METHOD FOR SPRAY TANK CLEANOUT

Abstract: A method for facilitating cleanout of residual sulfonylurea pesticide from spray tank equipment comprising (i) formulating the sulfonylurea as an agriculturally suitable water-soluble salt composition before spray tank application, (ii) applying the salt composition to the crop and (iii) rinsing the tank substantially free of residual sulfonylurea more easily than is possible when the sulfonylurea is not formulated as a salt.

Description: METHOD FOR SPRAY TANK CLEANOUT Sulfonylureas, as a class, are highly active pesticides. For this reason, care must be taken to make sure that all traces of sulfonylurea are cleaned out of the spray equipment (hereafter referred to as spray tank) , which is used to apply pesticides to crops, before an applicator uses this equipment in a subsequent application to treat a crop that is sensitive or will be injured by the sulfonylurea used in the previous spray tank application. Adequate cleanout may require a rinsing procedure that is time- consuming and causes an environmental waste-water disposal problem. Salts of the sulfonylureas are generally known as are methods for making them. What has not been appreciated until now is the advantage that can be achieved in spray tank cleanout when the sulfonylurea active ingredient is applied in its salt form rather than in its acid form. The described salt formulations can be applied conventionally or using chemical injection technology since the soluble formulation gives a solution that can be uniformly injected into the spray boom. SUMMARY OF THE INVENTION This invention concerns a method for reducing residual sulfonylurea pesticide contamination of a spray tank from which the sulfonylurea is applied, comprising the steps: i) formulating the sulfonylurea active ingredient as an agriculturally suitable water soluble salt composition before spray tank application, thereby increasing solubility of the sulfonylurea and decreasing the amount of insoluble sulfonylurea available for residual contamination of the spray tank, ii) applying the sulfonylurea salt composition to the crop while minimizing buildup of insoluble sulfonylurea in the spray tank, and iii) rinsing the spray tank substantially free of residual sulfonylurea, after application, in an operation in which the sulfonylurea remaining in the spray tank is reduced significantly versus the amount remaining when sulfonylurea is not formulated as a water-soluble salt before application. The sulfonylureas whose spray tank buildup is curtailed by the method of this invention are the sulfonylurea acids either when used alone or with one or more tank mix partners. The bene its achieved by this invention have been found to be more pronounced when the sulfonylurea is employed with a tank mix partner. The benefits are even more noteworthy when earlier tank mixes have left organic deposits on inside spray tank surfaces. In such instances, it is believed that undissolved particles of the sulfonylurea are held by the organic deposit and kept from becoming resuspended or dissolved in the spray tank water. Thereafter, should the spray tank be employed on a crop sensitive to the sulfonylurea, damage may result either from migration into the tank water of particles formerly trapped by the organic deposit or by actual sloughing off of the organic deposit carrying embedded sulfonylurea particles with it. The problem of difficult spray tank cleanout is exacerbated by sulfonylureas used at relatively high concentrations. Since water solubility of the sulfonylurea