HK1175369B - Synergistic herbicidal composition containing fluroxypyr and penoxsulam, halosulfuron-methyl, imazamox or imazethapyr - Google Patents

Description

Synergistic herbicide composition containing fluroxypyr and penoxsulam, halosulfuron-methyl, imazamox or imazethapyr

The present invention relates to synergistic herbicidal compositions comprising (a) fluroxypyr and (b) at least one herbicide selected from penoxsulam, halosulfuron-methyl, imazapyr and imazethapyr for controlling weeds in crops, in particular rice, cereals and grain crops, pastures, rangelands, Industrial Vegetation Management (IVM) and turf. These compositions provide improved post-emergence (post-emergence) herbicide weed control.

Protection of crops from weeds and other vegetation that inhibit crop growth is a continuing problem in agriculture. To help combat this problem, researchers in the field of synthetic chemistry have produced a variety of chemicals and chemical formulations effective in controlling this unwanted growth. Many types of chemical herbicides have been disclosed in the literature and a large number have been used commercially.

In some cases, it has been shown that herbicidal active ingredients are more effective in combination than when applied individually, which is known as "synergism". As described in the Herbicide Handbook of the Weed Science society of America, origin Edition, 2002, p.462, "' synergism" is the interaction of two or more factors such that the effect when combined is better than would be expected based on the response of each factor when administered separately ". The present invention is based on the following findings: fluroxypyr, penoxsulam, halosulfuron-methyl and imazamox, each known to have herbicidal efficacy, show a synergistic effect when applied in combination.

The effect on plant growth of the herbicidal compounds forming the synergistic composition of the present invention is each already known in the art.

The present invention relates to synergistic herbicide mixtures comprising a herbicidally effective amount of (a) fluroxypyr and (b) an acetolactate synthase (ALS) inhibitor herbicide. ALS inhibitor herbicides include compounds from the sulphonamides, sulphonylureas and imidazolinones. Particularly useful ALS inhibitor herbicides include, but are not limited to, penoxsulam, halosulfuron-methyl, imazamox, and imazethapyr. The compositions may also contain agriculturally acceptable adjuvants and/or carriers.

The invention also relates to herbicidal compositions and methods of controlling the growth of undesirable vegetation, particularly in monocot crops, including rice, wheat, barley, oats, rye, sorghum, corn, pastures, grasslands, rangelands, fallowland, turf, IVM and aquatics, as well as the use of these synergistic compositions.

The species range of ALS inhibitors such as penoxsulam, halosulfuron-methyl, imazamox and imazethapyr, i.e., the weed species controlled by the various compounds, is broad and highly complementary to that of fluroxypyr. For example, it has been unexpectedly found that the combination of penoxsulam and fluroxypyr exhibits a synergistic effect on the control of the following plants when applied at or below this application rate as compared to the application rate of the individual compounds: cannabis sativa (Hemp Sesbania) (Sesbania exaltata; SEBEX), Texas weeds (Texawed) (Caperonia palustris; CNPPA), Phragmites japonica (Japan bulrush) (Scirpus junoides; SCPJU), Plantago depressa (narrow-leaved plantain) (Plantago lancelata L.; PLALA), and Echinochloa crusge (Echinochloa crus-galli; ECHCG). Similarly, it has been unexpectedly found that the combination of halosulfuron-methyl and fluroxypyr exhibits a synergistic effect on the control of the following plants when applied at or below the application rate as compared to the application rate of the compound alone: echinochloa crus-galli (ECHCG), Leptochloa chinensis (LEFCH), and yellow nutgrass (Cyperusesculentus; CYPES). Moreover, it has been unexpectedly found that the combination of imazamox and fluroxypyr exhibits a synergistic effect on the control of the following plants when applied at or below the application rate as compared to the application rate of the individual compounds: barnyard grass (Echinochloa crus-galli; ECHCG), broadleaf signalized grass (Brachiaria platyphylla; BRAPP), and Cyperus esculentus (Cyperus esculentus; Cypes). Moreover, it has been unexpectedly found that the combination of imazethapyr and fluroxypyr exhibits a synergistic effect on the control of the following plants when applied at or below the application rate as compared to the application rate of the individual compounds: euphorbia lathyris (Leptochloa spp, LEFSS) and fall millet (Fallpanicum) (Panicum dichotomiforum, Pandi).

