KR20070029203A - Herbicide composition - Google Patents

Abstract

The present invention

A) pretilachlor + prosulfocarb,

B) pretilachlor + mesotrione + prosulfocarb,

C) pretilachlor + pythaphthalide + benzulfuron,

D) pretilachlor + mesotrione + pyriphthalide + bensulfuron,

E) pretilachlor + mesotrione + pyriphthalide + imazosulfuron and

F) A herbicidal synergistic composition for the selective control of weeds, characterized in that it comprises a combination of herbicidal compounds selected from the group consisting of pretilachlor + mesotrione + pyriphthalide + pyrazosulfuron.

Description

Herbicide composition

The present invention preferably comprises a herbicidal active ingredient combination suitable for selectively controlling weeds (eg grass, broadleaf weeds and weeds), in particular ALS resistant weeds, in useful plants, such as rice crops. It relates to a novel herbicidal synergistic composition.

The present invention also relates to a method for controlling weeds defined as unwanted vegetation in crops of useful plants, and to the use of the novel compositions, for example, to act as desired control in undesired vegetation or its habitat. .

Compounds bensulfuron (64), imazosulfuron (456), mesotrione (515), pretilachlor (656), prosulfocarb (683) , Pyrazosulfuron-ethyl (694), pyriftalid 704 and agronomically acceptable salts thereof are described, for example, in The e-Pesticide Manual, version 3.0, 13th Edition, Ed. Herbicidal activity as described in CDC Tomlin, British Crop Protection Council, 2003-2004.

Surprisingly, the combination of various amounts of the active ingredient in question can cause pre-emergence and post-emergence, especially in crops of useful plants, without causing significant damage to useful plants. It has now been found that a synergistic effect can be obtained. In particular, a particular problem solved is the selective control of ALS resistant weeds in useful plants such as rice crops.

Thus, according to the present invention

A) pretilachlor + prosulfocarb,

B) pretilachlor + mesotrione + prosulfocarb,

C) pretilachlor + pythaphthalide + benzulfuron,

D) pretilachlor + mesotrione + pyriphthalide + bensulfuron,

E) pretilachlor + mesotrione + pyriphthalide + imazosulfuron and

F) A novel herbicidal synergistic composition for the selective control of weeds is proposed, comprising a combination of herbicidal compounds selected from the group consisting of pretilachlor + mesotrione + pyriphthalide + pyrazosulfuron .

Very surprisingly, the combination of the active ingredients exhibits in principle the action beyond the expected action on the weeds to be controlled, thus extending the range of action of the two active ingredients, in particular in two aspects: Good levels of action are maintained even with reduced utilization, and secondly, the compositions according to the present invention achieve high weed control levels even when each material becomes useless from an agricultural standpoint in the low usage range. As a result, the range of weeds to be controlled has become considerably wider, and the selectivity of crops of useful plants is further increased, which is necessary or required in case of unwanted overuse of the active ingredient. The composition according to the invention also allows greater flexibility for later crops, while maintaining good weed control in crops of useful plants.

The compositions according to the invention comprise the active ingredients mentioned in any mixing ratio, but generally have one excess of ingredients relative to each other.

In general, compound pretilachlor and prosulfocarb are used in the bidirectional mixture pretilachlor + prosulfocarb at a ratio of 300 to 600, and 2000 to 4000 (g / ha), and the compound pretilachlor, mesotri, respectively. On, prosulfocarb, pyridphthalide and bensulfuron are 300 to 600, 50 to 50 in the three-way mixture pretilachlor + mesotrione + prosulfocarb and pretilachlor + pyphthalphthalide + bensulfuron Used in ratios of 100, 2000 to 4000, 50 to 75, and 100 to 200 (g / ha), the compounds pretilachlor, mesotrione, pyriphthalide, bensulfuron, imazosulfuron and pyrazosulfuron are respectively Four-way mixture Pretilachlor + Mesotrione + Pytriphthalide + Bensulfuron, Pretilachlor + Mesotrione + Pyriphthalide + Imazosulfuron and Pretilachlor + Mesotrione + Pytriphthalide + Fira 600 to 300 in Seolfuron 50 to 100, 100 to 200, 50 to 75, 50 to 75, and 50 to 75 (g / ha).