active ingredient in its acid form is so low, tank mixes of the sulfonylureas are primarily suspensions. Suspended particles can collect on tank walls, in tubing, or be trapped by organic deposits that may be present inside the tank. If a later tank mix sends the sulfonylurea into solution or suspension, sensitive crops can be damaged. This problem is avoided by employing sulfonylureas in a water-soluble form. The sulfonylurea salt form shows a faster dissolution rate than the corresponding sulfonylurea acid, particularly evident at low pH's. Thus, at typical use rates, there will be little or no sulfonylurea particles to build up on interior tank surfaces or become imbedded in organic deposits that may have formed on such surfaces. Use of sulfonylureas in their salt form rather than their acid form has been found, under a variety of circumstances, to result in a greater than fourfold improvement in spray tank cleanout. Preferred salt cations (M) are the sodium, potassium, calcium, magnesium, ammonium and alkylammonium cations. Preferred sulfonylurea salts are the sodium and calcium salts of tribenuron methyl, the potassium salt of thifensulfuron methyl, the ammonium salt of chlorsulfuron and the potassium salt of metsulfuron methyl. BRIEF DESCRIPTION OF THE DRAWINGS The Figures represent comparisons in bar graph format of the data summarized in the Tables. Figure 1 shows a statistically significant distinction between ease of cleanout of sulfonylurea-tank partner mixtures (37% failure rate) vs. cleanout of corresponding sulfonylurea salt-tank partner mixtures (8% failure) . Figure 2 shows an even greater distinction when no tank partners are present (89% failure for sulfonylurea acid and 11% failure for the salt formulation) . DETAILS OF THE INVENTION Representative of the sulfonylureas whose salt forms are contemplated for us in the process of this invention are those of the formula: wherein: J is selected from the group 2=± 2=5. S=± 2=1 2=2. 2=3. ~-lQ J-ii 2=12 R is selected from the group H and CH 3 ; R 1 is selected from the group F, Cl, Br, N0 2 , ~ I -~ A alkyl, -^-C^ haloalkyl, C 3 -C 4 cycloalkyl, C 2 -C 4 haloalkenyl, C 1 -C 4 alkoxy, ^-^ haloalkoxy, C 2 -C 4 alkoxyalkoxy, C0 2 R 12 , C(0)NR 13 R 14 , S0 2 NR 15 R 16 , S(0) n R 17 , C(0)R 18 , CH 2 CN and L; R 2 is selected from the group H, F, Cl, Br, CN, CH 3 , 0CH 3 , SCH 3 , CF 3 and OCF 2 H; R 3 is selected from the group Cl, N0 2 , C0 2 CH 3 , C0 2 CH 2 CH 3 , S0 2 N(CH 3 ) 2 , S0 2 CH 3 , S0 2 CH 2 CH 3 , OCH 3 , and OCH 2 CH 3 ; R 4 is selected from the group C^^ alkyl, C ] _-C 2 haloalkyl, C 1 -C alkoxy, C 2 -C 4 haloalkenyl, F, Cl, Br, N0 2 , C0 2 R 12 , C(0)NR 13 R 14 , S0 2 NR 15 R 16 , S(0) n R 17 , C(0)R 18 and L; R5 is selected from the group H, F, Cl, Br and CH 3 ; R 6 is selected from the group C ! -C 3 alkyl, C 2 -C 2 alkoxy, C 2 -C 4 haloalkenyl, F, Cl, Br, C0 2 R 12 , C(0)NR 13 R 14 , S0 2 NR 15 R 16 , S(0) n R 17 , C(0)R 18 and L; R 7 is selected from the group H, F, Cl, CH 3 and CF 3 ; R 8 is selected from the group H, C x -C 3 alkyl and pyridyl; R 9 is selected from the group ^-0 3 alkyl, C x -C alkoxy, F, Cl, Br, N0 2 , C0 2 R 12 , S0 2 NR 15 R 16 , S(0) n R 17 , OCF 2 H, C(0)R 18 , C 2 -C 4 haloalkenyl and R 10 is selected from the group H, Cl, F, Br, ^-0 3 alkyl and C 1 -C 2 alkoxy; R 11 is selected from the group H, C 1 -C 3 alkyl, C x -C 2 alkoxy, C 2 -C haloalkenyl, F, Cl, Br, C0 2 R 12 , C(0)NR l3 R 14 , S0 2 NR 15 R 16 , S(0) n R 17 , C(0)R 18 and L; R 12 is selected from the group allyl and propargyl - and C 2 -C 3 alkyl