CN112165862A - Compositions and methods for controlling undesirable vegetation in crops - Google Patents

Abstract

The present disclosure relates to herbicidal compositions comprising a first herbicide selected from the group consisting of 2,4-DC, 2,5-DC, and mixtures thereof, and the second herbicide isoproturon; and methods for controlling undesirable vegetation in crops comprising applying a combination of a first herbicide and a second herbicide to the locus of the vegetation.

Description

Compositions and methods for controlling undesirable vegetation in crops

Technical Field

The present disclosure relates to herbicidal compositions and methods for controlling undesirable vegetation in crops.

Background

One recurring challenge in agriculture relates to controlling the growth of undesirable vegetation, which interferes with crop growth and reduces crop yield. To address this challenge, a number of chemicals and formulations have been developed and used in agriculture.

U.S. patent 4,405,357 discloses certain 3-isoxazolidinones which exhibit desirable selective herbicidal activity. In particular, such compounds have been shown to be effective in controlling grassy and broadleaf weed species while not affecting legume crops, particularly soybeans. Specifically disclosed in this patent are 2- [ (2, 4-dichlorophenyl) methyl ] -4, 4-dimethyl-3-isoxazolidone (CA No.81777-95-9) and 2- [ (2, 5-dichlorophenyl) methyl ] -4, 4-dimethyl-3-isoxazolidone (CA No. 81778-66-7). Both compounds are effective against many weeds.

In crop protection products, it is always desirable to increase the specific activity of the active ingredient, to provide resistance management or to broaden the activity spectrum for herbicidal compositions including control of other weed species. Mixtures of crop protection agents are often used to provide this improved activity.

Summary of The Invention

Surprisingly, it has now been found that certain combinations of 3-isoxazolidinones and isoproturon exhibit synergistic effects when used to control undesirable vegetation.

In one aspect, the present invention relates to a herbicidal composition comprising a first herbicide selected from the group consisting of 2- (2, 4-dichlorophenyl) methyl-4, 4-dimethyl-3-isoxazolidone ("2, 4-DC"), 2- (2, 5-dichlorophenyl) methyl-4, 4-dimethyl-3-isoxazolidone ("2, 5-DC"), and mixtures thereof; and a second herbicide isoproturon.

In another aspect, the present invention relates to a method of controlling undesirable vegetation in crops comprising applying to the locus of such vegetation a herbicidally effective amount of a combination comprising a first herbicide selected from the group consisting of 2,4-DC, 2,5-DC and mixtures thereof and a second herbicide isoproturon.

In a particular aspect, the present invention relates to a method for controlling undesirable vegetation in crops which comprises applying to the locus of such vegetation a herbicidally effective amount of a combination comprising a first herbicide, 2,4-DC and a second herbicide, isoproturon, wherein the undesirable vegetation comprises at least one of Alopecurus aqualis (short-awn foxail) and carex (L.) p.beauv (hardgrass), and the crop is wheat.

Detailed Description

The term "and/or" means any one of, any combination of, or all of the items associated with the term. The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, the indefinite articles "a" or "an" used in the claims are defined herein to mean one or more than one of the element in question. Thus, for example, reference to "a compound" includes a plurality of such compounds, and thus a compound X includes a plurality of compounds X. It should also be noted that the claims may be formulated to not include any optional elements, that is, optional elements that may or may not be present in the claimed embodiments. Accordingly, this statement is intended to serve as antecedent basis for use of such exclusive terminology as "solely," "only," and the like, or use of a "negative" limitation in connection with the recitation of claim elements.

Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, each range of values (of the form "from about a to about b," or, equivalently, "from about a to b," or, equivalently, "from about a-b") disclosed herein is to be understood as listing each value and range encompassed within the broader range of values. When a range is expressed from one or more lower limits to one or more upper limits, the range encompassed can be any recited lower limit to any recited upper limit.

While compositions and methods are described in terms of "comprising," "containing," or "including" various components or steps, the compositions and methods can also "consist essentially of" or "consist of" the various components or steps. All values and ranges disclosed above may be varied somewhat. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined herein. To the extent that any conflict in the use of a word or term in this specification with one or more patents or other documents incorporated herein by reference exists, a definition consistent with this specification shall apply.