Preferred weight mixing ratios are as follows:

Bidirectional mixture pretilachlor: 5-7: 30-50 for prosulfocarb,

5-7: 0.1-3: 30-50, respectively for three-way mixture pretilachlor: mesotrione: prosulfocarb;

Three-way mixture pretilachlor: methotrione: bensulfuron 5-7: 0.1-3: 1-3, respectively;

Four-way mixture Pretilachlor: Mesotrione: Pytriphthalide: Bensulfuron, Pretilachlor: Mesotrione: Pytriphthalide: Imazosulfuron and Pretilachlor: Mesotrione: Pytriphthalide: 5 to 7: 0.1 to 3: 1 to 4: 1 to 3, respectively, for pyrazosulfuron

The most preferred weight mixing ratio is as follows:

Bidirectional mixture pretilachlor: 6:40, respectively for prosulfocarb;

6: 1: 40, respectively for the mixture Pretilachlor: Mesotrione: Prosulfocarb;

6: 1: 1 for the mixture pretilachlor: methotrione: bensulfuron, respectively,

Four-way mixture Pretilachlor: Mesotrione: Pytriphthalide: Bensulfuron, Pretilachlor: Mesotrione: Pytriphthalide: Imazosulfuron and Pretilachlor: Mesotrione: Pytriphthalide: 6: 1: 2: 1 for pyrazolfuron, respectively.

The rate of use may also vary over a wide range, including soil condition, method of use (prior or post-germination, seed dressing, application to seed ditch, non-cultivation, etc.), crops, weeds or grasses controlled, effective climate It depends on other factors governing the conditions and method of use, the time of use and the target crop. The active ingredient mixtures according to the invention generally have an active ingredient mixing ratio of 0.05 to 7 kg per hectare, preferably 0.5 to 6 kg per hectare for a bidirectional mixture, an active ingredient mixing ratio of 2 to 6 kg per hectare for a three-way mixture, four directions It can be used in a mixture ratio of 0.5 to 2 kg of active ingredient per hectare per mixture.

The invention also relates to a method for selectively controlling grass and weeds in crops of useful plants, comprising treating the useful plants or their arable land or habitat simultaneously or at different times with the composition according to the invention.

Crops of useful plants in which the composition according to the invention can be used, in particular, include rice. The term “crop” is understood to include crops that are resistant to herbicides or herbicide classes (eg, ALS, GS, EPSPS, PPO and HPPD inhibitors) as a result of conventional breeding methods or genetic engineering. For example, an example of a crop that is resistant to imidazolinone, for example imazamox, by conventional breeding methods is Clearfield® summer rapeseed (Canula). Examples of crops that are resistant to herbicides by genetic engineering are, for example, glyphosate and glufosinate resistant corn varieties available commercially under the trade names RoundupReady® and LibertyLink®. It includes. Weeds controlled are monocotyledonous and dicotyledonous plants, for example, Asteraceae, Asteraceae, Azalea, Cereal, Oat, Datura, Perilla, Rye, Branch, Blood Fluff, Sparrow Owl, Honeysuckle, Cornflower, Rottboellia, Moth, Spruce, Cactus, Drake, Amaranth, Dried Persimmon, Sweet Potato, Chrysanthemum, Prunusaceae, Violet And canopy plants.

