EP0138945A4

EP0138945A4 - Glyphosate-type herbicidal compositions.

Info

Publication number: EP0138945A4
Application number: EP19840901474
Authority: EP
Inventors: David A Pate
Original assignee: Chevron Research and Technology Co; Chevron Research Co
Current assignee: Chevron USA Inc
Priority date: 1983-03-16
Filing date: 1984-03-02
Publication date: 1985-09-09
Also published as: CA1222639A; WO1984003607A1; AU561761B2; EP0138945A1; AU2698384A

Abstract

Glyphosate-type herbicidal compositions comprising a minor amount of an acifluorfen-type herbicide. The compositions exhibit an increased speed of phytotoxic action as compared with glyphosates and are especially useful in home and garden-type herbicidal applications.

Description

GLYPHOSATE-TYPE HERBICIDAL COMPOSITIONS

BACKGROUND OF THE INVENTION

This invention relates to improved glyphosate- type herbicidal compositions. Glyphosate (N-phosphonomethyl glycine) and its salts are well-known broad spectrum herbicides active against both annual and perennial weeds. This class of herbicides are especially known for their post-herbicidal effectiveness against grasses and are used for both large scale agricultural applications and also for home and garden-type applications. For home and garden applications the glyphosate class of herbicides suffers the disadvantage that they are relatively slow acting especially against certain difficult to kill weed and grass species, such as Bermuda grass. Thus, the common home and garden purchaser is frequently prone to use repeated applications of the herbicide where only one applicaton is necessary because they have failed to see any change in the weeds or undesired vegetation within the first few days or week. This problem is even more accentuated because the glyphosates act more effectively against mature plants than against young plants and most home and garden weed clean-up is done in the early growing season and hence against young plants.

An extensive review of Glyphosate and Related chemistry is set forth by J. E. Franz in IUPAC-Advances in Pesticide Chemistry; Gassbühler Ed. ( 1978-Zurich).

The synthesis and/or use of glyphosate-type herbicides is described in U.S. Patents Nos. 3,799,758; 3,835,000; 3,868,407; 3,950,402; 4,083,893; 4,147,719 and EPO Patent Application No. 19,384. U.S. Patent

No. 3,929,450 teaches that the herbicidal effectiveness of N-phosphonomethyl glycines can be increased by applying them with certain N-phosphonic acids. Farm Chemicals Handbook (1982) at page C-254 teaches that the isopropylamine salt of glyphosate may be tank mixed with Lasso^® atrazine, Princep^®, Lorox^®, Lexone and Sencor for use in certain minimum tillage systems. Acifluorfen, (i.e. 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid) and its salts, are well-known agricultural herbicides which may be applied for selective pre- and post-emergence control of annual broad leaf weeds and grasses in agricultural crops such as soybeans, peanuts, and other large-seeded legumes. These herbicides are generally more active against broad leaf weeds than grasses and are principally applied as post-emergent herbicides. The preparation and use of such herbicides are described in U.S. Patent No. 4,063,929. This patent also generally teaches that such herbicides can be applied in combination with other herbicides including a number of herbicides described in columns 6, 7 and 8 thereof.

Oxyfluorfen [i.e. 2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene] is another diphenyl ether-type agricultural herbicide designed for pre- and post-emergence control of a number of species of broad leaf weeds and grasses in crops such as soybean, chrn, cotton, etc. (see Farm Chemicals Handbook (1981) p. C-165). Oxyfluorfen has also been suggested for agricultural uses in combination with glyphosates apparently to increase its herbicidal effectiveness against grasses

Bifenox [i.e. methyl-5-(2,4-dichlorophenyloxy)-2-nitrobenzoate) is designed for pre- and post-agricultural herbicide applications particularly for broad leaf control. It has also been suggested to use bifenox in overlay with trifluralin, paraquats or the isopropylamine salt of glyphosate (see Farm Chemicals Handbook (1981) p. C-226). Other diphenyl ether herbicides include nitrofen

(i.e., 2,4-dichlorophenyl-p-nitrophenyl ether) and chlomethoxynil (i.e., 2,4-dichlorophenyl-3-methoxy-4-nitrophenyl ether). Various diphenyl ether-type herbicides are also described in U.S. Patents Nos. 3,652,645; 3,979,437; 4,093,446; 4,164,409; 4,192,669; 4,220,468 and British Patent Specification No. 1,521,472. SUMMARY OF THE INVENTION

It has now been surprisingly discovered that adding small amounts of acifluorfen, or its salts, to glyphosate-type herbicides substantially enhances the speed of phytotoxic action. Also, against certain difficult-to-kill weed or grass species, such as Bermuda grass, this increased speed of action is synergistic. Moreover, this enhanced speed of phytotoxic action does not produce any loss in overall effectiveness. This is especially surprising because the overall effectiveness of glyphosates is generally dependent upon a relatively large amount of foliage contact and translocation of glyphosate to the vital organs of the plant. Whereas, phenoxyether- type herbicides are known to cause cell rupture ("burning") and would be expected to reduce translocation, causing poorer overall glyphosate effectiveness; typically manifested by regrowth. Contrary to this, no significant, if any, loss in effectiveness or increased regrowth was observed for the present composition.

