WO1999057982A1

WO1999057982A1 - Crop-safened herbicidal mixtures

Info

Publication number: WO1999057982A1
Application number: PCT/US1999/010359
Authority: WO
Inventors: Daniel Carl Leep
Original assignee: E.I. Du Pont De Nemours And Company
Priority date: 1998-05-14
Filing date: 1999-05-12
Publication date: 1999-11-18
Also published as: AU3982699A

Abstract

This invention relates to herbicidal mixtures of at least one compound selected from Formulae (Ia) and (Ib) with a safener selected from Formulae (IIa), (IIb) and (IIc) wherein R?1, R2, R3 and R4¿ are as defined in the text, herbicidal compositions of said mixtures, and a method for the use of said mixtures to control undesired vegetation.

Description

TITLE CROP-SAFENED HERBICIDAL MIXTURES

FIELD OF THE INVENTION The present invention relates to mixtures of herbicides with safeners that reduce crop injury while retaining weed control.

BACKGROUND OF THE INVENTION The control of undesired vegetation is extremely important in achieving high crop efficiency. This can be achieved by the selective control of the growth of weeds in such useful crops as alfalfa, corn (maize), peanut (groundnut), potato, rape, rice, sorghum, soybean, sugar beet, tomato, vegetables, cool-season cereals including wheat, barley and rye, perennial plantation crops including banana, citrus, cocoa, coffee, grapes, hops, plantain, pineapple, oil palm, rubber, sugarcane, tea, fruit trees, nut trees and forests, and turf, among others. Unchecked weed growth in such useful crops can cause significant reduction in productivity and thereby result in increased costs to the consumers. The need for finding products that achieve such results continues to be commercially important.

Herbicidally active compounds are typically applied in combination with nonherbicidal formulating ingredients that facilitate application, increase wash-off resistance, improve penetration, etc. Certain rare combinations of herbicides with nonherbicidal compounds surprisingly reduce the herbicidal effect on crops while retaining useful weed control. The nonherbicidal compounds having this effect are termed "safeners" or "antidotes". By reducing crop injury while retaining control of weeds, effective weed-control selectivity is increased. Such valuable combinations have now been discovered.

SUMMARY OF THE INVENTION This invention relates to mixtures of chlorofluorobenzene herbicides with several compounds discovered to be useful safeners for these herbicides. The herbicidal mixtures comprise herbicidally effective amounts of at least one herbicidal compound selected from the group consisting of:

la

(6S-cis)- 1 -chloro-N-[2-chloro-4-fluoro-5-(6-fluorotetrahydro- 1 ,3-dioxo- lH-pyrrolo- [l,2-c]imidazol-2(3//)-yl)phenyl]methanesulfonamide (la), or an agriculturally useful salt thereof: and

lb ethyl α,2-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-lH-l,2,4-triazol-l-yl]- 4-fluorobenzenepropanoate (carfentrazone-ethyl, lb), or an agriculturally useful salt thereof; in combination with an antidotally effective amount of a safener compound selected from the group consisting of:

or an agriculturally useful salt thereof wherein

R¹ is Cι-Cι₂ alkyl, C₃-C₇ cycloalkyl, C₂-C₈ alkenyl or C₂-C₈ alkynyl, each optionally substituted with at least one radical selected from the group consisting of halogen, hydroxy, C1-C4 alkoxy and C1-C4 alkylthio;

or an agriculturally useful salt thereof wherein

R² is H, C_j-C₁ alkyl, C3-C7 cycloalkyl, C₂-C₈ alkenyl or C₂-C₈ alkynyl, each optionally substituted with at least one radical selected from the group consisting of halogen, hydroxy, C1-C4 alkoxy and C1-C4 alkylthio; and R³ is H, Cr-Cg alkyl, -Cg haloalkyl, C₂-C₈ alkoxyalkyl or Cγ-C₆ hydroxyalkyl; and

or an agriculturally useful salt thereof wherein

R⁴ is H, C,-C₁₂ alkyl, C₃-C₇ cycloalkyl, C^s alkenyl or C₂-C₈ alkynyl, each optionally substituted with at least one radical selected from the group consisting of halogen, hydroxy, — C4 alkoxy and C1-C₄ alkylthio.