Crops are also understood as those that have become resistant to pests by genetic engineering methods, such as Bt corn (European insect resistance), Bt cotton (cotton weevil resistance) and Bt potatoes (colorado leaf beetle resistance). An example of Bt maize is the Bt-176 maize hybrid from NK® (manufactured by Syngenta Seeds). Bt toxin is a protein naturally formed by Bacillus thuringiensis soil bacteria. Examples of toxins and transgenic plants capable of synthesizing such toxins are described in EP-A-451 878, EP-A-374 753, WO 93/07278, WO 95/34656, WO 03/052073 and EP-. A-427 529. Examples of transgenic plants that contain one or more genes encoding insect resistance and express one or more toxins include KnockOut® (corn), Yield Gard® (corn), NuCOTIN33B®. (Cotton), Bollgard® (cotton), NewLeaf® (potato), NatureGard® and Protexcta®. Plant crops and their seed material may be resistant to insect supply as well as to herbicides ("cumulative" transduction occurs). Seeds, for example, may express entomologically active Cry3 protein and at the same time may be glyphosate resistant. The term “crop” is also understood to include crops obtained by conventional breeding methods or by genetic engineering containing so-called production properties (eg, improved flavor, storage stability and nutrient content).

Arable land is understood to include the land on which crop plants are already growing, as well as the land from which these crop plants are to be grown.

The composition according to the invention can be used in unmodified form. However, compositions according to the invention are generally formulated in a variety of ways using formulation aids such as carriers, solvents and surfactant ingredients. The formulations may be in various physical forms, such as dust, gels, wet powders, water dispersible granules, water dispersible tablets, effervescent compressed tablets, emulsifiable concentrates, microemulsifiable concentrates, oil-in-water emulsions, fluid oils, aqueous dispersions , Oily dispersions, suspending agents, capsule suspensions, emulsifying granules, soluble liquids, water solubles (containing water or water-miscible organic solvents as carriers), saturated polymeric membranes or, for example, Manual on Development and Use of FAO Specifications for Plant Protection Products, 5th Edition, 1999]. The formulations can be used directly or diluted before use. Diluted formulations may be prepared, for example, with water, liquid fertilizers, micronutrients, biological entities, oils or solvents.

Formulations can be prepared, for example, by mixing the active ingredient with a formulation aid to obtain a composition in the form of finely divided solids, granules, solutions, dispersions or emulsions. The active ingredient may also be formulated with other auxiliaries such as finely divided solids, mineral oils, vegetable oils, modified vegetable oils, organic solvents, water, surfactants or combinations thereof. The active ingredient may also be contained in very fine microcapsules composed of polymers. Microcapsules contain the active ingredient in a porous carrier. This allows the active ingredient to be released in a controlled amount around it (slow release). Microcapsules generally have a diameter of 0.1 to 500 μm. They contain the active ingredient in an amount of about 25 to 95% by weight, based on the weight of the capsule. The active ingredient may be present in the form of a monolithic solid, in the form of fine particles in a solid or liquid dispersion or in the form of a suitable solution. Encapsulated membranes are, for example, natural and synthetic rubbers, celluloses, styrene-butadiene copolymers, polyacrylonitrile, polyacrylates, polyesters, polyamides, polyureas, polyurethanes or chemically modified polymers and specialty polymers. Pellets or other polymers known to those skilled in the art. Alternatively, the active ingredient is in the form of finely divided particles in the solid matrix of the base ingredient, in which case the microcapsules are not encapsulated.