For the reasons already noted above, this increased speed of action is especially desirable in home and garden herbicidal applications. Since, the herbicidal action will now be more rapidly observable, which in turn should obviate the tendency of the home gardener to use unnecessary repeated applications of the herbicide. In agricultural (large scale) applications the increased speed of action is, of course, desirable but of less importance because of the sophistication of those applying the herbicides and their awareness of the time required for the herbicide to take effect.

In one embodiment, the invention comprises a herbicidal composition comprising a post-emergent herbicidally effective amount of a glyphosate-type herbicide selected from the group of glyphosate and compatible salts or esters thereof and mixtures thereof; an amount of acifluorfen and/or compatible salts or esters thereof, effective to increase the post-emergence herbicidal speed of phytotoxic action of said glyphosate-type. herbicide and a compatible carrier. The invention also comprises a concentrate formulation comprising the aforementioned glyphosate-type herbicide and acifluorfen or salts or esters thereof.

In another embodiment the invention comprises a method for destroying vegetation which comprises applying a herbicidally effective amount of a glyphosate-type herbicide in combination with an amount of acifluorfen and/or compatible salts thereof, effective to increase the post-emergence herbicidal speed of action of said glyphosate herbicide; to the foliage and/or stems of said vegetation. Methods of preparing the aforementioned compositions are also encompassed within the invention.

A further description of the invention and preferred embodiments thereof is given hereinbelow. FURTHER DESCRIPTION OF THE INVENTION

AND PREFERRED EMBODIMENTS

The glyphosate-type compounds used in the present invention include compounds represented by Formulas I and la hereinbelow and also compounds which are metabolized by green plants to such compounds or more generally, to the phytotoxic functional equivalent of the compounds of Formulas I and la).

wherein Z is cyano; the group -COOR wherein R is hydrogen, lower alkyl, lower alkenyl, lower alkoxyalkyl, aryl, having 6 through 10 carbon atoms or substituted aryl having 1 through 3 substituents independently selected from the group of lower alkyl, lower alkoxy, halo, trifluoromethyl, nitro, and cyano, or a compatible salt- forming cation;

R¹ and R² are independently hydrogen; lower alkyl; aryl; substituted aryl; biphenyl; or a compatible salt forming cation. M^θ is a compatible salt-forming anion; R³ and R⁴ are independently hydrogen; lower alkyl; aryl; substituted aryl; or biphenyl; and Z¹ is cyano; or -COOR' wherein R' is as defined for R but is not a salt- forming cation. With respect to Formulas I and la, the preferred compounds are those wherein Z and Z¹ are -COOR and -COOR', respectively.

With respect to Formula I, the preferred compounds are those wherein R, R¹ and R² are independently hydrogen or a compatible cation. The organic ammonium salts of Formula (I), for example, wherein R is isopropyl amine cation, yield very good results and are commercially available. The organic sulfonium and sulfoxide salts, for example, wherein R¹ and/or R² are trimethyl sulfonium cation or trimethyl sulfoxide cation are also desirable.

With respect to Formula la, the preferred compounds are those wherein R ^1' and R^2' are independently lower alkyl or aryl and Z' is -COOR' wherein R is lower alkyl or aryl.

Compatible cations and compatible anions refer respectively to cations and anions which yield the salt form of the compounds of Formula (I) and (la), respectively, and which do not significantly adversely affect the herbicidal properties of the compound. Typically, the salt form is more water soluble than the free acid or base form and is hence desirable for formulation and application purposes.

Suitable compatible cations include, for example, cations of alkali metals, e.g. sodium, potassium, etc. alkali earth metals, e.g. calcium, magnesium; copper, zinc, iron, nickel manganese, ammonium, and organic ammonium cations, organic phosphonium cations and organic sulfonium and sulfoxide cations preferably having molecular weights below about 300. Suitable organic ammonium cations include cations derived from amines, including cyclic and heterocyclic amines containing 1 or 2 amine groups and includes, for example, alkyl amines, alkylene amines, alkene amines, and alkanol amines. Illustrative species of such amines include, for example: methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, n-amylamine, isoamylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, methylethylamine, methylisopropylamine, methyhexylamine, methylnonylamine, methylpentadecylamine, methyloctadecylamine, ethylbutylamine, ethylheptylamine, ethyloctylamine, hexylheptylamine, hexyloctylamine, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-amylamine, diiso- amylamine, dihexylamine, di-heptylamine, dioxtylamine, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobytylamine, tri-sec-butylamine, tri-n-amylamine, ethanolamine, n-propanolamine, isopropanolamine, diethanolamine, N,N-diethylethanolamine, N-ethylpropanolamine, N-butylethanolamine, allylamine, n-butenyl-2-amine, n-pentenyl-2-amine, 2,3-dimethylbutenyl-2-amine, di-butenyl-2-amine, n-hexenyl-2-amine and propylenediamine, primary aryl amines such as aniline, methoxyaniline, ethoxyaniline, o,m,p-toluidine, phenylenediamine, 2,4, 6-tribromoaniline, benzidine, naphthylamine, o,m,p-chloroaniline, and the like; heterocyclic amines such as pyridine, morpholine, piperidine, pyrrolidine, indoline, azepine and the like.

