hours, then the solid material is filtered off and washed with water. The filtrate is evaporated to dryness, 150 ml of diethyl ether and 150 ml of ethanol are added to the residue, and the solid material is filtered off again. 89.0 g of the desired product (60%) are obtained. The product melts at 199-200°C.

Analysis: for C16H14F2N2O4 calculated

57.15% C, 4.20% H, 8.33% N; found

57.20% C, 4.36% H, 8.33% N.

The following compounds were prepared according to the procedure of Example 2.

Example 3

1-(2,6-dimethoxybenzoyl)-3-(2,6-dibromophenyl)urea

The title compound melts at 214-215 °C.

Analysis:

for Ci6Hi4Br2N2O4 calculated

41.95% C, 3.08% H, 6.12% N; found

41.89% C, 2.93% H, 5.98% N.

Example 4 1-(2,6-diethoxybenzoyl)-3-(2,6-difluorophenyl)urea

The title compound melts at 129-130°C.

Analysis: for C18H18F2N2O4 calculated

59.34% C, 4.98% H, 7.69% N;

59.08% C, 5.10% H, 7.52% N.

It has been found that the novel compounds of formula I exhibit useful herbicidal activity when applied post-emergence and pre-emergence against a variety of weed species. The compounds described can be applied directly to the plants when they are young, but are preferably applied to the soil before the plants emerge. These compounds can either be applied to the soil using a conventional disc cultivator or harrow before sowing the desired crop, or they can be applied to the soil surface before the plants emerge. In this latter process, the active ingredients are not incorporated into the soil, but are simply allowed to leach into it, for example by rain.

The compounds of general formula I exhibit activity against a wide variety of different weed species, including the following:

Chenopodium album Amaranthus retroflexus Xanthium orientale Ambrosia ariémisiifolia Datura stramonium Ipomoea purpurea Digitaria sanguinalis Echinochloa crus galii Brassica juncea Setaria viridis Avena sativa Abutilon theophrasti Zinia elegans Portulaca oleracea Sida spinosa

Panicum dichotomiflorum Bidens frondosa Eclipta juncea Alopecurus myosuroides Galium aparine Matricaria chamomilla Stellaria media Varonica persica Acanthospermum hispidum Cenchrus echinatus Eleusine indica Richardia brasiliensis Solanum spp.

white merle, bent leaf ragweed, datura, virgin cucumber, dewberry, bloody hedgehog, chicken's foot, turnip green oat, deaf abutilon, ostrich, cabbage purslane, dogwood, field bindweed, primrose, chamomile, bird's-foot trefoil, Persian eleusinian eggplant and against a number of other species including unwanted weeds and grassy weeds.

It has also been found that the compounds of formula I are safe for a wide variety of desirable plants, such that they exhibit Zea mays Triticum aestivum

Oryza sativa Hordeum vulgare Glycine max Gossypium hirsutum Sorghum vulgare var.

Saccharatum Pisum sativum Medicago sativa Cucumis sativus Lycopersicon esculentum Arachis hypogaea Beta vulgaris Brassica napus Brassica oleracea capitata Brassica rapa

As already mentioned above, the compounds of the general formula I can be used in combination with other herbicides. Such combinations are advantageous when a broader spectrum of herbicidal activity against undesirable vegetation is desired than can be achieved by using the herbicide alone due to its exceptional selectivity. Representative examples of species of useful plants relatively tolerant to the compounds of the invention, depending on the concentration used, are:

corn wheat rice barley soybean cotton sorghum sugar peas alfalfa cucumber tomato peanuts oil beet sugar rape oilseeds cabbage turnips of the invention. For example, the compounds of the invention can be combined with herbicides that kill grass plants. Among the preferred herbicides against grass weeds, usable in the combinations forming the subject of the invention, are trifluralin, i.e. α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine of the formula

ethalfluralin, i.e. N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl j benzenamine of the formula

and oryzalin, i.e., 3,5-dinitro-4-dipropylaminophenylsulfonamide of the formula

The most preferred combination according to the invention is formed by trifluralin and 1-(2,6-dimethoxybenzoyl)-3-(2,6-difluorophenyl)urea.