As used herein, unless otherwise specified, the term "herbicide" refers to a mixture of compositions produced, sold or used in the field for the purpose of killing or otherwise inhibiting the growth of unwanted plants, such as, but not limited to, harmful or offensive weeds, broadleaf plants, grasses (grasses) and sedges; and can be used for crop protection, building protection or turf protection. The term "herbicide" includes herbicidal products for end use. The composition may be a pure compound, a solution of a compound, a mixture of compounds, an emulsion, a suspension, a solid-liquid mixture, or a liquid-liquid mixture.

The term "herbicide" also refers to a product that passes through the commercial channel from the producer to the end user, who can apply the herbicide to the affected field in the form in which it is sold, or mixed with other excipients.

The term "weeds" means and includes any plant that grows in an undesired location.

The term "herbicidally effective amount" means the amount of a composition or combination of the invention necessary to produce an observable herbicidal effect on the growth of the undesired plant, the observable herbicidal effect including one or more of the following: necrosis, death, growth inhibition, reproduction inhibition, proliferation inhibition of unwanted plants, and removal, destruction, or otherwise reducing their presence and activity.

The term "herbicidal active ingredient(s)" refers to an active ingredient or ingredients in a herbicide that cause the herbicide to prevent, destroy, repel, or mitigate any weeds. Other ingredients of herbicides that are not herbicidal active ingredients are excipients that aid in the formation, storage, or delivery of the herbicidal active ingredient to the target. The term "herbicidal composition" refers to a herbicide, and further refers to any composition comprising a herbicidal active ingredient, such as those described herein, and optionally comprising at least one excipient. The composition may be a solution or a mixture. Furthermore, the term "herbicidal composition" also refers to a product intended for manufacture, or any product intended to be formulated or repackaged into other agricultural products. The compositions include any of the formulation types described below, and also include one or more formulations comprising the herbicidal active ingredient mixed with a diluent prior to application to the plants.

The term "2, 4-DC" refers to 2- [ (2, 4-dichlorophenyl) methyl ] -4, 4-dimethyl-3-isoxazolidinone.

The term "2, 5-DC" refers to 2- [ (2, 5-dichlorophenyl) methyl ] -4, 4-dimethyl-3-isoxazolidinone.

The term "isoproturon" refers to 3- (4-isopropylphenyl) -1, 1-dimethylurea (i.e., N-dimethyl-N' - [4- (1-methylethyl) phenyl ] urea (CA No. 34123-59-6)).

At least one aspect of the present invention relates to a herbicidal composition or combination comprising a first herbicide selected from the group consisting of 2,4-DC, 2,5-DC, and mixtures thereof; and a second herbicide isoproturon. In one embodiment, the first herbicide is 2, 4-DC. In another embodiment, the first herbicide is a mixture of 2,4-DC and 2, 5-DC. If a mixture of 2,4-DC and 2,5-DC is used, the 2,4-DC and 2,5-DC may be present in any ratio. In a particular embodiment, 2,4-DC is present in excess of 2, 5-DC.

The second herbicide in the composition or combination is isoproturon. It is a photosystem II photosynthesis inhibitor.

In another embodiment, the compositions of the present invention may further comprise a third herbicide. As used in the present invention, the third herbicide does not interfere with the synergistic effect between the first herbicide and the second herbicide. A third herbicide may be used if it is desired to broaden the scope of weed control or prevent development of resistance. Examples of useful additional herbicides include, but are not limited to, acetochlor, aclonifen, ametryn, amicarbazone, atrazine, bispyribac, beflubutamid, S-fluorobutamid, bromoxynil, carfentrazone-ethyl, cyhalofop-butyl, 2,4-D, 2,4-DB, 2,4-DEB, dicamba, diflufenican, dimethachlor, mefenacet-P, flutolanil, ethoxysulfuron, flucetosulfuron, metribuzin, fomesafen, hexazinone, isoxaflutole, linuron, mesotrione, metamifop, pyroxafen, pyroxsulam, bromuron, metolachlor, cyclizine, metsulfuron-methyl, diuron, pendimethalin, dimethofen, pretilachlor, propanil, pyraclopyraflufen, quizalofen, buthiuron, thifensulfuron-methyl, metsulfuron-methyl, sulfentrazone, Trifluralin, their agriculturally acceptable salts, their esters, and mixtures of two or more thereof.