Suitable organic sulfonium and sulfoxide cations include, for example, C₁-C₁₀ alkyl, preferably lower alkyl, sulfonium and C₁-C₁₀ alkyl, preferably lower alkyl, sulfoxide cations, for example, trimethylsulfonium; ethyldimethylsulfonium; tripropylsulfonium; trimethylsulfoxide; triethylsulfoxide and the like. Suitable procedures for preparing such salts are for example described in U.S. Patent No. 4,315,765, which procedures are hereby incorporated by reference. Suitable phosphonium cations include those having the formula

wherein R^a, R^b, R^c and R^d are independently C₁-C₁₀ alkyl or phenyl, and preferably are lower alkyl. Suitable procedures for preparing such salts are, for example, described in U.S. Patent No. 4,341,549, which procedures are hereby incorporated by reference.

Examples of various suitable cation salt forms are also described in U.S. Patent No. 3,799,758 which disclosure is hereby incorporated by reference.

Suitable compatible anions include, for example, chloride, bromide, iodide, fluoride, sulfate, sulfite, bisulfite, phosphate, orthophosphate, carbonate, bicarbonate, acetate, butyrate, benzoate, maleate and the like. The compounds of Formulas (I) and (la) are generally known compounds and can be prepared by known methods, such as, for example, described in U.S. Patents Nos. 3,799,758; 3,835,000; 3,950,402; 4,067,719; 4,008,296; 4,252,554; 4,147,719 and 4,369,142 or by obvious modifications of known procedures.

A wide variety of compounds which are metabolized by green plants or functionally equate to the phytoxic active moiety of glyphosate can be also used. Such compounds include, for example, the compounds represented by the following formulas (which also encompass the compounds of Formulas I and la above):

wherein M, R¹, R², R³ and R⁴ are as defined herein- above;

Z² is -CH₂CN; -CONHOH (or its tautomer, i.e. -C(OH)=NOH); -CH₂COOR wherein R is hydrogen, a compatible salt-forming cation, lower alkyl, lower alkenyl, lower alkoxyalkyl, aryl or substituted aryl; or -CONR⁷R⁸ wherein R⁷ and R⁸ are independently hydrogen, lower alkyl, lower alkenyl, lower alkoxyalkyl, aryl, substituted aryl, or a compatible salt-forming cation;

Z³ is -CH₂CN; -CONHOH; -C(OH)=NOH (or its tautomer);

-CH₂COOR' wherein R' is hydrogen, lower alkyl, lower alkenyl, lower alkoxyalkyl, aryl or substituted aryl; or -C0NR^7'R^8' wherein R^{7 '} and R^8' are independently hydrogen, lower alkyl, lower alkenyl, lower alkoxyalkyl, aryl or substituted aryl; wherein R⁵ is lower alkyl, lower alkoxy, hydroxy, lower alkanoyl, arylcarbonyl, substituted arylcarbonyl, trifluoroacetyl, lower alkylthioalkanoyl; amino, alkylamino, nitro, nitroso, or a radical having the formula:

-COOR⁹- -OCH₂COOR¹⁰; -CH₂PO(OR^1') (OR^2'); -S(O)_mR¹¹; -SO-X-R¹¹; or -COS(O)_mR¹²;

wherein R⁹ is lower alkyl, lower aklenyl, aryl, or substituted aryl; R¹¹ is lower alkyl, aryl or substituted aryl; X is -O- or -S-; R¹² is lower alkyl, lower alkenyl, lower alkynyl, aryl, substituted aryl, lower arylalkyl, or substituted lower arylalkyl, m is 0, 1, or 2, and R^1' , R^2' and R¹⁰ are independently selected from the group of substituents defined for R¹ hereinabove;

R⁶ is hydrogen; lower alkyl; aryl; substituted aryl; lower arylalkyl; lower substituted arylalkyl; -COOR', wherein R' is hydrogen, lower alkyl, lower alkenyl, lower alkoxyalkyl, aryl or substituted aryl; -PO(OR³) (OR⁴) wherein R³ and R⁴ are as defined hereinabove.

