AU2007242910B2 - Herbicidal formulations for combination salts of glyphosate - Google Patents

Abstract

The present invention encompasses high strength formulations of glyphosate, particularly, the dimethylamine and triethanolamine salts of glyphosate, and more particularly, formulations comprising the combination of these salts with potassium 5 salts, and methods of use thereof. The formulations exhibit improved characteristics at high concentration.

Description

-1 AUSTRALIA Patents Act 1990 SPECIFICATION Name of Applicant: Donaghys Industries Limited Actual Inventors: YERITSYAN, Karen JENKINS, Timothy Allen Address for Service: CREATEIP Level 1, The Realm 18 National Circuit, Barton Canberra, ACT 2600 Australia Invention Title: Herbicidal formulations for combination salts of glyphosate The following statement is a full description of this invention, including the best method of performing it known to us:- HERBICIDAL FORMULATIONS FOR COMBINATION SALTS OF GLYPHOSATE FIELD OF THE INVENTION The present invention relates to high strength formulations of glyphosate, including 5 the dimethylamine and triethanolamine salts of glyphosate, and in particular, formulations comprising the combination of these salts with potassium salts, and methods of use thereof BACKGROUND OF THE INVENTION Glyphosate is a known, effective herbicide. There are several organic ammonium 10 salts of glyphosate useful as herbicides, including the methylamine salt and dimethylamine salt, and, as an example, monoalkylammonium and dialkylammonium (see, e.g., US 4,405,531). Various glyphosate formulations are currently marketed, many of which are aqueous solutions that can be used as is or diluted prior to use. 15 Typically the glyphosate is provided as a salt that exhibits sufficiently high solubility in water to provide a high strength herbicidal formulation. For example, high strength formulations are known for the isopropylamine salt (IPA), the monoethanolamine (MEA) salt, and various formulations of the potassium (K) salt of glyphosate (see, 20 e-g., US 6,277,788; US 6,365,551; WO 01/89302). A high strength formulation is desirable for a variety of economic and environmental reasons, For example, it is desirable to provide a high strength formulation to reduce shipping and handling costs and to reduce the amount of packaging material that 25 must be disposed. The high strength formulations are preferably stable and retain potency during storage and shipping. Furthermore, the high strength formulation are optimally provided as a clear, homogeneous liquid that is stable at temperatures at least as high as 50*C and does not exhibit any precipitation at temperatures as low as 0*C. 30 However, high strength formulations can result in high viscosity. For example, formulations of the commonly used IPA salt of glyphosate become increasingly viscous at concentrations greater than 350 gram acid equivalent per liter (gae/i), particularly at concentrations greater than 440 gae/L. The high viscosity makes the 2 formulation difficult to measure and pump, especially at the lower temperatures typically encountered at the beginning of the growing season. The available glyphosate formulations typically include a surfactant. Inclusion of a 5 surfactant can be desirable, as the resulting formulation can exhibit increased herbicidal activity or other improved characteristics. For example, glyphosate formulations are known to include alkylbetaine surfactants in combination with other surfactants (see, e.g., WO 03/067689). 10 A major limitation of the MEA and K salts of glyphosate is the incompatibility with a wide range of surfactants. In particular, polyoxyethylene alkylamines are only compatible with the MEA salt of glyphosate when the sum of the total average number of carbon atoms plus the average number of oxyethylene groups is equal to or less than 25 (see, e.g., US 6,277,788). Similady, many common surfactants are 15 not compatible with the glyphosate K salt solution. For example, alkylamine ethoxylate surfactants are only compatible (i.e., allow a homogeneous mixture) when the degree of ethoxylation is no more than about 5, and such surfactants have a higher potential to cause eye irritation. 20 In addition, certain surfactants can interact with the glyphosate salt to increase the viscosity of the herbicidal formulation. For example, some of the surfactants in the oxyalkylene alkylamine class of compounds, when combined with the glyphosate salt, increase the viscosity of the formulation. If the viscosity is too high, handling of the concentrated herbicide can be difficult. Furthermore. highly viscous liquids are 25 difficult to accurately measure, either for application to the plants or for dilution to a less concentrated spray solution. Depending upon the concentration and specific surfactant, the herbicidal formulation can form a gel, which makes most applications extremely difficult if not impossible to perform. 