Aminopyralid-based herbicidal compositions and uses thereof

Abstract

The present invention provides an herbicidal formulation comprising: (i) aminopyralid in the form of a free acid; (ii) a solvent combination comprising dimethyl sulfoxide (DMSO) and an additional solvent selected from an amide-based solvent; a ketone- based solvent; and a mixture thereof; and (iii) at least one surfactant.

Description

AMINOPYRALID-BASED HERBICIDAL COMPOSITIONS AND USESTHEREOFTECHNICAL FIELD

[0001] The present invention provides herbicidal formulations comprising aminopyralid in its free acid form; a solvent combination comprising dimethyl sulfoxide (DMSO) and an additional solvent selected from an amide-based solvent; a ketone-based solvent; and a mixture thereof; and a surfactant. The formulations of the invention are useful in controlling weed.BACKGROUND ART

[0002] Usually, in order for a herbicide to reach its site of action within a plant, it must cross several barriers such as the cell wall, the cell membrane (plasma membrane), and optionally organellar membranes within the plant cell. The herbicide then accumulates at its site of action and causes phytotoxicity, i.e., negative effects on plant growth. The passive absorption of a herbicide into a cell and its accumulation within the cell are both controlled by the physiochemical characteristics of the herbicide, more specifically its lipophilicity (ability to dissolve in lipids) and acidity properties.

[0003] Specifically, herbicides that are more lipophilic in nature will move across membranes more easily and if they are extremely lipophilic (high log Kow), these molecules may partition into the membrane and remain there. In contrast, hydrophilic herbicides (low log Kow) will move more slowly across lipophilic membranes, and if the log Kowis small enough, these hydrophilic molecules may not be able to enter the cell at all.

[0004] Furthermore, herbicides having ionizable groups vary in their ability to cross lipophilic membranes. For instance, herbicides that are uncharged are more lipophilic and therefore able to cross a lipid bilayer more readily. In contrast, charged herbicides are more hydrophilic and therefore will traverse a lipid bilayer more slowly.

[0005] Additionally, oil-based formulations, more specifically, emulsifible concentrate (EC) formulations, may have advantageous biological efficacy since these types of formulations contain active ingredient(s), organic solvent(s) and surfactant(s); and may further comprise agricultural excipients such as oil-based adjuvants. These excipients may improve the absorption of the active ingredient(s) by the weed(s) and enable to use lower doses of active ingredient per hectare compared to other types of formulations. The ECformulations create an oil-in-water emulsion when added to the spray tank, offer spontaneous emulsification on dilution, and deliver uniform application of the active ingredient(s).

[0006] WO 2011 / 094388 A2 discloses the use of tank mixes of commercially available soluble granules of aminopyralid tri- isopropanol ammonium salt and commercially available water dispersible granules comprising 2,4-D dimethyl amine, in rice.

[0007] In view of the above, there is a need to develop oil-based formulations comprising active ingredient(s) which has an ionizable group such as a carboxylic acid group, more specifically aminopyralid, wherein said ionizable group is in its neutral form, such as in its free acid form.SUMMARY OF INVENTION

[0008] It has now been found, in accordance with the present invention, that aminopyralidbased formulations, wherein the aminopyralid is in the form of its free acid, which comprise a solvent combination comprising DMSO and an additional solvent selected from an amide- based solvent, a ketone-based solvent, and a mixture thereof, specifically wherein said additional solvent is A A-di methyl decanamide, A-butyl-2-pyrrolidone (NBP), or acetophenone; and a surfactant, were stable even under accelerated storage conditions.

[0009] In one aspect, the present invention thus provides an herbicidal formulation comprising: (i) aminopyralid in the form of a free acid; (ii) a solvent combination comprising dimethyl sulfoxide (DMSO) and an additional solvent selected from an amide-based solvent; a ketone-based solvent; and a mixture thereof; and (iii) a surfactant.

[0010] In certain embodiments, said solvent combination comprises DMSO and an additional solvent selected from A-(Ci-Cs)alkyl pyrrolidone, preferably A-(Ci-Cs)alkyl-2- pyrrolidone; an amide of the formula R-C(O)-N-((Ci-C4)alkyl)2, wherein R is (C?-Ci3)alkyl optionally substituted, preferably at position a to the amide group, with a substituent selected from -OH, -O-(Ci-Ce)alkyl, -CN, and -NO2; a ketone of the formula R’-CO-R’, wherein R’ each independently is (Ci-Ce)alkyl, phenyl, or heteroaryl such as pyridyl, imidazolyl, and pyrimidinyl, or two of the R’s together with the carbon atom to which they are attached form a 5-7 membered ring; and a mixture thereof.