The compounds of Formulas lib - VII above are also generally known herbicidally active compounds and can be prepared by known procedures, or obvious modifications thereof (e.g. substitutions of appropriate solvents and appropriately substituted starting materials). Such compounds and procedures are, for example, described in U.S. Patents Nos. 4,035,177; 4,175,946; 4,251,258; 4,231,782; 4,322,238; 4,322,239; 4,323,387; 4,300,942; 4,300,943; U.S. Research Disclosure No. 220,001, filed July 20, 1982 (Derwent No. 73821 E/35); British Patent No. 2,090,596; Belgian Patent No. 888001 (Derwent No. 71783 D/40); Japanese Patent No. 5 6139408 (Derwent No. 91755 D/50); Japanese Patent No. 5 7099597 (Derwent No. 62700 E/30); European Patent Application No. 39310 (Derwent No. 83914 D/46); German Patent Application No. 2,361,382 (CA 39571e - Vol. 82, 1975); Japanese Patent No. 5 71205.95 (Derwent No. 7120595).

The acifluorfen-type compounds useful in the present invention can be represented by the formula:

wherein M' is hydrogen, lower alkyl, or a compatible salt-forming cation as already discussed hereinabove with respect to Formula (I) and preferably is an alkali metal cation.

The compound of Formula (VIII) wherein M' is a sodium cation is especially preferred as it affords very good results and is readily available commercially.

The compounds of Formula (VIII) are also generally known compounds and can be prepared by known procedures such as, for example, described in U.S. Patent No. 4,063,929, or by obvious modifications of known procedures.

Also, generally the esters of Formulas (I)-(VII) and (VIII) can be prepared by neutralization of the corresponding acid or hydroxy moiety with an alcohol or acyl halide. Similarly, the salts can be prepared via neutralization with the appropriate base or acid. Additional variation in the salt cation, if desired, can also be effected by anion exchange.

The composition of the present invention comprises one or more glyphosate-type compounds and an amount of one or more compounds of Formula (VIII) effective to increase the speed of phytotoxic action as compared with the glyphosate-type compuond per se. Typically, based on two common forms of the compounds of Formula (I) and Formula (VIII), i.e. the isopropylamine salt of glyphosate and the sodium salt of acifluorfen respectively, the composition of the present invention contains about from .1 to .5, preferably about from 0.2 to 0.4 parts by weight of Compound VIII per part of Compound I. In terms of general mole equivalent ratios, typically about from 0.12 to 0.3, preferably 0.14 to 0.23, mole equivalents, based on acifluorfen (i.e. Compound VIII wherein M is H), of Compound VIII is used per mole equivalent of glyphosate-type compound, based on glyphosate (i.e. Compound I wherein R, R¹ and R³ are each H). Lower ratios of Compound VIII to the glyphosate-type compound generally fail to produce a significant enhancement in the speed of action of Compound I whereas higher ratios of Compound VIII to glyphosate-type compound while increasing the speed of phytotoxicity, are not cost effective and can reduce the overall effectiveness of the glyphosate-type compound producing regrowth. The composition is preferably applied in a diluted form comprising a compatible carrier and is generally applied in the same manner as glyphosate-type herbicides and is effective against the same spectrum of broad leaf weeds and grasses with the exception that its phytotoxic action is much faster.

The increased speed of phytotoxicity afforded by the present composition is most .dramatic in the early growing season on young broad leaf weeds and grasses and especially on difficult-to-kill species of weeds and grasses, such as pennywort, creeping beggarweed, Bermuda grass, and bahiagrass. For example, in the case of Bermuda grass, the speed of phytotoxic action is even greater than the combined phytotoxic rates of glyphosate and acifluorfen. in the case of mature vegetation, the increase in speed of action afforded by the present invention is less dramatic because of the relative fast action afforded by glyphosates against mature plants.

The composition can be formulated as a liquid, solid, wettable powder, or aerosol and can be supplied as a concentrate designed for dilution prior to application or can be supplied as a ready-to-use formulation. Generally, the composition is preferably applied to the vegetation as a liquid or aerosol.

For ready-to-use applications the composition typically comprises about from 0.5 to 0.8 wt percent, preferably 0.6 to 0.7 wt percent of active ingredients, (based on isopropylamine salt of glyphosate plus the sodium acifluorfen salt. In the prescribed ratio given hereinabove) and the remainder compatible carrier optionally containing small amounts of suitable additives. The composition can also be formulated as a concentrate typically containing about from 0.8 to 100 wt percent active ingredients (i.e., glyphosate-type compound(s) plust compound(s) VIII in the prescribed ratio given hereinabove) and the remainder compatible carrier optionally containing small amounts of suitable additives. Where the concentrate is formulated as a liquid it typically contains about from 0.8 to 60 wt percent, preferably 1 to 55 wt percent, and more preferably, 1 to 50 wt percent, of said active ingredients and a compatible liquid carrier for example, water. Where the concentrate is supplied as a solid (e.g., powder, granules, etc.) the composition can be 100 wt percent (typically 2 to 100 wt percent) of said active ingredients or can optionally contain a compatible solid carrier (preferably water soluble or water flowable). By using water soluble salt forms of the glyphosate-type compound and Compound VIII and a water-soluble carrier (if any), the concentrate can be dissolved in water in the appropriate concentration and conveniently applied as a liquid.