30 In light of the above described problems, there is a continuing need for additional improvements in the relevant fields including improved high strength herbicidal formulations that exhibit low viscosity and are suitably efficacious. The present invention addresses these needs and provides a wide variety of benefits and advantages. 3 SUMMARY OF THE INVENTION It has now been found that the dimethylamine (DMA) and triethanolamine (TEA) salts of glyphosate can be used in combination with potassium (K) salts of glyphosate to allow the preparation of advantageous high strength liquid herbicide 5 formulations. The present invention encompasses a high strength herbicidal formulation comprising: (a) water, (b) glyphosate, predominantly in the form of the DMA/K or the TEA/K salts, in solution in the water in an amount of greater than about 350 gae/I of 10 the composition, and (c) optionally, at least one surfactant. In certain aspects, the high strength herbicidal formulation of the invention includes a herbicidally efficacious surfactant. This surfactant can be selected to enhance the herbicidal activity of the formulation and to minimize the viscosity of the high 15 strength formulation, or provide other advantages. In one aspect, the invention encompasses a high strength herbicidal composition comprising: (a) water, (b) glyphosate, predominantly in the form of a combination of dimethylamine salt and potassium salt, in solution in the water in an amount of about 20 400 grams or greater of acid equivalent per liter of the composition, wherein the composition is formulated to include dimethylamine in an amount of about 20% or greater, by weight, relative to potassium and (c) optionally, at least one surfactant and/or at least one humectant. 25 In one other aspect, the invention encompasses a high strength herbicidal composition comprising: (a) water, (b) glyphosate, predominantly in the form of a combination of triethanolamine salt and potassium salt, in solution in the water in an amount of about 400 grams or greater of acid equivalent per liter of the composition, wherein the composition is formulated to include triethanolamine in an amount of 30 about 10% or greater, by weight relative to potassium and (c) optionally, at least one surfactant and/or at least one humectant. In other aspects, the composition is formulated to include dimethylamine in an amount of about 20 to about 55%, by weight, relative to potassium, or in an amount 35 of about 50%, by weight, relative to potassium. 4 In still other aspects, the composition is formulated to include triethanolamine in an amount of about 10 to about 35%, by weight, relative to potassium, or in an amount of about 25%. by weight, relative to potassium. 5 In yet other aspects, the composition is formulated to include greater than about 540 grams of acid equivalent of glyphosate per liter of the composition, or greater than about 580 grams of acid equivalent of glyphosate per liter of the composition. 10 In another aspect, the surfactant of the composition is selected from the group consisting of alkyl polyglucosides, tallow alkylamines, ethoxylated propylene oxide, and ethylene oxide / propylene oxide block copolymer. In particular aspects, the surfactant is an alkyl polyglucoside. 15 In still another aspect, the humectant of the composition is selected from the group consisting of glycerol, sorbitol, and other mono and polyglycols. In particular aspects, the humectant is glycerol. In yet another aspect, the invention encompasses a method of inhibiting plant 20 growth which comprises applying to the plant a water-diluted composition of any one of the preceding aspects. Other aspects and embodiments of the invention are described herein below. 