Formulation aids suitable for the formulation of the compositions according to the invention are known per se. As liquid carriers water, toluene, xylene, petroleum ether, vegetable oils, acetone, methyl ethyl ketone, cyclohexanone, acid anhydride, acetonitrile, acetophenone, amyl acetate, 2-butanone, butyl carbonate, chlorobenzene, cyclo Hexane, cyclohexanol, alkyl esters of acetic acid, diacetone alcohol, 1,2-dichloropropane, diethanolamine, p-diethylbenzene, diethylene glycol, diethylene glycol abietate, diethylene glycol butyl ether, di Ethylene glycol ethyl ether, diethylene glycol methyl ether, N, N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, dipropylene glycol, dipropylene glycol methyl ether, dipropylene glycol dibenzoate, diproxytol , Alkylpyrrolidone, ethyl acetate, 2-ethyl hexanol, ethylene carbonate, 1,1,1-trichloroethane, 2-heptanone, alpha-pinene, d-limonene , Ethyl lactate, ethylene glycol, ethylene glycol butyl ether, ethylene glycol methyl ether, gamma-butyrolactone, glycerol, glycerol acetate, glycerol diacetate, glycerol triacetate, hexadecane, hexylene glycol, isoamyl acetate, iso Carbonyl acetate, isooctane, isopropane, isopropylbenzene, isopropyl myristate, lactic acid, laurylamine, mesityl oxide, methoxypropane, methoxypropanol, methyl isoamyl ketone, methyl isobutyl ketone, methyl laurate, Methyl octanoate, methyl oleate, methylene chloride, m-xylene, n-hexane, n-octylamine, octadecanoic acid, octylamine acetate, oleic acid, oleylamine, o-xylene, phenol, polyethylene glycol (PEG 400 Propionic acid, propyl lactate, propylene carbonate, propylene glycol, propylene glycol methyl ether, p-ch Ethylene, toluene, triethyl phosphate, triethylene glycol, xylenesulfonic acid, paraffin, mineral oil, trichloroethylene, perchloroethylene, ethyl acetate, amyl acetate, butyl acetate, propylene glycol methyl ether, diethylene glycol methyl ether, methanol Ethanol, isopropanol and high molecular weight alcohols such as amyl alcohol, tetrahydrofurfuryl alcohol, hexanol, octanol, ethylene glycol, propylene glycol, glycerol, N-methyl-2-pyrrolidone and the like can be used. have. Water is generally chosen as the carrier for diluting the concentrate. Suitable solid carriers are, for example, talc, titanium dioxide, pyrophyllite clay, silica, attapulgite clay, diatomaceous earth, limestone, calcium carbonate, bentonite, calcium montmorillonite, cottonseed husk, whole wheat, soy flour, pumice, wood Flour, ground walnut shells, lignin and, for example, CFR 180.1001. (c) & (d)].

Advantageously, various surfactant components are used in solid and liquid formulations, in particular formulations which can be diluted with a carrier before use. The surfactant component may be anionic, cationic, nonionic or polymeric, and they may be used as emulsifiers, wetting agents or suspending agents or for other purposes. Typical surfactant components include, for example, salts of alkyl sulfates such as diethanolammonium lauryl sulfate; Salts of alkyllaurylsulfonates such as calcium dodecylbenzenesulfonate; Alkylphenol-alkylene oxide addition products such as nonylphenol ethoxylates; Alcohol-alkylene oxide addition products such as tridecyl alcohol ethoxylate; Soaps such as sodium stearate; Salts of alkylnaphthalenesulfonates such as sodium dibutylnaphthalenesulfonate; Dialkyl esters of sulfosuccinate salts such as sodium di (2-ethylhexyl) sulfosuccinate; Sorbitol esters such as sorbitol oleate; Quaternary amines such as lauryl trimethylammonium chloride; Polyethylene glycol esters of fatty acids such as polyethylene glycol stearate; Block copolymers of ethylene oxide and propylene oxide; And salts of mono- and di-alkyl phosphate esters, and also further active ingredients described in "McCutcheon's Detergents and Emulsifiers Annual", MC Publishing Corp., Ridgewood, New Jersey, 1981.

In general, additional auxiliaries that can be used in agrochemical formulations include crystallization inhibitors, viscosity modifying components, suspending agents, dyes, antioxidants, blowing agents, absorbers, admixture aids, antifoaming agents, complexing agents, neutralizing or pH modifying ingredients and buffers, corrosion inhibitors. , Fragrances, wetting agents, absorption enhancers, micronutrients, plasticizers, glidants, lubricants, dispersants, thickeners, antifreezes, microbicides, and or liquid and solid fertilizers.

The formulation may also comprise additional active ingredients, for example additional herbicides, herbicide safeners, plant growth regulators, antifungals or pesticides.