This invention also relates to herbicidal compositions comprising effective amounts of the aforesaid mixtures and at least one of the following: surfactant, solid or liquid diluent. This invention also relates to a method of controlling undesired vegetation comprising applying to the locus of the undesired vegetation herbicidally effective amounts of the aforesaid mixtures.

In the above recitations, the term "alkyl", used either alone or in compound words such as "haloalkyl" includes straight-chain or branched alkyl, such as, methyl, ethyl, n-propyl, t-propyl and the different butyl isomers. "Alkoxy" includes, for example, methoxy, ethoxy, tt-propyloxy, isopropyloxy and the different butoxy isomers. The term "halogen", either alone or in compound words such as "haloalkyl", includes fluorine, chlorine, bromine or iodine. Further, when used in compound words such as "haloalkyl", said alkyl may be partially or fully substituted with halogen atoms which may be the same or different. The total number of carbon atoms in a substituent group is indicated by the " — Cj" prefix where i and j are numbers from 1 to 12.

Some of the compounds of Formulae Ila, lib and He can exist as one or more stereoisomers. The various stereoisomers include enantiomers, diastereomers, atropisomers and geometric isomers. One skilled in the art will appreciate that one stereoisomer may be more active and/or may exhibit beneficial effects when enriched relative to the other stereoisomer(s) or when separated from the other stereoisomer(s). Additionally, the skilled artisan knows how to separate, enrich, and/or to selectively prepare said stereoisomers. Accordingly, the compounds of the invention may be present as a mixture of stereoisomers, individual stereoisomers, or as an optically active form.

Some of the compounds of Formulae la and lb and Formulae Ila, lib and He can be present in the form of salts. In view of the close relationship between these compounds in their free forms and their agriculturally useful salts, including their equilibration under physiological and environmental conditions, hereinbefore and hereinafter any reference to Formulae la and lb and Formulae Ila, lib and He is to be understood as including both the free compounds and their agriculturally useful salts, where appropriate and expedient.

The salts of the compounds of Formulae la and lb and Formulae Ila, lib and He include acid-addition salts with inorganic or organic acids such as hydrobromic, hydrochloric, nitric, phosphoric, sulfuric, acetic, butyric, fumaric, lactic, maleic, malonic, oxalic, propionic, salicylic, tartaric, 4-toluenesulfonic or valeric acids. The salts of the compounds of Formulae la and lb and Formulae Ha, lib and He also include those formed with organic bases (e.g., pyridine, ammonia, or triethylamine) or inorganic bases (e.g., hydrides, hydroxides, or carbonates of sodium, potassium, lithium, calcium, magnesium or barium) when the compound contains an acidic group such as a carboxylic acid or enol. Preferred salts include the lithium, sodium, potassium, triethylammonium, and quaternary ammonium salts.

Preferred for reasons of better weed control or improved crop safety are mixtures of the invention comprising:

(1) the compound of Formula la and a compound selected from the compounds of Formula Ha, Formula lib and Formula He; and

(2) the compound of Formula lb and a compound selected from the compounds of Formula Ha, Formula lib and Formula He. Most preferred for reasons of better weed control or improved crop safety are:

(la) the mixture of Preferred (1) comprising the compound of Formula la and the compound of Formula Ha where R¹ is CH₂CH3, which is ethyl l-(2,4- dichlorophenyl)-5-(trichloromethyl)-lH-l,2,4-triazole-3-carboxylate (fenchlorazole-ethyl) ; (lb) the mixture of Preferred (1) comprising the compound of Formula la and the compound of Formula lib where R² and R³ are each CH₂CH3, which is diethyl l-(2,4-dichlorophenyl)-4,5-dihydro-5-methyl-lH-pyrazole-3,5-dicarboxylate (mefenpyr-diethy 1) ; (lc) the mixture of Preferred (1) comprising the compound of Formula la and the compound of Formula He where R⁴ is CH(CH3)(CH₂)₄CH3, which is