The term "compatible carrier" refers to carrier materials which are compatible with the herbicidally active ingredients and which do not significantly adversely affect their herbicidal properties save to dilute it.

The composition can also contain small amounts, typically less than 1-5 wt percent, of various optional additives such as wetting agents, stabilizers, emulsifiers, solvents, etc. Examples of such additives and general glyphosate formulations are, for example, described in U.S. Patent No. 4,315,765 which description is hereby incorporated by reference.

Suitable liquid carriers which can be used, include, for example, water, organic solvents, for exampie, benzene, toluene, kerosene, diesel fuel, fuel oil, petroleum naphtha, etc.

Solid carriers can also be used but are generally less convenient than liquid carriers. Suitable solid carriers include, for example, fine clays, walnut shell flour, cottonseed hulls, wheat flour, wood flour, etc.

The present invention can also be applied as an aerosol containing the glyphosate-type compound (s) and Compound(s) VIII in the prescribed ratio along with a suitable aerosol carrier, such as halogenated alkanes and optional additives.

For home and garden use, the composition is preferably applied as a liquid formulation containing about from 0.3 to 1, more preferably 0.4 to 0.7, weight percent of the glyphosate-type compound (based on the isopropylamine salt of glyphosate) and about from 0.08 to 0.5, more preferably 0.1 to 0.3, weight percent of Compound VIII, based on the sodium salt of acifluorfen. I have found that very good results are obtained using a glyphosate-type compound concentration of about 0.5 wt percent (based on the glyphosate isopropylamine salt) and a Compound VIII concentration of about 0.12 wt percent (based on the sodium salt of acifluorfen).

Based on mole equivalents of glyphosate-type compound and mole equivalents of Compound VIII, the liquid formulations preferably contain about from 0.017 to 0.06, more preferably gram mole equivalents, based on glyphosate, of the glyphosate-type compound and about from 0.002 to 0.013, more preferably 0.0025 to 0.008, gram mole equivalents, based on acifluorfen, of Compound(s) (VIII) per kilogram of formulation. Very good results are obtained using about 0.02 mole equivalents, based on glyphosate, of glyphosate-type compound and about 0.003 gram mole equivalents, based on acifluorfen, of

Compound VIII per kilogram of formulation. The remainder of the liquid formulation is liquid carrier or solvent optionally containing suitable additives as explained above. Water is generally the preferred carrier when water-soluble forms of the active compounds are used. The composition can also be formulated as an aerosol for home and garden applications having about the same concentration ranges of the glyphosate-type compound (s) and Compound (s) VIII as the liquid formulations described above. The formulation is then applied to the foliage and/or stems of the vegetation, for example, by simple spraying. As in the case of conventional home and garden glyphosate formulations, best results are obtained when the foliage is thoroughly wetted with the formulation.

The aforementioned compositions of the invention can be conveniently prepared by simple mixing or blending of the ingredients.

Definitions AS used herein, the following terms have the following meanings unless expressly stated to the contrary.

The term "Compounds I and la or I-VII" refers to the compounds defined by Formulas I and la or I-VII, respectively, given hereinabove, and includes mixtures thereof.

The term "Compound VIII" refers to the compounds defined by Formula VIII, given hereinabove, and includes mixtures thereof. The term "alkyl" refers to both straight-chained and branch-chained alkyl groups. The term "lower alkyl" refers to alkyl groups having 1 through 6 carbon atoms and includes, for example, methyl, ethyl, isopropyl, t-butyl, pentyl, hexyl and the like. The term "alkylene" refers to the group -(CH₂)_n-. The term "alkenyl" refers to the unsaturated counterpart of alkyl having one or two double bonds. The term "lower alkenyl" refers to alkenyl having 2 through 6 carbon atoms.

The term "alkoxy" refers to the group R¹ O- wherein R¹ is alkyl. The term "lower alkoxy" refers to alkoxy having 1 through 6 carbon atoms. The term "alkoxyalkyl" refers to the group

R'OR"- wherein R' and R" are each independently alkyl.

The term "lower alkoxyalkyl" refers to the group R'OR"- wherein R' and R" are each lower alkyl and having a total of from 2 through 8 carbon atoms. Typically R" is methyl.

The term "lower alkylamine" refers to the group

R¹R²N- wherein R¹ is lower alkyl and R² IS hydrogen or lower alkyl.

The term "aryl" refers to aryl groups having 6 through 10 carbon atoms and includes phenyl, naphthyl, and the like. The preferred aryl group is phenyl.

The term "substituted aryl" refers to aryl groups having 1 through 3, preferably 1 or 2, substituents independently selected from the group of lower alkyl, lower alkoxy, halo, trifluoromethyl, cyano, nitro and hydroxy. The preferred substituted aryl group is substituted phenyl.