The composition according to the invention further comprises additives comprising vegetable or animal oils, mineral oils, alkyl esters of such oils or mixtures of such oils and oil derivatives. The amount of oil additive used in the composition according to the invention is generally from 0.01 to 10% based on the amount of the spray mixture. For example, the oil additive may be added to the spray tank at the desired concentration after preparing the spray mixture. Preferred oil additives are mineral or vegetable oils such as rapeseed oil, olive oil or sunflower oil, emulsified vegetable oils such as AMIGO® [manufacturer: Long-Fran Canada Inc. (Rhone) Poulenc Canada Inc.), alkyl esters of vegetable oils such as methyl derivatives, or animal oils such as fish oil or resins. Preferred additives, for example, contain essentially 80% by weight of alkyl esters of fish oil, 15% by weight of methylated rapeseed oil and 5% by weight of conventional emulsifiers and pH modifiers as active ingredients. Particularly preferred oil additives include alkyl esters of important C ₈ -C ₂₂ fatty acids, especially methyl derivatives of C ₁₂ -C ₁₈ fatty acids, for example methyl esters of lauryl acid, palmitic acid and oleic acid. Are known as methyl laurate (CAS-111-82-0), methyl palmitate (CAS-112-39-0) and methyl oleate (CAS-112-62-9), respectively. Preferred fatty acid methyl ester derivatives are Emery® 2230 or 2231 (manufactured by Cognis GmbH). These and other oil derivatives are also known in Compendium of Herbicide Adjuvants, 5th Edition, Southern Illinois University, 2000.

The use and action of oil derivatives can be further enhanced by combining with surfactant components, such as nonionic, anionic or cationic surfactants. Suitable anionic, nonionic and cationic surfactants are described on pages 7 and 8 of WO 97/34485. Preferred surfactant components are anionic surfactants of the dodecyl-benzylsulfonate type, in particular calcium salts thereof, and nonionic surfactants of the fatty alcohol ethoxylate type. Particular preference is given to ethoxylated C ₁₂ -C ₂₂ fatty alcohols having an ethoxylation degree of from 5 to 40. An example of a commercially available surfactant is the Genapol type (manufactured by Clariant AG). Preference is furthermore given to silicone surfactants, in particular polyalkyl-oxide-modified heptamethyltrisiloxane, which is commercially available as, for example, Silwet L-77®, and also to perfluorinated surfactants. desirable. The content of the surfactant component relative to the total additive is generally 1 to 30% by weight. Examples of oil additives consisting of surfactants and oil mixtures or mineral oils or derivatives thereof include Edenor ME SU®, Turbocharge® (manufactured by Syngenta AG, CH) and actifron ( Actipron®® (manufacturer: BP Oil UK Limited, GB).

The surfactant component may also be used in the formulation alone, without oil additives.

In addition, the addition of organic solvents to the oil additive / surfactant mixture may further enhance the action. Suitable solvents are, for example, Solvesso® (manufactured by ESO) and Aromatic Solvent® (manufactured by Exxon Corporation). The content of such solvents may be about 10 to 80% by weight based on the total weight. Such oil additives which can be combined with a solvent are preferably described, for example, in US-A-4 834 908. The commercially available oil additives described in this document are known under the trade name MERGE® (BASF Corporation). A further oil additive preferred according to the invention is SCORE® [Syngenta Crop Protection Canada].

In addition to the oil additives described above, alkyl pyrrolidone formulations (eg Agrimax®) may be added to the spray mixture to enhance the activity of the compositions according to the invention. In addition, synthetic latex formulations such as polyacrylamide, polyvinyl compounds or poly-1-p-methane (eg, Bond®, Courier® or Emerald®) may be used. . In addition, a solvent containing propionic acid, such as Eurogkem Pen-e-trate®, may be mixed into the spray mixture as an activity enhancer.

