WO2006105873A2

WO2006105873A2 - Weed control

Info

Publication number: WO2006105873A2
Application number: PCT/EP2006/002717
Authority: WO
Inventors: Muhammad Yuli Irianto
Original assignee: Syngenta Participations Ag
Priority date: 2005-04-07
Filing date: 2006-03-24
Publication date: 2006-10-12
Also published as: TWI383746B; CN101150952A; CN101150952B; TW200721975A; MY145607A; WO2006105873A3; WO2006105873A8; GB0507093D0; BRPI0610512A2

Abstract

A method for selectively controlling weeds in rice, in particular weeds in transplanted and direct-seeded rice, using a 2-benzoyl-l,3-cyclohexanedione derivative, in particular mesotrione, is disclosed.

Description

WEED CONTROL

The present invention relates to a method for selectively controlling weeds in rice, in particular weeds in transplanted and direct-seeded rice, using a 2-benzoyl-l ,3- cyclohexanedione derivative, in particular mesotrione.

US 5,318,947 discloses a method for controlling harmful plants in rice with 2- benzoyl-l,3-cyclohexanedione derivatives.

It has now surprisingly been found by the present inventors that at least one particular 2-benzoyl-l ,3 -cyclohexanedione derivative is highly toxic to rice crop, and in particular indica rice, when applied by conventional methods, i.e. spraying.

Accordingly, the present invention provides a method for selectively controlling harmful plants in a rice crop, said method comprising applying a 2-benzoyl-l, 3- cyclohexanedione derivative directly into the paddy field water. Suitably, the 2-benzoyl- 1 ,3-cyclohexanedione derivative is applied by drip application, splash application or distribution of GR formulations.

Drip application is the direct application of liquid products into the paddy water- generally performed during the last levelling of the rice field.

Splash application is the application directly into the paddy water by spreading/distributing the chemical either by handhold small bottles or spray guns.

Solid- Granular formulations are distributed by hand or by machine directly into the paddy field.

In one preferred embodiment of the invention, the rice crop comprises an indica- type or japonica-type rice crop; preferably an indica-type rice crop. Suitably, the 2-benzoyl-l, 3-cyclohexanedione derivative is a compound of formula (I)

wherein X represents a halogen atom; a straight- . or branched-chain alkyl or alkoxy group containing up to six carbon atoms which is optionally substituted by one or more groups -OR¹ or one or more halogen atoms; or a group selected from nitro, cyano, - CO₂R², -S(O)_1nR¹, -0(CH₂)_TOR¹, -COR², -NR²R³, -SO₂NR₂R³, -CONR²R³, -CSNR²R³ and -OSO₂R⁴;

R¹ represents a straight- or branched-chain alkyl group containing up to six carbon atoms which is optionally substituted by one or more halogen atoms; R² and R³ each independently represents a hydrogen atom; or a straight- or branched-chain alkyl group containing up to six carbon atoms which is optionally substituted by one or more halogen atoms;

R⁴ represents a straight-or branched-chain alkyl, alkenyl or alkynyl group containing up to six carbon atoms optionally substituted by one or more halogen atoms; or a cycloalkyl group containing from three to six carbon atoms; each Z independently represents halo, nitro, cyano, S(O)_mR⁵, OS(O)JR⁵, C_1-6 alkyl, C_1-6 alkoxy, C_1-6 haloalkyl, C_1-6 haloalkoxy, Q-_θhaloalkoxyQ-ealkyl, carboxy, C_1-6 alkylcarbonyloxy, C_1-6 alkoxycarbonyl, C_1-6 alkylcarbonyl, amino, C_1-6 alkylamino, C_1-6 dialkylamino having independently the stated number of carbon atoms in each alkyl group, C_1-6 alkylcarbonylamino, C_1-6 alkoxycarbonylamino, C_1-6 alkylarmnocarbonylamino, C_1-6 dialkylaminocarbonylamino having independently the stated number of carbon atoms in each alkyl group, C_1-6 alkoxycarbonyloxy, C_1-6 alkylaminocarbonyloxy, C_1-6 dialkylcarbonyloxy, phenylcarbonyl, substituted phenylcarbonyl, phenylcarbonyloxy, substituted phenylcarbonyloxy, phenylcarbonylamino, substituted phenylcarbonylamino, phenoxy or substituted phenoxy;

R⁵ represents a straight- or branched-chain alkyl group containing up to six carbon atoms which is optionally substituted by one or more halogen atoms; each Q independently represents C_1-4 alkyl or -CO₂R⁶ wherein R⁶ is C_1-4 alkyl; m is zero, one or two; n is zero or an integer from one to four; r is one, two or three; and p is zero or an integer from one to six.