25 BRIEF DESCRIPTION OF THE DRAWINGS This invention is described with reference to specific embodiments thereof and with reference to the figures. FIGS. 1A-11B: Field testing results for Roundup Transorb@ 540 (FIG. 1A) and 30 Glyphosate 580 TEA (FIG. 18) photographed on Day 14, post application (see Examples). DETAILED DESCRIPTION OF THE INVENTION As noted above, the most commonly used formulations of high strength glyphosate 35 are IPA and K salts. The main disadvantages of IPA salt formulations are high 5 viscosity of the solution and high flammability of IPA starting material. This creates inconvenience and potential risk during handling and manufacturing. In contrast to IPA, DMA has a higher flash and boiling point and supplied as 40% 5 solution. The maximum stable concentration for DMA glyphosate is 560 gae/. The DMA formulation has suitable viscosity and stability, and to increase the concentration of active ingredient above 560 gae/l, the present disclosure demonstrates that a mixed salt of glyphosate can be used. As another alternative to IPA, TEA can be used as cations source. TEA formulations have very high viscosity, 10 so to address this, the present disclosure demonstrates that a mixed salt can be used. In particular, the present inventors have discovered highly advantageous formulations of DMA/K and TEA/K. For the DMA/K combination, it was found that 15 one particularly advantageous concentration of cautions is 50% DMA and 50% K. For the TEA/K combination, it was found that one particularly advantageous concentration of cations is 25% TEA and 75% K. In one aspect of the invention, the DMA can be included, for example, at an amount 20 of about 20%, about 25%, about 30%, about 35%, about 40%, about 43%, about 45%, about 48%, about 50%, about 53%, about 55%, about 58%, or about 60%, or greater, by weight, relative to potassium, or about 20 to about 55%, about 40 to about 45%, about 45 to about 50%, about 45 to about 55%, about 50 to about 55%, or about 55 to about 00%, by weight, relative to potassium. 25 In another aspect of the invention, the TEA can be included, for example, at an amount about 10%, about 12%, about 15%. about 18%, about 20%, about 23%, about 25%, about 28%, or about 30% or greater, by weight, relative to potassium, or about 10 to about 35%, about 15 to about 20%, about 20 to about 25%, about 20 to 30 about 30%, about 25 to about 30%, about 30 to about 35%, or preferably, about 25 to about 30%, by weight, relative to potassium. The DMA and TEA salts of glyphosate provide certain advantages over other salts that have been commercialized. In particular, the suggested formulations provide 35 safer options for high loaded glyphosate formulation production, produce stable, practically and economically convenient herbicide concentrates, compared to IPA 6 formulations. The suggested formulations also allow higher acid equivalent concentrations than commercially available K salts. The TEA/K product has good viscosity, stability, and is inherently safer to produce, 5 as compared to other formulations. The disclosed formulation of TEA/K glyphosate has concentration of 580 gae/, with mixed salts as disclosed herein. Notably, glasshouse and field trials have shown that visible results are much faster in the case of TEA/K mixed formulation, as compared to each of these salt formulations separately. It is postulated that TEA increases the speed of glyphosate uptake into 10 plants. The faster action of TEA/K mixed salt formulation is clearly advantageous compared to the single salts. Furthermore, the DMA/K and TEA/K salts have a lower molecular weight than the IPA or MEA salts. Thus, at a given salt concentration, the DMA/K 15 and TEA/K salts of glyphosate have a higher glyphosate acid equivalent content than the IPA or MEA salt. Thus, in one aspect, the present invention is directed to a high strength herbicidal concentrate composition comprising the DMA or TEA salt of glyphosate and an 20 efficacious surfactant. More specifically, the present invention provides a high strength herbicidal concentrate composition comprising; (a) water, (b) glyphosate, predominantly in the form of the DMA/K or TEA/K mixed salts, in solution in the water in an amount greater than about 350 gae/l of the composition, and (c) optionally at least one surfactant. 25 The herbicidal formulation includes the glyphosate salt in an amount sufficient to provide the high strength formulation. In preferred embodiments, the high strength herbicidal formulation includes greater than about 350 gae/l based upon the glyphosate acid equivalent of the glyphosate salt; more preferably, the high strength 30 herbicidal formulation includes greater than about 440 gae/l based upon the glyphosate acid equivalent of the glyphosate salt; most preferably, the high strength herbicidal formulation includes greater than about 480 gae/I based upon the glyphosate acid equivalent of the glyphosate salt. 35 In one aspect, the formulation includes, e.g., about 350 gae/, about 360 gaell, about 380 gae/l, about 400 gae/, about 420 gae/l, about 440 gae/l, about 460 gae/l, about 7 480 gae/i, about 500 gae/i, about 520 gae/, about 540 gae/l, about 560 gae/I, about 580 gae/I, or about 600 gael/, or greater glyphosate, with upper limits based on solubility. 