AU2003201298B2 - Stable Liquid Compositions of Sulfonamide Bridged Herbicides - Google Patents

Description

TITLE OF THE INVENTION STABLE LIQUID COMPOSITIONS OF SULFONAMIDE BRIDGED HERBICIDES 5 BACKGROUND OF THE INVENTION Various formulations have been developed to allow the dilution and efficacious application of biologically active components onto plants for the control of various 10 weeds. Formulation types commonly include suspension concentrates, emulsions, emulsion concentrates, and dispersible powders and granules. For ease of use and measurement water dilutable liquid formulations are most preferable. Other desirable enhancements which may be 15 derived from a formulation are rain fastness and improved penetration of the leaf cuticle. For additional convenience to the end user a combination of complementary active compounds which may have very different physical properties may be blended in the one 20 pack. Thus, it is known to combine an oil soluble active compound with an insoluble suspended solid active. For example the oil soluble active may coexist as an aqueous emulsion with an aqueous dispersed suspension of the solid. 25 2 Unfortunately, certain sulfonylurea herbicides are reactive to polar solvents. They undergo nucleophillic attack for example by polar methyl pyrrolidones or hydrolyse in water. The subsequent breaking of the 5 sulfonamide link inactivates the molecule. Although such compounds are sufficiently stable to make dilution and application from water practicable, long term storage as a liquid formulation has been complicated by poor stability in solution or as an aqueous suspension. 10 Improvements in the stability of aqueous suspensions of sulfonylureas is claimed by Frisch et al (US 5,707,926) by the use of particular polyacrylate derivatives. Although a general claim is made for sulfonylureas, extensive examples of improved stability include only 15 amidosulfuron with these coformulants. To include herbicidally active esters or liquid oils in the formulation would require the use of more difficult suspension emulsion technology. Although such a formulation vehicle is feasible no practical examples 20 demonstrating both the physical and chemical stability of this type of formulation are given in the above. Sandell (US 4,599,412) describes a process for the preparation of solutions of stable sulfonylurea salts. 25 Improved chemical stability is achieved by drying the solvents with molecular sieves. Illustrative examples 3 make extensive use of the sodium, lithium or ammonium salts and solutions are prepared from highly polar solvents such as NMP, gamma-butyrolactone, or triethylphosphate. The process suffers from the 5 disadvantage of having to prepare the salts from commercially available free acids. The molecular sieves must be filtered and can only be reused a few times before they need to be disposed of or regenerated. 10 Narayan et al (US 5,731,264) teach that certain sulfonylurea or sulfamoylurea herbicides can be both dissolved and stabilised in mixtures of gamma butyrolactone, propylene glycol, acetonitrile or propylene carbonate and a hydrophobic solvent and 15 emulsifiers. The resulting homogeneous emulsifiable concentrate formulations could also include phenoxy herbicide esters but had half lives of only between 2 to 5 years. In a further development of this concept of an anhydrous emulsion concentrate Jon et al (US 6255350) 20 used an additional drying step with molecular sieves or included the stabiliser "Stabaxol 1". They were able to achieve a retention of only 44 or 45% metsulfuron-methyl after 8 days accelerated storage at 520C. To be useful as commercial formulations greater stability is highly 25 desirable.