Suitably, X is chloro, bromo, nitro, cyano, C_1-4 alkyl, -CF₃, -S(O)_1nR¹, or -OR¹; each Z is independently chloro, bromo, nitro, cyano, C_1-4 alkyl, -CF₃, -CH₂OCH₂CF₃, -OR¹, -OS(O)_mR⁵ or -S(O)_1nR⁵; n is one or two; and p is zero. Preferably, the 2-benzoyl-l,3-cyclohexanedione of formula (I) is selected from the group consisting of 2-(2'-nitro-4'-methylsulphonylbenzoyl)-l,3-cyclohexanedione, 2- (2 ' -nitro-4 ' -methylsulphonyloxybenzoyl)- 1 ,3 -cyclohexanedione, 2-(2 ' -chloro-4 ' - methylsulphonylbenzoyl)-l,3-cyclohexanedione, 2-(2'-chloro-3'-trifluoroethoxymethyl- 4'-methylsulphonylbenzoyl)-l ,3-cyclohexanedione, 4,4-dimethyl-2-(4- methanesulphonyl-2-nitrobenzoyl)-l,3-cyclohexanedione, 2-(2-chloro-3-ethoxy-4- methanesulphonylbenzoyl)-5-methyl-l ,3-cyclohexanedione and 2-(2-chloro-3-ethoxy-4- ethanesulphonylbenzoyl)-5-methyl-l,3-cyclohexanedione; most preferably is 2-(2'-nitro- 4'-methylsulphonylbenzoyl)-l,3-cyclohexanedione. The 2-benzoyl- 1 ,3-cyclohexanedione of formula (I) may exist in enolic tautomeric forms that may give rise to geometric isomers. Furthermore, in certain cases, the various substituents may contribute to optical isomerism and/or stereoisomerism. AU such tautomeric forms, racemic mixtures and isomers are included within the scope of the present invention. The 2-benzoyl-l,3-cyclohexanedione may be present in either the acid (non- chelated form) or as the metal chelated form. The metal chelated form of the 2-benzoyl- 1,3-cyclohexanedione may be made by adding a metal stabilizing salt to the suspoemulsion formulation. Examples of suitable stabilizing metal salts that may be used include calcium, beryllium, barium, titanium, magnesium, manganese, zinc, iron, cobalt, nickel and copper salts; most suitable are magnesium, manganese, zinc, iron, cobalt, nickel and copper salts; especially preferred is a copper salt, for example copper hydroxide. Suitably, the concentration of stabilizing metal salts in the suspoemulsion formulation of the invention is from 0.01 to 4.0%, and preferably from 0.02 to 1.5%. In a further embodiment of the invention, the 2-benzoyl-l,3-cyclohexanedione may be applied in combination with one or more additional active ingredients. Such additional active ingredients include herbicides, fungicides, insecticides and the like. In particular, a chloroacetamide, for example pretilachlor, butachlor, s-metolachlor, acetochlor, alachlor etc., maybe applied in combination with the 2-benzoyl- 1,3- cyclohexanedione. The 2-benzoyl- 1 ,3-cyclohexanedione may be applied to the paddy field water either before or shortly after seeding. In a preferred embodiment, the 2-benzoyl-l,3- cyclohexanedione derivative is applied before seeding or after seeding but pre-emergence of the rice crop. The rate at which the 2-benzoyl-l,3-cyclohexanedione derivative is applied will depend on a number of factors, for example the weeds to be controlled, the climatic conditions etc. In general an application rate of between 0.5g ai/ha and 50Og ai/ha is appropriate, for example between 50g and 25Og ai/ha. The specific rate to be applied will be readily determinable by the skilled person.