5 In another aspect, the formulation includes, e.g., about 350 to about 360 gae/, about 360 to about 380 gae/l, about 380 to about 400 gae/, about 400 to about 420 gaell; about 420 to about 440 gae/I, about 440 to about 460 gae/l, about 460 to about 480 gae/l, about 480 to about 500, about 500 to about 520 gae/I, about 520 to about 540 gaelI, about 540 to about 560 gae/, about 560 to about 580 gae/, about 10 580 to about 600 gae/I glyphosate. It can include a range of about 350 gae/I and greater, with upper limits based on solubility. In preferred aspects, the present invention is directed to a high strength herbicidal formulation that is storage stable at high temperatures. That is, the formulation 15 forms a dear, homogeneous, stable solution that does not exhibit cloudiness under the storage conditions. More preferably, the formulations of the present invention are stable at temperatures greater than or equal to about 50"C. In addition, the high strength herbicidal formulation should not exhibit separation or 20 precipitation (or crystallization) of any of the components at low temperatures. For example, the high strength formulation remains a clear solution at temperatures below about 10"C, about 8"C, about 6"C, about 4*C, about 2"C, or preferably at temperatures below about 0"C. 25 The term "predominantly" in the present disclosure means that at least 50 percent, preferably at least 75 percent and more preferably at least 90 percent by weight of the glyphosate, expressed as acid equivalents, is present as the DMA/K or TEA/K salts. The balance can be made up of other salts, such as the IPA salt, provided that the formulation remains a clear, homogeneous liquid that is stable at temperatures 30 at least as high as 50"C and does not exhibit any precipitation at temperatures as low as 10 C. For example, the amount can be at least about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90% or about 95% 35 DMA/K or TEA/K salts, or about 50 to about 55%, about 55% to about 60%, about 60 to about 65%, about 65 to about 70%; about 70 to about 75%, about 75 to about 8 80%, about 80 to about 85%, about 85 to about 90%, about 90 to about 95%, or preferably about 50 to about 100% DMA/K or TEA/K salts. The high strength herbicidal formulation can also include a surfactant, for example, 5 in an efficacy-enhancing amount. In preferred embodiments, the surfactant is selected to be compatible in solution with the high concentration of the glyphosate in the herbicidal formulation. By use of the term "compatible" in the present application, it will be understood by those skilled in the art to include within its meaning that the resulting solution does not exhibit a phase separation or precipitation in the 10 formulation that can be initially observed as a cloudiness and which is typically determined at a specified temperature. Combinations of surfactant and DMA/K or TEA/K salts of glyphosate can be selected to remain compatible in the formulation at high concentration. The resulting 15 aqueous composition can be provided as a high strength herbicidal formulation. The DMA and TEA salts of glyphosate are compatible with a wide variety of surfactants. Preferred surfactants are selected from: alkyl polyglucosides, e.g., AGNIQUE PG 8107, tallow alkylamines, ethoxylated propylene oxide and ethylene oxide / propylene oxide block copolymer based surfactants, separately or as a mixture (e.g., 20 from about 1:1 to about 6:1, or about 1:6 to about 6:1). Non-limiting examples of commercially available alkyl polyglucosides include, for example, AGNIQUET", or AGRIMULTM surfactants from Cognis Corporation. Cincinnati, Ohio; Atlox surfactants from Uniqema, New Castle, Del. 19720; or AG 25 surfactants from AKZO NOBEL Surface Chemistry, LLC, such as: AGNIQUE PG 8105 Surfactant-an alkyl polyglucoside in which the alkyl group contains 8 to 10 carbon atoms and having an average degree of polymerization of 1.5; AGNIQUE PG 8166 Surfactant-an alkyl polyglucoside in which the alkyl group contains 8 to 16 carbon atoms and having an average degree of polymerization of 1.6; AGNIQUE 30 PG 266 Surfactant-an alkyl polyglucoside in which the alkyl group contains 12 to 16 carbon atoms and having an average degree of polymerization of 1.6; AGNIQUE PG 9116 Surfactant-an alkyl polyglucoside in which the alkyl group contains 9 to 11 carbon atoms and having an average degree of polymerization of 1.6; AGNIQUE PG 264-U Surfactant-an alkyl polyglucoside in which the alkyl group contains 12 to 35 16 carbon atoms and having an average degree of polymerization of 1.4; AGNIQUE PG 8107 Surfactant-a C6.