4 SUMMARY OF THE INVENTION Accordingly, the object of this invention is to provide an anhydrous oil based liquid of certain water sensitive 5 sulfonylurea and sulfamoylurea herbicides which can be stored for extended periods with minimal deterioration of the physical and chemical properties of the formulation e.g. such that it meets the requirements of a two year shelf life. 10 In the present invention additional stability is achieved by suspending the sulfonylurea in an oil as a dispersed suspension. To achieve this the oil suspension requires the use of a dispersed clay to create the correct 15 rheology to prevent settling of the suspended solids. To activate and swell the clay normally requires the use of a small amount of water in a polar solvent. Such solvents and water still create a destabilizing effect on the more sensitive sulfonylureas. However we have found 20 that satisfactory formulations can be made without these polar activators. An additional advantage of this invention is the ability to combine with the active herbicide an effective rate of 25 adjuvant which may include certain specialty surfactants and mineral or vegetable oil in the one formulation. An 5 exception to the single formulation concept may be made in the case where additional shelf life stability is desired. Formulations may be in two parts: the first part containing the actives in oil suspension and the 5 second part containing emulsifier and adjuvant. The two parts are readily combined just prior to use. Thus, in a first broad aspect of the invention there is provided a stable oil suspension of a bridged 10 sulfonoylurea or sulfamoylurea herbicide, usable on dilution with water, including by weight: a) 0.10 to 50% of one or more sulfonylurea or sulfamoylurea herbicides 15 b) 1 to 90% of a hydrophobic solvent selected singly or jointly from the group consisting of vegetable oil, C8 to C18 fatty acid esters and petroleum distillates 20 c) 2 to 50% of a mixture of anionic and or non ionic surfactants d) 0.1 to 5% of an inert anhydrous suspending aid. 25 It is a further object of the present invention to provide a synergistic combination of certain herbicidally 6 active esters with an oil suspension of the said sulfonylurea herbicides which provide enhanced herbicidal action. 5 As a further enhancement of this invention the sulfonylurea or sulfamoylurea herbicides previously only formulated as water dispersible granules may now be incorporated in a single mixture with a wide range of liquid actives to achieve enhanced herbicidal activity. 10 Thus, it has been discovered that formulations of certain sulfonylureas made according to the first broad aspect of this invention show a surprising amount of synergism when combined with trichlobutoyl, the butoxyethyl ester of 15 triclopyr acid. In a further aspect of enhanced herbicidal activity it has been discovered that formulations of this invention when compared to the action of the sulfonylurea alone 20 show a surprising activity in accelerated leaf necrosis and stem die-back (commonly referred to brownout) of a number of woody weeds especially blackberry. A quick brownout enables farmers to conduct follow-up spraying in the same season as they can easily observe any misses or 25 under applied areas.

7 In a second broad aspect of the invention there is provided an oil suspension herbicide of sulfonylurea and triclopyr ester, usable on dilution with water, including by weight: 5 a) 0.10 to 10% of one or more sulfonylurea or sulfamoylurea herbicides b) 1 to 70% of a hydrophobic solvent selected singly 10 or jointly from the group consisting of vegetable oil, C8 to C18 fatty acid esters and petroleum distillates c) 5 to 50% of a mixture of anionic and or non-ionic 15 surfactants. d) 0.1 to 5% of an inert anhydrous suspending aid. e) 0.3 to 40% triclopyr as an oil miscible ester. 20 DETAILED DESCRIPTION OF THE INVENTION The active agricultural chemical in the present invention is a sulfonylurea or a sulfamoylurea having the general 25 formula: 8 X-(N)j-SO 2 -N-C-N-Y I I Il I R3 R 0 1 O R2 where X is a substituted aromatic/heterocyclic moiety or an electron withdrawing group e.g. a substituted 5 sulfamoylurea group; Y is a heterocyclic moiety; R1 , R2 , R 3 , is hydrogen or a lower alkyl group. When n=O the formula is a sulfonylurea, e.g. metsulfuron-methyl; 10 and when n=1 the formula is a sulfamoylurea, e.g. cyclosulfamuron. Both the sulfonylurea and sulfamoylurea compounds have a labile sulfonamide bridge which is susceptible to hydrolysis. Alternatives for X and Y are provided in Table 1 below. 15 Table 1 X Y Name Company C1 Cib chlorsulfuron duPont N ( N 9 C02CH2 sulfometuron- duPont N methyl CM* C C~zImetsulfuron- duPont CO2CK3 N methyl 00N CH3 thifensulfuron duPont -methyl .<N S C N N OCH3 CCH Chalosulfuron- Nissan C1 methyl Monsanto N NNN IN OCH3 CHIcHzCr, OCHJ prosulfuron Ciba N Geigy o <QN o K primisulfuron- Ciba methyl Geigy -OCH3 Oc 10 OCH2CH2C1 triasulfuron Ciba

OCH

2

H

2 CIGeigy N Nj CH3 ethoxysulfuron Agrevo N CH1 3 cyclo- American sulfamuron Cyanamid N c=O o CH 3

OCH

3 amidosulfuron Agrevo \N o N-CH 3 OCH3 Q4 nicosulfuron duPont CN(CH3) jN NN _ _ _ _ _ _ _ _ _ _ _ _ OCr' 3 _ _ _ _ _ 11 rimsulfuron duPont ClN N OCH N(CH3) 2 trisulfuron- Ciba CO2CH 3 N methyl Geigy -<QN qx

OCHCF.