1 -methylhexyl [(5-chloro-8-quinolinyl)oxy]acetate (cloquintocet-mexyl); (2a) the mixture of Preferred (2) comprising the compound of Formula lb and the compound of Formula Ha where R¹ is CH₂CH3, which is ethyl l-(2,4- dichlorophenyl)-5-(trichloromethyl)- 1H- 1 ,2,4-triazole-3-carboxylate (fenchlorazole-ethyl);

(2b) the mixture of Preferred (2) comprising the compound of Formula lb and the compound of Formula lib where R² and R³ are each CH2.CH3, which is diethyl l-(2,4-dichlorophenyl)-4,5-dihydro-5-methyl-lH-pyrazole-3,5-dicarboxylate (mefenpyr-diethyl); and (2c) the mixture of Preferred (2) comprising the compound of Formula lb and the compound of Formula He where R⁴ is CH(CH3)(CH₂)4CH₃, which is 1 -methylhexyl [(5-chloro-8-quinolinyl)oxy]acetate (cloquintocet-mexyl). Also preferred are herbicidal compositions comprising aforesaid preferred mixtures and at least one of the following: surfactant, solid or liquid diluent. Further preferred embodiments are methods of controlling undesired vegetation comprising applying to the locus of the vegetation herbicidally effective amounts of the aforesaid preferred mixtures and preferred herbicidal compositions.

The preferred crops for application of the mixtures of the invention are cool-season cereals including wheat, barley, oats and rye. Wheat and barley are particularly preferred crops.

DETAILS OF THE INVENTION The Formula la compound can be prepared as described in PCT publication WO 97/15576. The synthesis involves the reaction of the hydroxy compound of Formula 1 with diethylaminosulfur trifluoride (DAST) in dichloromethane solution.

The Formula lb compound can be prepared as described in U.S. 5,125,958. The synthesis involves coupling of the aniline of Formula 2 with ethyl acrylate (3) under diazotization conditions involving tert-butyl nitrite and copper(II) chloride in acetonitrile.

Safeners of Formula Ila and their agriculturally useful salts can be prepared as described in U.S. 4,639,266. Safeners of Formula lib and their agriculturally useful salts can be prepared by methods described in WO 91/07874. Safeners of Formula He and their agriculturally useful salts can be prepared by methods described in U.S. 4,881,966. Combinations of the Formula la herbicide (Compound 1) and the Formula lb herbicide (Compound 2) with the particular safeners of Formulae Ha, lib and He identified in Index Table A are illustrative of the scope of this invention.

Index Table A

Safeners

Safener Formula El R2 E R⁴

1 Ha H — — —

2 Ha CH₂CH₃ — — —

3 lib — H H —

4 lib — CH₂CH₃ H —

5 lib — H CH₂CH₃ —

6 lib — CH₂CH₃ CH₂CH₃ —

7 He — — — H

8 He — — — CH(CH₃)(CH₂)₄CH₃

These combinations thus include those listed in the following Mixture Table A.

Mixture Table A

Compound Safener Compound Safener Compound Safener

1 1 7 2 5

2 1 8 2 6

3 2 1 2 7

4 2 2 2 8

5 2 3

6 2 4

In Mixture Table A, the ratio of the herbicidal compound of Formula la (Compound 1) to each safener of Formulae Ha, lib or He (Safeners 1-8) are in general 10:1 to 1 : 10 by weight, with weight ratios of 4:1 to 1:4 preferred for most uses. The ratio of the herbicidal compound of Formula lb (Compound 2) to each safener of Formulae Ha, lib or He (Safeners 1-8) are in general 10:1 to 1:10 by weight, with weight ratios of 4:1 to 1:4 preferred for most uses. Formulation

The mixtures of at least one compound of Formulae la and lb with the Formulae Ha, lib or He compounds can be formulated in a number of ways: (a) the Formulae la and/or lb and Formulae Ha, lib or He compounds can be formulated separately and applied separately, with preferably the Formulae Ha, lib or He safeners applied first; or

(b) more preferably the Formulae la and/or lb and Formulae Ha, lib or He compounds can be applied simultaneously in an appropriate weight ratio, e.g., as a tank mix; or

(c) most preferably the Formulae la and/or lb and Formulae Ha, lib or He compounds can be formulated together in the proper weight ratio.