optionally substituted by at. least one member independently selected from halogen, C 1 -C 2 alkoxy and CN; R 13 is selected from the group H, ^-0 3 alkyl and C x -C 2 alkoxy; R 14 is C; L -C 2 alkyl; R 15 is selected from the group H, C 1 -C 3 alkyl, C x -C 2 alkoxy, allyl and cyclopropyl; R 16 is selected from the group H and 0-^-0 3 alkyl; R 17 is selected from the group ^-0 3 alkyl, C 1 -C 3 haloalkyl, allyl and propargyl; R 18 is selected from the group C^^ alkyl, C x -C 4 haloalkyl and C 3 -C 5 cycloalkyl optionally substituted by halogen; n is 0, 1 or 2; M is a cation; L is / R 3 N N H I j is selected from the group H and C 2 -C 3 alkyl; W is selected from the group 0 and S; X is selected from the group H, C 1 -C alkyl, C 1 -C 4 alkoxy, C 2 -C haloalkoxy, C 1 -C 4 haloalkyl, C ~C haloalkylthio, ^-^ alkylthio, halogen, C -C 5 alkoxyalkyl, C 2 -C 5 alkoxyalkoxy, amino, ~-ι~-~ 3 alkylamino and di {C^-C^ alkyl)amino; Y is selected from the group H, - -d alkyl, C ~C alkoxy, ^-0 4 haloalkoxy, C-^-C^ alkylthio, ~-ι-C haloalkylthio, C 2 -C 5 alkoxyalkyl, C 2 -C 5 alkoxy¬ alkoxy, amino, C^- -C^ alkylamino, di (C_ι-C 3 alkyl)amino, C 3 -C alkenyloxy, C 3 -C 4 ■ alkynyloxy, C -C 5 alkylthioalkyl, C 2 -C 5 alkylsulfinylalkyl, C 2 -C 5 alkylsulfonylalkyl, Cι~ c 4 haloalkyl, C 2 -C alkynyl, C 3 -C 5 cycloalkyl, azido and cyano; Z is selected from the group CH and N; provided that i) when one or both of X and Y is C x haloalkoxy, then Z is CH; and ii) when X is halogen, then Z is CH and Y is OCH 3 , OCH 2 CH 3 , N(OCH 3 )CH 3 , NHCH 3 , N(CH 3 ) 2 or OCF 2 H. Salts of the following sulfonylureas are preferred for use in the disclosed process: 2-chloro-N-[ [ (4- methoxy-6-methyl-l,3,5-triazin-2-yl)amino]carbonyl]- benzenesulfonamide (chlorsulfuron) ; methyl 2-[[[[(4,6- dimethyl-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]- benzoate (sulfometuron methyl); ethyl 2-[ [ [ [ (4-chloro- 6-methoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]- benzoate (chlorimuron ethyl); methyl 2-[ [ [ [ (4-methoxy- 6-methyl-l,3,5-triazin-2- yl)amino]carbonyl]amino]sulfonyl]benzoate (metsulfuron methyl); methyl 2-[ [ [ [ (4,6-dimethoxy-2- pyrimidinyl)amino]carbonyl]amino]sulfonyl]-6- (trifluoromethyl)-3-pyridine-carboxylate; methyl 2- [ [ [ [ [4-ethoxy-6-(methylamino)-1,3,5-triazin-2- yl]amino]carbonyl]amino]sulfonyl]benzoate (etha etsulfuron methyl) ; 2-(2-chloroethoxy)-N-[ [(4- methoxy-6-methyl-l,3,5-triazin-2-yl)amino]carbonyl]- benzenesulfonamide; ethyl 5-[ [[ [(4,6-dimethoxy-2- pyrimidinyl)amino]carbonyl]amino]sulfonyl]-l-methyl-l-ff- pyrazole-4-carboxylate; N-[[(4,6-dimethoxy-2- pyrimidinyl)amino]carbonyl]-3—(ethyisulfonyl)-2- pyridinesulfonamide (rimsulfuron) ; methyl 3-[[[[(4- methoxy-6-methyl-l,3,5-triazin-2- yl)amino]carbonyl] mino]sulfonyl]-2- ■ thiophenecarboxylate (thifensulfuron methyl) ; methyl 2- [[[ [N-(4-methoxy-6-methyl-l,3,5-triazin-2-yl)-N- methylamino]carbonyl]amino]sulfonyl]benzoate (tribenuron methyl) ; methyl 2-[[[[[ (4,6-dimethoxy-2- pyrimidinyl)amino]carbonyl]amino]- sulfonyl]methyl]benzoate (bensulfuron methyl) ; 2-[ [[[(4,6-dimethoxy-2- pyrimidinyl)amino]carbonyl]amino]sulfonyl] -N r N- dimethyl-3-pyridinecarboxamide (nicosulfuron) ; methyl 2-[ [[[[4,6-bis (difluoro-methoxy)-2-pyrimidinyl]amino]- carbonyl]amino]sulfonyl]benzoate; methyl 2-[ [[[[4- dimethylamino)-6-(2,2,2-trifluoroethoxy)-1,3,5-triazin- 2-yl]amino]carbonyl]amino]sulfonyl]-3-methylbenzoate; and N-[[ (4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-1- methyl-4-(2-methyl-2H-tetrazol-5-yl)-lH-pyrazole-5- sulfonamide. More preferred are