Whilst the 2-benzoyl-l,3-cyclohexanedione derivative may be applied alone, in practice, the composition is applied as a formulation containing the various adjuvants and carriers known to or used in the industry for facilitating dispersion. The choice of formulation and mode of application for any given compound may affect its activity, and selection will be made accordingly. For example, the herbicidal composition of this invention may be a dustable powder, gel, a wettable powder, a water dispersible granule, a water-dispersable or water-foaming tablet, a briquette, an emulsifϊable concentrate, a microemulsifiable concentrate, an oil-in-water emulsion, a water-in-oil emulsion, a dispersion in water, a dispersion in oil, a suspoemulsion, a soluble liquid (with either water or an organic solvent as the carrier), an impregnated polymer film, or other forms known in the art. These formulations may be suitable for direct application or may be suitable for dilution prior to application, said dilution being made either with water, liquid fertilizer, micronutrients, biological organisms, oil or solvent. The compositions are prepared by admixing the active ingredients with adjuvants including diluents, extenders, carriers, and conditioning agents to provide compositions in the form of finely-divided particulate solids, granules, pellets, solutions, dispersions or emulsions. Thus, it is believed that the active ingredients could be used with an adjuvant such as a finely-divided solid, a mineral oil, a liquid of organic origin, water, various surface active agents or any suitable combination of these. The active may also be contained in very fine microcapsules in polymeric substances. Microcapsules typically contain the active material enclosed in an inert porous shell which allows escape of the enclosed material to the surrounds at controlled rates. Encapsulated droplets are typically about 0.1 to 500 microns in diameter. The enclosed material typically constitutes about 25 to 95% of the weight of the capsule. The active ingredient may be present as a monolithic solid, as finely dispersed solid particles in either a solid or a liquid, or it may be present as a solution in a suitable solvent. Shell membrane materials include natural and synthetic rubbers, cellulosic materials, styrene- butadiene copolymers, polyacrylonitriles, polyacrylates, polyesters, polyamides, polyureas, polyurethanes, other polymers familiar to one skilled in the art, chemically- modified polymers and starch xanthates. Alternative very fine microcapsules may be formed wherein the active ingredient is dispersed as finely divided particles within a matrix of solid material, but no shell wall surrounds the microcapsule.

Suitable agricultural adjuvants and carriers that are useful in preparing the compositions of the invention are well known to those skilled in the art.

Liquid carriers that can be employed include water, toluene, xylene, petroleum naphtha, crop oil, acetone, methyl ethyl ketone, cyclohexanone, acetic anhydride, acetonitrile, acetophenone, amyl acetate, 2-butanone, chlorobenzene, cyclohexane, cyclohexanol, alkyl acetates, diacetonalcohol, 1,2-dichloropropane, diethanolamine, p- diethylbenzene, diethylene glycol, diethylene glycol abietate, diethylene glycol butyl ether, diethylene glycol ethyl ether, diethylene glycol methyl ether, N,N-dimethyl formamide, dimethyl sulfoxide, 1,4-dioxane, dipropylene glycol, dipropylene glycol methyl ether, dipropyleneglycol dibenzoate, diproxitol, alkyl pyrrolidinone, ethyl acetate, 2-ethyl hexanol, ethylene carbonate, 1,1,1-trichloroethane, 2-heptanone, alpha pinene, d- limonene, ethylene glycol, ethylene glycol butyl ether, ethylene glycol methyl ether, gamma-butyrolactone, glycerol, glycerol diacetate, glycerol monoacetate, glycerol triacetate, glycerol triacetate, hexadecane, hexylene glycol, isoamyl acetate, isobornyl acetate, isooctane, isophorone, isopropyl benzene, isopropyl myristate, lactic acid, laurylamine, mesityl oxide, methoxy-propanol, methyl isoamyl ketone, methyl isobutyl ketone, methyl laurate, methyl octanoate, methyl oleate, methylene chloride, m-xylene, n-hexane, n-octylamine, octadecanoic acid, octyl amine acetate, oleic acid, oleylamine, o-xylene, phenol, polyethylene glycol (PEG400), propionic acid, propylene glycol, propylene glycol monomethyl ether, propylene glycol mono-methyl ether, p-xylene, toluene, triethyl phosphate, triethylene glycol, xylene sulfonic acid, paraffin, mineral oil, trichloroethylene, perchloroethylene, ethyl acetate, amyl acetate, butyl acetate, propylene glycol monomethyl ether and diethylene glycol monomethyl ether, methanol, ethanol, isopropanol, and higher molecular weight alcoholds such as amyl alcohol, tetrahydrofurfuryl alcohol, hexanol, octanol, etc., ethylene glycol, propylene glycol, glycerine, N-methyl-2-pyrrolidinone, and the like. Water is generally the carrier of choice for the dilution of concentrates.