The invention also describes a method of controlling undesirable plants, which is characterized in that a combination of a benzoylphenylurea of the general formula I is applied to these plants together with another herbicide, in an effective amount inhibiting the growth of the plants. The application rate required for each individual herbicide in the above combination depends on a number of factors, including the type of weeds and grasses to be controlled, the type of herbicides to be used in combination, climatic and soil conditions, the weed population and related factors. In general, the compounds of the invention are used in combination with other herbicides in a ratio of about 1 to 10 parts by weight of the benzoylphenylurea of the invention to about 10 to 1 part by weight of the other herbicide. Preferably, these ratios of active ingredients range from 1 to 4 parts by weight of the compound of the general formula I to 3 to 1 part by weight of the other herbicide. A particularly preferred combination contains the individual herbicidally active ingredients in a weight ratio of approximately 1:1. The combinations according to the invention are applied in doses effective to control unwanted plants to the desired extent.

These rates generally range from about 0.056 to about 16.8 kg of active ingredient per hectare. The active ingredients described are preferably applied at rates of about 0.28 to 8.96 kg/ha. The required concentration of active ingredient in any given case varies depending on the type of weed being controlled, the type of product, the type of soil, climatic conditions, etc.

The term "undesirable vegetation" as used above refers to both weeds and weed seeds present in the area to be treated with a compound of formula I in combination with another herbicide. The active ingredients described can be applied to the soil for selective control of unwanted plants by bringing the weed seeds into contact with the treated soil during germination and emergence. The active ingredients of the invention can also be used to directly control emerging weeds by contact with the above-ground parts of these plants.

The active ingredients of the invention can also be processed together with a suitable, agriculturally usable carrier or diluent to form appropriate compositions. These compositions contain, depending on the desired type of composition, from about 0.1 to about 95.0% by weight of the active ingredient. Compositions that can be applied by spraying are preferred, due to the speed and economy of their application.

Powder compositions typically contain from about 0.1 to 10% of the active ingredient. Powder compositions are prepared by intimately mixing and finely grinding the active ingredient with an inert solid such as crushed montmorillonite clay, attapulgite clay, talc, crushed volcanic rock, kaolin clay, or other inert, relatively dense, and inexpensive materials.

Most compositions containing the active ingredients of the invention are in the form of concentrated compositions for spray application in the form of aqueous dispersions or emulsions containing about 0.1 to about 10% of the active ingredient. Water-dispersible or emulsifiable compositions may be either solid (commonly known as wettable powders) or liquid (commonly known as emulsifiable concentrates).

A typical wettable powder is composed of a homogeneous mixture of the active ingredient, an inert carrier and surfactants. The concentration of the active ingredient typically ranges from about 25% to about 90% by weight. The inert carrier is typically selected from the group of materials including attapulgite clays, montmorillonite clays, diatomaceous earths and purified silicates. The surfactants, comprising about 0.5% to about 10% by weight of the wettable powder, are selected from the group including sulfonated lignins, condensed naphthalene sulfonates and alkyl sulfates.

A typical emulsifiable concentrate contains about 12 to 720 g of active ingredient per liter of liquid, the active ingredient being dissolved in a mixture of organic solvents and emulsifiers. The organic solvent is selected for this purpose taking into account its dissolving power and cost. Suitable solvents include aromatic solvents, especially xylenes and aromatic petroleums. Hydrophilic co-solvents, such as cyclohexanone and glycol ethers, such as 2-methoxyethanol, may also be added. Other organic solvents, including terpene solvents and petroleum, may also be used. Suitable emulsifiers for the preparation of emulsifiable concentrates are selected from the group consisting of alkylbenzenesulfonates, naphthalenesulfonates and non-ionic surfactants, such as alkylphenols with ethylene oxide, these emulsifiers being used in the same percentage concentrations as in the case of wettable powders.