The term "lower arylalkyl" refers to the group ArR'- wherein Ar is aryl and R' is lower alkyl. Preferably, R¹ is methyl or ethyl and/or Ar is phenyl.

The term "lower substituted lower arylalkyl" refers to the group A'rR'- wherein A'r is substituted aryl and R' is lower alkyl.

The term "alkanoyl" refers to the group

wherein R' is alkyl. The term " lower alkanoyl" refers to the group

wherein R' is lower alkyl.

The term "arylcarbonyl" refers to the group

wherein Ar is aryl.

The term "substituted arylcarbonyl" refers to the group

wherein Ar' is substituted aryl.

The term "lower alkylthioalkanoyl" refers to the group

wherein R' and R'' are independently lower alkyl. Preferably, the lower alkylthioalkanoyl has from 2 through 8 carbon atoms.

A further understanding of the invention can be had from the following non-limiting examples.

Example 1

In this example, the formulations of the present invention were field-tested for their speed of phytotoxicity against a variety of mature broad leaf weeds and mature grasses. Side-by-side comparison tests were also conducted at the same time against the same mature weed and grass species using formulations containing only the glyphosate compound or only the acifluorfen compound at the same concentration. Four replicate one square foot plots of the subject plants were tested for each weed and grass species per formulation. An untreated plot was also run at the same time for each species as a check.

The formulations were prepared by diluting standard commercial 41%, by weight, solutions of the isopropylaraine salt of glyphosate (sold under the Trademark Roundup® by the Monsanto Company of St. Louis, Missouri, U.S.A.) and/or a standard commercial 21.4%, by weight, solution of the sodium salt of acifluorfen (sold under the Trademark Blazer^® by the Rohm and Haas Company of Philadelphia, Pennsylvania, U.S.A.) with the appropriate amount of water to yield the concentrations indicated in the tables set forth below.

The formulations were applied to the foliage of the test plant with a trigger sprayer to give thorough coverage. Accordingly, as in home and garden use, different amounts of formulation were applied to the plant depending on the size of the plant. The average amount of formulation used per replicate for a given formulation is indicated in the tables given below. The plants were periodically observed and rated for phytotoxic effects and physiological response to the treatment. A rating scale of 0 to 100 was used, 0 representing no phytotoxicity and 100 representing complete kill. The above-described tests were conducted late in the growing season under field conditions (i.e. outside as opposed to greenhouse testing) and were designed to duplicate home and garden applications. The tests were conducted in the state of Florida during the months of October-November. A series of tests were also conducted during the months of November-December in the states of Washington and Oregon but, were discarded, even though generally showing quicker action for the combination versus glyphosate alone, because of unsettled weather conditions. The results of the Florida tests are summarizedlowing tables.

As can be seen from Tables 1-4, the glyphosate plus acifluorfen formulations of the present invention exhibit increased speeds of phytotoxicity over glyphosate alone at the same concentration. This is shown by the increased phytotoxicity shown in the 3- to 7-day period after application as compared with glyphosate alone. In some instances the increased phytotoxicity extends beyond this period but ultimately glyphosate alone is generally effective alone to give substantially complete control.

This increase in speed of phytotoxicity is perhaps more surprising in the case of grasses since glyphosate is well recognized to already have exceptional activity against grasses and lesser activity against broad leaf weed. Whereas acifluorfen is known to have better activity against broad leaf weed and only relatively modest activity against grasses. Moreover, in the case of difficult-to-control grasses, such as Bermuda grass, this increase in speed of phytotoxicity in the 3- to 5-day period for weight ratios of 0.25 to 0.5 parts acifluorfen salt per part glyphosate salt (i.e., Tests Nos . 8 and 9 - Table 2) was greater than the result obtained by the raw summation of the phytotoxicity for glyphosate and acifluorfen at those concentrations and times. (Also, in the case of Bermuda grass, St. Augustine grass and Bahia grass, the phytotoxic effect of acifluorfen alone was not permanent and a reduction in phytotoxicity rating occurred after about 14 days due to regrowth). in the case of the two broad leaf plants tested, although still faster than glyphosate alone, the combination showed an initial reduction in speed of phytotoxicity at acifluorfen concentrations of 0.25 and 0.5 weight percent as compared with acifluorfen alone at these concentrations, but was equivalent or better after 14 days.

Obviously, many modifications and variations of the invention, described hereinabove and below, can be made without departing from the essence and scope thereof.