[0011] In other aspects, the present invention relates to methods for using an herbicidal formulation as defined above, i.e., an EC formulation containing aminopyralid in its free acid form. In one particular such aspect, disclosed herein is a method of controlling pest,such as a weed, comprising applying to a locus where control of said pest is desired, such as a field of crop, an effective amount of a formulation as defined herein.DETAILED DESCRIPTION

[0012] In one aspect, disclosed herein is an herbicidal formulation comprising: (i) aminopyralid in the form of a free acid thereof, i.e., wherein its carboxylic acid group is in its free acid form; (ii) a solvent combination comprising DMSO and an additional solvent selected from an amide-based solvent; a ketone-based solvent; and a mixture thereof; and (iii) at least one surfactant.

[0013] Aminopyralid (4-amino-3,6-dichloropyridine-2-carboxylic acid) is a synthetic auxin in the pyridine carboxylic acid class of herbicides. Auxins are plant hormones that regulate several plant activities, including development of the plant embryo, leaf formation, phototropism, gravitropism, apical dominance, fruit development, abscission, and root initiation. Auxins are actively transported into cells by a transmembrane transporter protein and leave the cells by facilitated diffusion through a different transporter. Based on studies of various auxin analogues, it was postulated that the import mechanism allows auxinic herbicides into the cell, but they cannot leave the cell through the exporter. Cellular effects caused by auxinic herbicides include alteration in cell wall elasticity and gene expression. Additionally, non-productive tissue growth if often induced, resulting in epinasty and phloem disruption, preventing the movement of photosynthate and causing death in days to weeks.

[0014] Aminopyralid provides systemic postemergence broad-spectrum control of several key noxious and invasive annual, biennial and perennial weed species, as well as agronomic broadleaf weeds. Aminopyralid can also provide residual weed control activity controlling re-infestations and reducing the need for re-treatment depending on the rate applied and the target weeds.

[0015] Particular amide-based solvents referred to herein are those of the formula V-(Ci- Cs)alkyl pyrrolidone, e.g., 7V-(Ci-Cs)alkyl-2-pyrrolidone. Non-limiting examples of solvents of the formula 7V-(Ci-Cs)alkyl-2-pyrroli done include N-butyl-2-py rroli done (NBP).

[0016] Other particular amide-based solvents referred to herein are those of the formula R-C(O)-N-((Ci-C4)alkyl)2, e.g., R-C(O)-N-(CHa)2, wherein R is (C?-Ci3)alkyl optionally substituted, preferably at position a to the amide group, with a substituent selected from -OH, -O-(Ci-Ce)alkyl, -CN, -NO2, and a mixture thereof. Non-limiting examples of solvents of the formula R-C(O)-N-((Ci-C4)alkyl)2 include N, -di methyl decanamide.

[0017] Particular ketone-based solvents referred to herein are those of the formula R’-CO- R’, wherein R’ each independently is (Ci-Ce)alkyl, phenyl, or heteroaryl such as pyridyl, imidazolyl, and pyrimidinyl, or two of the R’s together with the carbon atom to which they are attached form a 5-7 membered ring. Non-limiting examples of solvents of the formula R’-CO-R’ include acetophenone (wherein one of R’ is phenyl and the other R’ is methyl).

[0018] The term "alkyl" typically means a linear or branched hydrocarbyl having, e.g., 1- 13 carbon atoms and includes, e.g., methyl, ethyl, w-propyl, isopropyl, / / -butyl, sec-butyl, isobutyl, tert-butyl, w-pentyl, 2,2-dimethylpropyl, w-hexyl, w-heptyl, w-octyl, w-decanyl, and the like. Preferred are (Ci-Ci2)alkyls or (Ci-Cio)alkyls, more preferably methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, and w-decanyl. The alkyl may optionally be substituted by one or more group s / substituents each independently selected from, e.g., -OH, -O-(Ci- Ce)alkyl, -CN, and -NO2.

