IE66326B1 - Synergistically acting compositions and method of regulating plant growth - Google Patents

Abstract

The invention relates to synergistic agents and methods of regulating plant growth, which contain, as active substance of the formula I, the ethyl ester of 4-cyclopropyl-3,5-cyclohexanedione-1-carboxylic acid, of the formula I together with a synergistically effective amount of a phenol ether of the formula II or of a chloroacetanilide of the formula III or of a dinitroaniline of the formula IV or of ethyl N-benzoyl-N-(3,4-dichlorophenyl)-DL-alaninate, or of 1,1-dimethylpyridinium chloride, 2-chloro-N,N-trimethylethylammonium chloride, 2-chloroethylphosphonic acid, 1-phenyl-4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)-pent-1-en-3-ol, 1-(4-chlorophenyl)-3,3-dimethyl-1-(1H-1,2,4-triazol-1-yl)-butan-2-ol or of 5-(1-methylthiocyclopropan-1-yl)-[-(trans-2-chloroallyloximino)-propio nyl]-cyclohexane-1,3-dione. R1 to R9 in formulae II to IV have the meaning given in the description. The agent is used for regulating, in particular for inhibiting, the growth of cereals and grass and is advantageously used post-emergence.

Description

Synergistically acting Compositions and Method of RegularingJPlant Growth The present invention relates to synergistic compositions containing plant growth regulating combinations of active compounds. The compositions according to this invention are suitable for regulating, especially inhibiting, the growth of crops of useful plants.

The invention relates further to a method of regulating, especially inhibiting, the growth of crops of useful plants, preferably of cereal, grass and other cultures and to the use of the new compositions.

From EP-B-0 126 713 or US-A-4 693 475 the ethyl ester of 4-cyclopropanoyl-3,5-cyclohexanedione-l-carboxylic acid of formula has become known. This active compound has good plant growth regulating, especially plant growth inhibiting, properties.

EP-A-0 338 986 has disclosed synergistically acting mixtures consisting of cyclohexanedionecarboxylic acid derivatives and -(trifluoromethanesulfonemido)-aceto-2,4-xylidide, and EP-A-0 224 441 has disclosed synergistically acting mixtures consisting of cyclohexanedionecarboxylic acid derivatives and sulfonylureas.

It has now surprisingly become evident that the plant growth regulating action of tha compound of formula I can be enhanced in a synergistic manner by adding to it certain active compounds from the group phenol ethers.

The invention therefore relates to synergistic compositions for regulating plant growth, which contain, besides inert carriers, auxiliaries and adjuvants, as active component ethyl 4-cyclopropionyl 3,5-cyclohexanedione-l-carboxylate of the formula I <9 and additionally a synergistically active amount of a phenol ether of 5 the formula II wherein Rx is the acid radical or the Ci-C^alkyl ester radical -CH2COOH, CH(CH3)C00H, (CH2)3COOH or nitrobenso-5-yl, R2 is chlorine or methyl, R3 is chlorine and R4 is hydrogen, chlorine or methyl.

The Invention also relates to the use of the plant growth regulating compositions, which contain the active compound of the formula I together with a synergistically acting amount of an active compound of the formula II, e.g. for inhibiting the growth of plants.

The compounds of the formulae I and II are known.

Ethyl 4-cyclopropionyl·· 3,5-cyclohexansdlone-l-carboxylate of the formula I is e.g. prepared as follows. ml of cyclopropanoyl chloride are slowly added dropwise to a solution, stirred at room temperature, of 60 ml of ethyl 3,5-cyclohexanediona-l-earboxylate and 25 ml of pyridine in 400 ml of dichloroethane. When everything has been added, the mixture Is stirred for a further 15 hours at room temperature. The reaction mixture is then filtered and the filtrate is washed with IN hydrochloric acid, dried, and evaporated to dryness and concentrated. The residual 0-acylated intermediary product is taken up in 200 ml of dichloroethane, 4 g of 4-dimethalaminopyridine [sic] are added and the mixture is refluxed for 4 hours. After cooling, the solution is then washed with IN hydrochloric acid, dried, and evaporated to dryness. The residue Is chromatographed for purification with hexane over a small column of silica gal. Evaporation of the solvent gives ethyl 4-cyclopropionyl-3,5cyclohexanedione-l~carboxylate as a pale oil with a refractive index of ng° 1.5350.