Suitable solid carriers include talc, titanium dioxide, pyrophyllite clay, silica, attapulgite clay, kieselguhr, chalk, diatomaceous earth, lime, calcium carbonate, bentonite clay, Fuller's earth, cotton seed hulls, wheat flour, soybean flour, pumice, wood flour, walnut shell flour, lignin, and the like. A broad range of surface-active agents are advantageously employed in both solid and liquid compositions, especially those designed to be diluted with carrier before application. The surface-active agents can be anionic, cationic, nonionic or polymeric in character and can be employed as emulsifying agents, wetting agents, suspending agents, or for other purposes. Typical surface active agents include salts of alkyl sulfates, such as diethanolammonium lauryl sulfate; alkylarylsulfonate salts, such as calcium dodecylbenzenesulfonate; alkylphenol-alkylene oxide addition products, such as nonylphenol-C.sub.18 ethoxylate; alcohol-alkylene oxide addition products, such as tridecyl alcohol-C.sub.16 ethoxylate; soaps, such as sodium stearate; alkylnaphthalenesulfonate salts, 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 dialkyl phosphate esters.

Other adjuvants commonly utilized in agricultural compositions include crystallization inhibitors, viscosity modifiers, suspending agents, spray droplet modifiers, pigments, antioxidants, foaming agents, light-blocking agents, compatibilizing agents, antifoam agents, sequestering agents, neutralizing agents and buffers, corrosion inhibitors, dyes, odorants, spreading agents, penetration aids, micronutrients, emolients, lubricants, sticking agents, dispersing agents, thickening agents, freezing point depressants, antimicrobial agents, and the like. The compositions can also contain other compatible components, for example, other herbicides, herbicide safeners, plant growth regulants, fungicides, insecticides, and the like and can be formulated with liquid fertilizers or solid, particulate fertilizer carriers such as ammonium nitrate, urea and the like or mixed with sand, or dirt (in the case of solid - granular application).

The present invention will now be illustrated further with reference to the following examples.

Comparative Example

IR-64- indica rice was directly seeded in muddy soil and herbicide treatment was applied 12 days after the seeding. Treatment was carried out as spray over the top of plants with a 4001/ha spray solution.

* with built-in surfactant

DAS - Days After Sowing; DAA - Days After Application

Example

During the last levelling run for the seedbed preparation of the paddy field the undiluted chemical was applied directly to the paddy water by hanging the bottle up-side- down to the tractor. The movement of the water during the levelling process distributes

10 the product in whole paddy water. At the same time the product is diluted in the large amount of the paddy water. The application should be made five to one days before seeding (DBS) to allow the product to settle to the soil. The remaining water is drained before seeding. Seeding of indica-type rice is carried out on treated muddy - dry soil.

DBS - Days Before Sowing; DAS - Days After Sowing

Claims

1. A method for selectively controlling harmful plants in a rice crop, said method comprising applying a 2-benzoyl-l,3-cyclohexanedione derivative directly into the paddy field water.

2. A method according to claim 1, wherein the 2-benzoyl-l,3-cyclohexanedione derivative is a compound of formula (I)

wherein X represents a halogen atom; a straight- or branched-chaiή alkyl or alkoxy group containing up to six carbon atoms which is optionally substituted by one or more groups -OR¹ or one or more halogen atoms; or a group selected from nitro, cyano, -CO₂R², - S(O)_1nR¹, -O(CH₂)_rOR\ -COR², -NR²R³, -SO₂NR₂R³, -CONR²R³, -CSNR²R³ and - OSO₂R⁴; R¹ represents a straight- or branched-chain alkyl group containing up to six carbon atoms which is optionally substituted by one or more halogen atoms;