[0019] In certain embodiments, the ratio between the DMSO and the additional solvent(s) composing the solvent combination referred to herein is from about 30: 1 to about 1 :30, e.g., from about 25: 1 to about 1 :20, from about 20: 1 to about 1 : 10, from about 15: 1 to about 1 :5, about 15: 1, about 10:1, about 5: 1, about 1 : 1, about 1 :2, about 1 :3, about 1 :4, or about 1 :5, respectively, by weight.

[0020] Particular such embodiments are those wherein the solvent combination comprises DMSO and an 7V-(Ci-Cs)alkyl-2-pyrrolidone such as 7V-butyl-2-pyrrolidone (NBP), as an additional solvent; and / or the weight ratio between the DMSO and the additional solvent is from 20: 1 to about 5: 1, e.g., from about 18: 1 to about 7: 1, from about 16: 1 to about 9: 1, from about 14: 1 to about 11 : 1, about 20: 1, about 19: 1, about 18: 1, about 17: 1, about 16: 1, about 15: 1, about 14: 1, about 13: 1, about 12: 1, about 11 : 1, about 10: 1, about 9: 1, about 8: 1, about 7: 1, about 6: 1, or about 5: 1, respectively.

[0021] Other particular such embodiments are those wherein the solvent combination comprises DMSO and an amide of the formula R-C(O)-N-((Ci-C4)alkyl)2 such as N,N- dimethyl decanamide, as an additional solvent; and / or the weight ratio between the DMSO and said additional solvent is from about 2: 1 to about 1 :5, e.g., from about 1.5: 1 to about 1 :3, from about 1 : 1 to about 1 :2, about 2: 1, about 1.5: 1, about 1 : 1, about 1 : 1.5, about 1 :2, about 1 :3, about 1 :4, or about 1 :5 respectively.

[0022] Yet other particular such embodiments are those wherein the solvent combination comprises DMSO and a ketone of the formula R’-CO-R’ such as acetophenone (wherein one of R’ is phenyl and the other R’ is methyl), as an additional solvent; and / or the weight ratio between the DMSO and the additional solvents is from 20: 1 to about 5:1, e.g., from about 18: 1 to about 7:1, from about 16: 1 to about 9: 1, from about 14: 1 to about 11 :1, about 20: 1, about 19: 1, about 18: 1, about 17: 1, about 16: 1, about 15: 1, about 14: 1, about 13:1, about 12: 1, about 11 : 1, about 10: 1, about 9: 1, about 8: 1, about 7:1, about 6: 1, or about 5: 1, respectively.

[0023] In certain embodiments, the at least one, e.g., one, two, three, four, or more, surfactant(s) comprised within the formulation of the present invention according to any one of the embodiments above, each independently, is selected from a dialkyl sulfosuccinate salt-based surfactant, an ethoxylated castor oil (e.g., Surfom® R 400 and Surfom® R 200), an alkyl benzene sulfonate salt-based surfactant (e.g., NINATE® 70B), a tri styrylphenol ethoxylate phosphate ester-based surfactant (e.g., Soprophor® 3D33), and a trialkyl amine oxide-based surfactant (e.g., lauryl dimethylamine N-oxide such as Steprow® GP 103). The term “surfactant” as used herein refers to any agriculturally acceptable material which imparts or improves emulsifiability, spreading, wetting, dispersibility, or other surfacemodifying properties of a herbicidal formulation, and optionally stability of said formulation, e.g., by inhibiting crystal growth or avoiding particle agglomeration.

[0024] Particular dialkyl sulfosuccinate salt-based surfactants referred to herein are those comprising a di-(C?-Ci2)alkyl sulfosuccinate alkali metal salt or a di-(C?-Ci2)alkyl sulfosuccinate alkaline earth metal salt. Non-limiting examples of di-(C?-Ci2)alkyl sulfosuccinate alkali metal salts include sodium dioctyl sulfosuccinate (e.g., Aerosol® OT- 75 and Aerosol® OT-100).

[0025] The term “alkali metal” as used herein refers to the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Together with hydrogen they constitute group 1, which lies in the s-block of the periodic table and they readily lose their outermost electron to form cations with charge +1.

[0026] The term “alkaline earth metal” as used herein refers to six chemical elements in group 2 of the periodic table, i.e., beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). The alkaline earth metals readily lose two electrons to form cations with charge +2, and an oxidation state of +2.

