NZ517784A

NZ517784A - Synergistic mixture of triclopyr and sulfonylurea such as metsulfuron-methyl to make a herbicide composition

Info

Publication number: NZ517784A
Application number: NZ51778402A
Authority: NZ
Inventors: Peter James Hayward; George William Mason; Wallace James Rae; Paul Garry Lobb; Natile Jo Winmill
Original assignee: Peter James Hayward; George William Mason
Priority date: 2002-03-14
Filing date: 2002-03-14
Publication date: 2004-10-29
Also published as: AU2003201298B2; AU2003201298A1

Abstract

Herbicide composition comprising a synergistic mixture of triclopyr and sulfonylurea such as metsulfuron-methyl is disclosed, wherein the weight ratio of triclopyr to metsulfuron-methyl ranges between 1:1 to 10:1.

Description

<div class="application article clearfix" id="description"> New Zealand Paient Spedficaiion for Paient Number 517784 INTELLECTUAL PROPERTY OFFICE OF N.Z. 1 4 MAR 2003 RBGIIVgD No: 517784 Date: 14 March 2002 NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION STABLE LIQUID COMPOSITIONS OF SULFONAMIDE BRIDGED HERBICIDES WE, PETER JAMES HAYWARD a New Zealand citizen 7 8 Plymouth Road, R D 4, New Plymouth, New Zealand and GEORGE WILLIAM MASON a New Zealand citizen of 18 Sutton Road, Omata, New Plymouth, New Zealand WALLACE JAMES RAE a New Zealand citizen of 8 Mahoe Street, New Plymouth, New Zealand do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement -1- Spec362 v7 7"1 March 2003 2 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 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 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 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. 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 sulfonamide link inactivates the molecule. Although such compounds are sufficiently stable to make dilution and Spec362 v7 7th March 2003 3 application from water practicable, long term storage as a liquid formulation has been complicated by poor stability in solution or as an aqueous suspension. Improvements in the stability of aqueous suspensions of sulfonylureas is claimed by Frisch et al (US 5,707,926) n by the use of particular polyacrylate derivatives. Although a general claim is made for sulfonylureas, extensive examples of improved stability include only 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 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. Improved chemical stability is achieved by drying the solvents with molecular sieves. Illustrative examples 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 disadvantage of having to prepare the salts from commercially available free acids. The molecular sieves Spec362 v7 7 th March 2003 4 must be filtered and can only be reused a few times before they need to be disposed of or regenerated. 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 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) 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 52°C. To be useful as commercial formulations greater stability is highly desirable. SUMMARY OF THE INVENTION Accordingly, the object of this invention is to provide an anhydrous oil based liquid of certain water sensitive sulfonylurea and sulfamoylurea herbicides which can be Spec362 v7 7"i March 2003 5 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. 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 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 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 adjuvant which may include certain specialty surfactants and mineral or vegetable oil in the one formulation. An 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 second part containing emulsifier and adjuvant. The two parts are readily combined just prior to use. Svec362 v7 7th March 2003 In a first broad aspect of the invention there is provided herbicide compositions comprising a synergistic mixture of triclopyr and metsulfuron-methyl with a weight ratio of triclopyr to metsulfuron-methyl of between 1:1 to 10:1. In a second broad aspect of the invention there is provided a stable oil suspension of metsulfon-methyl herbicide, usable on dilution with water, including by weight: a) 0.10 to 50% of metsulfon-methyl herbicides 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; c) 0.1 to 5% of an inert anhydrous suspending aid, d) 0.1% to 50% of triclopyr or its esters. It is a further object of the present invention to provide a synergistic combination of certain herbicidally active esters with an oil suspension of the said INTELLECTUAL PROPERTY OFCICF oc M„7 - e SE° 203*1 Spec362 v7 7 September 2004 REGBVED 7 sulfonylurea herbicides which provide enhanced herbicidal action. 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. 