Solid granular compositions are suitable for application to soil and contain the active ingredient in an amount of about 0.1 to 20% by weight. The granules consist of the active ingredient coated on a granular inert carrier, such as coarsely ground clay with a particle size of about 0.1 to 3 mm. The active ingredient is most conveniently applied to this clay by dissolving it in an inexpensive solvent and applying the solution to the clay of the desired particle size in a suitable mixer.

The active agents are applied to the plants by methods conventional in agrochemistry. Sprayable agents are readily applied using any of the numerous types of sprayers known and available in the art. Self-propelled sprayers, tractor-mounted sprayers, and trailed sprayers that apply water-dispersed agents through calibrated spray nozzles are suitable and effective. Metered application devices that can apply precisely measured amounts of granular agents to the soil are also suitable. The operator of the application device need only take care to adjust the device to apply the appropriate amount of water-dispersed or granular agent per hectare to achieve the desired application rate of active agent, and to achieve uniform distribution of this amount over the treated plants.

The active ingredients of the combinations according to the invention can be mixed as such and then prepared together into a suitable composition, or they can be individually processed into suitable compositions and then applied as a combination or individually to the location of undesirable plants.

The following examples serve to illustrate typical herbicidal compositions containing as active ingredient the compound of general formula I alone.

Wettable powder component concentration (% by weight) 1-(2,6-dimethoxybenzoyl)-3-(2,6-difluorophenyl) urea 50.0 nonionic wetting agent (Igepal) 5.0 lignosulfonate-based dispersant (Polyfon O) 5.0 precipitated hydrated silica as swelling agent (Zeolex 7) 5.0 clay 35.0

----The individual components are mixed and ground into a free-flowing powder which can be suspended in water for conventional spraying application. As the active ingredient in the above composition, it is of course possible to use any of the compounds of general formula I or a combination thereof with another herbicide.

Aqueous suspension component concentration (% by weight)

1- J 2,6-dimethoxybenzoyl J-3-

- (2,6-dichlorophenyl)urea 45.00 anionic wetting and dispersing agent based on lignosulfonate (Polyphone HJ 5.00 clay-type gelling agent (Min-u-gel 200) 2.00 antifoam additive (Antifoam C) 0.05 water 47.95 100.00

The above-mentioned components are thoroughly mixed and finely ground to form a suitable suspension, which is further diluted with water at the site of application. As an active substance in the above-mentioned composition, it is of course possible to use any of the compounds of general formula I or its combination with another herbicide.

Dust component concentration (% by weight)

1-(2,6-dimethoxybenzoyl)-3-(2,6-difluorophenylurea) 5.00

Infusoria clay (Diatomite 95.00

WOW

Benzoylphenylurea is thoroughly mixed with diatomaceous earth and the mixture is ground to a fine powder with a uniform particle size of approximately 16 to 40 µm. The dust thus obtained can be applied by a number of conventional methods, for example by air. As an active ingredient in the above composition, it is of course possible to use any of the compounds of general formula I or its combination with another herbicide.

Granule component concentration (% by weight)

1-(2,6-dimethoxybenzoyl)-3-(2,6-difluorophenyl)urea 5.0 aromatic petroleum 5.0 granular clay (Florex 30/60) 90.0

100.0

The herbicidally active substance is dissolved in petroleum and sprayed onto the granulated clay, usually with stirring, after which the resulting granulate is sieved to a uniform particle size. As the active substance in the above composition, it is of course possible to use any of the compounds of general formula I or a combination thereof with another herbicide.

The following section provides an example of a typical herbicidal composition containing the combination of the invention.

Tank-mix preparation component % by weight

1-(2,6-dimethoxybenzoyl)-3-(2,6-difluorophenyl) urea in the form of 50% wettable powder 60.0 trifluralin in the form of granulated concentrate (480 g/liter) 40.0

100.0

A wettable powder containing 50% by weight of the active ingredient of the general formula I is introduced into water and an emulsifiable concentrate containing 480 g of trifluralin per liter is added to the mixture while stirring. The resulting mixture is sprayed onto the soil surface, after which it is usually incorporated to a depth of about

7.5 to 10 cm.

The herbicidal efficacy of representative combinations of the invention is illustrated by the following field trials.