Mixtures of at least one compound of Formulae la and lb with the Formulae Ha, lib or He compounds will generally be used in formulation with an agriculturally suitable carrier comprising a liquid or solid diluent and/or a surfactant wherein the formulation is consistent with the physical properties of the active ingredients, mode of application and environmental factors such as soil type, moisture and temperature. Useful formulations include liquids such as solutions (including emulsifiable concentrates), suspensions, emulsions (including micro- emulsions and/or suspoemulsions) and the like which optionally can be thickened into gels. Useful formulations further include solids such as dusts, powders, granules, pellets, tablets, films, and the like which can be water-dispersible ("wettable") or water-soluble. Active ingredients can be (micro)encapsulated and further formed into a suspension or solid formulation; alternatively the entire formulation of active ingredient can be encapsulated (or "overcoated"). Encapsulation can control or delay release of the active ingredients. Sprayable formulations can be extended in suitable media and used at spray volumes from about one to several hundred liters per hectare. High-strength compositions are primarily used as intermediates for further formulation.

The formulations will typically contain effective amounts of active ingredients, diluent and surfactant within the following approximate ranges which add up to 100 percent by weight.

Weight Percent

Active

Ingredient Diluent Surfactant

Water-Dispersible and Water-soluble 5-90 0-94 1-15 Granules, Tablets and Powders.

Suspensions, Emulsions, Solutions 5-50 40-95 0-15 (including Emulsifiable Concentrates)

Dusts 1-25 70-99 0-5

Granules and Pellets 0.01-99 5-99.99 0-15

High Strength Compositions 90-99 0-10 0-2 Typical solid diluents are described in Watkins, et al., Handbook of Insecticide Dust Diluents and Carriers, 2nd Ed., Dorland Books, Caldwell, New Jersey. Typical liquid diluents are described in Marsden, Solvents Guide, 2nd Ed., Interscience, New York, 1950. McCutcheon 's Detergents and Emulsifiers Annual, Allured Publ. Corp., Ridgewood, New Jersey, as well as Sisely and Wood, Encyclopedia of Surface Active Agents, Chemical Publ. Co., Inc., New York, 1964, list surfactants and recommended uses. All formulations can contain minor amounts of additives to reduce foam, caking, corrosion, microbiological growth and the like, or thickeners to increase viscosity.

Surfactants include, for example, polyethoxylated alcohols, polyethoxylated alkylphenols, polyethoxylated sorbitan fatty acid esters, dialkyl sulfosuccinates, alkyl sulfates, alkylbenzene sulfonates, organosilicones, NN-dialkyltaurates, lignin sulfonates, naphthalene sulfonate formaldehyde condensates, polycarboxylates, and polyoxyethylene/polyoxypropylene block copolymers. Solid diluents include, for example, clays such as bentonite, montmorillinite, attapulgite and kaolin, starch, sugar, silica, talc, diatomaceous earth, urea, calcium carbonate, sodium carbonate and bicarbonate, and sodium sulfate. Liquid diluents include, for example, water, NN-dimethylformamide, dimethyl sulfoxide, N-alkylpyrrolidone, ethylene glycol, polypropylene glycol, paraffins, alkylbenzenes, alkylnaphthalenes, oils of olive, castor, linseed, tung, sesame, corn, peanut, cotton-seed, soybean, rape-seed and coconut, fatty acid esters, ketones such as cyclohexanone, 2-heptanone, isophorone and 4-hydroxy-4-methyl-2-pentanone, and alcohols such as methanol, cyclohexanol, decanol and tetrahydrofurfuryl alcohol.

Solutions, including emulsifiable concentrates, can be prepared by simply mixing the ingredients. Dusts and powders can be prepared by blending and, usually, grinding as in a hammer mill or fluid-energy mill. Suspensions are usually prepared by wet-milling; see, for example, U.S. 3,060,084. Granules and pellets can be prepared by spraying the active material upon preformed granular carriers or by agglomeration techniques. See Browning, "Agglomeration", Chemical Engineering, December 4, 1967, pp 147—48, Perry's Chemical Engineer's Handbook, 4th Ed., McGraw-Hill, New York, 1963, pages 8—57 and following, and WO 91/13546. Pellets can be prepared as described in U.S. 4,172,714. Water-dispersible and water-soluble granules can be prepared as taught in U.S. 4,144,050, U.S. 3,920,442 and DE 3,246,493. Tablets can be prepared as taught in U.S. 5,180,587, U.S. 5,232,701 and U.S. 5,208,030. Films can be prepared as taught in GB 2,095,558 and U.S. 3,299,566.