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 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 > 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 under applied areas. In a third broad aspect of the invention there is provided an oil suspension herbicide of metsulfuron- Spec3 62 v7 7 September 2004 INTELLECTUAL PROPERTY OFRGF OF M.Z " 8 SE? 200*} RECEIVED 8 methyl ticlopyr ester, usable on dilution with water, including by weight: a) 0.10 to 10% of metsulfuron-methyl herbicides b) 1 to 70% of a hydrophobic solvent selected singly or jointly from the group consisting of vegetable oil, C8 to C18 fatty acid esters and petroleum distillates c) 0.1 to 5% of an inert anhydrous suspending aid. d) 0.3 to 40% triclopyr as an oil miscible ester. DETAILED DESCRIPTION OF THE INVENTION The active agricultural chemical in the present invention is a sulfonylurea or a sulfamoylurea having the general formula: * X—(N S02—N —C —N—Y I I II I Rj Ri O Ri where X is a substituted aromatic/heterocyclic moiety or an electron withdrawing group e.g. a substituted sulfamoylurea group; Y is a heterocyclic moiety; Spec362 v7 7 September 2004 9 Ri / R2 / R3 1 is hydrogen or a lower alkyl group. When n=0 the formula is a sulfonylurea, e.g. metsulfuron-methyl; and when n=l 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. Table 1 X Y Name Company CHj N —/ -<0 N-< OCHs chlorsulfuron duPont ^. COaCHa C«3 ■0 en, sulfometuron-methyl duPont ^ COjpHs <0,* *-< OCHj metsulfuron-methyl duPont nc ^ s cchcih CHa -<0; OCHa thifensulfuron -methyl duPont Spec362 v7 7th March 2003 10 6. CI 'Jc—OCHi N 1 CHa OCHs -id halosulfuron-methyl Nissan Monsanto OCHj CH2CH2CF3 , / OCHj N^( -<Q" ■-< CHj prosulfuron Ciba Geigy O II OCHF N —/ OCH1 primisulfuron-methyl Ciba Geigy C—OCH3 OCH^THjCl OCHa -<0/ * CHa triasulfuron Ciba Geigy OCH3CH3 OCHs N -/ -Q N —( OCHJ ethoxysulfuron Agrevo 1 O 6 Spec362 v7 7tn March 2003 11 y CsaO OCHa N OCH3 cyclo-sulfamuron American Cyanamid \ /CH3 A O N—CHj 1 OCHa N —/ 4 OCHij amidosulfuron Agrevo 0 II ^^ CN(CHj>2 CQI N ock3 N "( -<0/ N~( 0ch3 nicosulfuron duPont soachjchj N OCH3 $ 0CH3 rimsulfuron duPont /N. CO^CHa cib N(CH3>2 N~{ -<0/ N-< OCHaCFj trisulfuron-methyl Ciba Geigy Spec362 v7 7"1 March 2003 12 N och3 OCHj flazasulfuron Ishihara i X ^ s ochj 5 H 0 OCHa N "K -<0/ chs trifensulfuron -methyl duPont o-ch, »=( H Vch3 bensulfuron-methyl duPont Sulfonylurea herbicides are effective at dose rates of generally between 5 and 100 g per ha. They have a restricted mode of action, a limited spectrum and may show only a slow rate of brownout, so that effectiveness 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 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 Spec362 v7 7'n March 2003 13 spray application or areas completely missed during the initial application. Some examples of diluent agrochemicals for use herein include: (1) Phenoxy compounds: e.g. phenoxy acetates (MCPA esters), phenoxy propionates, and phenoxy butyrates (MCPB esters); (2) Chloroacetamide/chloroacetanilides (e.g. alachlor, acetachlor, and metolachlor); (3) Esters of pyridinecarboxylic acids: e.g. (fluoroxypyr-2-butoxy-l-methylethyl, triclopyr-butotyl, clopyralid-2-methylhexyl.) (4) Aryloxyphenoxypropionates: (diclofop-methyl, fenoxaprop, quizalofop-P-tefuryl, clodinafop) (5) Pyridinyloxyphenoxypropionates: (haloxyfop-methyl, 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 swellable clay, and optionally suitable emulsifiers. The Spec362 v7 7'n March 2003 14 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 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 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 emulsion and suspension or solution upon addition to water, although the possibility of dilution in oil for ULV application is not discounted. The convenience of a formulation in one part may be traded off to optimise the stability of the bridged 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 second part (b) a mixture of 5-100% anionic and or non-ionic and 5% - 95% of an oil diluent. An hydrophobic Spec362 v7 7'h March 2003 15 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 system of the invention. Illustrative examples are given in the following formulations: Example 1 emulsifiable concentrate. Hereinafter referred to as formulation TNL 1339 g/L triclopyr-butotyl. 142 gamma-butyrolactone 479.3 Teric 203 50 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 Example 2 emulsifiable concentrate. Hereinafter referred to as formulation TNL 1338 Spec362 v7 March 2003 16 g/L triclopyr-butotyl. 142 gamma-butyrolactone 477.3 Teric 203 50 dimethicone copolyol 400 metsulfuron-methyl 90% 26.7 triethanolamine 2 Total 1098 Example 3 suspension concentrate. Hereinafter referred to as formulation TNL 1770 g/L paraffinic Oil 784.5 Clayton HY * 12.5 metsulfuron-methyl 26.5 triclopyr-butotyl. 106.5 Total 930 ^Treated Bentone ex Southern Clay products Inc. Gonzales Texas 78629. 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.. Spec362 v7 7th March 2003 17 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 prior to the addition to a spray tank. Example 5 suspension concentrate. Hereinafter referred to as formulation TNL 1648 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 Spec362 v7 7th March 2003 18 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 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 < 1 Op.. The formulations in Examples 3 and 5 were stored at 54°C for 14 days following the guidelines of GIFAP Technical monograph, No 17. Other example formulations were stored under the conditions specified. 