The following compounds of the formula II are to be mentioned: Ila) the methyl ester of 2-nitro-5-(2,4-dichIorophenoxy)benzoic acid, common name BifenoxK , known from USP 3 776 715, see also The Pesticide Index 7th Ed. hy R. worthing and S. B. Walker, published by the British Crop Protection Council, Lavehham Press Ltd. 1983. lib) 2-(4-chloro-2-methylphenoxy)-propionic acid, common name Mecoprop or MCPP, known from GBP 820 180, see also The Pesticide Manual 7th Ed. 1983 7860. lie) 2-(2,4-dichlorophenoxy)acetic acid common name 2,4 D, see The Pesticide Manual 7th Ed. 1983 3780. lid) 2-(4-chloro-2-methylphenoxy)acetic acid, common name MCPA, see The Pesticide Manual 7th Ed. 1983 7790.

He) 4-(4-chloro-2-methylphenoxy)butyric acid, common name MCP3, see The Pesticide Manual 7th Ed. 1983 7810.

Plant growth regulators are substances which cause agronomically desired biochemical and/or physiological and/or morphological alterations in/on the plant.

The active substances contained in the compositions according to the invention have various effects on the plant growth, depending on the point in time of application, the dosage, the type of application and the environmental conditions. For example, the plant growth regulating mixtures of this invention can inhibit the vegetative growth of plants. This type of action is of interest on lawns, in the production of ornamental plants, in orchards, on verges, on sports grounds and industrial terrain, but also in the targeted inhibition of secondary shoots, such as in tobacco. In arable farming, inhibition of vegetative growth in cereals by means of thickened stems results in reduced lodging, and similar agronomical effects are achieved in oilseed rape, sunflowers, maize and other crop plants. Moreover, inhibition of the vegetative growth makes it possible to increase the number of plants per unit area. Another field of application of growth inhibitors is the selective control of ground-cover plants in plantations or crops with substantial distances between the rows by powerful inhibition of growth without killing these ground-cover plants, so that competition with the main crop is eliminated but agronomically positive effects, such as prevention of erosion, nitrogen fixation and loosening of the soil, are retained.

Plant growth regulators can influence crop yield in a quantitative way (e.g. flow of latex) or a qualitative way (e.g. sugar content), the apical dominance can be broken and the forming of side-shoots promoted (e.g. in ornamental plants), the drop of fruit and flowers can ba promoted (e.g. thinning out in fruit trees in order to break the alternance, fruit abscission in olives, for mechanical harvesting), the ripening of fruits can be harmonised, sped up or delayed by means of growth regulators (e.g. opening of the capsules in cotton, ripening of tomatoes or bananas).

* With plant growth regulators, plants can be made more resistant to environmental stress such as drought, cold or salt concent in the soil. The defoliation of crop plants can, finally, be induced at a fixed time so that mechanical harvesting in crops like cotton, potatoes or vines is facilitated or made possible.

A method of inhibiting plant growth is understood to mean direction of the natural development of the plant without altering, in the sense of a mutation, the life cycle of the plant as determined by the genetic make-up. The method of growth regulation is applied at a point In time of development of the plant, to be determined in each individual case. The active substance mixtures can be applied before or after emergence of the plants, for example as early as in the seed stage, or to the seedlings, to roots, tubers, stalks, leaves, flowers or other parts of the plant. This can be effected for example by applying the active substance itself or in the form of a composition to the plants and/or by treating the culture medium of the plant (soil).

The synergistic compositions according to this invention are preferably used for growth inhibition in monocotyledonous cultures, such as cereal and grasses, but also in dicotyledonous cultures, with post-emergence application.

The synergistic mixtures according to this invention are used in general at application rates of 50 g per hectare to 5000 g per hectare. The proportion between the amount of the compound of the formula I and the synergistxcally acting amount of the compound of the formula II can vary in wide ranges. As a rule, the proportion between the compound of the formula I and the synergistically acting co-component of the formula II lies between 100:1 and 1:20, preferably between 10:1 and 1:10.