Herbicide formulations generally comprise from 1 to 99.9% by weight comprising from 0.1 to 99% by weight, in particular from 0.1 to 95% by weight of the active ingredient mixture of the composition according to the invention and preferably from 0 to 25% by weight Contains formulation aids. While commercially available products are preferably formulated as concentrates, end-users generally can use the formulation diluted. Preferred formulations in particular have the following composition (% = weight%; "active ingredient mixture" is a mixture of compounds according to the compositions of the invention):

Emulsifiable Concentrate:

Active ingredient mixture: 1 to 95%, preferably 60 to 90%

Surfactant component: 1 to 30%, preferably 5 to 20%

Liquid carrier: remaining amount

Dust:

Active ingredient mixture: 0.1 to 10%, preferably 0.1 to 5%

Solid carrier: 99.9 to 90%, preferably 99.9 to 99%

Suspension Concentrate:

Active ingredient mixture: 5 to 75%, preferably 10 to 50%

Surfactant component: 1 to 40%, preferably 2 to 30%

Water: remaining amount

Wettable Powder:

Active ingredient mixture: 0.5 to 90%, preferably 1 to 80%

Surfactant component: 0.5 to 20%, preferably 1 to 15%

Solid carrier: remaining amount

Granules:

Active ingredient mixture: 0.1 to 30%, preferably 0.5 to 15%

Solid carrier: 99.9 to 70%, preferably 99.5 to 85%

The invention is further illustrated by the following examples, without however limiting the invention.

F1. Emulsifiable concentrate a) b) c) d)

Active ingredient mixture 5% 10% 25% 50%

Calcium Dodecylbenzene-Sulfonate 6% 8% 6% 8%

Rapeseed oil Polyglycol ether 4%-4% 4%

(36 mol of ethylene oxide)

Octylphenol polyglycol ether-4%-2%

(Ethylene oxide 7-8 mol)

NMP--10% 20%

Aromatic Hydrocarbon Mixture C ₉ -C ₁₂ 85% 78% 55% 16%

An emulsion of any desired concentrate can be prepared by diluting the concentrate with water.

F2. Solution a) b) c) d)

Active ingredient mixture 5% 10% 50% 90%

1-methoxy-3- (3-methoxy-

Propoxy) -propane-20% 20%-

Polyethylene Glycol MW 400 20% 10%--

NMP--30% 10%

Aromatic Hydrocarbon Mixture C ₉ -C ₁₂ 75% 60%--

The solution is suitable for application in the form of microdrops.

F3. Wettable powder a) b) c) d)

Active ingredient mixture 5% 25% 50% 80%

Sodium Lignosulfonate 4%-3%-

Sodium Lauryl Sulfate 2% 3%-4%

Sodium Diisobutylnaphthalene

Sulfonate `-6% 5% 6%

Octylphenol Polyglycol Ether-1% 2%-

(Ethylene oxide 7-8 mol)

Highly dispersible silicic acid 1% 3% 5% 10%

Kaolin 88% 62% 35%-

In order to obtain a suspension of any desired concentration, the active ingredient is thoroughly mixed with the adjuvant and the mixture is thoroughly ground with a suitable mill to obtain a wettable powder which can be diluted in water.

F4. Coated granules a) b) c)

Active ingredient mixture 0.1% 5% 15%

Highly dispersible silicic acid 0.9% 2% 2%

Inorganic Carrier 99.0% 93% 83%

(Diameter 0.1-1mm)

Eg CaCO ₃ or SiO ₂

The active ingredient is dissolved in methylene chloride, the solution is sprayed onto the carrier and the solvent is evaporated sequentially under vacuum.

F5. Coated granules a) b) c)

Active ingredient mixture 0.1% 5% 15%

Polyethylene Glycol MW 200 1.0% 2% 3%

Highly dispersible silicic acid 0.9% 1% 2%

Inorganic Carrier 98.0% 92% 80%

(Diameter 0.1-1 mm)

Eg CaCO ₃ or SiO ₂

The finely divided active component is applied singly in a mixer to wet the carrier with polyethylene glycol. Non-dusty coated granules are obtained by this method.