Fluroxypyr is the general name for [ (4-amino-3, 5-dichloro-6-fluoro-2-pyridinyl) oxy ] acetic acid. Its herbicidal activity is described in The Pesticide Manual, fourtenth Edition, 2006. Fluroxypyr controls a variety of economically important broadleaf weeds. It can be used as the acid itself or as an agriculturally acceptable salt or ester. The use as ester is preferred, with methylheptyl ester (meptyl ester) being most preferred.

Penoxsulam is the common name for 2- (2, 2-difluoroethoxy) -N- (5, 8-dimethoxy- [1,2,4] triazolon- [1,5-c ] pyrimidin-2-yl) -6- (trifluoromethyl) benzenesulfonamide. Its herbicidal activity is described in the pesticide Manual, fourtenth Edition, 2006. Penoxsulam controls Echinochloa spp, as well as many broadleaf, sedge and aquatic weeds in rice, and Apera spp in grass, and many broadleaf weeds in cereals.

Halosulfuron-methyl is the common name for methyl 3-chloro-5- [ [ [ [ (4, 6-dimethoxy-2-pyrimidinyl) amino ] carbonyl ] amino ] sulfonyl ] -1-methyl-1H-pyrazole-4-carboxylate. Its herbicidal activity is described in The pesticide manual, fourtenth Edition, 2006. Halosulfuron-methyl controls many broad leaves and nut sedges in rice, corn, sorghum, sugar cane, nuts and turf.

Imazamox is the common name for 2- [4, 5-dihydro-4-methyl-4- (1-methylethyl) -5-oxo-1H-imidazol-2-yl ] -5- (methoxymethyl) -3-pyridinecarboxylic acid. Its herbicidal activity is described in The pesticide manual, fourtenth Edition, 2006. Imazamox controls many broadleaf weeds in corn, oilseed rape, alfalfa, peas and beans.

Imazethapyr is the common name for 2- [4, 5-dihydro-4-methyl-4- (1-methylethyl) -5-oxo-1H-imidazol-2-yl ] -5-ethyl-3-pyridinecarboxylic acid. Its herbicidal activity is described in The Pesticide Manual, fourtenth Edition, 2006. Imazethapyr controls many grasses and broadleaf weeds in alfalfa, pea, bean, soybean, and imidazolinone-resistant rice, as well as in corn.

The term herbicide as used herein is intended to mean an active ingredient that kills, controls, or otherwise adversely modifies the growth of plants. A herbicidally effective or plant controlling amount is an amount of active ingredient that results in an adversely modifying effect and includes deviations from natural development (natural deterioration), killing, regulation, dehydration, retardation, and the like. The terms plant and vegetation include germinated seeds, emerging seedlings, plants emerging from vegetative propagules, and established plants.

When the compounds of the synergistic mixture are applied directly to the plant or to the locus of the plant at any stage of growth or prior to sowing or germination, the compounds exhibit herbicidal activity. The observed effect depends on the plant species to be controlled, the growth stage of the plant, the application parameters of dilution and spray droplet size, the particle size of the solid components, the environmental conditions at the time of use, the specific compounds used, the specific adjuvants and carriers used, the soil type, etc., and the application rate of the chemicals. These and other factors can be adjusted as is known in the art to promote non-selective or selective herbicidal action. Generally, it is preferred to apply the compositions of the present invention post-emergence to relatively immature undesirable vegetation to achieve maximum control of weeds.

In the compositions of the present invention, the herbicidal effect is synergistic with a weight ratio of fluroxypyr (acid equivalent) to the ALS inhibitor herbicide (active ingredient) of from about 1:2 to about 140: 1.