sulfonylurea salts of the following sulfonylureas: 3-[[[ [ (4-methoxy-6-methyl- 1,3,5-triazin-2-yl)amino]carbonyl]amino]sulfonyl]-2- thiophenecarboxylate (thifensulfuron methyl) , methyl 2- [[[[(4-methoxy-6-methyl-l,3,5-triazin-2-yl)amino]- carbonyl]amino]sulfonyl]benzoate (metsulfuron methyl), methyl 2-[[[ [N-(4-methoxy-6-methyl-l,3,5-triazin-2-yl)- N-methylamino]carbonyl]amino]sulfonyl]benzoate (tribenuron methyl) and 2-chloro-N-[[ (4-methoxy-6- methyl-1,3,5-triazin-2-yl)amino]carbonyl]benzene¬ sulfonamide (chlorsulfuron) wherein M is selected from the group sodium, potassium, calcium, ammonium, and alkylammonium. Sulfonylurea salts of this invention can be used alone or in combination with other commercial herbicides (including other sulfonylureas or sulfonylurea salts), insecticides or fungicides. Mixtures containing sulfonylurea salts are particularly useful in minimizing spray tank cleanout when compared to the same mixtures containing the corresponding sulfonylurea acid. The data summarized in Table I (using Protocol I) show that the sulfonylurea acid plus tank mix partner suffered a failure rate of 37% (10 failures out of 27) whereas the corresponding alkali metal salt of the sulfonylurea plus tank mix partner had a failure rate of only about 8% (2 failures out of 24) . (NOTE: Test failure corresponds to a greenhouse result of >20% injury to sugarbeets in the bioassay test.) The data summarized in Table II (using Protocol II) show that in the absence of a tank partner, cleanout of the sulfonylurea salt formulation is equivalent to or more effective than cleanout of the corresponding sulfonylurea acid. The corresponding tank cleanout Protocols I and II are described after each table, followed by the bioassay protocol. Each of the percent injury figures in the tables is the average of two bioassay results of the two samples of the final ammonia wash water: one sample taken from the tank and one sample taken from the boom. TABLE T Sprayer Cleanout Sulfonylurea Plus Tank Mix Partner Sulfonylurea Thifensulfuron methyl Thifensulfuron methyl + Metsulfuron methyl (10:1) Thifensulfuron + Tribenuron methyl (2:1) Tribenuron methyl Potassium Salt of Thifensulfuron methyl Potassium Salt of Thifensulfuron methyl + Metsulfuron methyl (10:1) i percent injury to greenhouse sugarbeets after sprayed with final ammonia wash water from the tank cleanout procedure. TANK CLEANOUT PROTOCOL I (Sulfonylurea Plus Tank Mix Partner) Step 1 Add water to the tank and when half-filled, add the sulfonylurea or the sulfonylurea salt with agitation. Fill tank to the 90% level with water, add any tank mix partners, and finish filling the tank. Agitate the tank mix for a minimum of 5 to 10 minutes. Step 2 Spray the tank contents through the boom. Drain any remainder from the tank. Step 3 Rinse the interior tank surfaces with water; use. about 10% of the tank capacity. Spray this rinse through the boom. Drain the remainder from the tank. Step 4 Fill tank approximately half-full with fresh water and add the desired cleaning solution. Finish filling tank. Flush all lines and boom with cleaning solution (which can be water, or an ammonium hydroxide, or sodium hypochlorite solution) and agitate for 15 min. Spray 10 to 20 gallons of the wash through the boom. Drain the remaining tank contents. Step 5 Remove all nozzles, nozzle screens, in-line filters or filters of any type and clean thoroughly in a bucket of water and cleaning agent. Remove any residues or deposits using a brush. Step 6 Rinse the interior tank surfaces with fresh water; use about 