For further information regarding formulation, see U.S. 3,235,361, Col. 6, line 16 through Col. 7, line 19 and Examples 10-41; U.S. 3,309,192, Col. 5, line 43 through Col. 7, line 62 and Examples 8, 12, 15, 39, 41, 52, 53, 58, 132, 138-140, 162-164, 166, 167 and 169-182; U.S. 2,891,855, Col. 3, line 66 through Col. 5, line 17 and Examples 1-4; Klingman, Weed Control as a Science, John Wiley and Sons, Inc., New York, 1961, pp 81— 96; and Hance et al., Weed Control Handbook, 8th Ed., Blackwell Scientific Publications, Oxford, 1989.

In the following Examples, all percentages are by weight and all formulations are prepared in conventional ways. Compound 1 is the compound of Formula la, which is (6S-cis)- 1 -chloro-N-[2-chloro-4-fluoro-5 -(6-fluorotetrahydro- 1 ,3 -dioxo- lH-pyrrolo- [l,2-c]imidazol-2(3H)-yl)phenyl]methanesulfonamide, and Compound 2 is the compound of Formula lb, which is ethyl α,2-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo- lH-l,2,4-triazol-l-yl]-4-fluorobenzenepropanoate (carfentrazone-ethyl). Safener numbers are defined in Index Table A (page 6).

Example A High Strength Concentrate

Compound 1 9.0%

Safener 2 89.5% silica aerogel 0.5% synthetic amorphous fine silica 1.0%.

Example B Wettable Powder

Compound 1 52.0% Safener 6 13.0% dodecylphenol polyethylene glycol ether 2.0% sodium ligninsulfonate 4.0% sodium silicoaluminate 6.0% montmorillonite (calcined) 23.0%. Example C

Granule

Compound 1 5.0%

Safener 8 5.0% attapulgite granules (low volatile matter, 0.71/0.30 mm; U.S.S. No. 25-50 sieves) 90.0%. Example D

Aqueous Suspension Compound 1 5.0% Safener 8 20.0% hydrated attapulgite 3.0% crude calcium ligninsulfonate 10.0% sodium dihydrogen phosphate 0.5% water 61.5%.

Example E

Extruded Pellet Compound 1 2.3% Safener 8 22.7% anhydrous sodium sulfate 10.0% crude calcium ligninsulfonate 5.0% sodium alkylnaphthalenesulfonate 1.0% calcium/magnesium bentonite 59.0%.

Example F

High Strength Concentrate Compound 2 9.0% Safener 2 89.5% silica aerogel 0.5% synthetic amorphous fine silica 1.0%.

Example G

Wettable Powder

Compound 2 52.0%

Safener 6 13.0% dodecylphenol polyethylene glycol ether 2.0% sodium ligninsulfonate 4.0% sodium silicoaluminate 6.0% montmorillonite (calcined) 23.0%. Example H High Strength Concentrate

Compound 2 49.2%

Safener 8 49.3% silica aerogel 0.5% synthetic amorphous fine silica 1.0%.

Utility

Test results indicate that combinations of the chlorofluorobenzene herbicides of Formulae la and/or lb with a safener of Formulae Ha, lib or He affords highly active herbicidal mixtures, providing unexpected safening on cool-season cereal crops such as wheat, barley and rye, while retaining good efficacy for controlling many problem weeds in these crops. Certain combinations even show a greater-than-additive or synergistic effect on selected weeds.