In yet another embodiment, the third herbicide is selected from the group consisting of napropamide, aclonifen, topramezone, metazachlor, diflufenican, sulfentrazone, mesotrione, metsulfuron-methyl, thifensulfuron-methyl, and agriculturally acceptable salts thereof, esters thereof, and mixtures of two or more thereof.

In another embodiment, the compositions of the present invention may further comprise a herbicide safener selected from the group consisting of: bensulfuron, clomazone, cloquintocet-mexyl, prosulfuron, oxabetronitrile, cyprosulfamide, chlorsulfuron, dichloracrylamide, diclonone (dicyclonon), diametholate, penflufen, fenchlorazole, fenclorim, fluxoxime, fenclozole, ethyl isoxadifonate, pyraclofen-ethyl, mefenamate, benzotolone, naphthalic anhydride (1, 8-naphthalic anhydride), oxanil, N- (aminocarbonyl) -2-methylbenzenesulfonamide, N- (aminocarbonyl) -2-fluorobenzenesulfonamide, 1-bromo-4- [ (chloromethyl) sulfonyl ] Benzene (BCS), 4- (dichloroacetyl) -1-oxa-4-azaspiro [4.5] decane (MON 4660), 2- (dichloromethyl) -2-methyl-1, 3-dioxolane (MG 191), ethyl 1, 6-dihydro-1- (2-methoxyphenyl) -6-oxo-2-phenyl-5-pyrimidinecarboxylate, 2-hydroxy-NN-dimethyl-6- (trifluoromethyl) pyridine-3-carboxamide, 3-oxo-1-cyclohexen-l-yl 1- (3, 4-dimethylphenyl) -l, 6-dihydro-6-oxo-2-phenyl-5-pyrimidinecarboxylate, 2-dichloro-1- (2,2, 5-trimethyl-3-oxazolidinyl) -ethanone and 2-methoxy-N- [ [4- [ [ (methylamino) carbonyl ] amino ] phenyl ] sulfonyl ] -benzoyl Amines to increase safety for certain crops. It is noteworthy that the compositions of the present invention comprise cloquintocet-mexyl or mefenpyr-diethyl. It is noted that the compositions of the present invention comprise cloquintocet-mexyl.

In another aspect, the present invention relates to a method of controlling undesirable vegetation in a crop comprising applying to the crop a first herbicide comprising a herbicide selected from the group consisting of 2,4-DC, 2,5-DC, and mixtures thereof; and a second herbicide isoproturon are applied to the locus of such vegetation. As discussed further below, the combination may be administered as a single composition or as separate compositions.

In one embodiment, the undesirable vegetation includes at least one selected from grasses (grass weed) and broadleaf weeds. In another embodiment, the vegetation is selected from the group consisting of poa annua, aleurites polygama, Alopecurus macrogola, solanum nigrum, brachiaria latifolia, canada thistle, brome, Xanthium sibiricum (Xanthium pensylvanicum), ragweed, corn poppy, mallow wildweed, setaria viridis, goya, sticktight, herbicide-resistant Alopecurus macrogola, brettanomyces parvifolia, lolium italicum, stramonium, johnsongrass (Sorghum halepense), large digitaria sanguinea, canary grass, morning glory, stinging nettle, petunia (pitted glory), sida acutifolia, wheatgrass, paddley amaranthus, sugarcane, shepherd's purse, alata, sunflower (buckwheat in potato crops), nuus cornus indicus (maize), mustard grass (Sorghum), Sorghum halepense (Avena), Sorghum halepense (cornus), Sorghum halepense (berosa), Sorghum halepense (cornus), Sorghum halepense (berus), Sorghum halepense (see-grass) and Sorghum halepense), Sorghum halepense (see-grass) is, kola), ko, Goose intestine (Myosoton aquaticum), chickweed (Stellaria media) and Beckmannia syzigachne (Beckmannia syzigachne). In a preferred embodiment, the undesirable vegetation comprises at least one of physalis alkekengi, hardgrass, physalis japonica, goosegrass, chickweed and beckmark grass. In another preferred embodiment, the undesirable vegetation includes at least one of alopecurus, carex, alopecurus, gooseberry, chickweed and beckmark grass grown in wheat (Triticum aestivum).