10% of the tank capacity to remove all traces of the cleaning solution. Spray the rinse through the boom. Drain the remainder from the tank. Step 7 Fill tank half full and add ammonium hydroxide to give a concentration of 0.3% of ammonia. Finish filling the tank. Flush all lines and boom with the ammonium hydroxide solution, and let agitate for 15 min. Sample ammonia water wash in tank (sample used for bioassay test) . Spray 10 to 20 gallons through the boom and then sample at a nozzle (sample used for bioassay test) . Drain the remainder of the contents. Rinse all remaining ammonium hydroxide solution from the tank with fresh water. Note: Samples were buffered to an appropriate pH to insure stability of the sulfonylurea and then kept frozen prior to analyses. TABLE II Sprayer Cleanout Trials Sulfonylurea with no Tank Mix Partner Initial Sulfonylurea Concentration Percent Sulfpnylure? in Tank Mix Injury 1 Thifensulfuron methyl 550 ppm 28 550 ppm 32 550 ppm 17 Potassium Salt of 550 ppm 0 Thifensulfuron methyl 550 ppm 0 550 ppm 18 Chlorsulfuron 275 ppm 50 275 ppm 100 275 ppm 100 Ammonium Salt of 275 ppm 0 Chlorsulfuron 275 ppm 0 275 ppm 5 Metsulfuron methyl 275 ppm 85 275 ppm 100 275 ppm 30 Potassium Salt of 275 ppm 8 Metsulfuron methyl 275 ppm 0 Sodium Salt of 275 ppm 64 Metsulfuron methyl ■ ' ■ Percent injury to greenhouse sugarbeets after sprayed with final ammonia wash water from the tank cleanout procedure. TANK CLEANOUT PROTOCOL II (Sulfonylurea With No Tank artner) Step 1 Divide the sulfonylurea sample to be tested into 2 equal portions . Prepare a concentrated slurry with one portion, and a paste with the other portion. Spread and/or spray the paste and slurry onto the tank interior and let sit overnight . This procedure produces dried deposits on the tank surfaces to simulate worse-case field conditions . Step 2 Rinse the tank interior with clean water, using a volume of 10-20% of the tank capacity, allowing the rinse to flush through the boom and hoses . Step 3 Fill the tank with clean water and agitate for 10 minutes . Discard the water, flushing at least 10-20% through the boom and nozzles . Step 4 Remove any nozzles, nozzle screens and in-line filters and clean with fresh water . Step 5 Rinse the tank with clean water, using a volume of 10-20% of the tank capacity. Allow the rinse water to accumulate in the tank and then discard through the boom and nozzles . Drain any remaining rinse water from the tank . Step 6 Fill the tank half full with water and add ammonium hydroxide to give a concentration of 0.3% ammonia. Finish filling the tank. Flush all lines and boom with the ammonium hydroxide solution and let agitate for 15 minutes. Sample ammonia water wash in tank (sample used for bioassay test) . Spray 10-2.0% through the boom and then sample at a nozzle (sample used for bioassay test) . Drain the remainder of the tank contents. Rinse all remaining ammonium hydroxide solution from the tank with fresh water. NOTE: Samples are buffered to an appropriate pH to insure stability of the sulfonylurea and then kept frozen prior to analyses. BIOASSAY PROTOCOL The bioassay protocol employed to determine the percent injury of the crop (sugarbeets) sprayed with the final rinse solution after tank cleanout of the ingredients listed in the Tables is as follows. Sugarbeet seedlings (at the two-leaf stage) were grown in the greenhouse (14 hour photoperiod at 21°C with light and 10 hours at 17°C in the dark) and sprayed with unmodified samples of effluent from various sprayer cleanout procedures. An automatic belt sprayer