1 5 alkyl polyglucoside in which the alkyl group contains 8 9 to 10 carbon atoms and having an average degree of polymerization of 1.7; AGNIQUE PG 266 Surfactant-a C 1 2o alkyl polyglucoside in which the alkyl group contains 12 to 16 carbon atoms and having an average degree of polymerization of 1.6; AL 2575/AL 535 Surfactant--a C.- alkyl polyglucoside in which the alkyl group 5 contains 8 to 11 carbon atoms and having a HLB 12-13; Akzo Nobel AG 6202, AG 6206, or AG 6210 surfactants which are 2 ethylhexyl branched C, linear hexyl C; and linear Cr-Cr alkyl polyglucosides respectively. The alkyl polyglucosides may be present in the formulations of the invention in an amount of about 6 to about 12 percent by weight, based on the total weight of the composition. 10 In other aspects, the formulations for use in the present invention can be selected to include one or more of the following types of surfactants: alkoxylated alkylamine surfactants having 8 to 22 carbon atoms and a total of 1-20 alkylene oxide groups, available for example from Akzo Nobel as Ethomeena' C/i5, Ethomeenm T11 5, and 15 Ethomeen'h T/20 respectively; etheramine surfactants, such as Tomah"' E-14-2, TomahTM E-14-5 and TomahL" E-17-5 (or equivalents) respectively; quaternary ammonium surfactants, such as Ethoquad m C/12, EthoquadRm 18/12 or TomahTM Q-14-2; amphoteric surfactants, such as Geronol' CF/AS 30 from Rhodia or Tegom Betaine F 50 from Goldschmidt: alkylpolyglycosides such as Akzo Nobel AG 20 6202 or AG 6210; or anionic ester derivatives of alkylpolyglycosides such as the EucaroTh AGE surfactants. The surfactant may be present in the formulations of the invention in an amount of about 7 to about 15 percent weight/volume. Amounts of surfactant can be higher or lower depending on whether the surfactant is added as a substantive or auxiliary agent, in accordance with standard practice. 25 The surfactant can be included in the herbicidal formulation in a desired concentration. Preferably the desired concentration is sufficient to enhance the herbicidal activity of the resulting formulation over that observed with a comparable herbicidal formulation without the surfactant. More preferably, the herbicidal 30 formulation includes the surfactant in amounts not less then 10 g/l, for example, at least about 10 g/l, about 20 g/1, about 30 gI, about 40 g/l, about 50 g/l, about 60 g/l, about 70 g/l, about 80 g/Il, about 90 g/l, about 100 g/1, about 110 g/l, about 120 g/l, about 130 g/l, about 140 g1l, about 150 g1, about 160 g/l, about 170 g/l, about 180 g/l, about 190 g/Il, about 200 g/l, or about 210 g/l, or for example, about 10 gI to 35 about 50 gI, about 50 g/l to about 100 g/I, about 100 gl to about 150 g/1, or about 10 150 g/I to about 210 g/Il, or for example, between about 20 g/I and about 200 gI, or between about 100 g/l and about 150 g/l. It has been determined that with selection of a specific surfactant in combination 5 with the DMA/K or TEA/K salt of glyphosate, the characteristics (e.g., viscosity) of the resulting herbicidal formulation can be improved. Most preferred are mixtures of surfactants. For example, alkyl polyglucosides can improve viscosity, i.e., the viscosity of the formulation containing the blend of surfactants is significantly lower than that of formulations containing individual surfactants at the same concentration. 10 In preferred embodiments, the herbicidal formulation is provided to exhibit a viscosity of less than about 2500 cps, about 2000 cps, about 1000 cps, 500 cps, about 300 cps, about 200 cps, about 150 cps, or preferably less than about 100 cps or about 50 cps at around 25"C. The viscosity of the composition is expected to be 15 no more than 2500 cps, no more than 2000 cps, no more than 1500 cps, or no more than 1000 cps, at temperatures as low as O'C. Viscosity may be measured using any technique known to those skilled in the art, for example, using a Brookfield Synchro-lectric Model LV Viscometer. An apparent viscosity can be measured by first stirring the sample with a glass rod for 10 seconds, placing the sample on the 20 instrument, turning the instrument on, and measuring the value after 3 revolutions of the measuring dial. Typically the measurement is made using a #3 spindle rotating at 30 RPMs; however depending upon the viscosity of the sample, different spindles and differing rotational speeds can be utilized, as known by those skilled in the art. 25 In another aspect, the present invention is directed to a method of inhibiting plant growth with a herbicidal formulation. inhibition" of growth as used herein includes preventing, reducing, or stopping plant growth as well as killing plants and/or plant parts. The formulation can be provided as described herein. The formulation can be applied as a post-emergent or pre-emergent herbicide. The formulation can be 30 applied as a highly concentrated solution or preferably can be diluted with water prior to application. The formulations are preferably applied in an amount sufficient to induce a herbicidal effect. For example, a formulation prepared according the present 35 invention can be applied as an aqueous solution to plants including the plants' leaves, stems, branches, flowers, and/or fruit. The herbicidal formulation can be 11 applied in a herbicidally effective amount sufficient to inhibit plant growth or kill individual plants. The agricultural compositions prepared according to the present invention are highly 5 effective as herbicide compositions against a variety of weeds. The formulations of the present invention can be used as is or combined with other components including other agriculturally acceptable adjuvants commonly used in formulated agricultural products, such as emulsifiers, penetrants, preservatives, freeze point depressants, antifreezes and evaporation inhibitors, antifoam agents, 10 compatibilizing agents, sequestering agents, pH modifiers (buffers, acids, and bases), neutralizing agents, corrosion inhibitors, dyes, odorants, penetration aids, wetting agents, spreading agents, dispersing agents, thickening agents, pigments and/or dyes, fillers, carriers, colorants including salts such as calcium, magnesium, ammonium, potassium, sodium, and/or iron chlorides, fertilizers such as ammonium 15 sulfate and ammonium nitrate, urea, crop oil, humectants such as polyols and mono glycols (e.g., sorbitol, glycerol, butylene glycol, sorbitol, hexylene glycol, caprylyl glycol, neopentyl glycol, ethylene glycol, propylene glycol, polyethylene glycol), and other biologically and/or agriculturally active components, and the like. The concentrated agricultural formulations can be diluted in water and then applied by 20 conventional means well known to those in the art. The advantages of the high strength formulations of the invention include at least the following: 1) Manufacturing process incorporates non flammable raw materials, and produces no sharp amine smell in factory; 2) Formulations show compatibility 25 with a wide range of surfactants as compared to potassium only formulations; 3) Formulations allow use of biodegradable surfactants (e.g. alkyl polyglycosides), which are more environmentally friendly compared to amine ethoxylate surfactants used with IPA formulations; 4) Formulations require less packaging and less hazardous material for disposal; 5) Formulations are faster and provide better 30 uptake by plants (e.g., full kill in 10-12 days), requiring fewer surfactants (e.g., stickers) compared to other formulations (e.g., full kill in 2 or more weeks); 6) Formulations show stable viscosity which does not significantly change in a wide range of temperatures, making the formulations easy to handle and transfer even in colder weather. Further advantages of the high strength formulations include easier 35 transportation and storage, and more effective production. More final product is contained in each unit. For example, packaging of 1000 liters of a 36% solution 12 requires fifty 20 liter containers. In contrast, 1000 liters of a 58% solution gives the same quantity of active ingredient, but uses only thirty-one 20 liter containers. This provides clear economic benefits. 5 EXAMPLES The examples described herein are for purposes of illustrating embodiments of the invention. Other embodiments, methods, and types of analyses are within the scope of persons of ordinary skill in the molecular diagnostic arts and need not be described in detail hereon. Other embodiments within the scope of the art are 10 considered to be part of this invention. EXAMPLE 1: DMA salt of glyphosate at 560 gaell The tank was loaded with water and half of the required amount of glyphosate acid and the mixer was turn on. The DMA was pumped in at half rate and slow speed. 15 The calculated amount of DMA was based on a 40% solution. For different concentrations, the required adjustments were made. The rest of the glyphosate acid and DMA were added. This was mixed until all the glyphosate was dissolved. This was allowed to cool down. The physical appearance of the reaction mixture was checked, If cloudiness was noticed, some extra amount of DMA was pumped 20 in. The remaining ingredients were added in and the volume was adjusted with water. The sample was submitted for laboratory testing, and adjustments were made, if required. For 1000 Itr batch: EINGR$EDIENT: QUANTITY (kg): Glyphosate Acid 589.48 DM~A (40%soi.)(110% exta) 432.14 Glycero 10 AGNIQUE PG-81071f0'0 Antifoam 1520-US 3 25Water To volume 25 13 EXAMPLE 2: DMA/K salt of glyphosate at 580 gaell The vat was loaded with half of required amount of glyphosate acid. The calculated amount of DMA was based on a 40% solution. For different concentrations, the required adjustments were made. The calculated quantity of water was pumped in, 5 and then DMA solution was pumped in at low speed. The reaction mixture was allowed to cool down, and the rest of the glyphosate acid was added. Next, the potassium hydroxide was loaded, maintaining a temperature below 50*C. This was allowed to sit until all the glyphosate was dissolved. The physical appearance of solution was checked. In the case of noticeable cloudiness, some additional 10 potassium hydroxide was added. The remaining ingredients were added in. This was mixed. Water was added to bring to volume, and a sample was submitted for laboratory testing. The concentration of active ingredient was adjusted, if required. The calculated percentages were DMA - 50% calc.; potassium - 50% calc. 15 For 1000 Itr batch: INGREDIENT; QUANTITY (kg): Glyphosate Acid (95%) 610.53 DMA (40% soL) 1424 (calculated as 105% of 50% Glyphosate) Potassium Hydroxide 116.47 Glycerol 10 AGNIQUE PG-8107 100 Antifoam 1520-US 3 Water 100 + to volume Ammonium Sulphate' 12.21 EXAMPLE 3: TEA/K salt of glyphosate at 580 gall The vat was loaded with water and half of required amount of glyphosate acid. The calculated quantity of water was added in, and then the TEA was pumped in at low 20 speed. The reaction mixture was allowed to cool down, and the rest of glyphosate acid was added. The potassium hydroxide was then loaded, maintaining a temperature below 50"C. This was allowed to sit until all the glyphosate was dissolved. The physical appearance of the solution was checked. In the case of noticeable cloudiness, some additional potassium hydroxide was added. The rest of 14 the ingredients were added in. This was mixed and brought to volume with water. A sample was submitted for laboratory testing. The concentration of active ingredient was adjusted, if required. The calculated percentages were TEA - 25% calc.; potassium - 75% calc. 5 For 1000 Itr batch: INGREDIENT: QUANTITY (kg): Glyphosate Acid (95%) 610.53 TEA 135.73 Potassium Hydroxide 159.56 (calculated as 105%) Glycerol 10 AGNIQUE PG-8107 100 Antifoam 1520-US 3 Water 100 + to volume Ammonium Sulphate 12.21 For all of the preceding examples, additional ingredients, including surfactants, defoamers, and humectants, were put in after reaction mixture cooled down and all 10 ingredients had reacted. For all of the above, the formulated products showed excellent stability; pH range: 3.3 - 7; and density range: 1.12 - 1.6. EXAMPLE 4: Field trial of TEA 580 speed of kill in comparison to Roundup Transorb@ 15 Introduction: The purpose of the trial was to measure the Glyphosate 580 TEA (AGNIQUE"M AGNJQUE PG-B107 surfactant) speed of kill compared to Roundup Transorbe 540. The trial was conducted at Owen Chattertons Farm, Maddisons Road near Rolleston. The test crop was ryegrass and clover pasture. 20 Sprayer Calibration: Spray width 1.5 meter with Donaghys "small plot sprayer"; 2 x 1.5 m plots = 3 Sq Meter; Sprayer Calibration: 150 ml in 3 and half seconds in a 5 meter run.