The rate of application of the synergistic composition depends on the particular type of weed to be controlled, the degree of control desired, and the timing and method of application. The ALS inhibitor herbicide is applied at a rate of about 4g ai/ha to about 100g ai/ha and the fluroxypyr is applied at a rate of about 50g ae/ha to about 560g ae/ha.

The components of the synergistic mixtures of the present invention may be applied separately or as part of a multi-component herbicidal system, and the mixtures may be provided as a pre-mix or tank mix.

The synergistic mixtures of the present invention may be applied in combination with one or more other herbicides to control a wider range of undesirable vegetation. When used in combination with other herbicides, the compositions can be formulated with the other herbicide, tank mixed with the other herbicide, or applied sequentially with the other herbicide. Some of the herbicides that can be used in combination with the synergistic compositions of the present invention include: 2,4-D, fenchloramide (acetochlor), acifluorfen (acifluorfen), aclonifen (aclonifen), AE0172747, alachlor (alachlor), amidosulfuron (amidosulfuron), aminotriazole (amidotriazole), ammonium thiocyanate (ammonium thiocyanide), anilofos (anilifos), atrazine (atrazine), AVH 301, azimsulfuron (azimsulfuron), bensulfuron (bensulfuron-methyl), bentazone (bentazone), benthiocarb (benthiocarb), dicyclomethionone (bentazocycloron), bifenox (bifenox), bispyribac-sodium, bromacil (bromoxynil), bromoxynil (bromoxynil), butachlor (buthiol), buthiol (buthiocarb), buthiosulfuron (buthiocarb), buthiol (buthiocarb), buthiocarb (buthiol (buthiocarb), buthiocarb (buthiol (buthiocarb), buthiocarb (buthiol), buthiol (buthiocarb), buthiol (buthiocarb), buthiocarb (buthiol), buthiocarb (buthiocarb), buthiocarb (buthiocarb), bensulfuron-methyl) or (buthiocarb (bensulfuron)Bentazone (clomazone), clopyralid (clopyralid), cloransulam-methyl (cloramuron-methyl), cyclosulfamuron (cyclosulfamuron), cycloxydim (cycloxydim), cyhalofop-butyl (cyhalofop-butyl), dicamba (dicamba), dichlobenil (dichlobenil), dimethoate 2, 4-dichloropropionic acid (dichlorropp-P), diclosulam (diclosulam), diflufenican (diflufencan), diflufenzopyr (diflufenzopyr), dimethenamid (dimethenamid-P), diquat (diquat), dithiopyr (dithizor), diuron (diuron), EK2, penthiopyrad (EPTC), penetryn (EPT-751), carbenoxyfen-P), diquat (diquat), dithiopyr (dithiopyr), diuron (diuron), ethiron (EK 2, EPTC, penthiopyr (EPT-pyrad-751, carbenoxyne (7967, carbenoxyne (dimethylfon-P), ben-P (dimethylfon-P), dithiopyr (dimethylfon-P, dithiopyr (,fenoxaprop-P-ethyl,Bifenazol-diclofop-p-ethyl and diphenylAzole-ethyl (isoxadifen-ethyl), fentrazamide (fentrazamide), flazasulfuron (flazasulfuron), florasulam (florasulam), fluazifop-P-butyl, fluaziforon (fluazifop), fluazifop-P-butyl, fluaziforon (flueturon) (LGC-42153), flufenacet (flufenacet), flupyridate (flufenpyr-ethyl), flumetsulam (fluazifop), flumetsulam (flusilac-pentyl), flumetsulam (fluxazin), flumeturon (flunomiron), fluazifop (fluazifop), flumetsul (fluazifop), fluazifop (fluazifop-n), fluazifop-n (fluazifop), fluazifop (pyrazosulfuron (methyl), fluazifop (fluazifop-n (fluazifop), fluazifop (fluazifop-P, fluazifop-n (fluazifop-P-n (fluazifop), fluazifop (fluazifop-P, fluazifop-n (fluazifop, fluazifop-n (fluazifop, fluazifop-P (fluazifop-n (fluazifop) and a, Indene clomazone (indofenan), indaziflam, iodosulfuron (iodosulfofuron), ioxynil (ioxynil), ipfenbacazone (HOK-201), IR 5790, isoproturon (isoprotrotron)Oxamide (isoxaben), isoxabenCarfentrazone-ethyl (isoxaflutole), KUH-071, lactofen (lactofen), linuron (linuron), MCPA ester&Amine, 2-methyl-4-chloropropionic acid (mecoprop-P), mefenacet (mefenacet), mesosulfuron (mesosulfuron), mesotrione (mesotrione),Metolachlor (metamifop), metazosulfuron (NC-620), metolachlor (metolachlor), metosulam (metosulam), metamitron (Metroni)Ketones (metribuzin), metsulfuron (methylsufuron), molinate (molinate), MSMA, napropamide (napropamide), nicosulfuron (nicosulfuron), pyridate (norflurazon), OK-9701, orysastrobin (orthiomuron), oryzalin (oryzalin), propyne (propyne)(oxadiargyl) and,(oxadizon),Metribuzin (oxazichlometfone), oxyfluorfen (oxyfluorfen), paraquat (paraquat), pendimethalin (pendimethalin), and cyclopentadienClomazone, pethoxamid, picloram, flufenapyr (picolinafen), pyraflufen (picolinafen), mephos (piperaphos), pretilachlor (pretilachlor), primisulfuron (primisulfuron), cycloxydim (profoxdim), propachlor (propachlor), propanil (propaferon), propaferon (TH-547), propyzamide (propazamide), prosulfocarb (prosulfocarb), pyroronil (pyrazogyl), pyrazogyl (pyrazosulfuron), pyrazosulfuron (pyrazosulfuron), pyribenzoxim (pyribenzoxim) (LGC-40863), pyribenzoxim (pyribenzoxim), pyriminoxim (pyribenzoxim-methyl), pyriminoxim-methyl ether (pyriminostrobin-methyl), pyribenzoxim (pyribenzoxim-methyl), pyribenzoxim (quindox-ethyl), pyribenzoxim (quindox) (Kyol, pyrimethanil (S-ethyl), pyrimethanil (pyrimethanil-ethyl), pyrimethanil (pyrimethanil), pyrimethanil-ethyl, pyrimethanil), pyrimethanil (pyrimethanil), pyrimethanil (pyrimethanil-ethyl, pyrimethanil), pyrimethanil (pyrimethanil), pyrimethanil-ethyl (pyrimethanil), pyrimethanil-isopropyl-S-ethyl, pyrimethanil), pyrimethanil (pyrimethanil), pyrimethanil, tefuryltrione (AVH-301), terfenadine (terbacil), thiazopyr (thiopyrad), thiobencarb (thiobencarb), triclopyr (triclopyr), trifluralin (trifluralin) and triflusulfuron (tritosulfuron).