In yet another embodiment, the crop is selected from the group consisting of broadleaf crops and gramineous (grass) crops. In a preferred embodiment, the crops include bananas, beans, sugar beets, cassava, cereal crops, citrus, cocoa, coconut, coffee, corn, cotton, fiber crops, flowers, forage crops, forestry, groundnut, peanut, hops, horticulture, non-land crops, oil palm, oilseed rape, peas, pome fruit, potato, rice, stone fruit, spices, sugar cane, sunflower, tea, tobacco, tomatoes, nuts, turf, vegetable crops, vines, and grapes. In at least one embodiment, the crop is potato, soybean, corn, rice, sorghum, canola, barley, rye, cowpea or canola (canola). In a more preferred embodiment, the crop is wheat.

In a particular aspect, the present invention relates to a method of controlling undesirable vegetation in a crop comprising applying to the crop a first herbicide comprising a first herbicide selected from the group consisting of 2,4-DC, 2,5-DC and mixtures thereof; and a second herbicide isoproturon, wherein the vegetation comprises at least one of a myrtle and a hardwood, and the crop is wheat.

The compositions containing the active compounds/ingredients of the present invention may be used in any conventional agriculturally useful form, for example in a two-pack form, or in a ready-to-use formulation or in a tank-mix form. In addition, the active compounds may be provided (alone or pre-mix) in any suitable formulation type, such as Emulsifiable Concentrates (EC), Suspension Concentrates (SC), Suspoemulsions (SE), microcapsule suspensions (CS), water dispersible granules (WG), Emulsifiable Granules (EG), oil Emulsions (EO) and water Emulsions (EW), dispersible oil suspensions (OD), oil suspensions (OF), oil solutions (OL), soluble Solutions (SL), ultra low volume Suspensions (SU), ultra low volume liquids (UL), dispersible solutions (DC), Wettable Powders (WP), or any other technically feasible formulation. Such compositions can be formulated using excipients and formulation techniques known in the art for the separate formulation of herbicides. For example, the herbicide may optionally be mixed with other formulation ingredients.

The active ingredients of the composition may be provided in a single formulation or in a tank-mix form in which the active ingredients are each provided in separate formulations, which are typically tank-mixed with a diluent (e.g. water) prior to administration. The active ingredients are preferably co-formulated and provided in a single formulation to provide more convenient application, and more preferably in a formulation type such as WP, WG, SC, EC or CS formulations.

The active ingredient of the composition may be encapsulated or non-encapsulated. Encapsulation is often used to reduce the volatility of the herbicide or to provide a slow release of the herbicide. In a specific embodiment, the first herbicide of the composition is encapsulated (e.g., 2,4-DC, 2,5-DC, or both) and the second herbicide is not encapsulated.

When mixed with additional components, the compositions typically contain from about 0.01% to about 95% by weight of the active compound, with the remainder typically being excipients for formulating herbicides, such as diluents, surfactants, and the like.

The term diluent includes all liquid and solid agriculturally acceptable materials, including carriers that may be added to the herbicide to render it suitable for use or commercial form, including solvents, emulsifiers and dispersants. The diluent may be added during the formulation process, after the formulation process (e.g., by the user farmer or custom applicator), or both. Examples of suitable solid diluents or carriers are aluminium silicates, talc, calcined magnesium oxide, kieselguhr, tricalcium phosphate, cork flour, absorbent carbon black, chalk, silica and clays such as kaolin and bentonite. Examples of suitable liquid diluents include water, organic solvents (e.g., acetophenone, cyclohexanone, isophorone, toluene, xylene, petroleum fractions), amines (e.g., ethanolamine, dimethylformamide), and mineral, animal and vegetable oils (used alone or in combination).