The present invention also includes the preparation of agrochemical compositions, which are characterised by the intimate mixing of the active substance with one or more of the substances described herein.

Included is also a method of treating plants, which Is distinguished by the application of the compositions according co this invention.

* Mixtures of active compounds of the formula I and II are generally used in the fona of compositions and can be applied to the plant or the area to ba treated simultaneously or successively with other active compounds.

Suitable carriers and adjuvants may be solid or liquid and correspond to the appropriate substances used in the technique of formulation, such as natural or regenerated mineral materials, solvents, dispersants, wetting agents, adhesives, thickeners, binders or fertilisers.

The active compound mixtures according co the invention are used in unchanged form or preferably together with che auxiliaries usual in formulation technique and are processed therefore e.g. as emulsion concentrates or solutions which can be sprayed directly or diluted, dilute emulsions, wettable powders, soluble powders, dusts or granules, or by encapsulation in e.g. polymeric materials in a knO'-m way. The application methods, such as, spraying, atomizing, dusting, scattering, spreading or watering, like the type of composition, are selected according to the objectives pursued and the prevailing circumstances. Favourable application rates are in general 10 to 5 kg of active substance (AS) per ha; preferably 100 g co 2 kg of AS/ha.

The formulations, i.e. compositions, preparations or combinations comprising the active compound mixture of the compound of the formula I with a compound of the formula II and, where appropriate, a solid or liquid adjuvant, are prepared in a known manner, e.g. by intimately mixing and/or grinding the active compounds with extenders, e.g. solvents, solid carriers and, where appropriate, surface-active compounds (surfactants).

Suitable solvents may be: aromatic hydrocarbons, preferably the fractions C8 to C12 > e S · xylene mixtures or substituted naphthalenes, phthalates such as dibutyl phthalate or dioctyl phthalate, aliphatic hydrocarbons such as cyclohexane or paraffins, alcohols and glycols and their ethers and esters, such as ethanol, ethylene glycol, ethylene glycol monomethyl ether or ethyl ether, ketones such as cyclohexanone, strongly polar solvents such as N-methyl-2-pyrrolidone, dimethyl sulfoxide or dimethylformamide, as well as vegetable oils or epoxidised vegetable oils, such as epoxidised coconut oil or soybean oil; or water.

The solid carriers used, e.g. for dusts and dispersible powders, are normally natural ground minerals such as calcite, talc, kaolin, montmorillonite or attapulgite. In order to improve the physical properties it is also possible to add highly disperse silicic acid or highly disperse absorbent polymers. Suitable granulated adsorptive carriers are porous types, for example pumice, broken brick, sepiolite or bentonite; suitable nonsorbent carrier materials are, for example, calcite or sand. In addition, a great number of pregranulated materials of inorganic or organic nature can be used, such as especially dolomite or comminuted plant residues. Especially suitable adjuvants are, in addition, phospholipids.

Depending on the nature of the active compound mixture to be formulated, suitable surface-active compounds are non-ionic, cationic and/or anionic surfactants having good emulsifying, dispersing and wetting properties. The term surfactants will also be understood as comprising mixtures of surfactants.

Both so-called water-soluble soaps and water-soluble synthetic surfaceactive compounds may be suitable anionic surfactants.

As soaps there may be [lacuna] the alkali metal salts, alkaline earth metal salts or unsubstituted or substituted ammonium salts of higher fatty acids (Clo-C22) , e.g. the Na or K salts of oleic or stearic acid, or of natural fatty acid mixtures which can be obtained e.g. from coconut oil or tallow oil. Mention may also be made of fatty acid methyllaurin salts.

More frequently, however, so-called synthetic surfactants are used, especially fatty sulfonates, fatty sulfates, sulfonated benzimidazole derivatives or alkylarylsulfonates.