On glyphosate tolerant crops, glufosinate tolerant crops, dicamba tolerant crops, imidazolinone (imidazolinones) tolerant crops, sulphonylurea tolerant crops or 2, 4-D-tolerant crops, the synergistic compositions of the present invention may be further used in combination with: glyphosate, glufosinate, dicamba, imidazolinone, sulfonylurea, or 2, 4-D. It is generally preferred to use the synergistic compositions of the present invention in combination with herbicides which are selective for the crop to be treated and which complement the spectrum of weeds controlled by the application rates at which these compounds are used. It is further generally preferred to apply the synergistic composition of the present invention and other supplemental herbicides simultaneously, either as a combined formulation or as a tank mix.

The synergistic compositions of the present invention may be used to enhance their selectivity, typically in combination with known herbicide safeners such as benoxacor (benoxacor), benjamaicin (benthiocarb), brassinolide (brassinolide), mexyl (cloquintocet), chloranil (cyclotrinil), dazomet (daimuron), dichlormid (dichlormid), dicyclonon (dimeperot), disulfoton (dimeperote), disulfoton (disulphoton), fenchlorazole-ethyl (fenchlorazole-ethyl), fenclorim (fenclorim), sulfentrazone (flurazone), flumetoxime (fluxofenim), sulfentrazone (fenflurazone), to enhance their selectivityOxazole (furilazole), harpin protein, bis-benzeneEthyl isoxadifen-ethyl, mefenpyr-diethyl, MG 191, MON 4660, Naphthalic Anhydride (NA), oxabetrinil, R29148 and N-phenyl-sulphonylbenzoic acid amide. Cloquintocet-mexyl (mexyl) is a particularly preferred safener for the synergistic compositions of the invention, in particular for combating any detrimental effects of the synergistic compositions on rice and cereals.

The synergistic mixture of fluroxypyr and penoxsulam of the present invention also provides a safety effect when applied to sunflower (Helianthus annuus; HELAN) and Pteris vittata (Eremochloa; ERLOP). Another aspect of the invention is a method of protecting ciliate desert-grass and sunflower from the harmful effects of penoxsulam and fluroxypyr, respectively, comprising contacting ciliate desert-grass or sunflower with a safe amount of a synergistic mixture of penoxsulam and fluroxypyr, or applying a safe amount of a synergistic mixture of penoxsulam and fluroxypyr to an area under culture.

Indeed, it is preferred to use the synergistic compositions of the present invention in the form of a mixture comprising an herbicidally effective amount of the herbicidal component together with at least one agriculturally acceptable adjuvant or carrier. Suitable adjuvants or carriers should not produce phytotoxins on valuable crops, particularly at the concentrations used to apply the weed control selective composition in the presence of the crop, and should not chemically react with the herbicidal component or other composition ingredients. Such mixtures may be designed for direct application to the weeds or their locus, or may be concentrates or formulations which are normally diluted with additional carriers and adjuvants prior to application. They may be solids, for example, powders, granules, water-dispersible granules, or wettable powders; or a liquid, e.g., an emulsifiable concentrate, solution, emulsion, or suspension.

Suitable agricultural adjuvants and carriers for preparing the herbicidal mixtures of the present invention are well known to those skilled in the art. Some of these adjuvants include, but are not limited to, crop oil concentrate (mineral oil (85%) + emulsifier (15%)); nonylphenol ethoxylate; benzyl coconut alkyl dimethyl quaternary ammonium salt; a blend of petroleum hydrocarbon, alkyl ester, organic acid, and anionic surfactant; c₉-C₁₁An alkyl polyglycoside; a phosphorylated alcohol ethoxylate; natural primary alcohol (C)₁₂-C₁₆) An ethoxylate; di-sec-butylphenol EO-PO block copolymers; a polysiloxane-methyl end-cap; nonylphenol ethoxylate + urea ammonium nitrate; an emulsified methylated seed oil; tridecyl alcohol (synthetic) ethoxylate (8 EO); tallow amine ethoxylate (15EO) and PEG (400) dioleate-99.

Liquid carriers that can be used include water, toluene, xylene, naphtha, crop oil, acetone, methyl ethyl ketone, cyclohexanone, trichloroethylene, perchloroethylene, ethyl acetate, amyl acetate, butyl acetate, propylene glycol monomethyl and diethylene glycol monomethyl esters, methanol, ethanol, isopropanol, amyl alcohol, ethylene glycol, propylene glycol, glycerol, N-methyl-2-pyrrolidone, N, N-dimethyl alkylamides, dimethyl sulfoxide, liquid fertilizers, latex, and the like. For dilution of the concentrate, water is generally the carrier of choice.

Suitable solid carriers include talc, pyrophyllite clay, silica, attapulgite clay (attapulgus clay), kaolin, diatomaceous earth, chalk, diatomaceous earth, lime, calcium carbonate, bentonite, fuller's earth, cottonseed hulls, wheat flour, soybean flour, pumice, wood flour, walnut shell flour, lignin and the like.