Rates: Product Rates L/ Hec /200 C H 2 O 540 2.67 580 2.48 Rates are based on 1440 g/ha glyphosate active Time Schedule: Action Date 5 Trial Spray Date: Day 1 First Results: Day a Treatments: Following three treatments were applied in duplicate. Treatment mV7.5 SqmI herbicide m/ Surfactant ml Water ml 150 ml water 600 ml water Control

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500 Roundup Transorb 540 2.00 6.67 0. 493 GlyphOsae 580 TEA 1.86 6.21 0.5 494 10 Results: After 7 days of spray treatments, visual observations clearly showed higher degree of yellowness in Glyphosate 580 TEA plots compared to Roundup Transorb@ 540. These observations were photographed. SPAD meter (SPAD-502, hand-held chlorophyll meter, Specialty Products Agricultural Division, Minolta Corporation) was used to measure the ryegrass chlorophyll content for the three 15 treatments. Twenty eight ryegrass flag leaves were picked randomly from each treatment (14 leaves from each replication) and the chlorophyll content was measured by SPAD meter. The decrease in chlorophyll content as compared to control plots were related to speed of kill by the herbicides tested. After 7 days of spray, Glyphosate 580 TEA speed of kill was 41% percent greater than Roundup 20 Transorbe 540. Table: Ryegrass Chlorophyll Meter Readings Treatment SPAD Readings Control 45.85 Roundup Transorbe 540 25 Glyphosate 580 TEA 15.1 16 It was hypothesized that the faster kill speed of Glyphosate 580 TEA was attributable to the presence of nitrogen in amine form in Glyphosate 580 TEA and surfactant properties of TEA. In particular, the nitrogen containing organic 5 compound TEA presents a nitrogen source for weeds, which increases the uptake of salt, and TEA has properties of a surfactant, which also increases uptake It was concluded that Glyphosate 580 TEA showed excellent performance seven days post spraying based on the quantitative data on enhanced speed of kill/yellowing by Glyphosate 580 TEA as compared to Roundup Transorb. 10 All publications and patents mentioned in the above specification are herein incorporated by reference. Any discussion of the publications and patents throughout the specification should in no way be considered as an admission that such constitute prior art, or widely known or common general knowledge in the field. 15 Where the foregoing description reference has been made to integers having known equivalents thereof, those equivalents are herein incorporated as if individually set forth. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed 20 should not be unduly limited to such specific embodiments. It is appreciated that further modifications may be made to the invention as described herein without departing from the scope of the invention. The invention illustratively described herein may be practiced in the absence of any element or elements, or limitation or limitations, which are not specifically disclosed herein as essential. 25 In addition, in each instance herein, in embodiments or examples of the present invention, the terms 'comprising', 'including', etc. are to be read expansively without limitation. Thus, unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising' and the like are to be 30 construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say in the sense of "including but not limited tom. 17