was used, and the samples were applied at a rate of approximately 45 gal/A. Three replicate pots, with four sugarbeet plants/pot, were treated with each sample. The sprayer was rinsed 12 times between each sample to ensure that there would not be carryover between samples. Plants were held in the greenhouse until they were evaluated, 14 to 23 days after treatment. Injury of treated plants was assessed visually on a scale of 0 to 100 (0=no injury, 100=complete kill) compared to control plants. Injury ratings were based on the presence of various symptoms including reduced biomass, stunting, inhibited development, chlorosis, necrosis, leaf spotting, and leaf puckering or deformation. Formulation , Compounds of this invention will generally be used in formulation with an agriculturally suitable carrier comprising a liquid or solid diluent or an organic solvent. Use formulations include dusts, granules, pellets, . solutions, Table B, suspensions, emulsions, gels, actives in plastic, wettable powders, emulsifiable concentrates, dry flowables and the like, consistent with the physical properties of the active ingredient, mode of application and environmental factors such as soil type, moisture and temperature. 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 salts of sulfonylurea(s) , diluent and surfactant within the following approximate ranges which add up 100 weight percent. Water Dispersible 5 _ 9g Q _ 15 Granules/Pellets 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 and solvents are described in Marsden, Solvents Guide, 2nd Ed., Interscience, New York, 1950. McCutcheon 's Detergents and Emulsifierε 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, etc. Solutions are prepared by simply mixing the ingredients. Fine solid compositions are made by blending and, usually, grinding as in a hammer mill or fluid energy mill. Water-dispersible granules can be produced by agglomerating a fine powder composition; see for example, Cross et al., Pesticide Formulations, Washington, D.C., 1988, pp 251-259. Suspensions are prepared by wet-milling; see, for example, U.S. 3,060,084. Granules and pellets can be made 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 also be prepared as taught in DE 3,246,493. For further information regarding the art of 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 worked up in conventional ways. Compound 1 is the ammonium salt of chlorsulfuron. Example A Hiσh Strength Concentrate Compound 1 98.5% silica aerogel 0.5% synthetic amorphous fine silica 1.0%. Example B Wettable Powder Compound 1 65.0% sodium alkyl naphthalenesulfonate 2.0% sodium ligninsulfonate 4.0% sodium silicoaluminate 6.0% montmorillonite (calcined) 23.0%. Example C Granule Compound 1 10.0% attapulgite granules (low volative matter, 0.71/0.30 mm; U.S.S. No. 25-50 sieves) 90.0%. Example D Water Dispersible Granule/Pellet Compound 1 25.0% anhydrous sodium sulfate 10.0% crude calcium ligninsulfonate 5.0% sodium alkylnaphthalenesulfonate 1.0% ' calcium/magnesium bentonite 59.0%.

Claims: CLAIMS 1. A method for reducing residual sulfonylurea pesticide contamination of a spray tank from which the sulfonylurea is applied, comprising the steps: i) formulating the sulfonylurea as an agriculturally suitable water ' soluble salt composition before spray tank application, thereby increasing solubility of the sulfonylurea and decreasing the amount of insoluble sulfonylurea available for residual contamination of the spray tank, ii) applying the sulfonylurea salt composition to the crop while minimizing buildup of insoluble sulfonylurea in the spray tank, and iii) rinsing the spray tank substantially free of residual sulfonylurea, after application, in an operation in which the sulfonylurea remaining in the spray tank is reduced significantly versus the amount remaining when sulfonylurea is not formulated as a water-soluble salt before application. 