Herbicidally effective amounts of the compounds of Formulae la and/or lb and antidotally effective amounts of the safeners of Formulae Ha, lib or He will vary depending on environmental conditions, formulation, method of application, amount and type of vegetation present, etc. The use rate ratios of Formula la to Formulae Ha, lib or lie are in general 10:1 to 1:10 by weight, with weight ratios of 4:1 to 1 :4 preferred for most uses. The use rate ratios of Formula lb to Formulae Ha, lib or He are in general 10:1 to 1 :10 by weight, with weight ratios of 4:1 to 1:4 preferred for most uses. In general, the Formula la compound is applied at a rate from 1 to 100 g ai/ha, and preferably the Formula la compound is applied at a rate from 2 to 20 g ai/ha. In general, the Formula lb compound is applied at a rate from 1 to 100 g ai/ha, and preferably the Formula lb compound is applied at a rate from 8 to 40 g ai/ha. In general, the Formulae Ha, lib or He compounds are applied at rates from 0.1 to 1000 g ai/ha, and preferably the Formulae Ha, lib or He compounds are applied at rates from 0.5 to 120 g ai/ha.

For selective control of certain weed species in cereal crops, the mixtures of the invention are best applied when the cereal plants are at about the 1 -leaf through tillering stage and the weed plants are correspondingly young. One skilled in the art can readily determine application rates and ratios of the herbicides of Formulae la and/or lb to the safeners of Formulae Ha, lib or He as well as timing necessary for the desired level of weed control and crop safety.

The Formulae la and/or lb and Formulae Ha, lib or He mixtures of this invention can additionally be used in combination with other commercial herbicides, insecticides or fungicides. A mixture of one or more of the following herbicides with the Formulae la and or lb and Formulae Ha, lib or He mixtures of this invention may be particularly useful for weed control. Examples of other herbicides particularly useful as mixture partners are: 2,4-D, bentazon, benzoylpropethyl, bromoxynil, chlorsulfuron, chlortoluron, clodinafop, clopyralid, cyanazine, diallate, dicamba, diclofop, difenzoquat, diflufenican, fenchlorazole, fenoxaprop, flamprop-M-isopropyl, fluroglycophen-ethyl, fluroxypyr, glyphosate, imazamethabenz, ioxynil, isoproturon, linuron, MCPA, mecoprop, methabenzthiazuron, metosulam, metoxuron, metribuzin, metsulfuron methyl, N-[[(4,6-methoxy-2-pyrirnidinyl)- amino]carbonyl]-2-(ethylsulfonyl)imidazo[ 1 ,2-a]pyridine-3-sulfonamide (ISO-proposed: sulfosulfuron), neburon, paraquat, pendimethalin, propanil, prosulfocarb, prosulfuron, quinclorac, simazine, terbutryn, thifensulfuron methyl, tralkoxydim, triallate, triasulfuron, tribenuron methyl and trifluralin.

In certain instances, combinations with other herbicides having a similar spectrum of control but a different mode of action will be particularly advantageous for resistance management.

The following data demonstrate the surprising safening of the mixtures of this invention on cool-season cereal crops while retaining excellent efficacy against many weeds. The weed control afforded by the mixtures of this invention are not limited, however, to these species. Compound 1 is the compound of Formula la, which is (6S-c/s)-l-chloro-N-[2- chloro-4-fluoro-5-(6-fluorotetrahydro- 1 ,3-dioxo- lH-pyrrolo[ 1 ,2-c]imidazol-2(3H)- yl)phenyl]methanesulfonamide, and Compound 2 is the compound of Formula lb, which is ethyl α,2-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo- IH- 1 ,2,4-triazol- 1 -yl]- 4-fluorobenzenepropanoate (carfentrazone-ethyl). Safener numbers are defined in Index Table A (page 6).

TEST A Test Protocol The crops: winter wheat (Triticum aestivum, TRZAW), spring wheat (Triticum aestivum, TRZAS) and spring barley (Hordeum vulgare, HORVS); and the weeds: pigweed (Amaranthus retroflexus, AMARE), common lambsquarters (Chenopodium album, CHEAL), cleavers (Galium aperine, GALAP), kochia (Kochia scoparia, KCHSC), henbit (Lamium amplexicaule, LAMAM), scentless chamomile (Matricaria inodora, MATIN), wild buckwheat (Polygonum convolvulus, POLCO), Russian thistle (Salsola kali, SASKR), wild mustard (Sinapsis arvensis, SINAR), black nightshade (Solanum nigrum, SOLNI) and common chickweed (Stella ia media, STEME) were planted in a sterilized growing medium at the depths indicated and grown in a greenhouse approximately 10—17 days to the stages shown:

The pots were irrigated as needed with water containing 200 ppm N from 20-20-20 fertilizer. The greenhouse was maintained at approximately 21—24 °C during the day and 13—16 °C at night with 14 hours of daylight supplemented as needed by metal halide lamps.