The fatty sulfonates or sulfates are usually in the form of alkali metal < salts, alkaline earth metal salts or unsubstituted or substituted ammonium salts and contain an alkali [sic] radical of 8 to 22 carbon atoms, alkyl also including the alkyl moiety of acyl radicals, e.g. the Na or Ca salt of lignosulfonic acid, of dodecyl sulfate or of a mixture of fatty alcohol sulfates which is prepared from natural fatty acids.

These compounds also comprise the salts of the sulfates and sulfonic acids of fatty alcohol/ethylene oxide adducts. The sulfonated benzimidazole derivatives preferably contain 2-sulfonic acid groups and one fatty acid radical containing 8 to 22 carbon atoms. Examples of alkylarylsulfonates are the Na, Ca or triethanolamine salts of dodecylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, or of a condensation product of naphthalenesulfonic acid and formaldehyde.

Also suitable are corresponding phosphates, e.g. salts of the phosphoric ester of an adduct of p-nonylphenol with 4 to 14 moles of ethylene t oxide.

Suitable non-ionic surfactants are primarily polyglycol ether derivatives of aliphatic or cycloaliphatic alcohols, saturated or unsaturated fatty acids and alkylphenols, said derivatives containing 3 to 30 glycol ether groups and 8 to 20 carbon atoms in the (aliphatic) hydrocarbon moiety and 6 to 18 carbon atoms in the alkyl moiety of the alkylphenols.

Further suitable non-ionic surfactants are the water-soluble adducts of polyethylene oxide with polypropylene glycol, ethylenediaminopolypropylene glycol and alkylpolypropvlene glycol containing 1 to 10 carbon atoms in the alkyl chain, which adducts contain 20 to 250 ethylene glycol ether groups and 10 to 100 propylene glycol ether groups. These compounds usually contain 1 to 5 ethylene glycol units per propylene glycol unit.

Examples of non-ionic surfactants are nonylphenolpolyethoxyethanols, castor oil polyglycol ethers, polypropylene/polyethylene oxide adducts, tributylphenoxypolyethoxyethanol, polyethylene glycol and octylphenoxypolyethoxyethanol. t Fatty acid esters of polyoxyethylene sorbitols, such as polyoxyethylene sorbitan trioleate, are also suitable.

Cationic surfactants are above all quaternary ammonium salts which contain, as N-substituent, at least one alkyl radical having 8 to carbon atoms, and, as further substituents, unsubstituted or halogenated lower alkyl, benzyl or hydroxy-lower alkyl radicals. The salts are preferably in the form of halides, methyl sulfates or ethylsulfates, e.g. stearyltrimethylammonium chloride or benzyldi(2chloroethyl)ethylammonium bromide.

The surfactants customarily employed in the art of formulation are described, inter alia, in the following publications: Me Cutcheon's Detergents and Emulsifiers Annual” M C Publishing Corp., Ringwood New Jersey, 1980 Sisaly and Wood, Encyclopedia of Surface Active Agents, Chemical Publishin Co., Inc. New York, 1980.

The agrochemical compositions usually contain 0.1 to 99 X, in particular 0.1 to 95 X, of the active compound mixture according to the invention and 99.9 to 1 X, especially 99.8 to 5 X, of solid or liquid adjuvants, including 0 to 25 X, especially 0.1 to 25 X, of a surfactant.

While concentrated compositions tend to be the preferred commercial product, the end user as a rule uses diluted compositions.

The compositions can also contain further additives, like stabilisers, anti-foaming agents, viscosity regulators, binders, adhesives and fertilizers, or other active compounds in order to achieve specific effects.

Agrochemical compositions of this kind are part of the present invention.

Other biocidal active compounds or compositions can be admixed to the compositions of this invention. Thus the new compositions can contain, besides the abovementioned compounds of the formula 1 and of the formula II, e.g. insecticides, fungicides, bactericides, funglstaties, bacteriostatics or nematicides.