It is generally desirable to add one or more surfactants to the compositions of the present invention. Such surfactants are advantageously used in solid and liquid compositions, especially those designed to be diluted with a carrier prior to application. Surfactants can be anionic, cationic, or nonionic in nature, and can be used as emulsifying agents, wetting agents, suspending agents, or agents for other purposes. Surfactants which are conventionally used in the formulation field and which can also be used in the formulations of the invention are described in particular in "McCutcheon's detergents and Emulsifiers annular," MC Publishing Corp., Ridgewood, New Jersey, 1998 and "Encyclopedia of Surfactants," Vol.I-III, Chemical Publishing Co., New York, 1980-81. Typical surfactants include salts of alkyl sulfates, such as diethanolammonium lauryl sulfate; alkyl aryl sulfonates such as calcium dodecylbenzenesulfonate; alkylphenol-alkylene oxide addition products, e.g. nonylphenol-C₁₈An ethoxylate; alcohol-alkylene oxide addition products, e.g. tridecyl alcohol-C₁₆An ethoxylate; soaps, such as sodium stearate; alkyl naphthalene-sulfonates, such as sodium dibutylnaphthalene sulfonate; dialkyl esters of sulfosuccinates, such as sodium bis (2-ethylhexyl) sulfosuccinate; sorbitol esters, such as sorbitol oleate; quaternary amines, such as lauryl trimethyl ammonium chloride; fatty acidsPolyethylene glycol esters of (a), such as polyethylene glycol stearate; block copolymers of ethylene oxide and propylene oxide; and salts of monoalkyl and dialkyl phosphates; vegetable oils such as soybean oil, rapeseed oil, olive oil, castor oil, sunflower oil, coconut oil, corn oil, cottonseed oil, linseed oil, palm oil, peanut oil, safflower oil, sesame oil, tung oil and the like; esters of the above vegetable oils.

Other additives commonly used in agricultural compositions include compatibilizers, defoamers, sequestering agents, neutralizing agents and buffers, corrosion inhibitors, dyes, odorants, spreading agents, penetration aids, sticking agents, dispersants, thickeners, antifreeze agents, antimicrobial agents, and the like. The compositions may also comprise other compatible components, for example, other herbicides, plant growth regulators (plant growth regulants), fungicides, insecticides, and the like, and may be formulated with liquid fertilizers or solids, particularly fertilizer carriers such as ammonium nitrate, urea, and the like.

The concentration of the active ingredient in the synergistic composition of the present invention is generally from 0.001 to 98% by weight. Concentrations of 0.01 to 90% by weight are generally used. In compositions designed for use as concentrates, the active ingredient is generally present at a concentration of from 1 to 98wt%, preferably from 5 to 90 wt%. Such compositions are typically diluted with an inert carrier such as water prior to application, or applied directly to the flooded paddy field as a solid or liquid formulation. The diluted compositions usually applied to the weeds or the locus of the weeds usually comprise from 0.0001 to 10% by weight of active ingredient and preferably from 0.001 to 5.0% by weight of active ingredient.

The compositions of the present invention may be applied to weeds or their locus by the use of conventional ground or aerial dusters, sprayers, and granule applicators, by addition to irrigation or paddy water, and by other conventional methods known to those skilled in the art.

The following examples illustrate the invention.

Evaluation of post-emergent herbicidal Activity of mixtures in greenhouse

Seeds of the desired test plant species were planted in a surface area of 128 square centimeters (cm)²) The plastic pots of (1) have a pH of typically 7.2 and an organic matter content of typically 2.9% in a planting mixture of 80% mineral soil/20% grit. The growth medium is sterilized with steam. Plants were grown in a greenhouse maintained at about 29 ℃ during the day and 26 ℃ at night for 7-19 days using about 14-hour (h) photoperiod. Nutrients and water were added regularly and overhead 1000-watt metal halide lamps were used to provide supplemental lighting when needed. When plants reached the third to fourth true leaf stage (true leaf stage), they were treated with a postemergence leaf application (postemergence leaf applications). All treatments were performed using randomized complete block trial design (complete block three design), with each treatment repeated 4 times.