Claims

WHAT IS CLAIMED IS:

1. A herbicidal composition comprising:

(a) a phytotoxic effective amount of a glyphosate-type herbicide selected from the group of compounds having the formula:

wherein Z is cyano, or -COOR wherein R is hydrogen, lower alkyl, lower alkoxyalkyl, lower alkenyl, aryl, having 6 through 10 carbon atoms, or substituted aryl having 6-10 ring carbon atoms and having 1 through 3 substituents independently selected from the group of lower alkyl, lower alkoxy, halo, trifluoromethyl, nitro, and cyano; or a compatible salt-forming cation;

Z¹ is cyano or -COOR' wherein R' is hydrogen, lower alkyl, lower alkoxyalkyl, lower alkenyl, aryl having 6 through 10 carbon atoms, or substituted aryl as defined above;

R¹ and R² are independently hydrogen, lower alkyl, aryl having 6 through 10 carbon atoms, substituted aryl, as defined above, biphenyl, or a compatible salt-forming cation; R ³ and R⁴ are independently hydrogen, lower alkyl, aryl having 6 through 10 carbon atoms, or substituted aryl as defined above; and

M is a compatible cation; compounds which are metabolized by green plants to the phytotoxic functionality of the compounds of Formula I and la; and mixtures thereof;

(b) an amount of an acifluorfen-type herbicide selected from the group of compounds having the formula:

wherein M' is hydrogen, lower alkyl or a compatible salt forming cation, and mixtures thereof, which is effective to increase the speed of phytotoxic action of said glyphosate-type herbicide; and (c) a compatible carrier.

2. The composition of Claim 1 wherein said composition comprises said glyphosate-type herbicide and said acifluorfen-type herbicide in a ratio of about from 0.12 to 0.3 mole equivalents, based on acifluorfen, of said acifluorfen-type herbicide per mole equivalent, based on glyphosate, of said glyphosate-type herbicide.

3. The composition of Claim 2 wherein said composition comprises about from 0.14 to 0.23 mole equivalents, based on acifluorfen, of said acifluorfen-type herbicide per mole equivalent, based on glyphosate, of said glyphosate-type herbicide.

4. The composition of Claim 2 wherein said composition contains about from 0.017 to 0.044 gram mole equivalents, based on glyphosate, of said glyphosate-type herbicide and about from 0.003 to 0.013 gram mole equivalents, based on acifluorfen, of said acifluorfen-type herbicide per kilogram of said composition.

5. The composition of Claim 1 wherein said glyphosate-type herbicide is selected from the group of compounds having the Formulas I or la and mixtures of such compounds.

6. The composition of Claim 1 wherein said glyphosate herbicide is selected from the group of compounds of Formula I wherein Z is -COOR, wherein R is hydrogen, lower alkyl, lower alkenyl, lower alkoxyalkyl or a compatible salt-forming cation; and R 1 and R2 are independently hydrogen, lower alkyl, phenyl, substituted phenyl having 1 or 2 substituents selected from the group of alkyl, alkoxy or halo, or a compatible salt-forming cation; and mixtures thereof.

7. The composition of Claim 6 wherein said glyphosate-type herbicide is selected from the group of compounds, wherein R is hydrogen or a compatible cation aanndd RR 1 aanndd RR2 aarree iinnidependently hydrogen or a compatible salt-forming cation.

8. The composition of Claim 2 wherein said glyphosate-type herbicide is selected from the group of lower alkylamine salt of glyphosate and mixtures thereof.

9. The composition of Claim 2 wherein said acifluorfen-type herbicide is selected from the group of alkali metal salts of acifluorfen and mixtures thereof.

10. The composition of Claim 9 wherein said glyphosate-type herbicide is the isopropylamine salt of glyphosate.

11. The composition of Claim 10 wherein said acifluorfen-type herbicide is sodium acifluorfen salt.

12. The composition of Claim 2 wherein said glyphosate-type herbicide is selected from the group of trialkylsulfonium and trialkylsulfoxium salts of glyphosate and mixtures thereof.

13. The composition of Claim 12 wherein said acifluorfen-type herbicide is selected from the group of alkali metal salts of acifluorfen and mixtures thereof.

14. The composition of Claim 13 wherein said glyphosate-type herbicide is selected from the group of the trimethylsulfonium and trimethylsulfoxium salts of glyphosate and mixtures thereof.

15. The composition of Claim 14 wherein said acifluorfen-type herbicide is sodium acifluorfen salt.

16. The composition of Claim 1 wherein said carrier is a liquid.

17. The composition of Claim 2 wherein said carrier is a liquid.

18. The composition of Claim 1 wherein said carrier is an aerosol carrier.

19. The composition of Claim 1 wherein said glyphosate-type herbicide is selected from the group of compounds, and mixtures thereof, having the formulas:

or

wherein M, R¹, R², R³ and R⁴ are as defined in Claim

1;

Z² is -CH₂CN; -CONHOH; -C(OH)=NOH; -CH₂COOR wherein R is hydrogen, a compatible salt-forming cation, lower alkyl, lower alkenyl, lower alkoxyalkyl, aryl or substituted aryl; or -CONR⁷R⁸ wherein R⁷ and R⁸ are independently hydrogen, lower alkyl, lower alkenyl, lower alkoxyalkyl, aryl, substituted aryl, or a compatible salt- forming cation;