The compositions according to the invention can generally be formulated, in detail, in accordance with the following Examples: - 10 Formulation Examples Formulation Examples for synergistic active compound mixtures of the formulae I and II. CX - per cent bv weight:! a) Wettable powders a) b) mixture of active compound of the formula I and an active compound of the 25 X 50 X formula II Na lignosulfonate 5 X 5 X Na lauryl sulfate 3 X Na diisobutylnaphthalenesulfonate ~ 6 X octylphenol polyethylene glycol ether (7-8 mol of ethylene oxide) - 2 X highly disperse silicic acid 5 X 10 X kaolin 62 X 27 X c) X X X X The active compound mixture is thoroughly mixed with the adjuvants and the mixture is thoroughly ground in a suitable mill, affording wettable powders which can ba diluted with water to give suspensions of any desired concentration. b) Emulsifiable concentrate mixture of active compound of the formula I and an active compound of the formula II 10 X octylphenol polyethylene glycol ether (4-5 mol of ethylene oxide) 3 X Ca dodecylbenzenesulfonate 3 X castor oil polyglycol ether (36 mol of ethylene oxide) 4 X X cyclohexanone xylene mixture X Emulsions of any desired concentration can be obtained from these concentrates by dilution with water. c) Dusts a) b) mixture of active compound of the formula I and an active compound of the formula II 5 Z 8 Z talc 95 Z kaolin - 92 Z Ready-for-use dusts are obtained by mixing the active compound mixture with the carrier and grinding the mixture in a suitable mill. d) Extruder granules mixture of active compound of the formula I and an active compound of the formula II 10 Z Na lignosulfonate 2 Z carboxymethylcellulose 1 Z kaolin 87 Z The active compound mixture is mixed and ground with the adjuvants, and the mixture is moistened with 'water. This mixture Is extruded and then dried in a stream of air. e) Coated granules mixture of active compound of the formula I and an active compound of the formula II 3 Z polyethylene glycol (Mw 200) 3 Z kaolin 94 % The finely ground active compound mixture is uniformly applied, in s mixer, to the kaolin moistened with polyethylene glycol. Non-dusty coated granules are obtained In this manner. f) Suspension concentrate mixture of active compound of the formula I and an active compound of the formula II 40 X ethylene glycol 10 X nonylphenol polyethylene glycol ether (15 mol of ethylene oxide) δ X Na lignosulfonate 10 X carboxymethylcellulose 1 X silicone oil in the form of a X aqueous emulsion 1 X water 32 X The finely ground active compound mixture is intimately mixed with the adjuvants, giving a suspension concentrate from which suspensions of any desired concentration can be prepared by dilution with water.

Often it Is more practical to formulate the active substance of the formula I and the co-component of the formula IX application individually, and then to combine them in the desired mixing proportions shortly before the treatment in the applicator as a tank mix with water.

A synergistic effect is always present when th® action of the combination of active compounds I and II is greater than the expected action of the active Ingredients applied individually, according to Colby.

The expected growth-inhibiting action We for a given combination of two substances can be calculated as follows (cf. COLBY, S. Β.., ^Calculating synergistic and antagonistic response of herbicide combinations®, Weeds 15, pages 20-22, 1967): We = X , Γ · (ΛΟη°-1 100 in which: X - percentage inhibition of growth in the case of treatment with the compound of the formula I at a rate of application of p kg per hectare in comparison with the untreated control (- 0 %).

Y « percentage inhibition of growth in the case of treatment with a compound of the formula II at a rate of application of q kg per hectare in comparison with the untreated control.

We « expected growth-inhibiting action (percentage inhibition of growth in comparison with the untreated control) after treatment with the compound of the formula I and II at a rate of application of a + q kg of active ingredient per hectare.

If the action actually observed is greater than the expected value We then synergism is present.

The synergistic effect of the combinations of active compounds I and II is demonstrated in the following Examples.

Biological Examples Example 1: Growth -inhibition _ifl cereal Summer barley of the variety Iban is sown in 15 cm plastic pots with sterile soil and raised in a climatized room at a day temperature of 10 - 15°C and a night temperature of 5-10°C. The illumination period is 13.5 hours daily at an intensity of about 25000 lux.

About 34 days after sowing and thinning out to 4 plants per pot, the active substance or mixture is applied in an aqueous spray liquor at th® rate given in the table of results. The amount of water used is about 500 1/ha. After the application, the plants are kept in the greenhouse at a day temperature of at least 10°C. The illumination period is at least 13.5 hours daily.