Attempt 1

A field trial was conducted using the compound of Example 2 above and trifluralin as active ingredients. For use in this trial, a tank-mix preparation was prepared from these active ingredients by adding the compound of Example 2 as a 50% wettable powder to water under stirring and mixing this mixture with an emulsifiable concentrate containing 480 g of trifluralin per liter. This combined formulation was incorporated into the soil to a depth of 7.5 centimeters before sowing and the treated soil was sown with soybeans and cotton on the same day. The results obtained, as shown in Table I below, are expressed as percentage inhibition.

Table I

Efficacy of the combination of the compound of Example 2 and trifluralin

applied dose (kg/ha) compound from example 2 + trifluralin number of days after sowing soybean inhibition in % cotton tree datura take September 2.24 + 0.56 20 0.3 5.0 100.0 97.5 99.5 35 0 0 100.0 97.5 98.2 1.68 + 0.56 20 0 0 98.8 100.0 99.7 35 0 0 97.5 98.8 98.8 1.12 + 0.56 20 0 0 98.2 99.0 98.0 ·>·'·’ -V· 35 0 0 94.5 95.7 94.5 0.56 + 0.56 20 0 0 93.8 100.0 93.5 35 0 0 73.8 99.5 87.5

3 7 3 4 0

Attempt 2

A field trial was also conducted in Mississippi using a combination of the compound of Example 2 and trifluralin in cotton against a wide variety of weeds. The combination of active ingredients was prepared as a tank-mix preparation and incorporated into the soil prior to sowing as in the previous trial. The crop was sown 5 days after treatment.

The results obtained in this test are shown in the following Table II.

Table II

detected effect number of days after treatment applied dose (kg/ha compound from example 2 + trifluralin efficiency damage to cotton plants 40 2.24 + 0.84 0 5 to 7.5 cm tall 1.68 -j- 0.84 0 1.12 + 0.84 0 0.84 + 0.84 0 0.56 + 0.84 0 0.28 4- 0.84 0 untreated control 0 damage to cotton plants 90 2.24 + 0.84 0 in the early stages of flowering 1.68 -j- 0.84 0 1.12 + 0.84 0 0.84 + 0.84 0 0.56 + 0.84 0 - 0.28 4- 0.84 0 untreated control 0 damage to cotton plants 181 2.24 + 0.84 0 having 50 to 60% capsules 1.68 4- 0.84 0 open 1.12 4- 0.84 0 0.84 4- 0.84 0 0.56 4- 0.84 0 0.28 + 0.84 0 untreated control 0 number of cotton plants 51 2.24 + 0.84 109.7 always on two three-meter 1.68 + 0.84 102.6 lines 1.12 4- 0.84 97.4 0.84 4- 0.84 90.3 0.56 + 0.84 102.6 0.28 -4 0.84 95.4 untreated control 100.0 cotton seed yield 195 2.24 + 0.84 116.7 always from an area of 29.5 m ² 1.68 -4 0.84 134.4 1.12 -4 0.84 126.7 0.84 4- 0.84 132.2 0.56 4- 0.84 118.9 0.28 4- 0.84 113.3 untreated control 100.0 extermination of the bee 40 2.24 + 0.84 100.0 1.68 4- 0.84 100.0 1.12 4- 0.84 100.0 0.84 4- 0.84 100.0 0.56 + 0.84 100.0 0.28 4- 0.84 100.0 untreated control 0 90 2.24 + 0.84 100.0 1.68 + 0.84 100.0 1.12 + 0.84 100.0 0.84 4- 0.84 100.0 0.56 + 0.84 100.0 0.28 + 0.84 100.0 untreated control 0 181 2.24 + 0.84 100.0 1.68 4- 0.84 100.0 1.12 + 0.84 100.0 0.84 4- 0.84 . 100.0

effect investigated number of applied dose (kg/ha) effectiveness (%) days after compound from example 2 treatment + trifluralin eradication of purslane eradication of sedge eradication of Sida spinosa eradication of reed