Z³ is -CH₂CN; -CONHOH; -C(OH)=NOH; -CH₂COOR' wherein

R' is hydrogen, lower alkyl, lower alkenyl, lower alkoxyalkyl, aryl or substituted aryl; or -CONR^7'R^8' wherein R^7' and R^8' are independently hydrogen, lower alkyl, lower alkenyl, lower alkoxyalkyl, aryl or substituted aryl; wherein R⁵ is lower alkyl, lower alkoxy, hydroxy, lower alkanoyl, arylcarbonyl, substituted arylcarbonyl, trifluoroacetyl, lower alkylthioalkanoyl; amino, alkylamino, nitro, nitroso, or a radical having the formula:

-COOR⁹; -OCH₂COOR¹⁰; -CH₂PO(OR^1')(OR^2'); -S(O)_mR¹¹; -SO-X- R¹¹or -COS(O)_mR¹², wherein R⁹ is lower alkyl, lower alkenyl, aryl, or substituted aryl; R¹¹ is lower alkyl, aryl or substituted aryl; X is -O- or -S-; R¹² is lower alkyl, lower alkenyl, lower alkynyl, aryl, substituted aryl, lower arylalkyl, or substituted lower arylalkyl, m is 0, 1 or 2, and R^1' , R^2' and R¹⁰ are independently hydrogen, lower alkyl, aryl, substituted aryl, or a compatible cation, and R⁶ is hydrogen, lower alkyl, aryl, substituted aryl, lower arylalkyl, substituted lower arylalkyl; -COOR' wherein R' is as defined hereinabove; -PO(OR³)(OR⁴) wherein R³ and R⁴ are as defined in Claim 1; with the proviso that aryl refers to aryl groups having 6 to 10 carbon atoms; substituted aryl refers to aryl group having 6 to 10-ring carbon atoms and 1-3 substituents independently selected from lower alkyl, lower alkoxy, halo, trifluoromethyl, nitro, and cyano, and lower arylalkyl and substituted lower arylalkyl refer to such groups wherein the alkyl moiety is an unsubstituted lower alkyl and the aryl and substituted aryl moieties are as defined hereinabove.

20. A herbicide concentrate composition comprising a glyphosate-type herbicide selected from the group consisting of compounds having the formulas:

or

Z¹ is cyano or -COOR' wherein R' is hydrogen, low alkyl, lower alkoxyalkyl, lower alkenyl, aryl having 6 through 10 carbon atoms, or substituted aryl as defined above; R¹ and R² are independently hydrogen, lower alkyl, aryl having 6 through 10 carbon atoms, substituted aryl, a defined above, biphenyl, or a compatible salt-forming cation; R³ and R⁴ are independently hydrogen, lower alkyl, aryl having 6 through 10 carbon atoms, or substituted aryl as defined above; and

M is a compatible cation; compounds which are metabolized by green plants to the phytotoxic functionality of the compounds of Formula I and la; and mixtures thereof; and acifluorfen-type herbicide selected from the group cons isting of compounds having the formula:

wherein M' is hydrogen, lower alkyl or a compatible salt forming cation, and mixtures thereof; and wherein said composition comprises about from 0.12 to 0.3 mole equivalents, based on acifluorfen, of said acifluorfen-type herbicide per mole equivalent, based on glyphosate, of said glyphosate-type herbicide.

21. The composition of Claim 20 wherein said composition comprises about from 0.14 to 0.23 mole equivalents, based on acifluorfen, of said acifluorfen-type herbicide, per mole equivalent, based on glyphosate, of said glyphosate-type herbicide.

22. The composition of Claim 21, wherein said composition comprises a sum total of about from 0.8 to 100 weight percent of said glyphosate-type herbicide and said acifluorfen-type herbicide.

23. The composition of Claim 22 wherein said composition is a liquid and comprises a compatible liquid carrier and contains a sum total of about from 0.8 to 55 weight percent of said glyphosate-type herbicide and said glyphosate-type herbicide.

24. The composition of Claim 22, wherein said composition is a particulate solid and contains a sum total of about from 2 to 100 weight percent of said glyphosate-type herbicide and said acifluorfen-type herbicide.

25. A method for controlling broad leaf and grass plants which comprises contacting the foliage of said plants with a phytotoxic effective amount of the composition of Claim 1.

26. A method for controlling broad leaf plants and grass plants which comprises contacting the foliage of said plants with a phytotoxic effective amount of the composition of Claim 2.

27. A herbicidal composition comprising about from 0.4 to 0.7 weight percent of the isopropylamine salt of glyphosate; about from 0.1 to 0.3 weight percent of the sodium salt of acifluorfen in a weight ratio of about from 0.2 to.0.4 parts of said sodium acifluorfen salt per part of said glyphosate salt; and a compatible liquid carrier.

28. The composition of Claim 27 wherein said composition comprises about 0.5 weight percent of said isopropylamine salt of glyphosate and about 0.12 weight percent of said sodium salt of acifluorfen.