The evaluation takes place 14 to 35 days after the treatment (the duration is given in the results tables). The activity is expressed in percentage inhibition of new growth, compared to untreated plants. 0 X means no inhibitory action (growth as with untreated plants), 100 X means a complete halt to growth. The height of the new growth is represented in X of the average of that of the untreated controls.

Table 1: Active compound/ application rate g/ha Time of evaluation Days after application 34 days X growth inhibition I Ila observed expected (calculated according to Colby) 250 12 • 500 . 20 - - 1000 0 - - 2000 0 - 250 + 1000 57 12 250 + 2000 59 12 500 + 1000 71 20 500 4- 2000 69 20 I lib 34 days 250 12 500 - 26 - - 1000 8 - - 2000 12 . 250 + 1000 82 19 250 4- ,2000 86 23 500 + 1000 91 32 500 + 2000 91 35 I lie 34 days 250 12 500 - 28 - - 500 10 - - 1000 12 250 4- 500 35 21 250 4- 1000 42 23 500 4- 500 60 33 500 4- 1000 64 35 Table 2: Active Compound/ application rate Time Days of evaluation X growth observed inhibition expected (calculated according to Colby) after 20 application days g/ha I Ila 250 15 500 - 33 - - 1500 4 - - 3000 8 - 250 -r 1500 38 18 250 + 3000 38 22 500 + 1500 49 36 500 + 3000 49 38 *1

Claims (8)

Patent claims

1. A synergistieally acting composition for regulating plant growth, which is characterized in that it contains, besides inert carriers, auxiliaries and adjuvants, as active component ethyl 4-eyeIopropionyl3, 5- eyclohexanedlone-l- carboxy late of the formula I besides a synergistieally active amount of a further active compound selected from among phenol ethers of the formula XI wherein R x is the acid radical er the C 1 -C A alkyl ester radical -CH 2 COOH, CH(CH 3 )COOa, (CH 2 ) 3 COOH or nitrobenzo-5-yl, 8. 2 is chlorine or methyl, St 3 is chlorine and is hydrogen, chlorine or methyl.

2. A composition for regulating plant growth according to claim 1, which is characterized in that it contains, besides inert adjuvants and the active compound of the formula I, a synergistieally acting amount of a phenol ether of the formula II wherein Rj is the acid radical ©r the Gi-C^&Ikyl ester radical -CB 2 C003, 20 CH(CH 3 )COOH, (CH 2 ) 3 COOH or nltrobenso-5-yl, R 2 is chlorine or methyl, R 3 is chlorine aad B* is hydrogen, chlorine or methyl, or in the proportion active compound of the formula I to active compound of the formula II of 10:1 to 1:10. V

3. A composition for regulating plant growth according to claims 1 and 2, which is characterized in that it contains a synergistically acting amount of a compound selected from among 2-nicxo-5-(2,4dichlorophenoxy)benzoic acid, 2-(4-chloro-2-methylphenoxy)propionic

4. Δ composition for regulating plant growth according to claim 1, which is characterized in that it contains, besides 99.9 to 5% of solid or liquid adjuvants including 0.1 to 25% of a surfactant, 0.1 to 95% of a 10 combination of active compounds of the compound of the formula I with s compound of the formula II in the proportion of 100:1 to 1:10.

5. A method of regulating plant growth, which Is characterised is that one applies to che plants or their locus an active amount ef a composition according to claim 1 or respectively a task mis: containing 15 the active compound of the formula I and the miring partner of the formula ΙΪ. a.

6. A method of inhibiting plant growth in field cultures of useful plants or in grasses which is characterised in that one applies to the plants post emergence an active amount of a composition according to 20 claim 1. 5 acid, 2-(2,4-dichlorophenoxy)acetic acid, 2-(4-chloro-2-msthy1phenoxy)acetic acid and 4-(4-chloro-2-methylphenoxy)butyric acid.

7. A synergistically acting composition according to claim 1, substantially as hereinbefore described and exemplified»

8. „ A method according to claim δ of regulating plant growth, substantially as hereinbefore described.