0.56 + 0.84 100.0 0.28 + 0.84 100.0 untreated control 0 2.24 + 0.84 100.0 1.68 + 0.84 100.0 1.12 + 0.84 100.0 0.84 0.84 100.0 0.56 + 0.84 98.3 0.28 4- 0.84 100.0 untreated control 0 2.24 + 0.84 100.0 1.68 + 0.84 100.0 1.12 + 0.84 100.0 0.84 4- 0.84 100.0 0.56 4- 0.84 100.0 0.28 4- 0.84 93.3 untreated control 0 2.24 + 0.84 100.0 1.68 4- 0.84 99.3 1.12 4- 0.84 100.0 0.84 4- 0.84 100.0 0.56 4- 0.84 100.0 0.28 + 0.84 100.0 untreated control 0 2.24 + 0.84 33.3. 1.68 4" 0.84 6.7 1.12 4- 0.84 0 0.84 4- 0.84 0 0.56 + 0.84 0 0.28 + 0.84 0 untreated control 0 2.24 + 0.84 60.0 1.68 +- 0.84 0 1.12 + 0.84 0 0.84 4- 0.84 0 0.56 4- 0.84 16.7 0.28 4- 0.84 0 untreated control 0 2.24 + 0.84 75.0 1.68 4- 0.84 23.3 1.12 + 0.84 0 0.84 4- 0.84 10.0 0.56 + 0.84 13.3 0.28 + 0.84 0 untreated control 0 2.24 + 0.84 93.3 1.68 4- 0.84 96.7 1.12 + 0.84 90.0 0.84 4 0.84 78.3 0.56 4- 0.84 53.3 0.28 + 0.84 20.0 untreated control 0 2.24 + 0.84 100.0 1.68 4- 0.84 100.0 1.12 + 0.84 100.0 0.84 4- 0.84 100.0 0.56 + 0.84 96.7 0.28 4- 0.84 93.7 untreated control 0

T h e r e s 3

A field trial was conducted in Brazil to evaluate the herbicidal activity of the compound of Example 2, both alone and in combination with either ethalfluralin or oryzalin, as well as the tolerance of this active ingredient or combinations thereof to the crop plants. For both of these tests, the compound of Example 2 is formulated into a 50% wettable powder. For combination with the compound of Example 2, oryzalin is formulated into an aqueous suspension containing the active ingredient at a concentration of 480 grams per liter. In the above-mentioned test, the two formulations are mixed directly in a sprayer (tank-mix) and applied to the soil surface after sowing. Ethalfluralin is formulated into an emulsifiable concentrate containing the active ingredient at a concentration of 360 g/liter, combined with the compound of Example 2 and diluted with water to obtain a tank-mix formulation again. This formulation is then incorporated into the soil after sowing using a harrow with flexible tines. The results of the visual comparison of the condition on the treated and untreated control plots are recorded. The results obtained when applying the combination of the compound of Example 2 and ethalfluralin are shown in Table III below, and the results obtained when applying the combination of the compound of Example 2 and oryzalin are shown in Table IV.

Table III

Efficacy of the combination of the compound of Example 2 and ethalfluralin

detected effect number of days after treatment treatment applied dose (kg/ha) efficiency rice damage 16 compound 1.5 + 0.9 0 from example 2 1.0 + 0.9 0 + ethalfluralin 0.75 + 0.9 0 0.5 + 0.9 1.3 compound from example 2 1.0 0 untreated control 0 37 compound 1.5 + 0.9 0 from example 2 1.0 ’Ί 0.9 0 -f~ ethalfluralin 0.75 + 0.9 2.5 0.5 + 0.9 2.5 compound from example 2 1.0 0 untreated control 0 damage 16 compound 1.5 + 0.9 0 rice roots from example 2 1.0 + :0.9 0 -j- ethalfluralin 0.75 + 0.9 0 compound 0.5 + 0.9 ï from example 2 1.0 0 untreated control 0 37 compound 1.5 + 0.9 0 from example 2 1.0 + 0.9 2.5 ethalfluralin 0.75 + 0.9 0 0.5 + 0.9 0 compound from example 2 1.0 0 untreated control 0 extermination 37 compound 1.5 + 0.9 97.5 eleusinia from example 2 1.0 + θ,9 97.5 + ethalfluralin 0.75 0.9 95.0 0.5 + 0.9 95.0 compound from example 2 1.0 0 untreated control 0 extermination 37 compound 1.5 + 0.9 75.0 poppy from example 2 1.0 + θ,9 82.5 -j- ethalfluralin 0.75 + θ,9 77.5 0.5 + 0.9 66.3 compound from example 2 1.0 0 untreated control 0