19 Formulation Stability Table 2 Active Stability Conditions S.G. Initial assay %w Final Assay %w % active retained metsulfuron-methyl TNL 1339 40 °C glass Storage 3 days 1.098 2.16 1. 65 76.4% metsulfuron-methyl TNL 1338 40°C glass Storage 3 days 1.098 2.16 1. 50 69.4% metsulfuron-methyl TNL 1770 54 °C glass 0-14 days 0.930 2. 60 2. 45 94.2% metsulfuron-methyl TNL 1648 54 °C glass 0-14 days 0.911 2. 60 2.44 93.8% triclopyr-butotyl TNL 1648 54 °C glass 0-14 days 0. 911 11.97* 11. 60 96. 9% * The active ingredient is determined on triclopyr acid equivalent in the ester. TNL 1648 Physical Properties Table 3 pH stability Storage at 28 days PH initial pH 14 days pH 28 days 54°C glass 4.2 4.12 ! Spec362 v7 7th March 2003 20 Table 4 Emulsion stability 50 PPM water 20°C, dilution 2% v/v Conditions: TNL 1648 54°C in glass initial and 14 days % cream lhrs % cream 2hrs % cream 24hrs % cream initial sample 0.1% 0.1% 0.5% % cream post storage 0.1% 0.1% 1% Table 5 Viscosity and sedimentation Batch Initial 14 days TNL 1648 Brookfield Viscosity spindle #4 20 °C 3rpm 650 cps 6rpm 605 cps, 12 rpm 530 cps 3rpm 650 cps 6rpm 599 cps, 12 rpm 527 cps TNL 1648 sedimentation nil nil A two weeks accelerated storage stability trial at 54°C 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 climate. Examples 1 and 2 data confirm that it is difficult to make stable solution formulations of metsulfuron-methyl to meet the storage criteria. Spec362 v7 7th March 2003 21 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 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. 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 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. Example 7 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 incubation and compared to a water control. Such an Spec362 v7 7* March 2003 22 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 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 comparison with that of triclopyr and metsulfuron-methyl acting alone was thus calculated as ECso'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 EC50 determined 3 times. The total data set was used to determine an average EC5o value. The results are displayed in table 1. Spec362 v7 7th March 2003 23 Table 6 Millet EC5o ppb radish EC50 ppb triclopyr 2214 297 metsulfuron-methyl 330 45 3 triclopyr:1 metsulfuron-methyl 891 98 10 triclopyr:1 metsulfuron-methyl 931 168 1 triclopyr:1 metsulfuron-methyl 415 54 1 triclopyr:3 metsulfuron-methyl 392 101 The test of synergy was carried out according to the method described by Kull et al (Applied Microbiology 9 538 - 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 a ratio QA/Qa and QB/Qb 4. If the sum of the ratios for a mixture QA/Qa + Qn/Qb =1 the indication is the combined effect is additive. If j it is < 1 synergism has occurred; a value > 1 is j indicative of antagonism. i Spec362 v7 | 7"1 March 2003 24 The calculations for metsulfuron-methyl and triclopyr are displayed in Tables 2 and 3. Table 7 Triclopyr metsulfuron-methyl synergy calculation for Millet Millet EC50 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 Triclopyr metsulfuron-methyl synergy calculation f< radish Radish EC50 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 The data shows that synergy (sum <1) occurs on radish, a susceptible dicotyledon, at any ratio between 10:1 and Spec362 v7 7th March 2003 25 1:1. For the less susceptible millet, a monocotyledon, synergy is apparent a range of ratios of 10:1 1:3. In 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 . 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. The results are reported in the following table: Spec362 v7 7"* March 2003 26 Table 9 Weed code Rating data Rating Unit Trial evaluation interval ratio RUBFR Brown out % visual 7 DA-A RUBFR Brown out % visual 22 DA-A RUBFR Regrowth suppression. % visual 280 DA-A Name Rate and a.i. metsulfuron-methyl 12.5g/100L triclopyr 4.2g/100L 1:3 20 20. 0 99 metsulfuron-methyl 12.5g/100L triclopyr 12.5g/100L 1:1 27.5 52.5 100 metsulfuron-methyl 12.5g/100L triclopyr 37.5g/100L 3:1 55 65 98 metsulfuron-methyl 12.5g/100L triclopyr 125g/100L 10:1 27.5 70 100 metsulfuron-methyl 12.5g/100L 25. 0 20 100 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 Spec362 v7 7tn March 2003 27 metsulfuron-methyl actives. The results are summarised in Table 10. Table 10 Weed code ratio RUBFR RUBFR Rating data trie Brown out Regrowth Rating Unit to % visual suppression Trial eval interval mets 19 DA-A % visual 259 DA-A Name Rate and a. i. 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 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-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 Spec362 v7 7th March 2003 </div>