3 CH3

CF

3 odlH 3 flazasulfuron Ishihara NN N -N)

OCR

3 OCH3 trifensulfuron duPont N -methyl 5 C -OCH3 N Ni CH3

O-CH

3 bensulfuron- duPont

CG

1

CH

3 N methyl N C F2 N 0-CH 3 Sulfonylurea herbicides are effective at dose rates of generally between 5 and 100 g per ha. They have a 5 restricted mode of action, a limited spectrum and may show only a slow rate of brownout, so that effectiveness 12 of the herbicide may be in doubt for some time. It is therefore highly advantageous to combine this class of herbicide with oil soluble herbicides with a different mode of action and to achieve dilution of a highly potent 5 active ingredient in the most efficacious ratio and with a volume that can be easily measured in the field. Other advantages also include the reduction of tolerance and an increased rate of "brown out". Such an early indication of plant injury is useful in determining areas of low 10 spray application or areas completely missed during the initial application. Some examples of diluent agrochemicals for use herein include: 15 (1) Phenoxy compounds: e.g. phenoxy acetates (MCPA esters), phenoxy propionates, and phenoxy butyrates (MCPB esters); 20 (2) Chloroacetamide/chloroacetanilides (e.g. alachlor, acetachlor, and metolachlor); (3) Esters of pyridinecarboxylic acids: e.g. (fluoroxypyr-2-butoxy-1-methylethyl, triclopyr 25 butotyl, clopyralid-2-methylhexyl.) 13 (4) Aryloxyphenoxypropionates: (diclofop-methyl, fenoxaprop, quizalofop-P-tefuryl, clodinafop) (5) Pyridinyloxyphenoxypropionates: (haloxyfop-methyl, 5 fluazifop-butyl) The liquid delivery system in the stabilized liquid suspension concentrate of the invention includes an inert anhydrous carrier, such as a paraffinic oil, an oil 10 swellable clay, and optionally suitable emulsifiers. The carrier may be a simple oil or a mixture of oil and herbicide co-active and diluent. Suitably the carrier is present in the concentrate in an amount of about 5-95% by weight of the concentrate. Optionally, about 1-90% by 15 weight of a hydrophobic herbicidally active diluent may be included in the liquid suspension delivery system to enhance the advantageous characteristics of the concentrate. Particularly preferred herbicidally active dilutents are the esters of the pyridinecarboxylic acids 20 triclopyr, picloram, fluoroxypyr and clopyralid which have a known activity on a wide range of broadleaf and woody weeds. With this mixture a combination of anionic and/or nonionic surfactants, provides an advantageous liquid delivery system which emulsifies to form a stable 25 emulsion and suspension or solution upon addition to water, although the possibility of dilution in oil for 14 ULV application is not discounted. The convenience of a formulation in one part may be traded off to optimise the stability of the bridged 5 sulfonylurea. The system of the invention may also be formed from a twin pack comprising, (a) a liquid suspension of about 0.1-50% by weight of the active sulfonylurea compound, 0.1-10% of an oil swellable clay and about 10-90% by weight of the carrier oil, and a 10 second part (b) a mixture of 5-100% anionic and or non ionic and 5% - 95% of an oil diluent. An hydrophobic herbicide may be added to dilute either part (a) or (b). The twin pack may be admixed before use and then diluted with water to provide the preferred liquid delivery 15 system of the invention. Illustrative examples are given in the following formulations: 20 Example 1 emulsifiable concentrate. Hereinafter referred to as formulation TNL 1339 g/L triclopyr-butotyl. 142 gamma-butyrolactone 479.3 Teric 203 50 15 dimethicone copolyol 400 metsulfuron-methyl 90% 26.7 Total 1098 The metsulfuron-methyl present as the free acid is dissolved in the gamma-butyrolactone and blended with the other formulants to form an emulsifiable concentrate 5 Example 2 emulsifiable concentrate. Hereinafter referred to as formulation TNL 1338 g/L triclopyr-butotyl. 142 gamma-butyrolactone 477.3 Teric 203 50 dimethicone copolyol 400 metsulfuron-methyl 90% 26.7 triethanolamine 2 Total 1098 10 Example 3 suspension concentrate. Hereinafter referred to as formulation TNL 1770 g/L paraffinic Oil 784.5 Clayton HY * 12.5 16 metsulfuron-methyl 26.5 triclopyr-butotyl. 106.5 Total 930 *Treated Bentone ex Southern Clay products Inc. Gonzales Texas 78629. 5 The clay is dispersed into the paraffinic oil with high shear mixing until the full viscosity is created. The remainder of the ingredients are then blended in order and milled in a bead mill to obtain a metsulfuron-methyl volume mean particle size of <10p. 10 Example 4 emulsifiable concentrate. g/L paraffinic Oil 700.0 PEG-6 laurate 127.0 PEG-3 oleate 63.0 Total 890 The ingredients are blended in order. This formulation may then be mixed with the formulation in example 3 just 15 prior to the addition to a spray tank. Example 5 suspension concentrate. Hereinafter referred to as formulation TNL 1648 17 g/L paraffinic Oil 662.8 Clayton HT * 12.5 metsulfuron-methyl 28.4 triclopyr-butotyl. 107.3 PEG-6 laurate 63.0 PEG-3 oleate 37.0 Total 911 Example 6 suspension concentrate. g/L paraffinic Oil 702 Clayton HY * 12.5 metsulfuron-methyl 12.5 picloram iso-octylester. 103 PEG-6 laurate 63.0 PEG-3 oleate 37.0 Total 930 The clay is dispersed into the paraffinic oil with high 5 shear mixing until the full viscosity is created. The remainder of the ingredients are then blended in order and milled in a bead mill to obtain a metsulfuron-methyl volume mean particle size of <10p.