[0027] In certain embodiments, the herbicidal formulation of the invention according to any one of the embodiments above further comprises at least one, e.g., one, two, three, four, or more, agriculturally acceptable excipient(s) such as a stabilizer, an anti-freeze agent, a dispersant, a biocide, an anti-foaming agent, and a thickener.

[0028] The term “agriculturally acceptable excipient” as used herein refers to an essentially inert substance that can be used as a diluent and / or carrier for an active agent in a composition for treatment of plants and / or plant parts.

[0029] In certain embodiments, the formulation of the present invention according to any one of the embodiments above comprises aminopyralid in the form of its free acid as an herbicide and further comprises one or more, e.g., one, two, three, four, or more, additional herbicide(s), wherein said at least one additional herbicide is a synthetic auxin (also referred to herein as “ aminopyralid-additional herbicide(s)-based formulation )

[0030] The Herbicide Resistance Action Committee (HRAC) classifies herbicides into different groups according to their target sites, modes of action, symptoms induced, and / or chemical classes. One of these groups is the group of synthetic auxin herbicides that mimic the activity of the plant hormone auxin (indole-3- acetic acid, IAA). Synthetic auxins are most commonly used to control broadleaf weeds in small grain cereals, fallow, and rangeland systems, although some are used to control grass and sedge species (Todd et al., 2020).

[0031] In certain embodiments, the at least one additional herbicide comprised within the aminopyralid-additional herbicide(s)-based formulations of the present invention is one or more synthetic auxin herbicide(s) each independently selected from 2,4-D, fluroxypyr, and triclopyr, and said at least one additional herbicide is in the form of a free acid, salt, ester, or a mixture thereof.

[0032] Particular such embodiments are those wherein said at least one additional herbicide is 2,4-D. More particular such embodiments are those wherein the 2,4-D is in its free acid form.

[0033] Other particular such embodiments are those wherein said at least one additional herbicide is a mixture of fluroxypyr and triclopyr. More particular such embodiments are those wherein each of the fluroxypyr and triclopyr in the mixture is in the form of an ester thereof. Non-limiting examples of esters of fluroxypyr include Ci-Cs-alkyl esters and C1-C4- alkoxy-C2-C4-alkyl esters, such as methyl esters, ethyl esters, isopropyl, butyl, hexyl, heptyl, isoheptyl, isooctyl, 2-ethylhexyl, methylheptyl (MHE; meptyl), butoxypropyl (butometyl),and butoxyethyl esters; and aryl esters such as benzyl; and non-limiting examples of esters of triclopyr include butoxy ethyl.

[0034] Still more particular such embodiments are those wherein the fluroxypyr comprised within the mixture is in its meptyl ester form and the triclopyr comprised within the mixture is in its butoxy ethyl ester form.

[0035] Specific aminopyralid-additional herbicide(s)-based formulations of the present invention comprise aminopyralid in the form of a free acid; a solvent combination comprising DMSO and an amide of the formula R-C(O)-N-((Ci-C4)alkyl)2, wherein R is (C?-Ci3)alkyl; a mixture of an alkyl benzene sulfonate salt-based surfactant (e.g., NINATE® 70B), at least one ethoxylated castor oil (e.g., a mixture of Surfom® R 400 and Surfom® R 200), and a dialkyl sulfosuccinate salt-based surfactant wherein said dialkyl sulfosuccinate salt-based surfactant comprises a di-(C?-Ci2)alkyl sulfosuccinate alkali metal salt such as sodium dioctyl sulfosuccinate (e.g., Aerosol® OT-75 and Aerosol® OT-100); and 2,4-D in the form of a free acid. More specific such formulations are those wherein the ratio between the DMSO and said amide is from about 2: 1 to about 1 :5, respectively, respectively, by weight.

[0036] Other specific aminopyralid-additional herbicide(s)-based formulations of the present invention comprise aminopyralid in the form of a free acid; a solvent combination comprising DMSO and an amide of the formula R-C(O)-N-((Ci-C4)alkyl)2, wherein R is (C?-Ci3)alkyl; a mixture of an alkyl benzene sulfonate salt-based surfactant (e.g., NINATE® 70B), an ethoxylated castor oil (e.g., Surfom® R 400 and Surfom® R 200), a tri styrylphenol ethoxylate phosphate ester-based surfactant (e.g., Soprophor® 3D33), a trialkyl amine oxidebased surfactant (e.g., lauryl dimethylamine N-oxide such as Steprow® GP 103), and a dialkyl sulfosuccinate salt-based surfactant wherein said dialkyl sulfosuccinate salt-based surfactant comprises a di-(C?-Ci2)alkyl sulfosuccinate alkali metal salt such as sodium dioctyl sulfosuccinate (e.g., Aerosol® OT-75 and Aerosol® OT-100); and 2,4-D in the form of a free acid. More specific such formulations are those wherein the ratio between the DMSO and said amide is from about 2: 1 to about 1 :5, respectively, respectively, by weight.