Claims (16)

1. A high strength herbicidal composition comprising: (a) water, (b) glyphosate, predominantly in the form of a combination of dimethylamine salt and potassium salt, in 5 solution in the water in an amount of about 350 grams or greater of acid equivalent per liter of the composition, wherein the composition is formulated to include dimethylamine in an amount to form a salt with about 5% or greater, by weight, of total glyphosate and to include potassium in an amount to form a salt with a percentage of total glyphosate so that the combined sum of glyphosate in dimethylamine and potassium salts is at least 45% of 10 total glyphosate, and (c) optionally, one or more surfactants and/or one or more humectants.

2. The composition of claim 1, wherein the composition is formulated to include dimethylamine in an amount to form a salt with about 20 to about 55% by weight, of total 15 glyphosate and to include potassium in an amount to form a salt with a percentage of total glyphosate so that the combined sum of glyphosate in dimethylamine and potassium salts is at least 45% of total glyphosate.

3. The composition of claim 1, wherein the composition is formulated to include 20 dimethylamine in an amount to form a salt with about 50%, by weight, of total glyphosate and to include potassium in an amount to form a salt with a percentage of total glyphosate so that the combined sum of glyphosate in dimethylamine and potassium salts is at least 50% of total glyphosate. 25

4. The composition of claim 1, wherein the composition is formulated to include potassium in an amount to form a salt with about 20% to about 95%, by weight, of total glyphosate.

5. The composition of claim 2, wherein the composition is formulated to include 30 potassium in an amount to form a salt with about 30% to about 80%, by weight, of total glyphosate.

6. The composition of claim 1 or claim 3, wherein the composition is formulated to include potassium in an amount to form a salt with about 50%, by weight, of total 35 glyphosate. 20

7. The composition of any one of claims 1 to 6 which comprises greater than about 540 grams of acid equivalent of glyphosate per liter of the composition.

8. The composition of any one of claims 1 to 6 which comprises greater than about 560 5 grams of acid equivalent of glyphosate per liter of the composition.

9. The composition of any one of claims 1 to 6 which comprises greater than about 580 grams of acid equivalent of glyphosate per liter of the composition.

10 10. The composition of any one of claims 1 to 9, wherein the one or more surfactants are selected from the group consisting of alkyl polyglucosides and polymeric quaternary ammonium compounds.

11. The composition of any one of claims 1 to 9, wherein the one or more surfactants 15 comprise an alkyl polyglucoside.

12. The composition of any one of claims 1 to 9, wherein the one or more surfactants comprise a mixture of alkyl polyglucoside and polymeric ammonium quaternary compound in a ratio of about 1:9 to about 9:1. 20

13. The composition of any one of claims 1 to 12, wherein the one or more humectants are selected from the group consisting of glycerol, sorbitol, and other mono and polyglycols. 25

14. The composition of any one of claims 1 to 12, wherein the one or more humectants comprise glycerol.

15. A method of inhibiting plant growth which comprises applying to the plant the composition of any one of claims 1 to 14. 30

16. A method of inhibiting plant growth which comprises applying to the plant a water diluted formula of the composition of any one of claims 1 to 14. 21