Evaluation of post-emergent herbicidal Activity of mixtures in greenhouse

Treatments include the compounds listed in tables 1, 3,5 and 6, wherein each compound is administered alone or in combination. The formulated amounts of penoxsulam, halosulfuron-methyl, imazamox and fluroxypyr-meptyl were placed in a 60 milliliter (mL) glass vial and dissolved in a 60mL volume of an aqueous solution containing 1% volume to volume (v/v) ratio of Agri-dex crop oil concentrate. Compound requirements are based on an application volume of 12mL at a rate of 187 liters per hectare (L/ha). The spray solution of the mixture was prepared by adding the stock solution to the appropriate amount of the diluted solution to form 12mL of a spray solution with the active ingredients alone and in combination. The formulated compound was applied to plants using an overhead mantel track sprayer (rack sprayer) equipped with 8002E nozzles calibrated to deliver 187L/ha at a spray height 18 inches (43 centimeters (cm)) above the average plant canopy.

The treated plants and control plants were placed in the above greenhouse and watered by sub-irrigation (sub-irrigation) to prevent the test compounds from being washed away. Treatments were graded on days 7 to 21 after application (DAA) compared to untreated control plants. Weed control was scored on a scale of 0 to 100%, where 0 corresponds to no injury and 100 corresponds to complete kill.

Evaluation of post-emergence herbicidal Activity of mixture in field

Field trials were conducted in rice and turf using standard herbicide plot study methods. The ground size is typically 3x3 meters (m) to 3x10m (width x length), with each treatment repeated 4 times. Rice crops are grown using standard cultivation practices of fertilization, seeding, watering, flooding and maintenance to ensure good growth of the crops and weeds. Turf crops are a long established crop of ciliate desert grass that grows and maintains under standard cultivation practices of fertilization, watering, harvesting and disease maintenance to ensure good growth of crops and weeds.

All treatments for field testing used carbon dioxide (CO) calibrated to a spray volume of 187L/ha applied₂) Applied by a knapsack sprayer. Commercially available products of penoxsulam and fluroxypyr-meptyl were mixed in water at appropriately formulated product rates to achieve the desired rates based on unit area of application (hectare) to achieve the desired application rates indicated. None of the treatments were graded on days 7 to 33 after application compared to untreated control plants. Weed control was scored on a scale of 0 to 100%, where 0 corresponds to no injury and 100 corresponds to complete kill.

Table 2 demonstrates the herbicidal synergistic efficacy of penoxsulam + fluroxypyr-meptyl tank mix on weed control. Table 4 demonstrates the herbicidal synergistic safety of mixtures of penoxsulam + fluroxypyr-meptyl for both crops. Table 7 demonstrates the herbicidal synergistic efficacy of imazethapyr + fluroxypyr-meptyl tank mix on weed control. All treatment results (both for individual products and mixtures) are the average of 3-4 replicates, tank mixture interactions were significant at P >0.05 levels.

The Colby equation is used to determine the herbicidal effect expected from the mixture (Colby, s.r. conservation of the synthetic and antibacterial responses of the herbicidal combinations, weeds 1967, 15, 20-22).

The following equation was used to calculate the expected activity of a mixture comprising two active ingredients a and B:

expected activity = A + B- (A x B/100)

A = efficacy of the active ingredient a observed at the same concentration as used in the mixture.

B = efficacy of the active ingredient B observed at the same concentration as used in the mixture.

Some of the compounds tested, the application rates used, the plant species tested, and the results are listed in tables 1-7. All comparisons are averages of 3-4 replicates and significant at a level of P > 0.05. In tables 1-7, the ratios of penoxsulam, halosulfuron-methyl, imazamox and imazethapyr are expressed in grams active ingredient per hectare (g ai/ha), and the ratio of fluroxypyr is expressed in grams acid equivalent (g ae) per hectare.