[0037] Yet other specific aminopyralid-additional herbicide(s)-based formulations of the present invention comprise aminopyralid in the form of a free acid; a solvent combination comprising DMSO and A-(Ci-Cs)alkyl-2-pyrrolidone such as NBP; a mixture of an ethoxylated castor oil (e.g., Surfom® R 400 and Surfom® R 200) and a tri styrylphenol ethoxylate phosphate ester-based surfactant (e.g., Soprophor® 3D33); and a mixture offluroxypyr and triclopyr, each in the form of an ester thereof. More specific such formulations are those wherein the ratio between the DMSO and said 7V-(Ci-Cs)alkyl-2- pyrrolidone is from 20: 1 to about 5: 1 respectively, by weight.

[0038] Still other specific aminopyralid-additional herbicide(s)-based formulations of the present invention comprise aminopyralid in the form of a free acid; a solvent combination comprising DMSO and a ketone of the formula R’-CO-R’, wherein R’ each independently is (Ci-Ce)alkyl, phenyl, or heteroaryl such as pyridyl, imidazolyl, and pyrimidinyl, or two of the R’s together with the carbon atom to which they are attached form a 5-7 membered ring (such as acetophenone); a mixture of an ethoxylated castor oil (e.g., a mixture of Surfom® R 400 and Surfom® R 200), a dialkyl sulfosuccinate salt-based surfactant wherein said dialkyl sulfosuccinate salt-based surfactant comprises a di-(C?-Ci2)alkyl sulfosuccinate alkali metal salt such as sodium dioctyl sulfosuccinate (e.g., Aerosol® OT-75 and Aerosol® OT-100), and a tri styrylphenol ethoxylate phosphate ester-based surfactant (e.g., Soprophor® 3D33); a mixture of fluroxypyr and triclopyr each in the form of an ester thereof; and an epoxidized soybean oil (e.g., Surfom CE 3109) as a stabilizer. More specific such formulations are those wherein the ratio between the DMSO and said ketone is from about 20: 1 to about 5: 1, respectively, by weight.

[0039] In another aspect, the present invention relates to various agricultural uses, e.g., pre- and / or post-emergence weed control, in which a formulation as defined in any one of the embodiments above is utilized.

[0040] In one particular such aspect, disclosed herein is a method of controlling weed, also referred to herein as undesired vegetation, comprising applying to a locus an effective amount of a formulation as defined herein, in any one of the embodiments above.

[0041] The term "locus" as used herein refers not only to areas where the weed may already be developed, but also to areas where weeds have yet to emerge, and to areas under cultivation. Locus includes the crop and propagation material of the crop (all the generative parts of the crop such as seeds and vegetative plant material such as cuttings and tubers, which can be used for the multiplication of the plant). Examples of propagation material of the crop include seeds, tubers, spores, corms, bulbs, rhizomes, sprouts basal shoots, stolons, buds and other parts of plants, including seedlings and young plants, which could be transplanted after germination or after emergence from soil. Locus also includes the area surrounding the crop and the growing media of the crop, such as soil and crop field.

[0042] In certain embodiments, the locus is a field of crop. The term “crop” (or “plant”) as used herein refers to whole plants, plant organs (e.g., leaves, stems, twigs, roots, trunks, limbs, shoots, fruits, etc.), plant cells, or plant seeds. Non-limiting examples of crops are barley, wheat, oats, pasture, and rangeland. In particular such embodiments the crop is pasture.