Compound 1 was applied at 8 g ai/ha postemergence alone and in combination with 1 , 2 and 4 g ai/ha of Safener 2, Safener 6 or Safener 8. All samples were sprayed in a non- phytotoxic solvent in a volume of 309 L/ha. Assessments of crop response and weed control were made by visual inspection 14 days following application. A visual rating system was used based on a percentage scale from 0 to 100%, relative to adjacent untreated control plants. On this scale 0% represents no visual differences relative to an untreated control, and 100% represents complete kill of the given crop or weed species.

Table A represents visual assessments of crop response and specific weed control with Compound 1 applied alone and in combination with Safener 2, Safener 6 or Safener 8. Different ratios of Compound 1 to Safener 2, ratios of Compound 1 to Safener 6, ratios of Compound 1 to Safener 8, and different formulation types, also provide useful crop safening and weed control from the combinations.

TABLE A

Effect of Compound 1 and as Active Ingredient Alone and in Mixtures with Safeners 2, 6 and 8

TABLE A continued

As can be seen from Table A, mixtures of Compound 1 with Safener 2, Safener 6 or Safener 8 were found to cause significantly less injury to the wheat and barley compared to Compound 1 applied alone. Compound 1 alone and in combination with Safener 2, Safener 6 or Safener 8 gave 100% control of most weed species. In this test, combinations of Compound 1 with Safener 2 or Safener 8 appeared to increase control of Galium aparine. The surprising combination of crop safening and excellent weed control make these mixtures particularly commercially valuable.

TEST B Test Protocol

The crops: winter wheat (Triticum aestivum, TRZAW), spring wheat (Triticum aestivum, TRZAS), winter barley (Hordeum vulgare, HORVW) and spring barley (Hordeum vulgare, HORVS); and the weeds: common lambsquarters (Chenopodium album, CHEAL), cleavers (Galium aperine, GALAP), henbit (Lamium amplexicaule, LAMAM), wild buckwheat (Polygonum convolvulus, POLCO), Russian thistle (Salsola kali, SASKR), and black nightshade (Solanum nigrum, SOLNI) were planted in a sterilized growing medium at the depths indicated and grown in a greenhouse approximately 10-17 days to the stages shown:

Test B was comprised of six replicates. Compound 2 was applied at 16 g ai/ha postemergence alone and in combination 8 g ai/ha of Safener 2, Safener 6 or Safener 8. All samples were sprayed in a non-phytotoxic solvent in a volume of 309 L/ha. Assessments of crop response and weed control were made by visual inspection 5 days following application. A visual rating system was used based on a percentage scale from 0 to 100%, relative to adjacent untreated control plants. On this scale 0% represents no visual differences relative to an untreated control, and 100% represents complete kill of the given crop or weed species. Table B represents mean visual assessments of crop response and specific weed control with Compound 2 applied alone and in combination with Safener 2, Safener 6 or Safener 8. Different ratios of Compound 2 to Safener 2, ratios of Compound 2 to Safener 6, ratios of Compound 2 to Safener 8, and different formulation types, also provide useful crop safening and weed control from the combinations.

TABLE B

Mean* Effect of Compound 2 and as Active Ingredient Alone and in Mixtures with Safeners 2, 6 and 8

* Values are the mean response of six replicates.

As can be seen from Table B, mixtures of Compound 2 with Safener 2, Safener 6 or Safener 8 were found to cause significantly less injury to wheat and barley compared to Compound 2 applied alone. Compound 2 alone and in combination with Safener 2, Safener 6 or Safener 8 gave 98—100% control of the weed species. The surprising combination of crop safening and excellent weed control make these mixtures particularly commercially valuable.