Table 1.Weeding composition of penoxsulam and fluroxypyr-meptyl for gramineous weeds in greenhouse (Echinochloa crus-galli (ECHCG) activity.

Table 2.Weeding composition of penoxsulam and fluroxypyr-methyl heptyl ester for broadleaf weeds in fields (Plantago laneolata, PLALA; Caperonia palustris, CNPPA; and Sebex exaltata, SEBEX).

Table 3.Weeding composition of penoxsulam and fluroxypyr-meptyl for perennial water in greenhouse Rice weeds Scirpus juncoides(SCPJU) synergistic Activity.

Table 4.Weeding composition of penoxsulam and fluroxypyr-meptyl for sunflowers in field Synergistic activity of injury safety in (HELAN) and centipede (ERLOP).

Table 5.Herbicidal composition of halosulfuron-methyl and penoxsulam for paddy weeds in greenhouse (after application) Day 21 (DAA) grading) synergistic activity.

Table 6.Herbicidal composition of imazamox and penoxsulam for paddy weeds in greenhouse (after application) Day 21 (DAA) grading) synergistic activity.

Table 7.Weeding composition of imazethapyr + fluroxypyr-meptyl on gramineous weeds in field (Leptochloa spp, LEFSS and Panicum dichotomiforum, PANDI) synergistic activity.

BRAPP = Brachiaria platyphylla; broad leaf signal grass

CNPPA = peronia palustris; texas weeds

CYPES = Cyperus esculentus; yellow nut nutgrass flatsedge

ECHCG = echnochloa crus-galli; barnyard grass

ERLOP, = Eremochloa ophiurode; ciliate desert-grass

HELAN = Helianthus annuus; sunflower (Helianthus annuus L.)

LEFCH = Leptochloa chinensis; genus Euphorbia

LEFSS = Leptochloa spp, genus Euphorbia

PANDI=Panicum dichotomiflorum

PLALA = Plantago laniolata l.; herba plantaginis of narrow leaf

SCPJU = Scirpus juntide; japanese reed

SEBEX = Sesbania exaltata; cannabis sesbania

Ob = observed value (% control)

Ex = calculated value expected using Colby analysis (% control)

DAA = days post administration

g ai/ha = g active ingredient per hectare

g ae/ha = gram acid equivalent per hectare

Claims (8)

1. A synergistic herbicide mixture consisting of an herbicidally effective amount of (a) a methylheptyl ester of fluroxypyr and (b) penoxsulam, wherein the weight ratio of fluroxypyr to penoxsulam, on an acid equivalent basis, is from 1:2 to 140: 1.

2. An herbicidal composition comprising an herbicidally effective amount of an herbicidal component and agriculturally acceptable adjuvants and/or carriers, wherein the herbicidal component consists of the synergistic herbicidal mixture of claim 1.

3. A method of controlling undesirable vegetation which comprises contacting the vegetation or the locus thereof with or applying to soil or water to prevent the emergence or growth of vegetation an herbicidally effective amount of the herbicide mixture of claim 1 or the composition of claim 2.

4. The method of claim 3, wherein penoxsulam is applied at an application rate of 4g ai/ha to 100g ai/ha and the methylheptyl ester of fluroxypyr is applied at an application rate of 50g ae/ha to 560g ae/ha.

5. The method of claim 3 or 4, wherein the undesirable vegetation is controlled in cereal crops, rangelands, industrial vegetation management, or turf.

6. The method of claim 5, wherein the undesirable vegetation is controlled in rice.

7. The method of claim 3 or 4, wherein the undesirable vegetation is cannabis sesbania, texas weeds, japanese reed, psyllium strictum, or barnyard grass.

8. A method of protecting ciliate desert-grass and sunflower from the separate insults of penoxsulam and fluroxypyr which comprises contacting the ciliate desert-grass or sunflower with a safe amount of the synergistic herbicide mixture of claim 1 or the composition of claim 2 or applying a safe amount of the synergistic herbicide mixture of claim 1 or the composition of claim 2 to an area in culture.