[0043] Weeds that can be controlled by the method of the present invention are Bauhinia variegata, Bauhinia curvula, Lantana camara. Acacia fame si ana. Solanum lycocarpum, Eugenia dysenlerica. Doliocarpus denlalus. Sida glaziovii, Dioclea grandiflora. Solanum aculeatissimum, Sida acuta cv carpinifoha. Senna oblusifoHa. Hyptis suaveolens, Spermacoce latifolia, Sida rhombifoha. Vernonia polyanthes, Baccharis Irimera. Synedrellopsis grisebachii. Hyptis suaveolens, Senna oblusifoHa. Croton glandulosus. Sida cordifolia.

[0044] Unless otherwise indicated, all numbers expressing, e.g., amounts of components or ratios between components, used in this specification, are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification are approximations that may vary by up to plus or minus 10% depending upon the desired properties to be obtained by the present invention.

[0045] The invention will now be illustrated by the following non-limiting Examples.EXAMPLESExample 1. Preparation of aminopyralid (acid)-based formulations

[0046] The process for preparing the formulations involves adding solvents and surfactants in any order under gentle stirring. The mixture was then heated to 50°C, and the active ingredients were subsequently added in any order. The mixture undergoes continuous heating and stirring until complete dissolution of the active ingredients, resulting in a clear solution. Following this, the system was cooled, and the composition was filtered using filter paper. Several formulations have been prepared according to the above-mentioned procedure and their content in depicted in Table 1.Table 1Example 2. Physical chemical data for the formulations presented in Table 1

[0047] Materials and methods, (i) Visual aspect parameter: brief description of the aspect of the fresh sample; (ii) Concentration method: instrumental chromatographic analysis; (iii) Low temperature evaluation: sample is kept under 0°C for 7 days. Freezing and crystallization are monitored. If samples do not freeze or crystalize, it is approved on low temperature evaluation; (iv) Blooming: description of how spontaneous the dispersion of the sample is when added to water; (v) Emulsion stability: The emulsion of the sample in water (1% v / v in CIPAC standard water A, or 5% in CIPAC standard water D) is evaluated after 1 hour at 30°C. If sample shows phase separation as a cream, the volume is reported in percentage. After 24 hours the emulsion is evaluated and stirred again, and after 30 seconds, evaluate if there is cream, oil or solid separation. The observations are reported; (vi) Density: measurement is made in a densimeter instrument; (vii) pH: An emulsion containing 1% (v / v) of the product in distilled water is evaluated with a pHmeter. The result is reported; (viii) Freezing test: 0°C, 7 days: The sample is kept in a refrigerator at a temperature of 0°C for a duration of 7 days, followed by a visual assessment; and (ix) Crystallization: 0°C, 7 days: The sample is kept in a refrigerator at a temperature of 0°C for a duration of 7 days, followed by a visual assessment.Table 2

[0048] The physical evaluation for the formulation F-05, F-06, F-09, and F-10 is presented in Table 2; and the data obtained from accelerated storage stability for the formulations F- 10, F-25, and F-26 is presented in Tables 3-5, respectively.Table 3Table 4Acid equivalent - The amount of a pesticide expressed in terms of the parent acid or the amount that theoretically can be converted to the parent acid. Abbreviated as a.e.Table 5Results and discussion

[0049] The Examples show that formulations F-9, F-10, F-25, and F-26 were stable whereas formulations F-5 and F-6 did not form satisfying formulations. As shown in Table 1, formulations F-9, F-10, F-25, and F-26 contained, as a solvent combination, DMSO and an additional solvent, specifically M-V-di methyl decanamide (F-9, F-10), NBP (F-25), or acetophenone (F-26), as compared to F-5 which contained only soybean methyl ester as the solvent, and F-6 which contained the combination of DMSO and soybean methyl ester.

[0050] Formulations F-10, F-25, and F-26 showed also a good chemical stability under accelerated storage conditions, as depicted in Tables 3-5, respectively.

[0051] Additionally, when the NBP in formulation F-25 was replaced by the solvent methylated soybean oil, i.e., the solvent combination was DMSO and methylated soybean oil, crystallization was observed at low temperature.REFERENCESTodd O.E., Figueiredo M.R., Morran S., Soni N., Preston C., Kubes M.F., Napier R., Gaines T.A. Synthetic auxin herbicides: finding the lock and key to weed resistance. Plant Science, 2020, 300, 110631

Claims

CLAIMS1. An herbicidal formulation comprising: (i) aminopyralid in the form of a free acid;(ii) a solvent combination comprising dimethyl sulfoxide (DMSO) and an additional solvent selected from an amide-based solvent; a ketone-based solvent; and a mixture thereof; and(iii) at least one surfactant.