2. A method according to Claim 1 employing, in step i, the following sulfonylurea salt: wherein: J is selected from the group J-10 J-ll 2=12 2=12 J-14 R is selected from the group H and CH 3 ; R 1 is selected from the group F, Cl, Br, N0 2 , C j -^ alkyl, C 1 -C 4 haloalkyl, C 3 -C 4 cycloalkyl, C 2 -C 4 haloalkenyl, C 1 -C 4 alkoxy, C 2 -C 4 haloalkoxy, C 2 -C 4 alkoxyalkoxy, C0 2 R 12 , C(0)NR 13 R 14 , S0 2 NR 15 R 16 , S(0) n R 17 , C(0)R 18 , CH 2 CN and L; R 2 is selected from the group H, F, Cl, Br, CN, CH 3 , 0CH 3 , SCH 3 , CF 3 and OCF 2 H; R 3 is selected from the group Cl, N0 , C0 2 CH 3 , C0 2 CH 2 CH 3 , S0 2 N(CH 3 ) 2 , S0 2 CH 3 , S0 2 CH 2 CH 3 , OCH 3 , and OCH 2 CH 3 R 4 is. selected from the group C 1 -C 3 alkyl, C^C^ haloalkyl, C ! -C alkoxy, C 2 -C 4 haloalkenyl, F, Cl, Br, N0 2 , C0 2 R 12 , C(0)NR 13 R 14 , S0 2 NR 15 R 16 , S(0) n R 17 , C(0)R 18 and L; R 5 is selected from the group H, F, Cl, Br and CH 3 ; R 6 is selected from the group ^-^ alkyl, C 1 -C 2 alkoxy, C -C 4 haloalkenyl, F, Cl, Br, C0 2 R 12 , C(0)NR 13 R 14 , S0 2 NR 15 R 16 , S(0) n R 17 , C(0)R 18 and L; R 7 is selected from the group H, F, Cl, CH 3 and CF 3 ; R 8 is selected from the group H, C X _C 3 alkyl and pyridyl; R 9 is selected from the group C x -C 3 alkyl, C 2 -C 2 alkoxy, F, Cl, Br, N0 2 , C0 2 R 12 , S0 2 NR 15 R 16 , S(0) n R 17 , OCF 2 H, C(0)R 18 , C 2 -C 4 haloalkenyl and L; R O is selected from the group H, Cl, F, Br, C x -C 3 alkyl and C 1 -C 2 alkoxy; R i is selected from the group H, C ! -C 3 alkyl, C x -C 2 alkoxy, C 2 -C 4 haloalkenyl, F, Cl, Br, C0 2 R 12 , C(0)NR 13 R 14 , S0 2 NR 15 R 16 , S(0) n R 17 , C(0)R 18 and L; R 12 is selected from the group allyl and propargyl and C 1 -C 3 alkyl optionally substituted by at least one member independently selected from halogen, C x -C 2 alkoxy and CN; R 13 is selected from the group H, C^^ alkyl and C 1 -C 2 alkoxy; R 4 is C- J. -C 2 alkyl; R 15 is selected from the group H, C 2 ~C 3 alkyl, C x -C 2 alkoxy, allyl and cyclopropyl; R 16 is selected from the group H and C ~C 3 alkyl; R 17 is selected from the group C -C 3 alkyl, C 2 -C 3 haloalkyl, allyl and propargyl; R 18 is selected from the group C 2 -C alkyl, C ~C 4 haloalkyl and C 3 -C 5 cycloalkyl optionally substituted by halogen; n is 0, 1 or 2; M is a cation; L is Rj is selected from the group H and C ~C 3 alkyl; W is selected from the group 0 and S; X is selected from the group H, C ~C 4 alkyl, C -C 4 alkoxy, C 2 ~C haloalkoxy, C ~C haloalkyl, C -C 4 haloalkylthio, C ~C 4 alkylthio, halogen, C 2 -C 5 alkoxyalkyl, C 2 -C 5 alkoxyalkoxy, amino, C 2 -C 3 alkylamino and di(C 2 ~C 3 alkyl)amino; Y is selected from the group H, C -C alkyl, C 2 ~C 4 alkoxy, C x -C haloalkoxy, C ~C alkylthio, C 2 ~C 4 haloalkylthio, C 2 -C 5 alkoxyalkyl, C 2 -C 5 alkoxyalkoxy, amino, C ~C 3 alkylamino, di(C 2 ~C 3 alkyl)amino, C 3 -C 4 alkenyloxy, C 3 -C 4 alkynyloxy, C 2 -C 5 alkylthioalkyl, C 2 -C 5 alkylsulfinylalkyl, C 2 -C 5 alkylsulfonylalkyl, C x -C 4 haloalkyl, C 2 -C 4 alkynyl, C 3 -C 5 cycloalkyl, azido and cyano; Z is selected from the group CH and N; provided that i) when one or both of X and Y is C λ haloalkoxy, then Z is CH; and ii) when X is halogen, then Z is CH and Y is 0CH 