Claims

CLAIMS What is claimed is:

1. A mixture comprising a herbicidally effective amount of at least one herbicidal compound selected from the group consisting of:

which is (6S-c/5^,)-l-chloro-N-[2-chloro-4-fluoro-5-(6-fluorotetrahydro-l,3-dioxo-lH-pyrrolo- [ 1 ,2-c]imidazol-2(3H)-yl)phenyl]methanesulfonamide, or an agriculturally useful salt thereof; and

lb which is ethyl ╬▒,2-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-lH-l,2,4- triazol- 1 -yl]-4-fluorobenzenepropanoate, or an agriculturally useful salt thereof; in combination with an antidotally effective amount of a safener compound selected from the group consisting of:

or an agriculturally useful salt thereof wherein

R¹ is C_j-C₁ alkyl, C₃-C₇ cycloalkyl, C₂-C₈ alkenyl or C_j-C₈ alkynyl, each optionally substituted with at least one radical selected from the group consisting of halogen, hydroxy, C1-C4 alkoxy and C1-C4 alkylthio;

or an agriculturally useful salt thereof wherein

R² is H, C_jΓÇö C₁₂ alkyl, C3-C7 cycloalkyl, C₂-C alkenyl or C_j-C alkynyl, each optionally substituted with at least one radical selected from the group consisting of halogen, hydroxy, C1-C4 alkoxy and C1-C₄ alkylthio; and R³ is H, Cr-Cg alkyl, C,-C₈ haloalkyl, C^g alkoxyalkyl or C╬╣-C₆ hydroxyalkyl; and

or an agriculturally useful salt thereof wherein

R⁴ is H, C╬╣-C₁₂ alkyl, C3-C7 cycloalkyl, C₂-C₈ alkenyl or C -C₈ alkynyl, each optionally substituted with at least one radical selected from the group consisting of halogen, hydroxy, C_jΓÇö C4 alkoxy and CjΓÇö C4 alkylthio.

2. A mixture of Claim 1 wherein the herbicidal compound is (6S-c/s)-l-chloro-N- [2-chloro-4-fluoro-5-(6-fluorotetrahydro- 1 ,3-dioxo- lH-pyrrolo[ 1 ,2-c]imidazol-2(3H)- yl)phenyl]methanesulfonamide.

3. The mixture of Claim 2 wherein the safener compound is ethyl

1 -(2,4-dichlorophenyl)-5-(trichloromethyl)- IH- 1 ,2,4-triazole-3-carboxylate.

4. The mixture of Claim 2 wherein the safener compound is diethyl l-(2,4-dichlorophenyl)4,5-dihydro-5-methyl-lH-pyrazole-3,5-dicarboxylate.

5. The mixture of Claim 2 wherein the safener compound is 1-methylhexyl [(5-chloro-8-quinolinyl)oxy]acetate.

6. A mixture of Claim 1 wherein the herbicidal compound is ethyl ╬▒,2-dichloro-5- [4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-lH-l,2,4-triazol-l-yl]-4-fluorobenzene- propanoate.

7. The mixture of Claim 6 wherein the safener compound is ethyl 1 -(2 ,4-dichlorophenyl)-5 -(trichloromethyl)- IH- 1 ,2 ,4-triazole- 3 -carboxylate .

8. The mixture of Claim 6 wherein the safener compound is diethyl l-(2,4-dichlorophenyl)4,5-dihydro-5-methyl-lH-pyrazole-3,5-dicarboxylate.

9. The mixture of Claim 6 wherein the safener compound is 1-methylhexyl [(5-chloro-8-quinolinyl)oxy]acetate.

10. An agriculturally suitable composition for controlling the growth of undesired vegetation comprising an effective amount of the mixture of any of Claims 1ΓÇö9 and at least one of the following: surfactant, solid or liquid diluent.

11. A method for controlling the growth of undesired vegetation by applying to the locus of the undesired vegetation a herbicidally effective amount of the mixture of any of Claims 1-9.

12. The method of Claim 11 wherein the locus of the undesired vegetation is a crop of wheat or barley.