2. The herbicidal formulation of claim 1, wherein said amide-based solvent is selected from 7V-(Ci-Cs)alkyl pyrrolidone, preferably 7V-(Ci-Cs)alkyl-2-pyrrolidone; an amide of the formula R-C(O)-N-((Ci-C4)alkyl)2, wherein R is (C?-Ci3)alkyl; and a mixture thereof.

3. The herbicidal formulation of claim 2, wherein said 7V-(Ci-Cs)alkyl-2-pyrrolidone is A-butyl-2-pyrrolidone (NBP); and said amide of the formula R-C(O)-N-((Ci-C4)alkyl)2 is / f-di methyl decanamide.

4. The herbicidal formulation of claim 1, wherein said ketone-based solvent is a ketone of the formula R’-CO-R’, wherein R’ each independently is (Ci-Ce)alkyl, phenyl, or heteroaryl such as pyridyl, imidazolyl, and pyrimidinyl, or two of the R’s together with the carbon atom to which they are attached form a 5-7 membered ring.

5. The herbicidal formulation of claim 4, wherein said ketone of the formula R’-CO-R’ is acetophenone (one of R’ is phenyl and the other R’ is methyl).

6. The herbicidal formulation of claim 1, wherein the ratio between the DMSO and the additional solvent in said solvent combination is from about 30: 1 to about 1 :30, e.g., from about 20: 1 to about 1 :20, or from about 15: 1 to about 1 : 15, respectively, by weight.

7. The herbicidal formulation of claim 6, wherein: (i) the solvent combination comprises DMSO and an 7V-(Ci-Cs)alkyl-2-pyrrolidone such as 7V-butyl-2-pyrrolidone (NBP); and / or the weight ratio between the DMSO and said 7V-(Ci-Cs)alkyl-2-pyrrolidone is from 20: 1 to about 5: 1, respectively; (ii) the solvent combination comprises DMSO and an amide of the R-C(O)-N-((Ci-C4)alkyl)2 such as / ' . / ' -dimethyl decanamide; and / or the weight ratio between the DMSO and said amide is from about 2: 1 to about 1 :5, respectively; or (iii) the solvent combination comprises DMSO and a ketone of the formula R’-CO-R’ such as acetophenone (wherein one of R’ is phenyl and the other R’ is methyl); and / or the weight ratio between the DMSO and said ketone is from about 20: 1 to about 5: 1, respectively.

8. The herbicidal formulation of claim 1, wherein said at least one surfactant each independently is selected from a dialkyl sulfosuccinate salt-based surfactant, an ethoxylated castor oil (e.g., Surfom® R 400 and Surfom® R 200), an alkyl benzene sulfonate salt-based surfactant (e.g., NINATE® 70B), a tri styrylphenol ethoxylate phosphate ester-based surfactant (e.g., Soprophor® 3D33), a trialkyl amine oxide-based surfactant (e.g., lauryl dimethylamine N-oxide such as Steprow® GP 103), and a mixture thereof.

9. The herbicidal formulation of claim 7, wherein said dialkyl sulfosuccinate salt-based surfactant comprises a di-(C?-Ci2)alkyl sulfosuccinate alkali metal salt or a di-(C?-Ci2)alkyl sulfosuccinate alkaline earth metal salt.

10. The herbicidal formulation of claim 8, wherein said dialkyl sulfosuccinate salt-based surfactant comprises a di-(C?-Ci2)alkyl sulfosuccinate alkali metal salt such as sodium dioctyl sulfosuccinate (e.g., Aerosol® OT-75 and Aerosol® OT-100).

11. The herbicidal formulation of any one of claims 1-9, further comprising at least one agriculturally acceptable excipient such as a stabilizer, an anti-freeze agent, a dispersant, a biocide, an anti-foaming agent, and a thickener.

12. The herbicidal formulation of any one of claims 1-10, further comprising at least one additional herbicide, wherein said at least one additional herbicide is a synthetic auxin.

13. The herbicidal formulation of claim 11 , wherein said at least one additional herbicide is selected from 2,4-D, fluroxypyr, triclopyr, and a mixture thereof, and said at least one additional herbicide is in the form of a free acid, salt, ester, or a mixture thereof.