F6. Extruded granules a) b) c) d)

Active ingredient mixture 0.1% 3% 5% 15%

Sodium Lignosulfonate 1.5% 2% 3% 4%

Carboxylmethylcellulose 1.4% 2% 2% 2%

Kaolin 97.0% 93% 90% 79%

The active ingredient is mixed with the adjuvant and triturated and the mixture is wetted with water. The resulting mixture is extruded and then dried in an air stream.

F7. Dust a) b) c)

Active ingredient mixture 0.1% 1% 5%

Talcum 39.9% 49% 35%

Kaolin 60.0% 50% 60%

Ready to use dust is obtained by mixing the active ingredient with the carrier and grinding the mixture in a suitable mill.

F8. Suspension concentrate a) b) c) d)

Active ingredient mixture 3% 10% 25% 50%

Ethylene Glycol 5% 5% 5% 5%

Nonylphenol Polyglycol Ether-1% 2%-

(15 mol of ethylene oxide)

Sodium Lignosulfonate 3% 3% 4% 5%

Carboxymethylcellulose 1% 1% 1% 1%

37% formaldehyde aqueous solution 0.2% 0.2% 0.2% 0.2%

Silicone Oil Emulsion 0.8% 0.8% 0.8% 0.8%

Water 87% 79% 62% 38%

The finely divided active ingredient may be initially mixed with the adjuvant to prepare a suspension concentrate, and the suspension concentrate may be diluted with water to prepare a suspension of any desired concentrate.

It may be more practical to formulate the compounds present in the compositions according to the invention separately and then formulate them in the user phase in the desired mixing ratio in the form of a "tank mixture" in water immediately before application.

Biological Example

A synergistic effect is present, for example, when the action of the active ingredient combinations of the compounds according to the compositions of the invention is greater than the sum of the actions of the active ingredients when the active ingredients are respectively applied.

The herbicidal action expected to We for a given combination of two herbicides (A) and (B) can be calculated as follows: COLBY, SR, "Calculating synergistic and antagonistic response of herbicide combinations", Weeds 15, pages 20-22, 1967:

We = X + [Y. (100-X) / 100]

In the above equation,

X is the herbicidal action (%) for compound (A) treatment at a rate of pkg per hectare compared to untreated control (= 0%),

Y is the herbicidal action (%) for compound (B) treatment at a rate of qkg per hectare compared to untreated control.

Thus, if the activity observed is greater than the value expected by Colby's equation, there is a synergistic effect.

The expected herbicidal action of We for a given combination of three herbicides (A), (B) and (C) can be calculated as follows: COLBY, SR, "Calculating synergistic and antagonistic response of herbicide combinations" , Weeds 15, pages 20-22, 1967]:

We = X + Y + Z-[(XY) + (XZ) + (YZ) / 100] + [XYZ / 10000]

X is the herbicidal action (%) for compound (A) treatment at a rate of pkg per hectare compared to untreated control (= 0%),

Y is the herbicidal action (%) for compound (B) treatment at a rate of qkg per hectare compared to untreated control.

Z is the herbicidal action (%) for compound (C) treatment at a rate of qkg per hectare compared to untreated control.

Thus, if the observed activity is greater than the value expected by Colby's equation, there is a synergistic effect.

For a given combination of four herbicides (A), (B), (C) and (D), the herbicidal action expected to be We can be calculated as follows:

We = X + [Y. (100-X) / 100]

In the above equation,

X is the herbicidal action (%) for treatment of the mixture (A + B + C) at a rate of pkg per hectare compared to the untreated control (= 0%),

Y is the herbicidal action (%) for compound (D) treatment at a rate of qkg per hectare compared to untreated control.

Thus, if the activity of the four herbicide (A + B + C + D) combinations observed is greater than the value expected by Colby's equation, there is a synergistic effect.

The synergistic effect of the compositions of the invention is demonstrated in the following examples.