18 The formulations in Examples 3 and 5 were stored at 540C for 14 days following the guidelines of GIFAP Technical monograph, No 17. Other example formulations were stored under the conditions specified. 5 Formulation Stability Table 2 Active Stability Conditions S.G. Initial Final % active assay %w Assay %w retained metsulfuron-methyl 1.098 2.16 1.65 76.4% TNL 1339 400C glass Storage 3 days metsulfuron-methyl 1.098 2.16 1.50 69.4% TNL 1338 400C glass Storage 3 days metsulfuron-methyl 0.930 2.60 2.45 94.2% TNL 1770 540C glass 0-14 days metsulfuron-methyl 0.911 2.60 2.44 93.8% TNL 1648 540C glass 0-14 days triclopyr-butotyl 0.911 11.97* 11.60 96.9% TNL 1648 540C glass 0-14 days 10 * The active ingredient is determined on triclopyr acid equivalent in the ester. TNL 1648 Physical Properties 15 Table 3 pH stability Storage at 28 days pH pH 14 pH 28 19 initial days days 540C glass 4.2 4.12 Table 4 Emulsion stability 50 PPM water 200C, dilution 2% v/v Conditions: TNL 1648 % cream % cream 2hrs % cream 540C in glass initial lhrs 24hrs and 14 days % cream initial sample 0.1% 0.1% 0.5% % cream post storage 0.1% 0.1% 1% 5 Table 5 Viscosity and sedimentation Batch Initial 14 days TNL 1648 3rpm 650 cps 3rpm 650 cps Brookfield 6rpm 605 6rpm 599 cps, Viscosity spindle cps, 12 rpm 527 cps #4 20 C 12 rpm 530 cps TNL 1648 nil nil sedimentation 10 A two weeks accelerated storage stability trial at 540C is a standard FAO test to indicate 2 years ambient storage. An active retention of 85% for up to 25 g/L and 90% retention for a 25 to 100 g/L formulation is considered the minimum FAO requirement for a temperate 15 climate.