14. The herbicidal formulation of claim 12, wherein said at least one additional herbicide is: (i) 2,4-D; or (ii) a mixture of fluroxypyr and triclopyr.

15. The herbicidal formulation of claim 13, wherein said at least one additional herbicide is: (i) 2,4-D in the form of a free acid thereof; or (ii) a mixture of fluroxypyr and triclopyr, each in the form of an ester thereof.

16. The herbicidal formulation of claim 15, comprising:(i) aminopyralid in the form of a free acid; a solvent combination comprising DMSO and an amide of the formula R-C(O)-N-((Ci-C4)alkyl)2, wherein R is(C?-Ci3)alkyl; a mixture of an alkyl benzene sulfonate salt-based surfactant (e.g., NINATE® 70B), at least one ethoxylated castor oil (e.g., a mixture of Surfom® R 400 and Surfom® R 200), and a dialkyl sulfosuccinate salt-based surfactant wherein said dialkyl sulfosuccinate salt-based surfactant comprises a di-(C?-Ci2)alkyl sulfosuccinate alkali metal salt such as sodium dioctyl sulfosuccinate (e.g., Aerosol® OT-75 and Aerosol® OT-100); and 2,4-D in the form of a free acid;(ii) aminopyralid in the form of a free acid; a solvent combination comprising DMSO and an amide of the formula R-C(O)-N-((Ci-C4)alkyl)2, wherein R is (C?-Ci3)alkyl; a mixture of an alkyl benzene sulfonate salt-based surfactant (e.g., NINATE® 70B), an ethoxylated castor oil (e.g., Surfom® R 400 and Surfom® R 200), a tri styrylphenol ethoxylate phosphate ester-based surfactant (e.g., Soprophor® 3D33), a trialkyl amine oxide-based surfactant (e.g., lauryl dimethylamine N-oxide such as Steprow® GP 103), and a dialkyl sulfosuccinate salt-based surfactant wherein said dialkyl sulfosuccinate saltbased surfactant comprises a di-(C?-Ci2)alkyl sulfosuccinate alkali metal salt such as sodium dioctyl sulfosuccinate (e.g., Aerosol® OT-75 and Aerosol® OT- B); and 2,4-D in the form of a free acid;(iii) aminopyralid in the form of a free acid; a solvent combination comprising DMSO and A-(Ci-Cs)alkyl-2-pyrrolidone such as NBP; a mixture of an ethoxylated castor oil (e.g., Surfom® R 400 and Surfom® R 200) and a tri styrylphenol ethoxylate phosphate ester-based surfactant (e.g., Soprophor® 3D33); and a mixture of fluroxypyr and triclopyr, each in the form of an ester thereof; or(iv) aminopyralid in the form of a free acid; a solvent combination comprising DMSO and a ketone of the formula R’-CO-R’, wherein R’ each independently is (Ci-Ce)alkyl, phenyl, or heteroaryl such as pyridyl, imidazolyl, and pyrimidinyl, or two of the R’s together with the carbon atom to which they are attached form a 5-7 membered ring (such as acetophenone); a mixture of an ethoxylated castor oil (e.g., a mixture of Surfom® R 400 and Surfom® R 200), a dialkyl sulfosuccinate salt-based surfactant wherein said dialkyl sulfosuccinate salt-based surfactant comprises a di-(C?-Ci2)alkyl sulfosuccinate alkali metal salt such as sodium dioctyl sulfosuccinate (e.g.,Aerosol® OT-75 and Aerosol® OT-lOO), and a tri styrylphenol ethoxylate phosphate ester-based surfactant (e.g., Soprophor® 3D33); and a mixture of fluroxypyr and triclopyr each in the form of an ester thereof.

17. The herbicidal formulation of claim 16, wherein: (i) the ratio between the DMSO and said amide is from about 2: 1 to about 1 :5, respectively, respectively, by weight; (ii) the ratio between the DMSO and said A-(Ci-Cs)alkyl-2-pyrrolidone is from 20: 1 to about 5: 1 respectively, by weight; or (iii) the ratio between the DMSO and said ketone is from about 20: 1 to about 5: 1, respectively, by weight.

18. A method of controlling weed comprising applying to a locus an effective amount of the herbicidal formulation according to any one of claims 1-17.

19. The method of claim 18, wherein said locus is a field of crop.

20. The method of claim 19, wherein said crop is selected from barley, wheat, oats, pasture, and rangeland.

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