The composition may also contain surfactants, protective colloids, thickeners, penetrants, stabilizers, chelating agents, anti-caking agents, colorants, corrosion inhibitors and dispersants, such as spent sulfite pulp liquor and methylcellulose. The term surfactant as used herein refers to agriculturally acceptable materials that impart emulsifying, stability, spreadability, wettability, dispersability, or other surface modifying properties. Examples of suitable surfactants include lignosulfonates, fatty acid sulfonates (e.g., lauryl sulfonate), condensation products of formaldehyde and naphthalene sulfonates, alkylaryl sulfonates, ethoxylated alkylphenols, and ethoxylated fatty alcohols. Other known surfactants for use with herbicides are also acceptable.

The compositions may be administered in various combinations of active ingredients. For example, they may be applied in a single "ready-mix" form or a tank mix. Thus, the active ingredients are used in combination, not necessarily in physical combination or even simultaneously. In other words, the active ingredients may be administered separately and/or sequentially, as long as administration of the second active compound occurs within a reasonable period of time from the administration of the first active compound, for example within 24 hours or within 48 hours. The composition may be applied post-emergence. In a preferred embodiment, the composition is applied early after emergence. In a particular embodiment, the composition of the invention is applied to protect wheat at its four-leaf stage.

The rate of application of the composition will vary depending on a number of factors, such as the target weeds, the extent of infestation, weather conditions, soil conditions, crop species, mode of application, and time of application.

The weight ratio of the first herbicide to the second herbicide is preferably selected to provide synergistic weed control. Such amounts are also referred to as synergy amounts and can be readily determined by one skilled in the art using well known principles. Typically, the weight ratio of the first herbicide (e.g., 2,4-DC or 2,5-DC) to the second herbicide (i.e., isoproturon) is from 1:1 to 1:20, from 1:1 to 1:15, or from 1:1 to 1: 10.

An effective amount of the combination of the first herbicide and the second herbicide is any amount that has the ability to prevent undesirable vegetation. Typically, the first herbicide (e.g. 2,4-DC or 2,5-DC) is used in an amount from a lower limit of 50g a.i./ha to an upper limit of 200, 500 or 1000g a.i./ha, preferably from 50 to 500g a.i./ha, such as from 75g to 125g a.i./ha; the second herbicide (i.e. isoproturon) is used in an amount from a lower limit of 1500 or 1000g a.i./ha to an upper limit of 2000, 2500 or 4000g a.i./ha, preferably from 500 to 2500g a.i./ha, such as from 750 to 1125g a.i./ha. However, higher doses and especially lower doses may also provide sufficient control.

Additional herbicides can also be used as long as they do not interfere with the synergistic effect between the first and second herbicides. Additional herbicides may be used if it is desired to broaden the scope of control or prevent development of resistance. Examples of additional herbicides that can be used in the present invention include, but are not limited to, those described above.

Synergy was calculated using the Colby method. As used herein, the terms "synergistic" and "synergistic" or the phrase "in a synergistic manner" refer to the in vivo interaction of two or more biologically active compounds (in the present case, a first herbicide and a second herbicide) such that their combined effect when applied together is greater than the sum of the effects observed when each is applied individually. In this way, the application rate of the herbicide combination can be lower than the use rates registered, thereby reducing the overall chemical burden on the field to which such a combination is applied.

The Colby method for determining synergy is described in Colby, s.r., "calculating synergy and antagonism of herbicide combinations", Weeds 1967,15, p 20-22, which is incorporated herein by reference. According to this method, by means of the Colby equation: e ═ X + Y- (XY/100) determines the presence of a synergistic effect between the two active ingredients. Using the Colby method, the presence of a synergistic interaction between two active ingredients is determined by first calculating the expected activity 'E' of the mixture based on the activities of the two components applied separately. In the above equation, 'X' is the percent herbicidal activity of the control of the disclosed 3-isoxazolidinones applied as a mixture at a ratio 'X'. The term 'Y' is the herbicidal activity of the second activity (isoproturon) applied as a mixture at the ratio 'Y'. This equation calculates the "expected" herbicidal activity of a mixture of 'E', i.e., 'X' for the ratio 'X' and 'Y' for the ratio 'Y'. If 'E' is below the observed activity, then there is a synergy. If the herbicidal effects are strictly additive and no interaction is found, 'E' will be equal to or higher than the activity observed.