20 Examples 1 and 2 data confirm that it is difficult to make stable solution formulations of metsulfuron-methyl to meet the storage criteria. 5 Suspension formulations however are more stable. Examples 3 and 5 which are the formulated according to the invention satisfies the minimum requirement. Examples 3 and 4 illustrate the use of a minimal 10 sulfonylurea oil suspension for use as a twin pack formulation. Thus approximately equal concentrations of each formulation may be added together just before use and diluted in a suitable quantity of water to make an efficacious scrubweed spray mix. 15 To those skilled in the art other examples of incorporation into a twin pack system of other adjuvants and co-actives will be apparent. For instance where long term storage stability of the co-active or adjuvant with 20 the sulfonylurea is unsatisfactory, the twin pack system may be used to isolate the sulfonylurea ingredient while still retaining the easy to measure and mix benefits of the invention. 25 Example 7 21 To rapidly determine the biological performance of herbicides the inhibition of root growth may be used. Serial dilutions of the compounds of interest are applied to seeds, and root growth measured after 72 hours of 5 incubation and compared to a water control. Such an experiment was used to assess the action of the herbicides, triclopyr and metsulfuron-methyl. The concentration at which the root growth was inhibited to 50% of its length compared to the untreated water control 10 was calculated as the end point and is hereafter referred to the EC50 value. The performance of metsulfuron-methyl and triclopyr acting together in ratios of 1:3, 3:1 1:10 and 1:1 in 15 comparison with that of triclopyr and metsulfuron-methyl acting alone was thus calculated as EC 5 o' s for two plant species millet and radish. Twelve seeds per plate were incubated for 72 hours using a range of concentrations. Each plate was replicated at from 2 to 5 times and each 20 EC 5 o determined 3 times. The total data set was used to determine an average EC 5 o value. The results are displayed in table 1. 25 22 Table 6 Millet EC 5 o ppb radish EC 5 o ppb triclopyr 2214 297 metsulfuron-methyl 330 45 3 triclopyr:1 metsulfuron- 891 98 methyl 10 triclopyr:1 931 168 metsulfuron-methyl 1 triclopyr:1 metsulfuron- 415 54 methyl 1 triclopyr:3 metsulfuron- 392 101 methyl The test of synergy was carried out according to the method described by Kull et al (Applied Microbiology 9 5 538 - 541, 1961) the calculation is described as follows: 1. The quantity of compound A producing an end point - Qa 2. The quantity of compound B producing an end point - Qb 3. The quantity of each component of the mixture producing end points - QA and QB and expressing each as 10 a ratio QA/Qa and QB/Qb 4. If the sum of the ratios for a mixture QA/Q QB/Qb 1 the indication is the combined effect is additive. If it is < 1 synergism has occurred; a value > 1 is indicative of antagonism.

23 The calculations for metsulfuron-methyl and triclopyr are displayed in Tables 2 and 3. 5 Table 7 Triclopyr metsulfuron-methyl synergy calculation for Millet Millet EC 5 o ppb QA QB QA/Qa QB/Qb Sum triclopyr 2214 Metsulfuron 331 -methyl Ratio 3:1 891 668 223 0.302 0.673 0.975 Ratio 10:1 931 846 84.6 0.382 0.256 0.638 Ratio 1:1 415 208 208 0.094 0.063 0.721 Ratio 1:3 392 98 294 0.044 0.888 0.932 Table 8 10 Triclopyr metsulfuron-methyl synergy calculation for radish Radish EC 5 o ppb QA QB QA/Qa QB/Qb Sum triclopyr 297 Metsulfuron 45 -methyl Ratio 3:1 98 73.5 24.5 0.25 0.54 0.79 Ratio 10:1 168 153 15.3 0.52 0.34 0.86 Ratio 1:1 54 27 27 0.091 0.060 0.69 Ratio 1:3 101 25 76 0.084 1.69 1.77 24 The data shows that synergy (sum <1) occurs on radish, a susceptible dicotyledon, at any ratio between 10:1 and 1:1. For the less susceptible millet, a monocotyledon, synergy is apparent a range of ratios of 10:1 1:3. In 5 view of the lower herbicide cost effectiveness of triclopyr active the preferred ratio for cost effective activity is between 3:1 and 1:1 triclopyr to metsulfuron methyl. 10 Example 8 In order to assess the outcome of a spray application a visual assessment of leaf necrosis and stem dieback or "brownout" of several tank mix combinations of triclopyr 600 g/L EC and metsulfuron-methyl 20g/kg WDG were made. 15 The results are reported in the following table: Table 9 Weed code ratio RUBFR RUBFR RUBFR Rating data Brown out Brown out Regrowth Rating Unit % visual % visual suppression. Trial evaluation interval 7 DA-A 22 DA-A % visual 280 DA-A Name Rate and a.i. metsulfuron-methyl 1:3 20 20.0 99 12.5g/100L triclopyr 4.2g/100L 25 metsulfuron-methyl 1:1 27.5 52.5 100 12.5g/100L triclopyr 12.5g/100L metsulfuron-methyl 3:1 55 65 98 12.5g/100L triclopyr 37.5g/100L metsulfuron-methyl 10:1 27.5 70 100 12.5g/100L triclopyr 125g/100L metsulfuron-methyl 25.0 20 100 12.5g/100L triclopyr 4.2g/100L 15.0 22.5 0 triclopyr 12.5g/100L 32.5 52.5 2.5 triclopyr 37.5g/100L 20.0 62.5 0 triclopyr 125g/100L 37.5 75 5.0 A further trial was laid down to confirm the activity of the fully formulated combination of triclopyr and metsulfuron-methyl actives. The results are summarised 5 in Table 10. Table 10 Weed code ratio RUBFR RUBFR Rating data trick Brown out Regrowth Rating Unit to % visual suppression Trial eval interval mets 19 DA-A % visual 259 DA-A Name Rate and a.i.