Example B1: Pre-germination Test

Test plants are sown in seed trays under greenhouse conditions. Standard soil is used as cultivation material. In the pre-germination stage, both herbicides alone and as a mixture are applied to the surface of the soil. The application rate depends on the optimum concentration demonstrated under field or greenhouse conditions. The test is evaluated after 2 to 4 weeks (100% = the plant dies completely; 0% = no phytotoxic action on the plant).

The test compound shows excellent results.

Example B2: Post Germination Test

Test plants are grown in seed trays at post-application stage under greenhouse conditions. Standard soil is used as cultivation material. In the pre-germination stage, both herbicides alone and as a mixture are applied to the surface of the soil. The application rate depends on the optimum concentration demonstrated under field or greenhouse conditions. The test is assessed after 8 to 22 days (100% = the plant dies completely; 0% = no phytotoxic action on the plant). The mixture used gives good results in this test.

Table B1: After 8 days of application (8DAA), herbicidal action after germination of a composition according to the invention comprising pretilachlor and prosulfocarb:

Application rate (g / ha) % Damage to bark (Echinochloa oryzicola) Estimates based on Colby Pretilachlor 66 90 - Prosulfocarb 200 0 - Pretilachlor + Prosulfocarb 66 + 200 95 90

Table B2: 22 days after application (22DAA), herbicidal action after germination of a composition according to the invention comprising pretilachlor and prosulfocarb:

Application rate (g / ha) % Damage to Echinochloa crus-galli Estimates based on Colby Pretilachlor 66 50 - Prosulfocarb 200 20 - Pretilachlor + Prosulfocarb 66 + 200 90 60

Table B3: 22 days after application (22DAA), herbicidal action after germination of a composition according to the invention comprising pretilachlor and prosulfocarb:

Application rate (g / ha) % Damage to Scirpus spp. Estimates based on Colby Pretilachlor 66 30 - Prosulfocarb 200 20 - Pretilachlor + Prosulfocarb 66 + 200 90 44

Table B4: 22 seconds after application (22DAA), herbicidal action after germination of a composition according to the invention comprising pretilachlor and prosulfocarb:

Application rate (g / ha) % Damage to Lindernia spp. Estimates based on Colby Pretilachlor 66 50 - Prosulfocarb 200 80 - Pretilachlor + Prosulfocarb 66 + 200 100 90

Table B5: After 8 days of application (8DAA), herbicidal action after germination of the composition according to the invention, comprising pretilachlor, mesotrione and prosulfocarb:

Application rate (g / ha) % Damage to bark Estimates based on Colby Pretilachlor 66 90 - Mesotrion 6.25 0 - Prosulfocarb 200 0 - Pretilachlor + Mesotrione + Prosulfocarb 66 + 6.25 + 200 95 90

Table B6: 22 days after application (22DAA), herbicidal action after germination of the composition according to the invention, comprising pretilachlor, mesotrione and prosulfocarb:

Application rate (g / ha) % Damage against Pebbles Estimates based on Colby Pretilachlor 66 50 - Mesotrion 6.25 0 - Prosulfocarb 200 20 - Pretilachlor + Mesotrione + Prosulfocarb 66 + 6.25 + 200 85 60

Claims (4)

A) pretilachlor + prosulfocarb, B) pretilachlor + mesotrione + prosulfocarb, C) pretilachlor + pythaphthalide + benzulfuron, D) pretilachlor + mesotrione + pyriphthalide + bensulfuron, E) pretilachlor + mesotrione + pyriphthalide + imazosulfuron and F) A herbicidal synergistic composition for selective control of weeds, characterized in that it comprises a combination of herbicidal compounds selected from the group consisting of pretilachlor + mesotrione + pyriphthalide + pyrazosulfuron. A method for controlling undesired vegetation in crops of useful plants, comprising applying a herbicidally effective amount of the composition according to claim 1 where control is required. The method of claim 2, wherein the weeds are ALS resistant weeds. The method according to claim 2 or 3, wherein the crop plant is rice.