The following table in the following examples summarizes the% control of the tested weed species and the% control observed versus the expected values for the mixtures of 3-isoxazolidinone compounds tested alone or in combination with isoproturon in the field trials.

The invention is illustrated by the following examples.

Synthesis example 1

Preparation of 2- (2, 4-dichlorobenzyl) -4, 4-dimethylisoxazolidin-3-one (2,4-DC)

Step A: preparation of 4, 4-dimethylisoxazolidin-3-one sodium salt (CAS No.107746-05-4)

44-dimethyl-3-isoxazolidone (CAS No.81778-07-6) was added to water followed by aqueous sodium hydroxide to form a solution with a pH of 9.5 to 9.7. The resulting salt solution was used directly in the next step.

And B: preparation of 2- (2, 4-dichlorobenzyl) -4, 4-dimethylisoxazolidin-3-one

To an aqueous solution of 4, 4-dimethylisoxazolidin-3-one sodium salt is added a catalytic amount of tetrabutylammonium bromide and the solution is heated to 50-60 ℃. 2, 4-dichlorobenzyl chloride was added at such a rate that the reaction temperature was maintained between 50-60 ℃ for 30 minutes to 1 hour. The reaction was inoculated with the previously prepared product and continued until all of the 2, 4-dichlorobenzyl chloride was consumed. The resulting slurry was cooled to ambient temperature and filtered. The resulting solid was washed once with water, twice with heptane and again with water and then dried at about 50 ℃ (75% to 77% yield). The heptane washings were combined to recover unreacted 4, 4-dimethylisoxazolidin-3 one sodium salt, 2, 4-dichlorobenzyl chloride, and the O-alkylated by-product (i.e., 3- [ (2, 4-dichlorophenyl) methoxy ] -4, 5-dihydro-4, 4-dimethylisoxazole).

And C: preparation of 2- (2, 4-dichlorobenzyl) -4, 4-dimethylisoxazolidin-3-one

Methanol was added to the combined heptane washings obtained in step B (i.e., containing unreacted 4, 4-dimethylisoxazolidine-3-sodium salt, 2, 4-dichlorobenzyl chloride, and O-alkylated by-product 3- [ (2, 4-dichlorophenyl) methoxy ] -4, 5-dihydro-4, 4-dimethylisoxazole) and the solution was heated to 40 ℃. Dry HCl gas was passed through the solution while maintaining the temperature between 40-45 ℃ for 1.5 hours. The reaction was held at 40 ℃ for 4-6 hours. The two layers of the reaction were separated and the bottom (aqueous) layer was back-flushed with heptane. The combined heptane layers were distilled to give 2, 4-dichlorobenzyl chloride and traces of 2- (2, 4-dichlorobenzyl) -4, 4-dimethylisoxazolidin-3-one and 4, 4-dimethylisoxazolidin-3-one (CAS No.81778-07-6) for direct use in step A of subsequent batches. The bottom layer (aqueous layer) was treated with 10% sodium hydroxide to give 4, 4-dimethylisoxazolidin-3-one sodium salt, which was used directly in step a of the subsequent batch.

Biological examples: evaluation of herbicidal efficacy after emergence

Preparation of the composition for testing

By combining 44.0% 2,4-DC, 1.5% TERGITOL^TMXD (Dow Chemical company), ETHOX ERS 01293(Ethox Chemicals), 6.0% propylene glycol, 0.13% propylene glycol

A 2% aqueous solution of M xanthan gum (CPKelco a Huber Company), 0.15% DOW AF defoamer (DOW Chemical Company) and 46.7% water (all by weight%) and milling the mixture until a D90 particle size is obtained (90% of the particles have this diameter) of less than about 50 microns to make a SC formulation of 2, 4-DC.

A 50% WP preparation of isoproturon was obtained from the market (registration No. pd20040658, jiangsu kuaikanghua gmbh).