26 metsulfuron-methyl 3:1 83.0 100 12.5g/100L triclopyr 37.5/100L metsulfuron-methyl 16 100 12.5g/100L Blackberry is typical of many woody weeds in its ability to recover and regrow 9 to 18 months after even severe 5 herbicide defoliation. The table shows that about 12.5g/100L triclopyr is required to give significant brownout within the period of 7 - 22 days, but even at the highest rate of 125g/100L it does not give long term control. In the mixtures of triclopyr and metsulfuron 10 methyl there is no antagonistic effect on the long term action of the metsulfuron-methyl on long term control but the desirable brownout effect is retained at ratios of triclopyr to metsulfuron-methyl greater than 1:1 and optimally at 3:1. When fully formulated with oils and 15 surfactants the early brown out is further enhanced. The objects of the present invention are therefore met by the preferred embodiments discussed above.

27

Claims (11)

1. A storage stable, liquid, non-aqueous, herbicidal composition comprising an oil suspension of a sulfonamide bridged sulfonylurea selected from the group consisting of: metsulfuron-methyl, chlorsulfuron, sulfometuron, thifensulfuron-methyl, rimsulfuron, halosulfuron-methyl, prosulfuron, trisulfuron-methyl, triasulfuron, ethoxysulfuron, cyclosulfamuron, amidosulfuron, trisulfuron-methy, flazasulfuron, trifensulfuron-methyl, and bensulfuronmethyl; the herbicidal composition being further characterized in that it includes by weight: (a) 0.1-50% of sulfonamide bridged sulfonylurea; (b) 1-70% of a hydrophobic inert anhydrous carrier selected singly or jointly from the group consisting of vegetable oil, C8 to C18 fatty acid esters and a petroleum distillate; (c) 0.1-5% of an inert anhydrous suspending aid; (d) 2-50% of one or more anionic or non-ionic emulsifiers with the proviso that the emulsifier(s) is not an ethoxylated fatty amine type surfactant.

2. The composition according to claim 1 wherein the sulfonamide bridged sulfonylurea is selected from the group consisting of metsulfuron-methyl, chlorsulfuron, sulfometuron, thifensulfuron-methyl, rimsulfuron and halosulfuron-methyl.

3. The composition according to claim I or claim 2 wherein the sulfonamide bridged sulfonylurea is metsulfuron-methyl.

4. The composition according to any one of the preceding claims wherein the hydrophobic inert anhydrous carrier is a petroleum distillate.

5. The composition according to any one of the preceding claims wherein the petroleum distillate is paraffinic oil. Amended Claims AU (IC) 5 May 2009 28

6. The composition according to any one of the preceding claims wherein the inert anhydrous suspending agent is an oil swellable clay.

7. The composition according to any preceding claim, further characterized in that it is usable on dilution with water.

8. A twin pack providing for the storage stable, liquid, non-aqueous, herbicidal composition composition according to any one of the preceding claims wherein the components are provided in separate containers or as separate compartments within the same container, the twin pack comprising: A) (a) 0.1-50% of sulfonamide bridged sulfonylurea; (b) 1-70% of a hydrophobic inert anhydrous carrier selected singly or jointly from the group consisting of vegetable oil, C8 to C18 fatty acid esters and petroleum distillates; (c) 0.1-5% of an inert anhydrous suspending aid; and B) (d) 5-100% anionic or non-ionic emulsifier (e) 10--95%hydrophobic inert anhydrous carrier

9. A method of forming the storage stable, liquid, non-aqueous, herbicidal composition according to any one of claims I to 7 wherein the inert suspending aid is dispersed into the hydrophobic inert anhydrous carrier with high shear mixing, blended with the sulfonamide bridged sulfonylurea, and the mixture is milled in a bead mill to obtain a sulfonylurea mean particle size of < 10 pm, then combined with anionic or non-ionic emulsifiers.

10. The herbicidal composition according to any of claims I to 7 substantially as herein described with reference to the accompanying Examples 4-6. Amended Claims AU (IC) 5 May 2009 29

11. The method of forming the composition according to claim 9 substantially as herein described with reference to the accompanying Examples 4-6. PIPERS, Patent Attorneys for ZELAM LIMITED Amended Claims AU (IC) 5 May 2009 30