R² and R³ each independently represents a hydrogen atom; or a straight- or branched- chain alkyl group containing up to six carbon atoms which is optionally substituted by one or more halogen atoms; R⁴ represents a straight-or branched-chain alkyl, alkenyl or alkynyl group containing up to six carbon atoms optionally substituted by one or more halogen atoms; or a cycloalkyl group containing from three to six carbon atoms; each Z independently represents halo, nitro, cyano, S(O)_mR⁵, OS(O)_1nR⁵, C_1-6 alkyl, C_1-6 alkoxy, C_1-6 haloalkyl, C_1-6 haloalkoxy, carboxy, C_1-6haloalkoxyC_1-6alkyl, C_1-6 alkylcarbonyloxy, C_1-6 alkoxycarbonyl, C_1-6 alkylcarbonyl, amino, Ci_-6 alkylamino, C_1-6 dialkylamino having independently the stated number of carbon atoms in each alkyl group, Ci_-6 alkylcarbonylamino, Ci_-6 alkoxycarbonylamino, C_1-6 alkylaminocarbonylamino, C_1-6dialkylaminocarbonylamino having independently the stated number of carbon atoms in each alkyl group, C_1-6 alkoxycarbonyloxy, C_1-6 alkylaminocarbonyloxy, Ci_-6dialkylcarbonyloxy, phenylcarbonyl, substituted phenylcarbonyl, phenylcarbonyloxy, substituted phenylcarbonyloxy, phenylcarbonylamino, substituted phenylcarbonylamino, phenoxy or substituted phenoxy; R⁵ represents a straight- or branched-chain alkyl group containing up to six carbon atoms which is optionally substituted by one or more halogen atoms; each Q independently represents C_1-4 alkyl or -CO₂R⁶ wherein R⁶ is C_1-4 alkyl; m is zero, one or two; n is zero or an integer from one to four; r is one, two or three; and p is zero or an integer from one to six.

3. A method according to claim 2, wherein the 2-benzoyl-l,3-cyclohexanedione derivative is selected from the group consisting of 2-(2'-nitro-4'- methylsulphonylbenzoyl)-l,3-cyclohexanedione, 2-(2'-nitro-4'- methylsulphonyloxybenzoyl)- 1 ,3 -cyclohexanedione, 2-(2 ' -chloro-4 ' - methylsulphonylbenzoyl)- 1 ,3 -cyclohexanedione, 2-(2 ' -chloro-3 ' -trifluoroethoxymethyl- 4'-methylsulphonylbenzoyl)-l,3-cyclohexanedione, 4,4-dimethyl-2-(4- methanesulphonyl-2-nitrobenzoyl)-l,3-cyclohexanedione, 2-(2-chloro-3-ethoxy-4- methanesulphonylbenzoyl)-5-methyl-l,3-cyclohexanedione and 2-(2-chloro-3-ethoxy-4- ethanesulphonylbenzoyl)-5-methyl-l,3-cyclohexanedione.

4. A method according to claim 3, wherein the 2-benzoyl- 1,3 -cyclohexanedione derivative is 2-(2'-nitro-4'-methylsulphonylbenzoyl)-l ,3 -cyclohexanedione.

«

5. A method according to any one of claims 1 to 4, wherein the 2-benzoyl-l,3- cyclohexanedione derivative is applied in combination with one or more additional active ingredients.

6. A method according to claim 5, wherein the one or more additional active ingredients is a chloroacetamide.

7. A method according to any one of claims 1 to 6, wherein the 2-benzoyl-l,3- cyclohexanedione derivative is applied either before or shortly after seeding.

8. A method according to claim 7, wherein the 2-benzoyl-l,3-cyclohexanedione derivative is applied before seeding.

9. A method according to claim 7, wherein the 2-benzoyl-l,3-cyclohexanedione derivative is applied after seeding but before the rice crop emerges.

10. A method according to any one of claims 1 to 9, wherein the 2-benzoyl-l,3- cyclohexanedione derivative is applied at a rate of between 0.5g ai/ha to 500g ai/ha.

11. A method according to any one of claim 1 to 10, wherein the rice crop is an indica-type or japonica-type rice crop.

12. A method according to claim 11, wherein the rice crop is an indica-type rice crop.