effect investigated number of treatments days after treatment applied dose effectiveness (%) (kg/ha)

extermination of the sedge 37 compound 1.5 + 0.9 97.5 from example 2 1.0 + 0.9 100.0 + ethalfluralin 0.75 + 0.9 100.0 0.5 + 0.9 100.0 compound from example 2 1.0 100.0 untreated control 0 extinction of "Brazil 37 compound 1.5 + 0.9 90.0 Calalilly from example 2 1.0 + 0.9 82.5 + ethalfluralin 0.75 + 0.9 82.5 0.5 . + 0.9 77.5 compound from example 2 1.0 0 untreated control 0 damage to soybeans 17 compound 1.5 + 1.5 0 from example 2 1.0 + 1.5 0 + oryzalin compound 0.75 + 1.5 0 from example 2 1.0 0 untreated control 0 31 compound 1.5 7.5 from example 2 1.0 + 1.5 0 + oryzalin 0.75 + 1.5 0 compound from example 2 1.0 5.0 untreated control 0 soybean sprouting 31 compound 1.5 + .1.5 82.7 from example 2 1.0 + 1.5 75.6 + oryzalin compound 0.75 1.0 + 1.5 • 96.6 from example 2 82.2 untreated control 100.0 damage 17 compound 1.5 + 1.5 0 soybean roots from example 2 1.0 + 1.5 0 + oryzalin 0.75 + 1.5 0 compound from example 2 1.0 0 untreated control 0 31 compound 1.5 ^; + 1.5 10.0 from example 2 1.0. -4-1.5 7.5 + oryzalin compound 0.75 + 1.5 10.0 from example 2 1.0 5.0 untreated control 0 extermination 31 compound 1.5 + 1.5 98.2 Cenchrus echinatus from example 2 1.0 + 1.5 95.0 + oryzalin compound 0.75 + 1.5 96.3 from example 2 1.0 0 untreated control 0 extermination 31 compound 1.5 + 1.5 100.0 blood dewdrops from example 2 1.0 + 1.5 100.0 + oryzalin 0.75 + 1.5 100.0 compound from example 2 1.0 0 untreated control 0 extermination 31 compound 1.5 + 1.5 92.0 poppy from example 2 1.0 + 1.5 90.0 + oryzalin compound 0.75 + 1.5 85.0 from example 2 1.0 0 untreated control 0

22 effect investigated number of treatments applied dose efficacy (% j days after (kg/haj treatment

extermination of the sedge 31 compound 1.5 + 1.5 100.0 from example 2 1.0 + 1.5 100.0 + oryzalin 0.75 + 1.5 100.0 compound from example 2 1.0 98.8 untreated control 0 extermination 31 compound 1.5 + 1.5 97.5 Sida spinosa from example 2 1.0 + 1.5 96.3 -j- oryzalin compound 0.75 + 1.5 100.0 from example 2 1.0 0

untreated control

Claims (1)

SUBJECT A herbicidal composition comprising as active ingredient a combination of a compound of formula (I) wherein: OF THE INVENTION both R ¹ are the same and are methyl or ethyl and R ² and R ³ are the same and are fluorine, chlorine or bromine, and a second herbicide selected from the group consisting of α, α, α-trifluoro-2,6-dinitro-N, N-dipropyl-p-toluidine, N ethyl-N- (2-methyl-2-propenyl) -2,6-dinitro-4- (trifluoromethyl) benzenamine and 3,5-dinitro-4-dipropylaminophenylsulfonamide, in a weight ratio of the compound of formula I to the second herbicide of 4: 1 to 1: 3, together with one or more agriculturally acceptable carriers or diluents.