Claims

<div class="application article clearfix printTableText" id="claims"> 28 triclopyr to metsulfuron-methyl greater than 1:1 and optimally at 3:1. When fully formulated with oils and surfactants the early brown out is further enhanced. The objects of the present invention are therefore met by the preferred embodiments discussed above. Spec362 v7 7"* March 2003 29 WHAT WE CLAIM IS:

1. Herbicide compositions comprising a synergistic mixture of triclopyr and metsulfuron-methyl with a weight ratio of triclopyr to metsulfuron-methyl of between 1:1 to 10:1

2. A stable oil suspension of metsulfuron-methyl herbicide including by weight:

a) 0.10 to 50% of metsulfuron-methyl herbicide;

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;

c) 0.1 to 5% of an inert anhydrous suspending d) 0.1% to 50% of triclopyr acid or its esters.

3. "An oil suspension herbicide of metsulfuron-methyl and triclopyr ester, including by weight:

a) 0.10 to 10% of metsulfuron-methyl herbicides;

Spec362 v7

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30

b) 1 to 70% of a hydrophobic solvent selected singly or jointly from the group consisting of vegetable oil, C8 to C18 fatty acid esters and petroleum distillates;

c) 0.1 to 5% of an inert anhydrous suspending aid;

d) 0.3 to 40% triclopyr as an oil miscible ester.

4. A stable oil suspension of metsulfuron-methyl herbicide, usable on dilution with water, including by weight:

a) 0.10 to 50% of metsulfuron-methyl herbicide;

b) 1 to 90% of a hydrophobic solvent selected i

singly or jointly from the group consisting of vegetable oil, C8 to C18 fatty acid esters and petroleum distillates;

c) 2 to 50% of a mixture of anionic and or non-ionic surfactants;

d)

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0.1 to 5% of an inert anhydrous suspending aid,

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31

> e) 0.1% to 50% of triclopyr acid or its esters.

5. An oil suspension herbicide of metsulfuron-methyl and triclopyr ester, usable on dilution with water, including by weight:

0.10 to 10% of metsulfuron-methyl herbicides;

1 to 70% of a hydrophobic solvent selected singly or jointly from the group consisting of vegetable oil, C8 to C18 fatty acid esters and petroleum distillates;

5 to 50% of a mixture of anionic and or non-ionic surfactants;

0.1 to 5% of an inert anhydrous suspending aid;

0.3 to 40% triclopyr as an oil miscible ester.

6. An oil suspension herbicide composition according to claims 3 and 5 wherein the metsulfuron-methyl and compositions of triclopyr and metsulfuron-methyl comprise synergistic mixtures with a weight

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7 September 2004

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ratio of triclopyr to metsulfuron-methyl of between 1:1 and 10:1

An oil suspension herbicide composition according to claims 3 and 5 wherein the metsulfuron-methyl and esters of pyridinecarboxlyic acid: clopyralid, picloram and fluroxypyr.

An oil suspension herbicide composition according to claims 2 and 3 wherein the emulsifiers and or herbicide mixture is stored separately and added prior to use.

The oil suspension of claim -4—2_ 3 —4. wherein the metsulfuron-methyl has the general formula:

where X is a substituted aromatic/heterocyclic moiety or an electron withdrawing group;

Y is a heterocyclic moiety;

Rl , R2 , R3 , is hydrogen or a lower alkyl group and n=0.

X—fNV-SO2—N -C — N—Y

1 I II I

R* Ri O R2

Spec362 v7

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33

10. The oil suspension of claim 9 wherein X is a substituted sulfonamyl group.

11. The oil suspension of any one of claims 2 to 10 wherein the suspending aid is oil swellable clay.

12. The oil suspension of any one of claims 2 to 10 wherein the suspending oil is paraffinic oil, and an oil swellable clay.

13. The oil suspension of any one of claims 4 to 10 wherein the suspending oil is paraffinic oil, an oil swellable clay and suitable emulsifiers.

14. The oil suspension of any one of the preceding claims substantially as herein described with reference to the Examples.

PETER JAMES HAYWARD GEORGE WILLIAM MASON and By their Attorney DON HOPKINS & ASSOCIATES

Per:

Spec362 v7

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