The mixture of 2,4-DC and isoproturon was provided in a tank mix by mixing the SC preparation of 2,4-DC and the 50% WP preparation of isoproturon prior to use.

Efficacy testing

The compositions were tested for herbicidal efficacy. The test crop was wheat and the test weeds were myrtle and hardwood. For the post-emergence test, wheat was planted on a field with naturally occurring and well-irrigated target weeds prior to application of the composition. Weed control was assessed by applying the test compositions individually and in combination by spray application at the rate indicated in the four-leaf stage of wheat and someday after treatment (DAT), as shown in tables 1 and 2 below.

The observed control (%) was calculated by the following formula:

wherein X₀And X₁The number of weeds before and after treatment in the same area

Table 1: prevention and treatment of Aleurites communis in wheat

As is clear from tables 1 and 2, the combination of 2,4-DC and isoproturon demonstrated synergistic weed control, with the measured weed control being higher than that predicted by the Colby formula.

The present disclosure is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Features of the disclosed embodiments may be combined, rearranged, omitted, etc., within the scope of the invention, to produce additional embodiments. Moreover, some features may sometimes be used to advantage without the corresponding use of other features. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention.

Claims (18)

1. A herbicidal composition comprising a first herbicide selected from the group consisting of 2,4-DC, 2,5-DC, and mixtures thereof; and a second herbicide isoproturon.

2. The composition of claim 1, wherein the first herbicide is 2, 4-DC.

3. The composition of claim 1 or claim 2, wherein the weight ratio of the first herbicide to the second herbicide is from about 1:1 to about 1: 20.

4. The composition of claim 1 or claim 2, wherein the first herbicide and the second herbicide are present in a pre-mix or tank-mix.

5. A method for controlling undesirable vegetation in a crop comprising applying to the locus of the undesirable vegetation a herbicidally effective amount of a combination comprising a first herbicide and a second herbicide, wherein the first herbicide is selected from the group consisting of 2,4-DC, 2,5-DC and mixtures thereof and the second herbicide is isoproturon.

6. The method of claim 5, wherein the first herbicide is 2, 4-DC.

7. The method of claim 5, wherein the undesirable vegetation comprises at least one selected from grasses and broadleaf weeds.

8. The method of claim 7, wherein the undesirable vegetation includes at least one of Alopecurus aequalis sobol, Harpagophytum procumbens (Sclerochlora dura (L.) P.Beauv), Alopecurus japonicus (Alopecurus japonica), gooseberry (Myosoton aquaticum), Stellaria media, and Syzigara syzigarne (Beckmannia syzigachne).

9. The method of claim 5, wherein the crop is selected from broadleaf crops and gramineous crops.

10. The method of claim 9, wherein the crop is selected from the group consisting of bananas, beans, sugar beets, cassava, cereal crops, citrus, cocoa, coconut, coffee, corn, fiber crops, flowers, forestry, forage crops, grapes, groundnuts, hops, horticulture, non-land crops, oil palm, oilseed rape, peas, peanuts, pome, potatoes, rice, spices, stone fruit, sugar cane, sunflowers, tea, tobacco, nuts, turf, vegetable crops, vines, and wheat.

11. The method of claim 5, wherein the combination is applied post-emergence.

12. The method of claim 5, wherein the combination is applied early post-emergence.

13. The method of claim 5, wherein the combination is administered as a composition in a pre-mix or tank mix.

14. The method of claim 13, wherein the composition is applied by spray application.

15. The method of claim 5, wherein the weight ratio of the first herbicide to the second herbicide is from 1:1 to 1: 20.

16. The method of claim 5, wherein the first herbicide is applied in an amount of 50 to 1000g a.i./ha and the second herbicide is applied in an amount of 1 to 4000g a.i./ha.

17. The method of claim 16, wherein the first herbicide is applied in an amount of 100 to 500g a.i./ha and the second herbicide is applied in an amount of 1000 to 2000g a.i./ha.

18. The method of claim 5, wherein the crop is wheat and the undesirable vegetation comprises at least one of alopecurus, carex, alopecurus japonicus, gooseberry, chickweed and beckmark grass.