3 , 0CH 2 CH 3 , N(OCH 3 )CH 3 , NHCH 3 , N(CH 3 ) 2 or OCF 2 H. 3. A method according to Claim 2 employing a sulfonylurea salt of a sulfonylurea selected from the group: 2-chloro-N-[[(4-methoxy-6-methyl-l,3,5-triazin- 2-yl)amino]carbonyl]benzenesulfonamide (chlorsulfuron) ; methyl 2-[[[[ (4,6-dimethyl-2- pyrimidinyl)amino]carbonyl]amino]sulfonyl]benzoate (sulfometuron methyl) ; ethyl 2-[[[[(4-chloro-6-methoxy- 2-pyrimidinyl)amino]carbonyl]amino]sulfonyl] enzoate (chlorimuron ethyl) ; methyl 2-[ [[[ (4-methoxy-6-methyl'- 1,3,5-triazin-2-yl)amino]- carbonyl]amino]sulfonyl]benzoate (metsulfuron methyl); methyl 2-[[[[ (4,6-dimethoxy-2-pyrimidinyl)amino]- carbonyl]amino]sulfonyl]-6-(tri luoromethyl)-3- pyridinecarboxylate; methyl 2-[[ [[[4-ethoxy-6-(methyl- amino)-1,3,5-triazin-2-yl]amino]carbonyl]amino]- sulfonyl]benzoate (ethametsulfuron methyl) ; 2-(2- chloroethoxy)-N-[[ (4-methoxy-6-methyl-l,3,5-triazin-2- yl)amino]carbonyl]benzenesulfonamide; ethyl 5-[[[[ (4, - dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]- l-methyl-lH-pyrazole-4-carboxylate; N-[ [(4,6-dimethoxy- 2-pyrimidinyl)amino]carbonyl]-3-(ethylsulfonyl)-2- pyridinesulfonamide (rimsulfuron) ; methyl 3-[[ [[ (4- methoxy-6-methyl-l,3,5-triazin-2-yl)amino]carbonyl]- amino]sulfonyl]-2-thiophenecarboxylate (thifensulfuron methyl) ; methyl 2-[[[ [N-(4-methoxy-6-methyl-l,3,5- triazin-2-yl)-N-methylamino]carbonyl]amino]sulfonyl]- benzoate (tribenuron methyl); methyl 2-[[[[[(4,6- dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]- methyl]benzoate (bensulfuron methyl); 2-[[[[(4,6- dimethoxy-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]- N, --V-dimethyl-3-pyridinecarboxamide (nicosulfuron) ; methyl 2-[ [ [ [ [4, 6-bis (difluoromethoxy)-2- pyrimidinyl]amino]carbonyl]amino]sulfonyl]benzoate; methyl 2-[ [ [ [ [4-dimethylamino)-6-(2,2,2- trifluorόethoxy)-1,3,5-triazin-2- yl]amino]carbonyl]amino]sulfonyl]-3-methylbenzoate; and N-[ [ (4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-1- methyl-4-(2-methyl-2H-tetrazol-5-yl)-lH-pyrazole-5- sulfonamide. 4. A method according to Claim 3 employing a salt of at least one member of the group methyl 3- [ [[[ (4-methoxy-6-methyl-l,3,5-triazin-2- yl)amino]carbonyl]amino]sulfonyl]-2- thiophenecarboxylate (thifensulfuron methyl) , methyl 2- [ t [ [ (4-methoxy-6-methyl-l,3,5-triazin-2- yl)amino]carbonyl]amino]sulfonyl]benzoate (metsulfuron methyl) , methyl 2- [ [ [ [N-(4-methoxy-6-methyl-l,3,5- triazin-2-yl)-N-methylamino]carbonyl]amino]sulfonyl]- benzoate (tribenuron methyl) and 2-chloro-N-[[ (4- methoxy-6-methyl-l,3,5-triazin-2- yl)amino]carbonyl]benzenesulfonamide (chlorsulfuron) wherein M is selected from the group sodium, potassium, calcium, ammonium, and alkylammonium. 5. A method according to Claim 3 employing a sulfonylurea salt in the absence of a tank mix partner. 6. A method according to Claim 4 employing a sulfonylurea salt in the absence of a tank mix partner. 7. A method according to Claim 3 employing a sulfonylurea salt in the presence of a tank mix partner. 8. A method according to Claim 4 employing a sulfonylurea salt in the presence of a tank mix partner. 9. A method according to Claim 6 wherein spray tank cleanout is improved by a factor of at least . 10. A method according to " Claim 8 wherein the . spray tank cleanout is improved by a factor of at least 4.

Inventors: CAHILL WILLIAM ROBERT JR, PUGH LUANN MARSHALL, CAHILL, WILLIAM, ROBERT, JR., PUGH, LUANN, MARSHALL
Applicants: DU PONT, E.I. DU PONT DE NEMOURS AND COMPANY
Application year: 1993
Main classification: A01N47
IPC codes: A01N47